EP1701035A1 - Pump and feeding device - Google Patents

Abstract

The pump has a piston defining chambers (82, 89) with a cylinder. The chambers have volumes varying, in phase opposition, progressively with the piston rotation, so that one chamber is alternatively in positions of aspiration and repression of liquid via an inlet and an outlet respectively, and the other is alternatively in positions of aspiration and repression of gas, liquid or mixture of both via an inlet and an outlet respectively. An independent claim is also included for an installation supplying a liquid consuming device e.g. burner, with a fuel oil, susceptible of containing a gas, from a tank containing fuel oil, including a pump.

Description

• un piston disposé dans la cavité et délimité par une face périphérique extérieure cylindrique de révolution autour de l'axe avec un diamètre sensiblement identique à celui de la face périphérique intérieure de la cavité, pour établir un contact mutuel glissant et étanche au fluide à pomper, et par une première face frontale placée en regard du premier fond de la cavité, la face périphérique extérieure du piston présentant un premier chambrage localisé adjacent à la première face frontale et s'étendant sur moins de 180° en référence à l'axe de telle sorte que le premier chambrage et la première face frontale du piston délimitent avec la face périphérique intérieure et avec le premier fond de la cavité une première chambre étanche susceptible d'être placée en communication alternativement avec la première entrée et avec la première sortie sans pouvoir communiquer en même temps avec la première entrée et avec la première sortie,
• des moyens pour animer le piston, par rapport au cylindre, d'un mouvement simultané de rotation autour de l'axe, dans un sens constant, et de va-et-vient le long de l'axe, de telle sorte que le piston passe successivement et cycliquement, par rapport au cylindre :
  • à des positions d'aspiration par la première chambre, dans lesquelles le premier chambrage fait face à la première entrée et la première face frontale s'éloigne progressivement du premier fond, au fur et à mesure de la rotation, de façon à augmenter progressivement le volume de la première chambre, et
  • à des positions de refoulement par la première chambre, dans lesquelles le premier chambrage fait face à la première sortie et la face frontale se rapproche progressivement du premier fond, au fur et à mesure de la rotation, de façon à réduire progressivement le volume de la première chambre.

The present invention relates to a pump of the type comprising a cylinder having an axis and defining a blind cavity delimited by a cylindrical inner peripheral face of revolution about the axis and by a first bottom, the inner peripheral face having a first inlet and a first fluid outlet to be pumped, arranged in positions at least approximately radially opposite to the axis and each extending less than 180 ° with respect to the axis,

• a piston disposed in the cavity and delimited by an outer cylindrical peripheral face of revolution about the axis with a diameter substantially identical to that of the inner peripheral face of the cavity, to establish a mutual contact sliding and impervious to the fluid to be pumped, and by a first end face placed facing the first bottom of the cavity, the outer peripheral face of the piston having a first chamber located adjacent to the first end face and extending over less than 180 ° with reference to the axis of such so that the first recess and the first end face of the piston delimit with the inner peripheral face and with the first bottom of the cavity a first sealed chamber may be placed in communication alternately with the first input and with the first output without being able to communicate at the same time with the first entry and with the first exit,
• means for animating the piston, with respect to the cylinder, with a simultaneous movement of rotation about the axis, in a constant direction, and back and forth along the axis, so that the piston passes successively and cyclically, with respect to the cylinder:
  • at suction positions by the first chamber, in which the first chamber faces the first inlet and the first end face progressively moves away from the first base, as the rotation progresses, so as to progressively increase the volume of the first chamber, and
  • at discharge positions by the first chamber, in which the first chamber faces the first outlet and the front face progressively approaches the first bottom, as and when the rotation, so as to gradually reduce the volume of the first room.

A pump of this type, which makes it possible to dispense with valves and control means for such valves for controlling the intake and the exhaust, is known in various embodiments, an example of which is marketed by the American company FLUID METERING, INC.

The cylinder of this known pump has only one inlet and one outlet, and its piston has correspondingly a single recess.

When this known pump is used to feed a liquid-consuming device, such as a liquid fuel burner, from a tank containing this liquid, itself containing more or less what will be described later. "volatile substances", ie substances which, under the effect of suction, are likely to be released in the form of entrained gas bubbles with the pumped liquid, it is a mixture of liquid and gas which is routed to the liquid consumer device.

Admittedly, it is intended to heel the piston of this known pump, that is to say to establish a contact between its first end face and the first bottom of the blind cavity, at the end of discharge, to reduce in any as far as possible the dead spaces in which gas could come to accumulate and then stagnate, to the detriment of the flow rate of the pump given the compressible nature of this gas, which furthermore mixes the gas with the liquid and can reduce in to some extent the disadvantages of the presence of the gas at the liquid consumer device, but this known pump is in no way likely to separate the gas from the liquid to convey only liquid to the consumer device. In addition, the concern to heel the piston in the cylinder requires to meet strict tolerances in the axial position of the piston during its movement back and forth axially inside the cylinder, which makes the manufacture of such a known pump, unless to choose, for safety, to avoid a true tailgating and, consequently, to reduce the effect produced on the bubbles present in the liquid.

The purpose of the present invention is to propose a pump of the type indicated in the preamble, which makes it possible to remedy these disadvantages.

• la cavité est délimitée, axialement à l'opposé du premier fond par rapport à la première entrée et à la première sortie, par un deuxième fond, et sa face périphérique intérieure présente, dans des positions respectives décalées axialement par rapport aux positions respectives de la première entrée et de la deuxième sortie, dans le sens d'un éloignement par rapport au premier fond, et formant un même angle déterminé, en référence à l'axe, par rapport aux positions respectives de la première sortie et de la première entrée, une deuxième sortie et une deuxième entrée de fluide à pomper, s'étendant chacune sur moins de 180° en référence à l'axe,
• le piston est délimité, axialement à l'opposé de la première face frontale par rapport au premier chambrage , par une deuxième face frontale placée en regard du deuxième fond de la cavité et sa face périphérique extérieure présente, dans une position décalée axialement par rapport à la position du premier chambrage, dans le sens d'un éloignement par rapport à la première face frontale, et formant ledit angle déterminé, augmenté de 180°, par rapport à la position du premier chambrage, en référence à l'axe, un deuxième chambrage localisé adjacent à la deuxième face frontale et s'étendant sur moins de 180° en référence à l'axe de telle sorte que le deuxième chambrage et la deuxième face frontale du piston délimitent avec la face périphérique extérieure et avec le deuxième fond de la cavité une deuxième chambre étanche susceptible d'être placée en communication alternativement avec la deuxième entrée et avec la deuxième sortie sans pouvoir communiquer en même temps avec la deuxième entrée et avec la deuxième sortie, et isolée de façon étanche de la première chambre, de telle sorte que, lors dudit mouvement du piston par rapport au cylindre :
  • les positions d'aspiration par la première chambre correspondent à des positions de refoulement par la deuxième chambre, dans lesquelles le deuxième chambrage fait face à la deuxième sortie et la deuxième face frontale se rapproche progressivement du deuxième fond, de façon à réduire progressivement le volume de la deuxième chambre, et
  • les positions de refoulement par la première chambre correspondent à des positions d'aspiration par la deuxième chambre, dans lesquelles le deuxième chambrage fait face à la deuxième entrée et la deuxième face frontale s'éloigne progressivement du deuxième fond, de façon à augmenter progressivement le volume de la deuxième chambre.

For this purpose, the pump according to the invention is characterized in that:

• the cavity is delimited, axially opposite the first bottom relative to the first inlet and the first outlet, by a second base, and its inner peripheral face has, in respective positions axially offset with respect to the respective positions of the first inlet and the second outlet, in the direction of a distance relative to the first bottom, and forming a same determined angle, with reference to the axis, relative to the respective positions of the first outlet and the first inlet, a second output and a second fluid inlet to be pumped, each extending less than 180 ° with reference to the axis,
• the piston is delimited, axially opposite the first end face with respect to the first recess, by a second end face placed facing the second bottom of the cavity and its outer peripheral face presents, in a position axially offset with respect to the position of the first recess, in the direction of a distance relative to the first end face, and forming said determined angle, increased by 180 °, relative to the position of the first recess, with reference to the axis, a second localized chambering adjacent to the second end face and extending less than 180 ° in reference to the axis so that the second recess and the second end face of the piston delimit with the outer peripheral face and with the second bottom of the cavity a second sealed chamber capable of being placed in communication alternately with the second input and with the second output without power communicating at the same time with the second inlet and with the second outlet, and sealingly insulated from the first chamber, so that, during said movement of the piston relative to the cylinder:
  • the suction positions by the first chamber correspond to discharge positions by the second chamber, wherein the second chamber faces the second outlet and the second end face is gradually approaching the second bottom, so as to gradually reduce the volume from the second bedroom, and
  • the discharge positions by the first chamber correspond to suction positions by the second chamber, in which the second chamber faces the second inlet and the second end face. progressively away from the second bottom, so as to gradually increase the volume of the second chamber.

