US3667876A

US3667876A - Rotary fluid flow machines

Info

Publication number: US3667876A
Application number: US99975A
Authority: US
Inventors: Michael David Boyd
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-12-21
Filing date: 1970-12-21
Publication date: 1972-06-06
Anticipated expiration: 1989-06-06

Abstract

A ROTARY FLUID FLOW MACHINE COMPRISING A BODY, AN AXIAL MEMBER OR SHAFT ROTATABLE RELATIVE TO THE BODY, AND A GENERALLY ANNULAR MEMBER MOUNTED FOR AXIAL RECIPROCATION AND ROTATION IN A GENERALLY ANNULAR CAVITY DEFINED BETWEEN THE BODY AND THE SHAFT. THE AXIAL MEMBER AND THE BODY ARE RELATIVELY ROTATABLE, AND THE ANNULAR MEMBER IS PROVIDED WITH UNDULATING END SURFACES. THE AXIAL CAVITY IS DEFINED BY SPACED CONCENTRIC INNER AND OUTER CYLINDRICAL SURFACES AND BY A PAIR OF AXIALLY SPACED END SURFACES OF UNDULATING CONFIGURATION, EACH COOPERATING WITH A SEPARATE ONE OF THE UNDULATING SURFACES OF THE ANNULAR MEMBER, WHEREBY THE ANNNULAR MEMBER IS CONSTRAINED BY ENGAGEMENT BETWEEN THE TWO END SURFACES FOR MOVEMENT IN THE CAVITY OF THE TYPE INVOLVING A FIRST AXIAL ROTATIONAL COMPONENT OF MOTION AND A SECOND AXIAL RECIPROCATORY COMPONENT. BETWEEN EACH PAIR OF COOPERATING END SURFACES, A PLURALITY OF CHAMBERS IS DEFINED, THE VOLUMES OF WHICH UNDERGO CYCLIC VARIATION WHEN THE ANNULAR MEMBER UNDERGOES SUCH MOVEMENT. THE ANNULAR MEMBER IS AFFIXED TO A CYLINDRICAL SLEEVE WHICH DEFINES TWO AXIAL CYLINDRICAL EXTENSIONS TO THE MEMBER, ONE TO EITHER AXIAL SIDE THEREOF, ONE CYLINDRICAL SURFACES OF THE SLEEVE SLIDINGLY ENGAGING ONE CYLINDRICAL SURFACE OF THE AXIAL MEMBER. THE BODY IS PROVIDED WITH PORTS DEFINED BY ROOT PORTIONS OF THE UNDULATING SURFACES ON THE BODY AND COOPERATING TRANSVERSE EDGES OFTHE SLEEVE EXTENSIONS, AND COMMUNICATION BETWEEN THE PORTS AND THE RESPECTIVE CHAMBERS IS CONTROLLED BY THE SLEEVE DURING RECIPROCATING MOTION THEREOF.

Description

June 6, 1972 M. D. BOYD ROTARY FLUID FLOW MACHINES 6 Sheets-Sheet 1 Filed Dec. 21, 1-970 FIG. 2

FIG. 3

June 6, 1972 M. o. BOYD ROTARY FLUID FLOW MACHINES 6 Sheets Sheet 2 Filed Dec. 21, 1970 FIG. 50.

FIG. 5b.

FIG. 6.

June 6, 1972 M. o. BOYD ROTARY FLUID FLOW MACHINES 6 Sheets-Sheet Filed Dec. 21, 1970 June 1972 M. o. BOYD 3,667,876

ROTARY FLUID mow MACHINES Filed Dec. 21, 1970 6 Sheets-Sheet '4.

June 6, 1972 M. o. BOYD ROTARY FLUID FLOW MACHINES Filed Dec. 21, 1970 June 6, 1972 M. D. BOYD 3,667,876

ROTARY FLUID FLOW MACHINES Filed Dec. 21, 1970 6 Sheets-Sheet 6 FIG. l4.

United States Patent Int. Cl. F02b 53/00 US. Cl. 418-68 22 Claims ABSTRACT OF THE DISCLOSURE A rotary fluid flow machine comprising a body, an axial member or shaft rotatable relative to the body, and a generally annular member mounted for axial reciprocation and rotation in a generally annular cavity defined between the body and the shaft. The axial member and the body are relatively rotatable, and the annular member is provided with undulating end surfaces. The axial cavity is defined by spaced concentric inner and outer cylindrical surfaces and by a pair of axially spaced end surfaces of undulating configuration, each cooperating with a separate one of the undulating surfaces of the annular member, whereby the annular member is constrained by engagement between the two end surfaces for movement in the cavity of the type involving a first axial rotational component of motion and a second axial reciprocatory component. Between each pair of cooperating end surfaces, a plurality of chambers is defined, the volumes of which undergo cyclic variation when the annular member undergoes such movement. The annular member is affixed to a cylindrical sleeve which defines two axial cylindrical extensions to the member, one to either axial side thereof, one cylindrical surface of the sleeve slidingly engaging one cylindrical surface of the axial member. The body is provided with ports defined by root portions of the undulating surfaces on the body and cooperating transverse edges of the sleeve extensions, and communication between the ports and the respective chambers is controlled by the sleeve during reciprocating motion thereof.

CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of application Ser. No. 826,046, filed May 2, 1969, and now abandoned.

BACKGROUND OF THE INVENTION This invention relates to rotary fluid flow machines such as pumps, engines and meters.

In particular, the invention is concerned with rotary fluid flow machines of the type comprising a body, an axial member rotatable relative to the body, and a generally annular member mounted for axial reciprocation and rotation in a generally annular cavity defined between the body and the shaft, the axial member and the body being relatively rotatable and the annular having undulating end surfaces, the cavity being defined by spaced, concentric inner and outer cylindrical surfaces and by a pair of axially spaced end surfaces of undulating configuration, each co-operating with a separate one of the undulating surfaces of the annular member, whereby the annular member is constrained, by engagement between the two end surfaces of each co-operating pair of end surfaces for movement in the cavity comprising a first axial rotational component of motion and a second axial to and fro reciprocatory component; there being defined, between each pair of co-operating end surfaces, a plurality of chambers, the volumes of which chambers undergo cyclic variation when said member undergoes such movement,

3,667,876 Patented June 6, 1972 and the body being provided with port means to said chambers.

Machines of the above kind have been proposed previously and representative examples are described in, for example, French patent specification 450,392 to M. Peter VOIl Ditmar and British patent specification 13,677 to Frederick Wheatley.

However, the machines have not proven to be practical because of difliculties in arranging for the drive to be transferred from or to the rotating parts, and because of the difl'iculty of providing constructions which permit adequate sealing of the rotating parts and proper inlet and outlet porting to the chambers.

SUMMARY OF THE INVENTION The present invention seeks to provide an improved construction which may be arranged to at least partly avoid some or all of these difficulties and is particularly concerned with providing an improved porting and sealing arrangement.

According to this invention, a rotary fluid flow machine of the above kind is characterized in that the annular member is aflixed to a cylindrical sleeve which defines two axial cylindrical extensions to the member, one to either axial side thereof, one cylindrical surface of the sleeve slidingly engaging one cylindrical surface of the axial member, said port means including first ports defined by root portions of the undulating surfaces on said body and co-operating transverse edges of said sleeve extensions, and communication between the sets of ports and the respective chambers being controlled by said sleeve during reciprocating motion thereof.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention may be better understood reference is now made to the accompanying drawings in which:

FIG. 1 is a diagrammatic side view of a machine of the kind with which the invention is concerned with portion thereof shown in section;

FIG. 2 is a section on the line 2--2 in 'FIG. 1;

FIG. 3 is a fragmentary section on the line 3-3 in FIG. 2;

FIG. 4 is a perspective view of a piston member incorporated in the machine shown in FIGS. 1 to 3;

FIGS. 5a to 5c are fragmentary views corresponding to portion of FIG. 3 and together illustrating the manner of operation to the machine;

'FIG. -6 is a view corresponding to FIG. 3 but illustrating a modification of the invention;

FIGS. 7a to 7d are fragmentary views each corresponding to portion of FIG. 6 and together illustrating the manner of operation of the embodiment of FIG. 6;

FIG. 8 is a transverse section of a machine constructed in accordance with the invention and taken on the line 8-8 in FIG. 9;

FIG. 9 is a part section on the line 99 in FIG. 8;

FIG. 10 is a perspective view of a piston incorporated in the machine of FIGS. 8 and 9;