• la valeur 0°, auquel cas les première et deuxième entrées sont situées d'un même premier côté de l'axe et les première et deuxième sorties sont situées d'un même deuxième côté de l'axe, opposé au premier côté, ce qui peut faciliter l'implantation de la pompe, alors que les premier et deuxième chambrages occupent des positions angulaires opposées par rapport à l'axe, et
• la valeur 180°, auquel cas la première entrée et la deuxième sortie sont situées d'un même premier côté de l'axe alors que la deuxième entrée et la première sortie sont situées d'un même deuxième côté de l'axe, opposé au premier, mais les premier et deuxième chambrages sont situés d'un même côté de l'axe, ce qui peut faciliter la fabrication du piston.

The value of said determined angle can be freely chosen, but it is preferred to choose it in a group comprising:

• the value 0 °, in which case the first and second inputs are located on the same first side of the axis and the first and second outputs are located on the same second side of the axis, opposite the first side, which can facilitate the implantation of the pump, while the first and second chambers occupy opposite angular positions with respect to the axis, and
• the value 180 °, in which case the first input and the second output are located on the same first side of the axis while the second input and the first output are located on the same second side of the axis, opposite the first, but the first and second chambers are located on the same side of the axis, which can facilitate the manufacture of the piston.

If, in an installation also characteristic of the present invention, intended to feed a liquid-consuming device, such as a liquid fuel burner, into said liquid capable of containing a gas, from a vessel containing said liquid and more or less than what has been described as "volatile substances", capable of generating said gas, said installation comprising means for pumping said liquid into the tank via a degasser, a lower part of which is intended to contain a variable quantity of the liquid and of which an upper part is intended to contain a variable quantity of said gas and, if appropriate, of said liquid, the pumping means are constituted by a pump according to the invention, of which the first inlet and the first outlet are respectively connected to the lower part of the degasser and the consumer device and whose second inlet and the second outlet are re linked respectively to the upper part of the degasser and to the tank, the combination of the degasser and the pump according to the invention makes it possible to convey to the consumer device a liquid practically free of gas, and to cause the return to the tank of the separated gas. liquid, if necessary accompanied by a greater or lesser amount of liquid.

Then, instead of simply mixing the gas and the liquid in the same way as the aforementioned known pump, the pump according to the invention allows a real degassing of the liquid.

When it comes to supplying liquid fuel to a device such as a burner, the use of a pump according to the invention is compatible with the most modern burners, whose proper functioning is incompatible with the presence of a more or less controlled amount of gas in the liquid fuel.

Preferably, in such an installation, the axis of the pump is disposed substantially horizontally and the first and second outlets are rotated upwards, which makes it possible for the optionally pumped gas to leave gravity more easily. second output and ensures permanently the presence, at these two outputs, a sufficient amount of liquid to maintain a gas seal between the outer peripheral face of the piston and the inner peripheral face of the cylinder is that is to say, also between the first and second chambers, so as to prevent the gas present in the second chamber from mixing with the liquid present in the first chamber.

This permanent presence of liquid also has a particular interest at the second outlet when gas must pass through the second inlet, the second chamber and the second outlet, as is the case in such a facility, and tends to stagnate in the dead zones of the pump by affecting, due to its eminently compressible character, the flow thereof through the second inlet and the second outlet through the second chamber.

Indeed, it makes it possible to ensure that, as soon as the second chamber reaches the second outlet and if the second chamber contains gas, a liquid re-aspiration in the second chamber promotes the return of this gas, before repression of the liquid possibly pumped with the gas, and that, when the second chambering leaves the second outlet, the second chamber is filled with liquid whose presence contributes to the aforementioned seal and promotes the initiation of pumping by the second inlet even if gas is present at the level of this one, by a tendency of this gas to be replaced in the second the liquid is then pushed back to the second inlet before being sucked back with the liquid from the degasser.

Complementary arrangements may advantageously be provided to facilitate these different effects.

Thus, while the first inlet and the first outlet may advantageously have a substantially identical section, it is advantageous to provide that the second outlet has a section greater than that of the second inlet, which facilitates at this level the separation of the gas, which then tends to rise and leave naturally the second outlet, and the liquid which, thus, tends to remain only permanently present at the second outlet, to, on the one hand, contribute to the aforementioned sealing effect and, d on the other hand, to avoid any risk of re-aspiration of the gas by the pump as well when the piston reaches its delivery position by the second chamber that when it leaves this position to return to its suction position by the second chamber, c ' that is to say, any risk of accumulation of gas in the dead spaces of the pump to the detriment of the flow thereof due to the eminently compressible nature of this gas.

It can also be provided for this purpose that the pump comprises, within the second outlet, a partition disposed along a mean surface generated by generatrices parallel to the axis and subdividing the second outlet into two conduits of respective constant section, which can advantageously be identical for the two ducts, or, when the axis of the pump is oriented horizontally and the first and second outlets facing upwards, orienting the pump for this purpose obliquely so that the second outlet is arranged on one side of a vertical plane including the axis, this side being chosen such that said direction is upward, and connecting the second outlet to the vessel by a channel subdivided internally, for a part of its length, adjacent to the second output, in a lower duct, upstream with reference to said direction, and in an upper duct, downstream with reference to said direction, having res sections constant lenses, by a partition disposed along a mean surface generated by generatrices parallel to the axis, said sections being advantageously identical.

Tests have shown that such a subdivision of the second outlet and / or of the pipe connecting it to the tank makes it possible to create at the second outlet a sweep of liquid, causing the gas to move away from the second outlet and thus avoiding its re-aspiration via the latter.

It is also possible, in the case of such an oblique orientation of the pump, to connect the second inlet to the upper part of the degasser by a pipe, which forms a bend, convex downwards, near said second inlet, at a lower level than the latter, and has a section narrowed internally, a lower zone of said elbow to said second inlet, which ensures a permanent presence of liquid at the second inlet and a priming of the suction via the latter, the simple fact of the discharge to it, when the second chamber reaches the suction position, a small amount of liquid and sucked up by the second outlet at the moment when the second room has previously left the discharge position.

In an installation according to the invention, it is furthermore preferably provided a check valve passing from the second outlet to the tank, to avoid a defusing of the connection of the second outlet to the tank when the pump is stopped. , and controlled means for stopping the connection between the first output and the consumer device.

It is understood, however, that the use of a pump according to the invention is not limited to such a feed system of a liquid consuming device with degassing thereof, and it is not possible to It would be beyond the scope of the present invention to use for other purposes a pump according to the invention.

The means for animating the piston of the above-mentioned movement with respect to the cylinder can be realized in different ways and, in particular with regard to the rotational component of this movement, by magnetic coupling with rotating drive means placed at the outside the cavity, then completely closed.

However, an embodiment is preferred in which the means for animating the piston of said movement relative to the cylinder comprise a receiver shaft integral with the piston, forming a coaxial projection on the second face. front of the piston and passing through the second bottom, and drive means of said receiving shaft located outside the cavity, the receiving shaft being delimited, in the direction of a distance from the axis, by a cylindrical outer peripheral surface of revolution around it, with a diameter smaller than that of the outer peripheral face of the piston and the second bottom having the shape of a ring of revolution about the axis, having an inner periphery in contact sliding and sealed with the outer peripheral face of the receiving shaft, being for example constituted by an annular seal of revolution about the axis, having an outer periphery in contact with and sealed with the inner peripheral face of the cavity. One skilled in the art will readily understand that such an embodiment of the second bottom is particularly simple.

The axial back-and-forth component of the above-mentioned movement of the piston with respect to the cylinder can also be obtained by various means, in particular by transforming the rotation component into such an axial back-and-forth component, that one could for example using for this purpose means similar to those that comprises the aforementioned known pump, wherein the drive means driving the piston in rotation are angularly offset relative to the piston and drive it by mechanical connection articulated at a point offset from to the respective axes.

However, an embodiment is preferred in which the driving means of the receiving shaft comprise motor means having a motor shaft coaxial with the receiving shaft, fixed axially with respect to the cylinder and driven in rotation about the axis. in said direction, with respect to the cylinder, and mechanical connection means between the motor shaft and the receiving axis, ensuring a mutual rotational connection about the axis and an elastic thrust of the receiving shaft, relative to the cylinder, in an axial direction from the second end face of the piston to the first end face of the piston, and wherein the first end face of the piston and the first bottom comprise cam means, in mutual axial support, to translate the rotation of the piston, about the axis, relative to the cylinder, by an axial back and forth movement.

A controlled variation in the speed of rotation of the drive shaft then makes it possible to vary in a predetermined manner the flow rate of the pump according to the invention, namely in particular the flow rate of the liquid pumped through the first chamber and supplied , in the case of an installation according to the invention, the device consuming liquid.

In addition to the fact that a coaxial mounting of the drive means and the piston is a much simpler solution, mechanically, and much more favorable, in terms of transmission of forces and therefore in terms of wear and longevity, that the known solution, it will be observed that the realization of the mechanical connection means between the motor shaft and the receiving axis in a form ensuring an elastic thrust of the receiving shaft, relative to the cylinder, in an axial direction from the second face front of the piston to the first front face thereof ensures an automatic safety against an abnormal increase in pressure inside the first chamber, namely that which ensures the pumping of the only liquid in an installation according to the present invention, and therefore to ensure a security for example when closing the connection between the first output and the consumer device of liquid in the case of an installation according to the present invention.