FIG. 11 is a circumferential section through the combustion chamber of the embodiment of FIGS. 8 and 9 looking outwardly;

FIG. 12 is a circumferential section through the combustion chamber of the embodiment shown in FIGS. 8 and 9 but looking inwardly;

FIG. 13 is an enlarged, fragmentary axial cross-sectional view of the machine shown in FIG. 8 and illustrating the manner of fitting of bearings therein;

FIG. 14 is a longitudinal cross-section of an alternative form of rotary fluid flow machine constructed in accordance with the invention; and

FIG. 15 is an enlarged, fragmentary, cross-section corresponding to FIG. 9 but illustrating a modification to the machine shown therein.

DESCRIPTION OF Til-IE PREFERRED EMBODIMENTS Referring firstly to FIGS. 1 to 4, the machine shown therein comprises three coaxial, generally annular,

members

11, 12, and 13, together with a pair of

concentric cylinders

14, 16 which are also coaxial with each other and with the three

members

11, 12 and 13. The inner surface 16a of outer cylinder 16 is in sealing contact with the

outer surfaces

11a, 12a and 13a of the

members

11, 12 and 13 while the outer surface 14a of the innermost cylinder 14 is in sealing engagement with the innermost surfaces of the

members

11, 12 and 13. The members 11,

12, 13 and the

cylinders

14, 16 are each separately slidable relative to each other in the direction of the axis of the machine and are also each separately rotatable about this axis.

The annular member 12 is shown in more detail in- FIGS. 3 and 4. The end surfaces 17, '18 are of undulating form each comprising a series of crest portions with alternate trough portions 21. The troughs 21 on each of the

surfaces

17, 18 coincide with crests 19 on the

other surfaces

18, 17. As best appreciated from FIG. 3, the

surfaces

17, 18 are, when viewed from the side, of somewhat sinusoidal form. The pitch of each one of the surfaces 17, 18 (that is the distance between adjacent crests at points equidistant from the axis of the member) is constant and equal to that of the

other surfaces

18, 17. The transitions of the gradients of the

surfaces

17, 18 from positive to negative is gradual, there being no sharp changes in gradient. The surfaces are such that lines representing the intersections of each surface with planes containing the axis of the member are at a constant angle to the axis of the member. I v

The respective facing end surfaces 22, 24 of members 11 and 13 are also of undulating form.

, These surfaces are shaped to provide a series of outwardly extending crest portions 26, -28 each sequential pair of

crests

26, 28 being separated by a trough portion 2 7 2 9. The

crests

26, 28 are regularly spaced so that the pitches of the curves defined by the

surfaces

22, 24 are constant, these pitches also being equal, in this instance, for the two curves. The portions of the curves defining the troughs 27, '29 are smooth, the progression of the gradient from positive to negative about the center of the troughs being gradual. However, the

crests

26, 28 are of peaked form, the curves defining the peaks exhibiting sharp changes from positive to negative gradient at the peaks. The curves representing the side elevations of the

surfaces

22, 24 are thus somewhat cylindrical in configuration.

One manner of operation of the machine is now de- 55 der 16 for rotation and member 12 is axially slidably secured to cylinder 14 for rotation and relative reciprocation. Members 11, 13 are fixed in the relationship shown in FIG. 3, the crests 26 on member 11 being aligned with the crests 28 on member 13 and being spaced apart a distance slightly greater than the distance between the two

surfaces

17, 18 of member 12 as measured in the longitudinal direction of the machine. Accordingly, member 12 is free to rotate around the axis of the machine together with cylinder 14, and relative to cylinder 16 and members 11, 13. During such rotation, the member 12 will be constrained to execute a continuous reciprocatory movement by virtue of a camming action between the

crests

26, 28 on members 11, 13 and the respective surfaces 18, .17 on member 12. The resultant, combined reciprocation and rotation of member 12 is illustrated in FIGS. (a), 5(1)) and 5(c).

The member 12 is shown as moving from top to bottom FIG. 5(a) shows member 12 at a position in which the crests on member 12 are aligned with the troughs 27 on member 11. The member 12 is, at this point, in a condition of maximum axial displacement in the direction towards member 11. After advancement of the member 12 through a circumferential distance of somewhat less than one half of the pitch distance between

adjacent crests

26, 28 the member 12 is positioned as shown in FIG. 5(1)), and substantially at the fullest extent of movement towards member 13. FIG. 5 (c) shows the member 12 at a disposition slightly after the fullest extent of movement towards member 13, has been reached and when it has rotated through a distance corresponding to slightly more than one half of the pitch of the

crests

26, 28. Further rotational movement of member 12 beyond the position shown in FIG. 5 (0) results in return of the member to the position shown in FIG. 5(a).

The space defined between the facing surfaces 22, 24 of members 11, 13 the inner surface of cylinder 16, and the outer surface of cylinder 14 comprises a series of cavities 31. These are each divided into two

chambers

32, 33 by the member 12.

As best seen from FIGS. 5(a), 5(b) and 5(0), the chambers 32 vary in volume as member 12 rotates, and this variation in volume is utilizable to obtain pump or motor action from the machine. Motor action is now described with reference to FIGS. 5(a), 5 (b) and 5 (c).

It will be observed that these figures show a port opening 34 which extends through the wall of cylinder 16. The wall of cylinder 14 has a similar port 36 (FIG. 1). Each cavity 31 has a pair of like

ports

34, 36. A combustible fuel-air mixture is introduced into each chamber 33 via ports 36 when member 12 is positioned to give a maximum volume of the chamber. This condition occurs when member 12 is at the extreme of its reciprocatory movement towards member 11 and thus at the position shown in FIG. 5(a) it will be seen that, in this condition, the

ports

34, 36 are uncovered by member 12 to permit the flow of fluid into chamber 33, but that, in this condition there is no communication of ports with the chambers 32.

Subsequent rotation of member 12 causes the member 12 to pass over

ports

34, 36 until these no longer communicate with chambers 33 but rather communicate with chambers 32 (FIG. 5(b)). The chambers 33 are thus completely closed and subsequent rotational movement causes compression of fluid within the chamber.

Shortly after the point of maximum compression of working fluid in chamber 33 occurs, the working fluid is gnited, as for example, by a spark plug, causing increase in pressure within chamber 33 and thereby driving the member 12 towards member 11, While simultaneously causing rotation of member 12. This movement, illustrated in FIG. 5(c) is the power stroke of the engine. After expansion of the burned working fluid, member 12 moves to a position in which a following undulation thereon is positioned in each chamber 33 as is shown in FIG. 5(a), while both exhaust and inlet are effected via the

ports

34 and 36.

It will be appreciated that the cycle comprising inlet compression, expansion and exhaust of working fluid occurs simultaneously in each chamber 33 and further, because of the symmetrical arrangement of the parts comprislng the machine, the same cycle can be repeated in the chambers 32. Thus compression and expansion of working fluid in the chambers 33 may occur during expansion and compression in the chamber 32, so that the machine comprises a double acting arrangement.

The above described arrangement functions in a manner analogous to a conventional two-stroke motor. FIG. 6 shows a modified construction adapted to operate on a four-stroke cycle. In this case, the end members 13a, 11a are modified somewhat in that the respective end surfaces 22a, 24a are of similar form to the

surfaces

17, 18 provided on member 12 while the surfaces 17a,

18a on the intermediate member 12a correspond in form to the

surfaces

22 and 24 in the embodiment of FIGS. 1 to 4. The surfaces 22a, 24a each comprise a series of crests 41 separated by intermediate troughs 42. The gradient of the surfaces 22a, 24a varies smoothly between positive and negative values, the pitch between adjacent crests 41 being constant and there being no sharp changes in gradient of the curves. The surfaces 17a, 18a comprise crests 44 separated by troughs 46, the crests 44 being peaked so that there is a sharp change of gradients thereat. The pitch between adjacent crests 44 is constant and corresponds to the pitch of the crests 41 on members 11a, and 13a. The peaks 44 on surface 18a are displaced circumferentially one-half of the pitch distance between crests 44 with respect to the crests on surface 17a.

FIGS. 70 to' 7d illustrate the manner of operation of a motor utilizing the

members

11a, 12a and 13a, the members 11a, 13a being secured together for simultaneous rotation and reciprocation. The relative disposition of the two parts 11a, 13a is such that troughs 42 on the two members 11a, 13a are opposite and the crests 41 on the two members are also opposite. The members 11a, 13a are, in the following description, considered to be stationary.