To achieve the cam means, in a particularly simple form, it can be provided that the first end face has the shape of an oblique pan, with respect to the axis, so as to approach axially the second end face by radially approaching the first recess, and that the first bottom has a localized support for said sloping portion, in a zone offset from the axis and located downstream of the first and second outlets and upstream of the first and second inputs, with reference said direction, substantially at 90 ° with respect to the first and second outputs and the first and second inputs, with reference to the axis.

However, it would be possible to achieve differently the cam means and, for example, to make the first bottom in the form of an oblique pan with respect to the axis and to arrange on the first front face a deflected support of the piston, in the axial direction, on this oblique pan. We could then adjust the flow rate of the pump only by adjusting the speed of rotation of the piston relative to the cylinder, but also by adjusting the inclination of the first bottom relative to the axis with the effect of a change in the amplitude of the axial reciprocation of the piston .

Other features and advantages of the various aspects of the present invention will emerge from the description below, relating to a non-limiting example of an installation according to the invention and a pump according to the invention, as well as the appended drawings.

FIG. 1 schematically illustrates an installation for supplying a liquid fuel burner from a tank open to the open air by means of a pump according to the invention associated with a degasser.

FIGS. 2 and 3 show this pump in the position it preferably occupies in such an installation, respectively in section through a vertical axial plane or, preferably, an oblique plane, marked II-II in FIG. 3, and by an axial plane perpendicular thereto, marked III-III in Figure 2 and corresponding to a view from above.

Figure 4 shows a view of the end cylinder in an axial direction marked IV in Figure 5 and from the first bottom to the second bottom if we refer to the pump as a whole.

FIGS. 5 and 6 show a view of this cylinder, in section through an axial plane coinciding, respectively, with that of FIG. 2 and with that of FIG. 3 and marked respectively with V-V and VI-VI in FIG. 4.

FIG. 7 shows a view of the pump and of parts, adjacent thereto, of ducts connected respectively to the second inlet and to the second outlet, in section through a plane perpendicular to the axis, indicated at VII-VII at Figure 2, while the piston occupies with respect to the cylinder, during its rotation, a position corresponding to the beginning of the communication of the second chamber with the second output.

FIG. 8 illustrates, in an extract of FIG. 2, a relative position of the piston and the cylinder corresponding to the end of the communication of the second chamber with the second outlet.

FIG. 1 illustrates an installation according to the invention for feeding a liquid fuel burner 1, of the type known as a "rotating cup burner", integrated in a boiler, not shown, from a tank 2, open to the open air 3 in the upper part and constituting a reserve of this liquid fuel 4, for example domestic fuel oil, which may contain a greater or lesser amount of what has been described as " volatile substances ", ie for example liquid hydrocarbons likely to pass into the gaseous phase under the effect of the depression generated by pumping, or air intimately mixed with the fuel oil.

For this purpose, is provided a pump according to the invention 5, which will be detailed later and which we see in Figure 1 that it has an axis 6 then oriented substantially horizontally, two inputs 7 and 8 mutually offset parallel to this axis and located below it, namely in the example shown in the same plane including the axis 6 and oriented vertically or, preferably, obliquely forming relative to a vertical plane 102, including the axis 6, an angle α less than 90 ° and preferably less than 60 °, ie for example of the order of 30 ° as illustrated in FIGS. 7 and 8, this plane being indicated at 9 in FIGS. 4 and in FIGS. 7 and 8. Next to each of the inlets 7 and 8 in a respective radial direction with reference to the axis 6, namely in the example illustrated along the same average plane 9, above the axis 6 and in mutually offset positions parallel to this axis 6, the pump 5 has a respective outlet 11, 12 by which it respectively represses what it sucks through the inlet 7 and that it sucks through the inlet 8, under conditions which will be described later.

Each of the inlets 7 and 8 is connected sealingly, by a respective pipe 13, 14, to a degasser 15 which is itself sealingly connected to the tank 2 by a dip tube 16 having a lower end provided with a strainer 17 near a non-referenced bottom of this tank 2, so that the strainer 17 continuously bathes in the liquid fuel 4 inside the tank 2.

The degasser 15 has the form of a vertical enclosure 18, sealed and delimiting an interior space 19, a lower part, which constitutes the major part, permanently contains a volume 20 of liquid fuel and an upper portion may according to the quantity of gas separating from the liquid fuel 4 sucked into the tank 2 through the strainer 17, under the effect of the suction vacuum generated by the pump 5 in the plunger tube 16 leading to the degasser 15, containing a variable volume 21 of gas, it being understood that this volume 21 can be canceled if the liquid fuel 4 sucked into the tank 2 is free of volatile substances as understood here, in which case the volume of liquid fuel 20 to the interior of space 19 fills the whole of the latter.

The dip tube 16 opens into the interior space 19 of the chamber 18 to a level such that, preferably, its mouth 22 to the inner space 19 is in the upper part thereof. The pipe 13 opens into this inner space 19 in the form of a dip tube having a lower end 23 near a non-referenced bottom of the chamber 18, at a lower level than that of the mouth 22 of the dip tube 16 and as, therefore, this lower end 23 is permanently located inside the volume 20; the duct 14 opens into the interior space 19 of the chamber 18 by an end 24 located in the upper part of this interior volume 19 to be located as far as possible inside the volume 21 of gas separated from the liquid inside the degasser 15, it being understood that the volume 20 of liquid can sometimes be brought to reach the level of this end 24.

In the interior space 19 of the chamber 18 is disposed a filtering wall 25 which separates from the mouth 22 of the dip tube 16 the lower end 23 of the end dip tube of the pipe 13 and the end 24 of the pipe 14 , in order to prevent penetration, into the pipes 13 and 14, of any solid impurities contained in the liquid fuel 4 pumped into the tank 2.

The internal space 19 of the chamber 18 is depressurized by the suction of the pump 5, at its inputs 7 and 8, which causes a pumping effect of the liquid fuel 4, by the plunger tube 16, inside the tank 2, and a suction of degassed liquid fuel in the occupying volume the lower part of the chamber 18, through the pipe 13 and the inlet 7 of the pump 5, whereas, according to the respective proportions of the volumes 20 and 21, that is to say according to the proportion of gas evolved by the liquid fuel 4, pumped into the tank 2 and arriving in the inner space 19, the inlet 8 and the pipe 14 can suck either gas alone or liquid fuel, or a mixture of the two.

The outlet 11 associated with the inlet 7 and fed exclusively with liquid fuel, that is to say the outlet 11 placed in a position substantially diametrically opposite that of the inlet 7 with reference to the axis 6, above it, is connected to the burner 1 by a pipe 26 provided with means 27 allowing, in a controlled manner, to close this pipe 26 or to open it. The means 27 may be constituted for example by a solenoid valve as shown in FIG.

The outlet 12 associated with the inlet 8, that is to say placed in a substantially diametrically opposite position with respect to this inlet 8 with reference to the axis 6, sometimes fed with liquid fuel, sometimes with gas, sometimes with a mixture of the two, opens as for it on a lower end of a section, rising from this outlet 12, a pipe 28 back to the tank 2, inside which this pipe 28 opens with a 29 end generally located above the upper level of the liquid fuel 4, inside the tank 2, that is to say in the open air 3 to allow the return to the tank 4 of the liquid fuel possibly pumped into the volume 21 and the evacuation to the open air 3 of gas possibly pumped into the volume 21.

At a distance from the outlet 12 of the pump 5 sufficient to allow the permanent maintenance, immediately above this outlet 12, in the ascending section of the pipe 28, a certain volume 30 of liquid fuel surmounted by a certain 31, the duct 28 comprises a nonreturn valve 32 passing from the outlet 12 to the end 29 of the pipe 28 and blocking in the opposite direction, which nonreturn valve 32 is preferably also arranged so that a certain volume 33 of liquid fuel remains permanently above it, to increase its sealing against a passage in a direction from the end 29 to the outlet 12, under the combined effects of gravity who is exerted on this volume 33 and a cyclically generated depression in the section of the pipe 28 located between the outlet 12 and the check valve 32, by a re-aspiration of a portion of the liquid fuel volume 30 through the outlet 12, immediately preceding each gas discharge by this outlet 12, according to a phenomenon which manifests itself in a pump according to the present invention, when the fluid to be pumped is compressible, that is to say contains a greater or lesser proportion. volatile substances, able to pass into the gaseous phase under the effect of suction vacuum by the pump, and which will be described in more detail later.

The pipes 13 and 26 preferably have the same passage section, and it may be the same for the pipe 14 or the pipe 28, which, however, preferably has a passage section greater than that of the pipe 14, for reasons and under conditions which will emerge from the rest of the description.

The gravity exerted on the volume 30, the aforementioned cyclic reaspiration of a portion of this volume 30 and the permanent presence of the fuel alone in the pipe 26, in which this liquid fuel is also subjected to the action of gravity and to a similar effect of cyclic re-aspiration before each discharge through its outlet 11, allow to maintain the inside of the pump 5 permanently in a bath of liquid fuel, thus contributing to obtaining seals useful for pumping, as will be understood on reading the rest of the description, relating to the pump 5 according to the invention itself, with reference to FIGS. 2 to 8, all or part of which is found the axis 6, the inputs 7 and 8, the mean axial plane 9 and the outlets 11, 12.