FIG. 7a shows two of a number of

chambers

49, 51 defined to opposite sides of member 12 and in adjacent pairs of troughs. Member 12a is positioned at an intermediate axial position with respect to the members 11a, 13a. At the location of every second crest on members 13a and between that crest and the adjacent crest 42 on the member 11a there are situated a pair of

ports

52, 53, these comprising respectively exhaust and inlet ports of the

chambers

51, 49. In the condition shown in FIG. 7a it will be seen that the port 53 communicates with chamber 49. In this condition chamber 49 is nearing its maximum volume and expanding as the member 12a moves from top to bottom of the figure. During this expansion working fluid is admitted via the port 53 and this admission continues until port 53 is closed by passage of member 12a thereacross (FIG. 7b). During subsequent rotational movement of member 12a fluid in chamber 49 is compressed due to decrease of the volume of the chamber as shown in FIG. 7b. When the chamber 49 has just passed a condition of minimum volume, the working fluid is ignited to cause increase in the pressure thereof, subsequently causing rotational movement of member 1211 and also movement thereof away from member 13:: as is shown in FIG. 7c. During the next half cycle of movement, the following exhaust port 52 comes into communication with the chamber 49, being uncovered by member 12a (FIG. 7d) so that burned working fluid leaves the chamber 49 during compression of the volume thereof. This cycle is repeated indefinitely while at the same time a similar but time displaced cycle of events takes place in the chambers 51.

FIGS. 8 to 12 show a machine operating in a manner analogous to that described with reference to FIGS. 5a to 50 but constructed in accordance with the invention. The motor includes an outer casing or body 60 made up of a generally cylindrical part 61 closed at each end by a pair of

end members

62, 63 respectively. Part 61 has four exhaust ports 93 which extend through the side wall thereof at equi-angular dispositions. The ports 93 are of elon gate slot-like form and are disposed at points equi-distant from the axial ends of part 61.

The

members

62, 63 each have a separate boss 64. The bosses 64 extend outwardly and are axially aligned and coaxial with cylindrical part 61. A hollow cylindrical axial member or shaft 65 is journalled in bearings 66, 67 retained in the respective bosses 64 for rotation relative to the casing 60 and about the axis of the engine.

Shaft 65 is provided with two sets of inlet ports 68, 69 respectively, located at longitudinally spaced points along the length of the shaft. The ports 68, 69 extend through the side wall of shaft 65. The shaft is also provided, over an intermediate portion of its length with splines 71.

The gaps between the internal bores 89 of the respective bosses 64 and the exterior of shaft 65 are sealed by annular seals 92, disposed one towards each end of shaft 65.

A piston 72 is carried on shaft 65. The piston includes cylindrical support portions or axial extensions 73 and, intermediate the length thereof, a radially extending skirt portion 74. The skirt portion 74 is of form generally like the member 12 shown in FIGS. 1 to 4. That is to say, it is of undulating configuration comprising two series of oppositely disposed crests 76 the crests of each series being separated by trough 77. Each surface has four crests 76 and four troughs 77. The form of the surfaces is best appreciated from a consideration of FIGS. 10, l1 and 12 together. At points radially close to the axis of the piston the cross-Sectional contour of the undulating surfaces is a smooth curve (FIG. 12), the crests '76 being somewhat sharper than the troughs 77. However, parts of the surfaces of the undulations are cut away progressively towards the periphery of the piston as indicated by reference numerals 78 and, at the external edge of the skirt portion, the crests 76 form discrete spaced apart projections 90, whereas the troughs 77 have fiat bases (FIGS. 10 and 11).

The spacing of the undulating surfaces on skirt 74 is such that there is a continuous marginal cylindrical surface 79 around the periphery of the skirt, which surface separates the two series of crests 76 and troughs 77. This surface is provided with a pair of axially spaced annular sealing rings 82 which are received in annular groove 81. The sealing rings 82 seal the annular gap bet between the interior surface of cylindrical part 61 and the surface 79 of the skirt. Cylinder 73 projects at each axial end beyond the skirt 74 and the peripheral edge portions are provided with annular seals 83 arranged one at each end of the cylinder and retained in the grooves therein. The purpose of these seals is described hereinafter.

The internal cylindrical surface 84 of cylinder 73 is splined and is provided with a plurality of pairs of spaced rows of rollers 86. These rollers are freely rotatable about radial axes and the spacing between the rows comprising each pair of rows is such that the splines on shaft 65 fit between these to allow relatively friction free axial sliding movement between the piston and shaft while precluding relative rotation of these members.

As best shown in FIG. 9, the piston is movable axially of shaft 65 to two extreme positions in each of which positions a separate one of the seals '83 on the piston is engaged with the bore -89 of the adjacent boss 64. When each one of the seals 83 is engaged with its associated bore 89, the other is disengaged so as to present an annular gap or first part 91 disposed adjacent the associated inlet ports 68, 69. Thus, movement of the piston controls communication of the inlet ports to spaces defined on opposite longitudinal sides of skirt 74.

The disposition of the sealing rings '82 on skirt 74 is such that whenever one of the gaps or first parts 91 is open, a corresponding exhaust port 93 is uncovered.

The end members 62, '63 correspond to the members 11 and 13 in the embodiment of FIGS. 1 to 4 and are provided with an undulating surface 96 (FIGS. 11 and 12). These surfaces 96 are of identical configuration and comprise crests 97 separated by troughs 98. Each surface 96 has four crests 97 and four troughs 98-. The curves defining the surfaces are such that the crests 97 are relatively peaked in form. The troughs 98 are defined, at the outermost peripheral edges of the surfaces, by relatively smooth curves butat the radially innermost points, the bases of the troughs are cut out as indicated by reference numeral 101 to maximize the area of overlap with the inlet ports 68 or 69. It will be seen that there are four chambers 104 defined between surface 96 on member 63 and piston 72 and four chambers 106 defined between surface 96 on member 62 and piston 72.

The engine is provided with a series of roller bearings 102, these being of conical form and extending generally radially of the axis of the machine and located a separate one at each crest 97 on the end members '62, 63, there being two sets of these rollers, one associated with each surface 96. The sliding frictional contact between the surfaces of the

members

11, 12 and 13 in the embodiment of FIG. 1 is thereby replaced by a rolling motion over the roller bearings 102.

The arrangement of bearings 102 is best seen from FIG. 13 which shows the manner of fitting of one bearing, the others being alike. The smaller end 121 is supported, for rotation, in a crest 97 of one undulating surface 96 by means not shown while the larger end is supported by a ball 122 which is engaged in a part spherical pocket 123 in the end of bearing 102 and via a Washer and spring onto the end of a bolt 126 which is threadably engaged in a tapped bore in outer wall 61.

A helical compression spring 127 is mounted within pocket 124 and resiliently engages ball 122 radially inwardly.

Thus, as wear in bearing 102 occurs, the bearing is pressed radially inwardly by spring 127 to maintain proper contact between the bearing and the undulating surfaces on end member 62 and on piston 73.

Each of the

end members

62, 63 is provided with openings 103 for the fitting of spark plugs or other ignition apparatus. In operation, the engine functions as previously described with reference to FIGS. 1 to 4, inlet and outlet of working fluid to

chambers

104, 106 being controlled by sliding movement of the piston 72. Inlet to each chamber 104 occurs via ports 69 and the corresponding gap 91 while inlet to each chamber 106 occurs via ports 68 and the corresponding gap 91. Exhaust from

chambers

104 and 106 occurs through the common exhaust ports 93. Working fluid for the engine may be supplied directly to the interior of shaft 65.

Because piston 72 is free to move longitudinally with respect to shaft 65, reciprocating movement thereof is not transferred to the shaft. Frictional resistance to the movement of the piston is minimized by use of the conical roller bearings 102 and the rollers 86. Such wear as might occur in the undulating surfaces on piston 72 and of the roller bearings 102 is compensated for by simple inward radial movement of the roller bearings 102. This inward movement may be arranged to occur automatically by the resilient bias applied to them.

It is to be noted that the sealing of the various ports is effected solely by annular seals and these are arranged such that centrifugal action tends to urge the seals in a direction which ensures an adequate seal. The arrangement of the porting is such as to take advantage of centrifugal action to assist in flow of working fluid through the engine. Also, operation of the parts is effected purely by sliding movement of piston 77.