All or some of these FIGS. 2 to 8 also show a plane 34 including the axis 6 and oriented perpendicularly to the plane 9, which plane 34 is therefore oriented substantially at 30 ° with respect to a horizontal plane 103 including the axis 6 in the use position of the pump 5 illustrated by way of example in Figures 1, 7 and 8; this position of use will serve as a reference for the following description of the pump 5 and its components.

These components comprise in particular, in a manner known per se, a cylinder 35 and a piston 36 having in common the axis 6, the cylinder 35 being fastened integrally on a support 37 fixed with respect to the liquid consumer device, namely in the illustrated example the burner 1, the tank 4 and degasser 15 and the piston 36 being driven by means including a motor 38, for example electric, carried by the support 37, a combination of movement, so simultaneously, a rotational movement about the axis 6, in a given direction 39, relative to the cylinder 35 and a reciprocating movement 40, along the axis 6, relative to the cylinder 35. When the plane 9 is oriented obliquely with respect to the vertical plane 102, as illustrated in FIGS. 7 and 8, the obliquity is such that the direction 39 is upward on the side of the vertical 102 on which the outlet 12 is located.

The cylinder 35, illustrated in isolation in FIGS. 4 to 6, has a generally symmetrical conformation with respect to the planes 9 and 34. It defines internally a blind cavity 41 delimited by an inner peripheral face 42 cylindrical of revolution about the axis 6 and by a bottom 43 which intersects the axis 6 and, in the example illustrated, is plane and perpendicular to this axis 6. At the opposite of the bottom 43 along the axis 6, the cavity 41 has an opening 44 at the level of which the face 42 is connected, by a circular edge 45 of axis 6, to a frustoconical inner peripheral face 47 of revolution about the axis 6 and flaring from the edge 45, in the sense of a distance relative to the inner peripheral face 42 and the bottom 43.

The inner peripheral face 42 and the base 43 are defined, respectively, by a tubular wall 48 and by a bottom wall 49, mutually integral and advantageously made in one piece, while the inner peripheral face 47 is at least for the essential constituted by a flange 50, annular of revolution about the axis 6, forming a protrusion outwardly of the tubular wall 48, in the direction of a distance relative to the axis 6, in an axially extreme zone opposite to the bottom wall 49, this flange 50 serving for fixing the cylinder 35 to the support 37, by means of a ring 51, annular of revolution between the axis 6, as illustrated in FIGS. and 3. Of course, however, that another integral mounting mode of the cylinder 35 on a support 37 could be chosen without departing from the scope of the present invention.

Following the same axis 52 perpendicular to the axis 6 and located in the plane 9, closer to the bottom 43 than the edge 45, the inlet 7 and the outlet 11 open into the inner peripheral face 42 through a respective orifice 53 , 54 which, when viewed along the axis 52, preferably has the shape of an oblong slot in a circumferential direction with reference to the axis 6 and symmetrical with respect to the plane 9. In the nonlimiting example illustrated, this shape is defined by an arc centered on the axis 52, extending about 240 ° with reference to the axis 52, opposite the bottom 43, symmetrically with respect to the plane 9, and by a rope of the same circle, towards the bottom 43; the diameter of the circular arc, which is identical for the two orifices 53 and 54, is smaller than that of the inner peripheral face 42, namely more precisely small enough with respect to the diameter of the inner peripheral face 42 so that each of the orifices 53, 54 extends over less than 180 ° with reference to the axis 6. In the example illustrated, thus, the diameter of each of the arcs of circles, corresponding respectively to the orifices 53, 54, is approximately equal to half the diameter of the inner peripheral face 42, but this relationship is indicated by way of non-limiting example.

The two orifices 53 and 54 thus provide the same passage section, which constitutes the useful section of the inlet 7 and the outlet 11, just as the pipes 13 and 26 preferably have sections over their entire length. useful mutually identical.

According to another axis 55 also perpendicular to the axis 6 and located in the plane 9, but closer to the circular edge 45 than the bottom 43 with reference to the axis 6, the inlet 8 and the outlet 12 open in the inner peripheral face 42 by a respective orifice 56, 57 which, when viewed along the axis 55, also preferably has the shape of an oblong slot in a circumferential direction to the axis 6 and symmetrical with respect to the plan 9. In the nonlimiting example illustrated, this shape is identical to that of the orifices 53 and 54, that is to say combines a circular arc symmetrical with respect to the plane 9, centered on the axis 55 and presenting , with reference to this axis 55, a diameter and an angular development identical to those of the orifices 53 and 54, and a cord of the same circle, so as to offer the same passage section and to extend angularly, with reference to the axis 6, less than 180 ° respectively. However, the circular arcs partially delimiting the shape of the orifices 56 and 57 are turned away from those which partially delimit the orifices 53 and 54.

The two orifices 56 and 57 thus have the same passage section which, in this example, is identical to that of the orifices 53 and 54 but could also be different, as will be readily understood by one skilled in the art. This passage section could constitute the useful section of the inlet 8 and the outlet 12, respectively, and the pipes 14 and 28 could have the same useful section, slightly greater than that of the inlet 8 and the outlet 12, respectively over their entire respective length, but a different relative sizing is preferred which will emerge from the rest of the description.

However, in the direction of a distance from the axis 6 along the respective axis 52, 55, each of the orifices 53, 54, 56, 57 opens onto a respective cavity 63, 65, 64, 58, respectively coaxial , presenting perpendicularly to the respective axis a section which, slightly greater than that of the respective orifice, is identical for all the cavities 63, 65, 64, 58 in the illustrated example. Each of these cavities 63, 65, 64, 58, which respectively materialize the inlet 7, the outlet 11; the inlet 8 and the outlet 12, is constituted by a respective tubular ferrule 66, 68, 67, 62 coaxial interlocking, respectively, of the pipe 13, the pipe 26, the pipe 14 and the pipe 28 , each of these tubular end pieces being made in one piece with the tubular wall 48.

More precisely, each of the cavities 63, 65, 64, 58 is delimited, in the direction of a distance relative to the respective axis, by an inner peripheral face of the tip 66, 68, 67, 62 respectively corresponding, which is cylindrical of revolution about the respective axis with a substantially identical diameter to that of the arcuate portion of the contour of the orifice 53, 54, 56, 57 respectively corresponding.

However, in a variant shown schematically in phantom in Figure 5, it is also possible that the outlet orifice 57 opens, in the direction of a distance relative to the axis 6, a cavity 58 having perpendicular to the axis 55 a much larger section than that of this orifice 57, to communicate to the outlet 12 itself a section also greater than that of the inlet 8 constituted by the cavity 64.

More precisely, in this variant, as it has been illustrated, the cavity 58 is delimited by an inner peripheral face 59 cylindrical in revolution about an axis 60 located in the plane 9, parallel to the axis 55 but offset by relative to it, parallel to the axis 6, towards the circular edge 45 and the flange 50, and the diameter of this inner peripheral face 59 is greater than that of the arcuate portion of the contour of the orifice 57. The offset between the axes 55 and 60, measured along the axis 6, is substantially equal to the difference between the respective radii of the orifice 57 and of the inner peripheral face 59, so that the latter extends the orifice 57, in the direction of a distance relative to the axis 6, in the respective zones of this orifice 57 and of this inner peripheral face 59 closest to the bottom 43, and that the cavity 58 thus emerges, on the side of the orifice 57 corresponding to the flange 50, a space 61 offset parallel to the axis 6 relative to the orifice 57 and thus facilitating the release of the gas that can exit through the orifice 57 mixed with liquid fuel, that is to say a rise of this gas to form the volume 31 while the liquid fuel tends to constitute the volume 30 permanently.

The pipe 28 associated with the outlet 12 has in this case along its entire length a useful section identical to the passage section that the cavity 58 offers perpendicular to the axis 60, which is greater than that of the inlet 8 and the channel 14 associated therewith, and, in the example illustrated, the respective mutually identical sections of the inlet 7, the outlet 11 and the pipes 13 and 26 which are respectively associated with them, as has been schematized in Figure 1.

However, in order to facilitate the separation of the gas and the liquid fuel at the outlet 12, it is preferred to use provisions which make it possible to to dispense with giving the cavity 58 a section greater than that of the cavity 64, that is to say which make it possible to conform identically to the end pieces 66, 67, 68, 62, and will now be described, with reference to FIGS. 7 and 8, on which identical tips 67 and 62 have been illustrated, to define cavities 64 and 58 of the same section at the inlet 8 and at the outlet 12 of the pump.

In this case, in its ascending section between the outlet 12 and the non-return valve 32, the pipe 28 has at its connection with the nozzle 62 and over a first part of its length, of the order of a few centimeters, to from it, a first passage section, substantially equal to that of the corresponding cavity 58. Generally, flexible, the pipe 28 coaxially extends the tip 62 at least on the portion of this first part closest to that- ci and can then bend over the rest of this first part, for example until it is oriented substantially vertically as illustrated in FIG. 7. On a second part of its length, going from the first part 1 to the check valve 32, and over the rest of its length, from the non-return valve 32 to the tank 2, the pipe 28 has a second passage section, substantially greater than the first passage section and for example on the order of three times this one.