Lublication inside the combustion chambers is effected by lubricant mixed with the working fluid while lubrication of the spline on shaft 65 may be accomplished by a suitable heat resistant residual lubricant, or may be injected into the bearing housings. Cooling of the piston 72 is effected principally by evaporation of working fluid and cooling of casing 60 may be accomplished in any conventional manner, as for example by use of a liquid cooling packet or by use of heat radiating fins.

The shaft 65 is provided at its forward end with a compressor 128 which operates to compress working fluid prior to entry into the chambers to provide a supercharging effect.

FIG. 14 shows an alternative form of machine constructed in accordance with the invention. It comprises a shaft 131 which is of annular form having a recessed center part 132 and a pair of enlarged end bosses 1 33, 134. Shaft 131 carries a compressor 130 at one end for compressing working fluid entering the machine. A set of inlet ports 136 are disposed in part 132 and extend therethrough at an axial disposition midway along shaft 131.

8 Shaft 131 is mounted within a casing 138 for rotation relative thereto. Casing 138 is annular in form, the shaft 131 being supported for rotation by bearings 139 carried by casing 138 and engaging

bosses

133, 134.

Casing 138 is internally splined as indicated by reference numerals 141 and a correspondingly splined sleeve 140, forming part of a piston 143, is mounted for axial movement on these splines by means of bearing 142. The manner of splining is thus analogous to that described in relation to the embodiment of FIGS. 8 to 13.

The part 132 of shaft 131, and the interior surface of casing 138, together define an annular cavity 144.

Piston 143 is mounted within cavity 144. In addition to the aforementioned sleeve 140, piston 143 also includes an inwardly extending peripheral skirt 147. Skirt 147 has at each axial end a separate undulating surface 148, .149. The surfaces 148, 149 co-operate with undulating surfaces 151, 152 defining end walls of cavity 144. The configurations of

surfaces

148, 149', 151 and 152 are the same as those of the undulating surfaces of the arrangement of FIGS. 1 to 13, except that the cut-out portions thereon are situated towards radially opposite edges.

Casing 138 is provided with two sets of axially spaced apart exhaust ports 154, 156 and sleeve reciprocates to regulate flow of fluid from the chamber defined between the pairs of undulating

surfaces

151, 148 and 149, 152 to the associated exhaust ports.

During this movement, ends 159, 161 move axially and separately into spaces 162, 163 between the casing 138 and

bosses

133, 134. Sealing of the machine is achieved by the use of annular sealing rings 164, 166 one on each end 159, 161 of sleeve 140. These are located on internal surfaces thereof and engage with the outer surfaces of the associated

bosses

133, 134. Skirt 147 on piston 143 has a pair of annular sealing rings 171, 172 on its interior peripheral surface and these sealingly engage the outer surface of the part 132- of shaft 131.

It will be seen that the embodiment of FIG. 14 comprises merely a modification of the arrangement of FIGS. 8 to 13 and wherein the radial dispositions of the parts are reversed.

The described embodiments of the invention have been advanced merely by way of example and it will be understood that numerous modifications may be made thereto. For example, while the machines described are internal combustion engines, machines constructed in accordance with the invention are equally suitable for use as pumps and other rotary fluid flow apparatus.

The machine of FIGS. 8 to 13 or that of FIG. 14 could, of course, be modified to utilize a piston of the kind shown in FIG. 6 so as to operate on a four-stroke principle.

FIG. 15 shows a modification of the machine shown in FIGS. 1 to 14 and in which seals 181, 182 sealing the annular gap between piston 72 and part 61 are on casing 60 instead of upon the piston. These seals are disposed one to either side of exhaust ports 91. In this instance, the gaps between portion 73 of piston 72 and

bosses

63, 64 are sealed by seals 183 carried on the interior surface of the bosses. Of course, the embodiment of FIG. 14 could be modified in like manner. While the embodiment of FIGS. 1 to 13 is described as operating with casing 60 stationary, it could, of course, be arranged to operate with shaft 65 stationary, so that the casing rotates. Likewise the casing 138 in the arrangement of FIG. 14 could be the rotating member.

Apart from the above modifications, the actual configuration of the surfaces upon the piston undulating end surfaces may be varied from the configuration shown.