In the first part of its length, namely preferably on the whole of this first part, as well as on the one hand, inside the cavity 58 and the orifice 57, to the vicinity of an extension geometrically the inner peripheral face 42 of the cylinder 35 opposite this orifice 57, and secondly, within the second part of its length, however limited to the immediate vicinity of the connection of this second part to the first part, the pipe 28 is internally divided into two parallel ducts 104 and 105 by a smooth partition 106, disposed along a mean surface generated by generatrices parallel to the axis 6 and so as to give each of the conduits 104 and 105 a respective constant section on the first portion of the length of the pipe 28. According to the preferred embodiment shown, these generators merge with diameters of the sectio n passage of the pipe 28 and intersect the axis 55 at right angles inside the cavity 58, where they are located in the plane 9, so that the two ducts 104 and 105 have the same section of passage, substantially equal to half of the passage section of the cavity 58 and the pipe 28, if one refers to the first part of the length thereof. It will be observed that, given the obliqueness of the pipe 28 at its connection with the nozzle 62, the duct 104 located upstream with reference to the direction 39 is located below the partition 106, while the conduit 105 located in downstream with reference to the direction 39 is located above the partition 106; these two ducts communicate inside the orifice 57, by an extreme edge of the partition 106, which is rectilinear and parallel to the axis 6, and mutually connect in the second part of the length of the duct 28.

In addition, while the pipe 14 preferably has a constant passage section, substantially equal to that of the first portion of the length of the pipe 28, over its entire length between its end 24 and a bend 107, convex towards down, that it forms in the immediate vicinity of its connection to the end piece 67, to which this bend 107 is connected by an approximately rectilinear section 108, of axis 55, it is preferred to reduce the passage section offered by this section 108, preferably from the lowest part of the elbow 107 to the immediate proximity of the orifice 56, inside the cavity 64, to a value less than that of the passage section offered by the orifice 56, and by example of the order of one-ninth of it, this value being indicated by way of non-limiting example. For this purpose, in the example shown, a tubular sleeve 109 of appropriate section and length is integrally inserted inside the section 108 and the cavity 64, but it would naturally be possible to use other means without going out for both of the scope of the present invention.

Given the roles that are provided respectively by the partition 106 at the outlet 12 of the pump 5 and the sleeve 109, or any other similar narrowing at the inlet 8 of the pump 5, in comparison with the output 12 of this- ci, which will be described later, the partition 106 and the sleeve 109, or any similar narrowing, should be considered as preferred arrangements not only of an installation comprising a pump 5 according to the invention, but also of this pump 5 to which these provisions could be integrated as soon as the manufacture thereof, regardless of its incorporation in such an installation.

Naturally, other designs may be chosen, in particular according to the nature of the pipes 13, 14, 26, 28, to materialize the inlets 7, 8 and the outlets 11, 12 of the cylinder 35, without being left out. both of the scope of the present invention. In particular, although an embodiment has been described in which, at one and the same time, a partition 106 divides the pipe 28 into two channels 104 and 105 at the outlet 12 of the pump and the pipe 14 has a localized narrowing at input 8 thereof, it would not depart from the scope of the present invention using these provisions independently of one another.

Likewise, a person skilled in the art will readily understand that the orifices 53, 54, 56, 57 may also be shaped differently than that described and illustrated, while, however, preferably retaining the respective shape of an oblong slot. circumferential direction, with reference to the axis 6, which makes it possible to reduce the dimension of each of the recesses 79 and 89 parallel to the axis 6 for an identical respective cross-section, that is to say, to also reduce the dead spaces likely to accumulate gas, whose stagnation inside the cylinder 35 would be unfavorable to the flow rate of the pump, given the compressibility inherent in the gases.

For reasons that will emerge from the following description, the bottom wall 49, essentially flat, locally has a bulge 69 outwardly, to define, in the bottom 43 of the cavity 41, a hollow housing 70 , blind, for a ball 71 having a smaller diameter than the bottom 43, namely of the order of half that of the bottom 43 in the non-limiting example illustrated.

This housing 70 and this ball 71 have an axis 72 offset from the axis 6, but parallel thereto in the plane 34, so that the direction 39 of coaxial rotation of the piston 36 relative to the cylinder 35 is downstream, outputs 11 and 12 to the inputs 7 and 8 on the same side of the plane 9 as the axis 72.

The diameter of the ball 71 and the depth of the housing 70, measured along the axis 72, that is to say parallel to the axis 6, between a flat bottom unreferenced thereof, perpendicular to the axis 72, and the bottom 43 are chosen such as the ball 71 forms a projection towards the inside of the blind cavity 41 parallel to the axis 6, with respect to the bottom 43 as shown in FIG. 3. More precisely, the depth of the housing 70 has an intermediate value between that of the radius of the ball 71 and that of the diameter thereof, namely of the order of three quarters of this diameter in the non-limiting example illustrated, and the housing 70 has perpendicularly to the axis 72 a constant circular section of a diameter substantially identical to that of the ball 71, so as to immobilize the ball 71 relative to the cylinder 35.

However, in the direction of the axis 6, the ball 71 is entirely set back towards the bottom 43 of the cavity 41, relative to the alignment, perpendicularly to the axis 6, of the zones of the orifices 53 and 54. closer to this background 43.

The ball 71 thus creates, along the axis 72, a projection located, relative to the bottom 43 of the blind cavity 41, parallel to the axis 6 thereof, to provide the piston 36, towards the bottom 43 in parallel. at the axis 6, a point support offset with respect to this axis 6.

The piston 36, which will now be described with reference to FIGS. 2 and 3, is disposed in the cavity 41, in a sealing relation with respect to the inner peripheral face 42 thereof, and at this point Indeed, it is delimited, in the direction of a distance from the axis 6, by an outer peripheral face 74 cylindrical of revolution about this axis 6 with a diameter substantially identical to that of the inner peripheral face 42, of such that there is further established between the faces 74 and 42, a guide relationship to the relative rotation about the axis 6 as well as to the relative translation parallel to this axis 6.

In a direction parallel to the axis 6, of the circular edge 45 of the inner peripheral face 42 of the cavity 41 towards the bottom 43 thereof, the outer peripheral face 74 of the piston 36 is connected to one face 75 of the latter, which is plane, intersecting the axis 6 but has relative to it an orientation different from 90 °, so that when the piston 36 is rotated about the axis 6 inside the cavity 41, in the direction 39, relative to the cylinder 35, maintaining a point support of the face 75 on the ball 71, towards the bottom 43 of the cavity 41, near the axis 72, the rotation of the piston 36 relative to the cylinder 35 is accompanied by the relative translation 40 back and forth, parallel to the axis 6.

It is then possible to choose as the motor 38 a motor, for example an electric motor, having an output shaft or motor shaft 85 arranged coaxially with the piston 36, immobile in translation along the axis 6 relative to the support 37 and to the cylinder 35 but rotated in the direction 39, around the axis 6, relative to the support 37 and to the cylinder 35, when the motor 38 is supplied with energy, this drive shaft 85 being connected to the piston 36 by transmission means ensuring a mutual bonding in rotation about the axis 6 while being compatible with a relative translation, reciprocating, parallel to the axis 6 and preferably being able to themselves elastically solicit the piston 36 to the bottom 43 of the blind cavity 41, as is the case in the illustrated example.

In this example, in which the motor 38 is located on the side of the support 37, that is to say opposite to the end face 75 with reference to the axis 6, the piston 36 bears solidarity for this purpose, for example by one-piece construction, a coaxial shaft 84, a motion receiver, disposed opposite to the end face 75 with reference to the axis 6 and delimited in the direction of a distance from the axis 6, on an axial dimension at least equal to the translational travel of the piston 36 inside the cylinder 35, parallel to the axis 6, during the relative back and forth movement 40, by an outer peripheral face 101 cylindrical of revolution about the axis 6 with a diameter smaller than that of the outer peripheral face 74 of the piston 36, that is to say also that of the inner peripheral face 42 of the cylinder 35. The outer peripheral face 101 of the receiving shaft 84 is connected to the peripheral face Oe exterior 74 of the piston 36 by a front face 88 thereof, which is annular, flat, perpendicular to the axis 6 and defines the piston 36 opposite its front face 75 with reference to the axis 6. The respective dimensions of the piston 36 and the cylinder 35 parallel to the axis 6 are chosen so that, during the aforementioned reciprocating movement 40, the outer peripheral face 101 is permanently housed inside the cavity 41. , that is to say situated axially between the circular edge 45 and the bottom 43 of the cavity 41.

The rotation of the motor shaft 85 in the direction 39 is then communicated to the receiving shaft 84 via a helical spring 93 of axis 6 interposed axially between the motor shaft 85 and the receiving shaft 84 and having an end portion 94, 95 integrally connected with the drive shaft 85 and with the receiving shaft 84, for example by interference fit on a respective coaxial pin 96, 97, as will be readily understood by one skilled in the art.

The pins 96 and 97 are spaced axially from each other, in any position of the piston 36 in its reciprocating movement 40, due to appropriate sizing, easily determined by a person skilled in the art, such that between the two end portions 94 and 95, the spring 93 has free turns 98 in sufficient number to be able to change between an axial expansion limit position, illustrated in Figure 3, in which the end face 75 is press the ball 71 in its zone 77 closest to the end face 88, that is to say the farthest from the bottom 43, parallel to the axis 6, and a limit position of maximum axial compression, not shown , in which it is in the immediate vicinity of its zone 76 farthest from the front face 88, that is to say the closest to the bottom 43, with reference to the axis 6, that the front face 75 s press on the ball 71.

Also easily determined by a person skilled in the art, the winding direction of the spring 93 is such that the rotation of the motor shaft 85 in the direction 39 and the resistance that the piston 36 tends to oppose a rotation in the same direction. direction, relative to the cylinder 35, result in an increase in a radial clamping effect applied by the end portions 94, 95 of the spring 93 on the pins 96 and 97, respectively.

The nature of the motor 38 and the mechanical connection between the motor shaft 85 and the receiving shaft 84 so as at the same time to drive the piston 36 to rotate about the axis 6 in the direction 39 relative to the cylinder 35 and the maintenance of the end face 75 in permanent support against the ball 71 could however be chosen differently, in a wide range of possibilities, without departing from the scope of the present invention.

The inclination of the end face 75 with respect to the axis 6, the projection that the ball 71 forms, parallel to this axis 6, on the bottom 43 of the blind cavity 41 and the offset of the axis 72 relative to the axis 6 are calculated so that, regardless of the orientation of the piston 36 about the axis 6 relative to the cylinder 35, the end face 75 never comes into contact of the bottom 43 of the cavity 41. It will be observed that the point support of the end face 75 on the ball 71 is always located in the immediate vicinity of the axis 72, and that the ball 71 could be replaced by any other means allowing provide a similar localized support offset from the axis 6, in particular along the axis 72.

Thus, according to a variant not illustrated but easily understandable by a skilled person, the ball 71 may be replaced by a conical projection of revolution about the axis 72 and defined by generatrices having, relative to this axis 72, an inclination identical to the inclination of the front face 75, relative to the axis 6, to permanently offer this end face 75 a support along one of these generators.

In its zone 76, as on most of its contour, that is to say more than 180 ° in reference to the axis 6, the face 75 is connected directly to the outer peripheral face 74 but, in its zone 77, it is connected by an edge 78, here rectilinear and located in a non-referenced plane perpendicular to the axis 6, further from the axis 6 than the axis 72, a recess 79 hollowed out, so located in the outer peripheral face 74 and adjacent to the end face 75. In the illustrated example, this recess 79 is delimited by a flat portion 80, which is parallel to the axis 6 and to which the end face 75 is connected by the edge 78 in its zone 77, and by a plane shoulder 81 perpendicular to the axis 6, ensuring the connection of the flat portion 80 to the outer peripheral face 74 opposite the edge 78 with reference to the axis 6. The flat part 80 is also connected to the outer peripheral face 74 by two straight edges, parallel to the axis 6 and not visible in the figures, as will readily be understood by a person skilled in the art.

• dans des positions d'aspiration du combustible liquide, par l'entrée 7, dans une chambre étanche 82 définie, à l'intérieur de la cavité 41, par le fond 43 de celle-ci, la face frontale 75 du piston 36, le méplat 80 et l'épaulement 81 définissant le chambrage 79 de celui-ci, et une zone correspondante de la face périphérique intérieure 42 de la cavité 41, et
• dans des positions de refoulement, vers la sortie 11, du combustible liquide ainsi aspiré par cette chambre 82.

The flat portion 80 extends angularly, between its two not shown edges, with reference to the axis 6, on an angular dimension of less than 180 ° and chosen, as well as the distance between the edge 78 and the shoulder 81 , parallel to the axis 6, depending on the orientation of the end face 75, of the projection that the ball 71 forms parallel to the axis 6 relative to the bottom 43 and the offset of the axis 72 relative to the axis 6, so that, as and when the piston 36 is rotated relative to the cylinder 35, around the axis 6, in the direction 39, with maintenance of the end face 75 in permanent support against the ball 71, the piston 36 passes successively and cyclically, relative to the cylinder 35:

• in suction positions of the liquid fuel, through the inlet 7, in a sealed chamber 82 defined, inside the cavity 41, by the bottom 43 thereof, the end face 75 of the piston 36, the flat 80 and the shoulder 81 defining the recess 79 thereof, and a corresponding zone of the inner peripheral face 42 of the cavity 41, and
• in discharge positions, towards the outlet 11, liquid fuel thus sucked by this chamber 82.

In the suction positions, the recess 79 faces the orifice 53 of the inlet 7 while the outer peripheral face 74 faces the orifice 54 of the outlet 11, to seal it sealingly, and the end face 75 progressively moves away from the bottom 43 of the cavity 41, as the rotation in the direction 39, so as to progressively increase the volume of the chamber 82, and to thereby create the desired effect of suction of the liquid fuel arriving through the inlet 7.

In the discharge positions, the recess 80 is against the orifice 54 of the outlet 11 while the outer peripheral face 74 of the piston 36 seals the orifice 53 of the inlet 7, and the front face 75 of the piston 36 is progressively closer to the bottom 43 of the cavity 41, as and when the rotation in the direction 39, so as to gradually reduce the volume of the chamber 82 and to discharge the liquid fuel to the outlet 11 .

The sizing, for this purpose, of the various parts of the cylinder 35 and the piston 36 and the sizing of the ball 71 or any other localized projection replacing it can be easily determined by the skilled person.

Similarly, such a person skilled in the art can easily conceive that instead of being delimited by a flat surface 80, plane, and by a shoulder 81, also plane, the recess 79 could have another conformation, the conformation indicated in FIG. non-limiting example being however preferred because of a great simplicity of manufacture that entails.

It will be observed that in addition to its role as a means of mechanical connection between the axially fixed but rotating motor shaft 85 and the piston 36, in permanent resilient support by its end face 75 against the ball 71, the spring 93 plays a role of against an abnormal increase in the pressure inside the sealed chamber 82 since such an increase in pressure can result in an increase in the volume of the chamber 82 by axial compression of the spring 93 between its two extreme sections 94 and 95.

By appropriate dimensioning of the parts of the piston 36 and the cylinder 35 respectively closest to the front face 75 and the bottom 43, it could be done so that from a determined threshold, during such a pressure increase. , the end face 75 is sufficiently far from the bottom 43 so that establishes a direct connection, through the cavity 41, between the outlet 11 and the inlet 7, that is to say that disappears l pumping effect via the chamber 82.

The pumping effect of the liquid fuel sucked by the inlet 7 and discharged through the outlet 11, which has just been described, does not, however, constitute the sole function of the pump according to the invention 5, which is moreover designed for also suck the gas, the liquid fuel or the mixture of gas and liquid fuel that reaches it through the inlet 8, to drive it through the outlet 12.

For this purpose, the piston 36 is arranged so as to delimit in sealing manner, inside the cavity 41 of the cylinder 35, another chamber 83 located opposite the chamber 82 with reference to the axis 6, under conditions such that the volume of this chamber 83 varies in phase opposition with the change in volume of the sealed chamber 82, during the rotation of the piston 36 about the axis 6 relative to the cylinder 35, in the direction 39 with support of the end face 75 against the ball 71, and in such a way that the chamber 83 communicates with the inlet 8 while being sealed from the outlet 12 and has a progressively increasing volume to create a suction effect by the inlet 8 when the sealed chamber 82 is placed opposite the outlet 11, and, conversely, is placed in communication with the outlet 12 being sealed against the inlet 8, and progressively decreases in volume, when the sealed chamber 82 is placed in communication with the inlet 7.

For this purpose, between the inner peripheral face 42 of the cavity 41 and the outer peripheral face 101 of the receiving shaft 84 is interposed a seal 86, annular of revolution about the axis 6, having an inner periphery 99 in sliding and sealing contact with the outer peripheral face 101 of the receiving shaft 84, and an outer periphery 100, fixedly and sealingly attached to the inner peripheral face 42 of the cavity 41, in an axial position such as this joint 86 is no obstacle to the reciprocating movement 40 of the piston 36 with respect to the cylinder 35 and remains permanently in sealing contact with the receiving shaft 84 during this reciprocating movement 40.

This seal 86, which is axially turned towards the bottom 43 of the cavity 41, another bottom 87 thereof, and a portion of the inner peripheral face 42 of the cavity 41 immediately adjacent to the bottom 87, axially of the same side thereof as the bottom 43, delimits the chamber 83 with respect to the cylinder 35.

As regards the piston 36, this chamber 83 is delimited in part by the end face 88, facing away from the end face 75 and facing the bottom 87, and by a recess 89 formed in the outer peripheral face 74 the piston 36 in the immediate vicinity of this end face 88 and in an angular position, with reference to the axis 6, angularly offset by 180 ° relative to the recess 79, relative to which this recess is further axially offset.

More specifically, the end face 88 of the piston 36 is connected over more than 180 °, with reference to the axis 6, to the outer peripheral face 74 of the piston 36 in the direction of a distance relative to the axis 6, but on the remainder of its contour, in this sense, it is delimited by a straight edge 90 substantially parallel to the edge 78 and located at a distance from the axis 6 intermediate between the respective radii of the outer peripheral faces 101 and 74. By this edge 90, it is connected to a flat part 91 itself substantially parallel to the flat surface 80 and hollowed out in the outer peripheral face 74, set back towards the axis 6 with respect thereto, on one side of the axis 6 opposite that of the flat 80. This flat 91 defines the recess 89 with a shoulder 92 plane, perpendicular to the axis 6 and turned away from the shoulder 81. This shoulder 92 connects the flat 91 to the outer peripheral face 74 of the piston 36, axially opposite the edge 90, and the flat 91 is also connected to the outer peripheral face 74 by two unrepresented edges, rectilinear and parallel to the axis 6, by ratio to which they mutually spaced angularly less than 180 °. More precisely, these two edges are mutually angularly offset, with reference to the axis 6, identical to the edges, also parallel to the axis 6, delimiting the flat surface 80 in the circumferential direction with reference to this axis 6.

It is understood that, as the recess 79, the recess 89 could have a different shape than that just described, it being understood that it is currently preferred for reasons of ease of manufacture.

• les positions précitées de refoulement du combustible liquide par la chambre étanche 82 correspondent à des positions d'aspiration de gaz, de combustible liquide ou d'un mélange des deux par la chambre 83, dans lesquelles le chambrage 89 fait face à l'orifice 56 de l'entrée 8 et la face frontale 88 s'éloigne progressivement du fond 87 constitué par le joint 86, de façon à augmenter progressivement le volume de la chambre 83 alors que la face périphérique extérieure 74 du piston 36 obture de façon étanche l'orifice 57 menant à la sortie 12, et
• les positions précitées d'aspiration de combustible liquide par la chambre étanche 82 correspondent à des positions de refoulement de l'air, du combustible liquide ou du mélange des deux par la chambre 83, dans lesquelles le chambrage 89 fait face à l'orifice 57 menant à la sortie 12 et la face frontale 88 se rapproche progressivement du fond 87, de façon à réduire progressivement le volume de la chambre 83, alors que l'orifice 56 de l'entrée 8 est obturé de façon étanche par la face périphérique extérieure 74 du piston 36,
  sans que la chambre 83 puisse être jamais mise en communication simultanément avec les deux orifices 56 et 57, de même que la chambre 82 ne peut être mise en communication simultanément avec les deux orifices 53 et 54.

The recess 89 is positioned and dimensioned, axially and angularly with reference to the axis 6, so that the chamber 83 is sealed against the chamber 82 permanently, because of the tight and sliding contact of the peripheral face. outer surface 74 of the piston 36 against the inner peripheral face 42 of the cylinder 35, and that when the piston 36 rotates in the direction 39 inside the cylinder 35 with permanent support of the end face 75 against the ball 71:

• the aforesaid positions of delivery of the liquid fuel by the sealed chamber 82 correspond to suction positions of gas, liquid fuel or a mixture of the two by the chamber 83, in which the recess 89 faces the orifice 56 of the inlet 8 and the end face 88 moves away progressively from the bottom 87 formed by the gasket 86, so as to gradually increase the volume of the chamber 83 while the outer peripheral face 74 of the piston 36 sealingly closes the orifice 57 leading to the outlet 12, and
• the aforementioned liquid fuel suction positions through the sealed chamber 82 correspond to the discharge positions of the air, the liquid fuel or the mixture of the two by the chamber 83, in which the recess 89 faces the orifice 57 leading to the outlet 12 and the end face 88 is progressively closer to the bottom 87, so as to gradually reduce the volume of the chamber 83, while the orifice 56 of the inlet 8 is sealed by the outer peripheral face 74 of the piston 36,
  without the chamber 83 can never be in communication simultaneously with the two orifices 56 and 57, just as the chamber 82 can not be placed in communication simultaneously with the two orifices 53 and 54.

A person skilled in the art will easily determine the respective sizing of the different parts of the cylinder 35 and the piston 36 for this purpose.

A person skilled in the art will also easily understand that such an operation of the pump according to the invention, in which the chambers 82 and 83 work in phase opposition, could be obtained even if the inlet 8 and the outlet 12 were angularly offset. , identically, namely an angle of the same value and in the same direction, with respect to the inlet 7 and the outlet 11, respectively, with reference to the axis 6, since the chambering 89 would be shifted in the same direction, an angular distance having the value of said increased angle of 180 °, relative to the recess 79, with reference to the axis 6.

Given the aforementioned orientation of use of the pump 5, the gas possibly pumped by the inlet 8 tends to leave immediately, by gravity, the outlet 12 upwards while the liquid fuel possibly pumped by the same inlet 8 tends to remain by gravity inside the cavity 58 to thereby participate in the sealing of the mutual contact between the outer peripheral face 74 of the piston 36 and the inner peripheral face 42 of the cylinder 35, as well as the liquid fuel that passes through by the inlet 7, the sealed chamber 82 and the outlet 11.

In addition, any gas present in the chamber 83 when it enters into communication with the orifice 57 leading to this outlet 12 then leaves this chamber 83, in which a portion of the liquid thus present at this level is substituted for it. 12, and it is also the liquid that fills the chamber 83 at the moment when the communication with the orifice 57 stops, which avoids any re-aspiration of gas whose compressible character, if it were driven by the piston 36 to the dead spaces of the pump 5, seriously disrupt the operation thereof.

In this respect, the arrangement of a cavity 58 having a passage cross section greater than that of the orifice 56, 57, as illustrated in FIG. 5, facilitates an expansion separation of the gas.

• en favorisant une montée du gaz par le conduit aval supérieur 105 et une réaspiration de combustible liquide seul par le conduit amont inférieur 104 lorsque la chambre 83 commence à communiquer avec la canalisation 28, lors de la rotation du piston 36 dans le sens 39 par rapport au cylindre 35, comme on l'a schématisé à la figure 7, et
• en permettant ensuite, au fur et à mesure du refoulement du gaz, du combustible liquide ou d'un mélange des deux, hors de la chambre 83, vers la sortie 12, d'accompagner ce refoulement d'un balayage par du combustible liquide provenant du conduit 104, contournant le bord de la cloison 106 le plus proche du piston 36 et remontant par le conduit 105, et de contribuer ainsi à la montée du gaz, c'est-à-dire à l'éloignement de celui-ci vis-à-vis de la pompe 5, comme on l'a schématisé à la figure 8.

The subdivision of the pipe 28 into two ducts 104 and 105, respectively upstream downstream and downstream upper with reference to the direction 39, by a partition 106, as described with reference to FIG. 7, however proved to be more efficient to the tests:

• by promoting a rise of the gas by the upper downstream duct 105 and a re-aspiration of liquid fuel alone by the lower upstream duct 104 when the chamber 83 begins to communicate with the pipe 28, during the rotation of the piston 36 in the direction 39 relative to to the cylinder 35, as shown schematically in FIG. 7, and
• by subsequently allowing, as the gas is discharged, liquid fuel or a mixture of the two, out of the chamber 83, to the outlet 12, to accompany this discharge by a sweep by liquid fuel from duct 104, bypassing the edge of the partition 106 closest to the piston 36 and up through the conduit 105, and thereby contribute to the rise of the gas, that is to say to the distance of the latter to the pump 5, as shown schematically in Figure 8.

It is thus ensured that, in the normal operating mode of the pump 5, the piston 36 bathes as far as possible in liquid fuel inside the cylinder 35, and that gas is trapped therein. amount as low as possible.

In particular, it is ensured that the chamber 83 is filled with liquid fuel when it stops communicating with the outlet 12 and that liquid fuel will be pumped to the inlet 8 when, then, the chamber 83 will be placed again in communication with it, before the aspiration begins.

The presence of the sleeve 109, or any other similar throttling means of the pipe 14, between the elbow 107 and the inlet 8, and the tip 67, in turn allows the volume available between the elbow 107 to be reduced. and the orifice 56 for this discharge of a certain amount of liquid fuel when the chamber 83 communicates with the inlet 8, so that it is also ensured the presence of liquid fuel at this inlet 8, and the creation of a suction effect to the chamber 83, by the entry 8, as soon as the initial discharge has ceased, even if only gas or a mixture of gas and liquid fuel reaches the elbow 107, through the pipe 14, from the degasser 15; it is further ensured that the volume of liquid fuel initially discharged is then completely re-aspirated with liquid fuel, gas or a mixture of the two reaching the elbow 107 from the degasser 15.

Naturally, as in most liquid fuel pumps, a certain quantity of this fuel is introduced at each of the outlets 11 and 12 during the first commissioning of the pump 5 according to the invention, to benefit from this first implementation. service of the various favorable effects of the presence of liquid fuel not only at these outlets but also inside the cylinder 35, all around the piston 35, and at the inputs 7 and 8.

A person skilled in the art will readily understand that, although it is particularly suitable for supplying a burner with liquid fuel which may contain gas, a pump according to the invention could be used in any other application in which it is necessary. or it is preferable to perform an effective degassing of a liquid before conveying it to a user device, so that the installation which has been described with reference to FIG. 1 is only a non-limiting example of application of a pump according to the invention.

Similarly, a person skilled in the art will readily understand that the embodiment of such a pump which has just been described is only a non-limiting example with respect to which we can provide numerous variants, in particular with regard to the conforming chambers 79 and 89 and the driving mode of the piston 36 in its simultaneous movement of rotation and reciprocating axial with respect to the axial cylinder 35, in addition to the variants previously described whether they have been illustrated or not.

Claims (18)

Pump of the type comprising: - a cylinder (35) having an axis (6) and defining a blind cavity delimited by an inner cylindrical peripheral face (42) of revolution about the axis (6) and a first base (43), the inner peripheral face (42) having a first inlet (7) and a first fluid outlet (11) to be pumped, disposed in positions at least approximately radially opposite to the axis (6) and each extending less than 180 ° with reference to the axis (6), - A piston (36) disposed in the cavity (35) and defined by an outer peripheral face. (74) cylindrical of revolution about the axis (6) with a substantially identical diameter to that of the inner peripheral face (42) of the cavity (41), to establish a sliding and impermeable mutual contact with the fluid to be pumped, and by a first end face (75) facing the first bottom (43) of the cavity (41), the outer peripheral face (74) of the piston (36) having a first localized chamber (79) adjacent to the first end face (75) and extending less than 180 ° with reference to the axis (6) so that the first recess (79) and the first end face (75) of the piston (36) delimit with the inner peripheral face (42) and with the first bottom (43) of the cavity (41) a first sealed chamber (82) capable of being placed in communication alternately with the first inlet (7) and with the first outlet (11) without being able to communicate at the same time with the first entry (7) and with the first tie (11), - means (38, 71, 75, 93) for animating the piston (36), with respect to the cylinder (35), of a simultaneous movement of rotation (39) about the axis (6), in one direction constant, and back-and-forth (40) along the axis (6), so that the piston (36) passes successively and cyclically, relative to the cylinder (35): At suction positions by the first chamber (82), in which the first chamber (79) faces the first inlet (7) and the first end face (75) progressively moves away from the first base (43) , as and when rotated, so as to gradually increase the volume of the first chamber (82), and At discharge positions through the first chamber (82), in which the first chamber (79) faces the first outlet (11) and the end face (75) progressively approaches the first bottom (43), as and as the rotation proceeds, so as to progressively reduce the volume of the first chamber (82), characterized in that - the cavity (41) is delimited, axially opposite the first bottom (43) relative to the first inlet (7) and the first outlet (11), by a second bottom (87), and its peripheral face interior (42) has, in respective positions axially offset relative to the respective positions of the first inlet (7) and the first outlet (11), in the direction of a distance relative to the first bottom (43), and forming a same angle determined with reference to the axis (6), with respect to the respective positions of the first output (11) and the first input (7), a second output (12) and a second input (8) of fluid to be pumped, each extending less than 180 ° with reference to the axis (6), - the piston (36) is delimited, axially opposite the first end face (75) relative to the first recess (79), by a second end face (88) placed opposite the second bottom (87) of the cavity (41) and its outer peripheral face (74) has, in a position axially offset with respect to the position of the first recess (79), in the direction of a distance relative to the first end face (75), and forming said determined angle, increased by 180 °, relative to the position of the first recess (79), with reference to the axis (6), a second localized recess (89) adjacent to the second end face (88) and extending over less than 180 ° with reference to the axis (6) so that the second recess (89) and the second end face (88) of the piston (36) delimit with the outer peripheral face (42) and with the second bottom (87) of the cavity (41) a second sealed chamber (83) which can be pla alternatively communicating with the second input (8) and the second output (12) without being able to communicate at the same time with the second input (8) and with the second output (12), and sealed from the first chamber (82), so that during said movement of the piston (36) relative to the cylinder (35): The suction positions by the first chamber (82) correspond to discharge positions by the second chamber (83), in which the second chamber (89) faces the second outlet (12) and the second end face ( 88) progressively approaches the second bottom (87), so as to gradually reduce the volume of the second chamber (83), and • the discharge positions by the first chamber (82) correspond to suction positions by the second chamber (83), in which the second chamber (89) faces the second inlet (8) and the second end face ( 88) progressively moves away from the second bottom (87), so as to gradually increase the volume of the second chamber (83). Pump according to Claim 1, characterized in that the said angle has a value chosen from a group comprising the value 0 ° and the value 180 °. Pump according to any one of claims 1 and 2, characterized in that the means (38, 71, 75, 93) for animating the piston (36) of said movement relative to the cylinder (35) comprise a receiving shaft (84) integral with the piston (36), forming a coaxial projection on the second end face (88) of the piston (36) and passing through the second bottom (87), and driving means (38, 93) of the said receiving shaft (84) located outside the cavity (41), the receiving shaft (84) being delimited, in the direction of a distance from the axis (6), by an outer circumferential face (101) cylindrical of revolution around it, with a diameter smaller than that of the outer peripheral face (74) of the piston (36) and the second bottom (87) having the shape of a ring of revolution about the axis (6), having an inner periphery in sliding and sealing contact with the outer peripheral face (101) of the receiving shaft (84 ). Pump according to claim 3, characterized in that the second bottom (87) is constituted by an annular seal (86) of revolution about the axis (6), having an outer periphery in contact with and sealingly with the inner peripheral face (42) of the cavity (41). Pump according to any one of claims 3 and 4, characterized in that the drive means (38, 93) of the receiving shaft (84) comprise motor means (38) having a motor shaft (85) coaxial with the receiving shaft (84), fixed axially with respect to the cylinder (35) and rotated about the axis (6), in said direction, relative to the cylinder (35), and means (93) of connection between the motor shaft (85) and the receiving axis (84), mutually interconnecting in rotation about the axis (6) and an elastic thrust of the receiving shaft (84) relative to the cylinder ( 35), in an axial direction from the second end face (88) of the piston (36) to the first end face (75) of the piston (36), and in that the first end face (75) of the piston (36) ) and the first bottom (43) comprise means (75, 71) forming a cam, in mutual axial support, to translate the rotation of the piston (36), about the axis (6), relative to the cylindr e (35), by an axial back and forth motion. Pump according to claim 5, characterized in that the first end face (75) has the shape of an oblique end with respect to the axis (6), so as to move axially towards the second end face (88) in radially approaching the first recess (79), and in that the first base (43) has a localized support (71) for said oblique end, in a zone offset from the axis (6) and situated downstream of the first and second outputs (11, 12) and upstream of the first and second inputs (7, 8), with reference to said direction, substantially at 90 ° with respect to the first and second outputs (11, 12) and the first and second inputs (7, 8), with reference to the axis (6). Pump according to any one of claims 1 to 6, characterized in that the first input (7) and the first outlet (11) have a substantially identical section. Pump according to any one of claims 1 to 7, characterized in that the second outlet (12) has a section greater than that of the second inlet (8). Pump according to any one of claims 1 to 8, characterized in that it comprises, inside the second outlet (12), a partition (106) arranged along a mean surface (plane 9) generated by generators parallel to the axis (6) and dividing the second outlet (12) into two ducts (104, 105) of respective constant section. Pump according to claim 9, characterized in that the two ducts (104, 105) having substantially the same section. Apparatus for supplying a liquid-consuming device (1), such as a liquid fuel burner, to said liquid capable of containing a gas, from a tank (2) containing said liquid and more or less volatile substances capable of generating said gas, said installation comprising means (5) for pumping said liquid into the tank (2) via a degasser (15), a lower part of which is intended to contain a variable quantity (20); ) of said liquid and an upper part of which is intended to contain a variable quantity (21) of said gas and, if appropriate, of said liquid,
characterized in that the pumping means (5) are constituted by a pump (5) according to any one of claims 1 to 10, whose first inlet (7) and the first outlet (11) are respectively connected to the part bottom of the degasser (15) and the consumer device (1) and whose second inlet (8) and the second outlet (12) are respectively connected to the upper part of the degasser (15) and the tank (4). Installation according to Claim 11, characterized in that the axis (6) is substantially horizontal and in that the first and second outlets (11, 12) are facing upwards. Plant according to Claim 12, characterized in that the pump (5) is oriented so that the second outlet (12) is arranged on one side of a vertical plane (102) including the axis (6), which side being chosen such that said direction (39) is upward. Plant according to claim 13, characterized in that the second outlet (12) is connected to the tank (4) by an internally subdivided pipe (28) over part of its length, adjacent to the second outlet (12), a lower duct (104), upstream with reference to said direction (39), and in an upper duct (105), downstream with reference to said direction (39), having respective constant sections, by a partition (106) arranged along a surface average generated by generatrices parallel to the axis (6). Installation according to claim 14, characterized in that said sections are substantially identical. Installation according to any one of claims 13 to 15, characterized in that the second inlet (8) is connected to the upper part of the degasser (15) by a pipe (14), which forms a bend (107), convex towards the bottom, near said second inlet (8), at a level lower than that thereof, and has a section (108) narrowed inwardly, from a lower zone of said elbow (107) to said second inlet (8); ). Installation according to any one of claims 11 to 16, characterized in that it comprises a non-return valve (32) passing from the second outlet (12) to the tank (2). Installation according to any one of claims 11 to 17, characterized in that it comprises controlled means (27) for stopping the connection between the first outlet (11) and the consumer device (1).

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