The curves defining the surfaces are not critical provided the desired variation in volume of the chambers occurs. The shaping of the curves may be designed for any particularly desired requirement such as to account for the expansion characteristics of the working fluid. Further, while, in the embodiment of FIGS. 1 to 4, the

curves defining the surfaces on the annular member 12 have no phase displacement, and in the embodiment of FIG. 6, the curves have a displacement amounting to 90, the invention may utilize different displacements to these. a

While, in the described embodiment, induction of working fluid takes place through ports in shaft 65, or in casing 138, this is not essential. In the embodiment of FIG. 8 induction could take place through ports in bosses 64, the ports 68 being dispensed with. Similarly, in the embodiment of FIG. 14, induction could take place through ports in bosses .133, 134, the ports 154, 156 being dispensed with.

The above and many other modifications may be made to the described construction within the scope of the appended claims.

What is claimed is:

1. In a rotary fluid flow machine of the type comprising a body, an axial member and a generally annular member mounted for axial reciprocation and rotation in a generally annular cavity defined between said body and said axial member, said axial member and said body being relatively rotatable and said annular member having undulating end surfaces, said cavity being defined by spaced, concentric inner and outer cylindrical surfaces and by a pair of axially spaced end surfaces of undulating configuration on said body and each of which cooperates with a separate one of the undulating surfaces of said annular member, whereby said annular member is constrained, by engagement between the two end surfacesof each cooperating pair of end surfaces for movement in said cavity comprising a first axial rotational component of motion and a second axial to and fro reciprocatory component; there being defined, between each pair of cooperating end surfaces, a plurality of chambers, the volumes of which chambers undergo cyclic variation when said member undergoes said movement, and the body being provided with port means to said chambers; the improvement wherein said annular mem ber is afiixed to a cylindrical sleeve which defines two axial cylindrical extensions to said member, one to either axial side thereof, one cylindrical surface of said sleeve slidingly engaging one cylindrical surface of said axial member, said port means including first ports defined by root portions of the undulating surfaces on said body and cooperating transverse edges of said sleeve extensions, and communication between the ports and the respective chambers being controlled by said sleeve during reciprocating motion thereof.

2. A rotary fluid flow machine as claimed in claim 1 wherein said inner cylindrical wall is defined by an exterior surface of said axial member and said outer cylindrical wall is defined by an interior surface of said body, said sleeve being axially slidingly engaged on said axial member and said annular member comprising a radially out- Wardly extending skirt on said sleeve.

3. A rotary fluid flow machine as claimed in claim 2 wherein the planes containing the roots of the undulating surfaces of the said annular member are separated by a continuous outer peripheral surface of said annular member, the said port means including further ports in a side wall of said body and extending to said outer cylindrical surface, the said further ports being disposed so that, at opposite extremes of reciprocating movement of the annular member, the said further ports communicate respectively with the chambers to an associated end of the machine.

4. A rotary fluid flow machine as claimed in claim 3 wherein said continuous outer peripheral surface is provided with one or more circumferential sealing strips which engage the said outer cylindrical surface.

5. A rotary fluid flow machine as claimed in claim 2 wherein there are provided a pair of cylindrical sealing strips, said body being provided with a pair of axial cylindrical bosses at the opposite axial ends thereof and through which the said axial member extends, said sealing strips being disposed either towards respective opposite axial ends of the outer surface of said sleeve or one upon the inner surface of each boss, the said extensions each separately being engageable, at the respective opposite extremes of movement of the annular member, in the respective spaces between the inner surfaces of the bosses of the said axial member, said sealing strips sealing the spaces between the inner surfaces of the bosses and the outer surface of the axial member at said extremes of reciprocatory movement of the annular member to allow said communication between the associated chambers and said first ports.

6. A rotary fluid flow machine as claimed in claim 3 wherein said roots are progressively enlarged, towards the outer periphery of the annular member, by cut-out portions of the annular member defined along the said planes.

7. A rotary fluid flow machine as claimed in claim 3 wherein said axial member is hollowed and has a first set of circumferentially arranged ports extending through the side wall thereof and a second set of circumferentially arranged ports extending through the side wall thereof and axially displaced from said first set, the first set of ports being disposed to be axially aligned substantially at a common transverse plane containing root portions of one undulating surface on said body and the other set are aligned substantially at a common transverse plane containing root portions of the other undulating surface on said body, the said root portions on said body being progressively enlarged towards the inner edges thereof by cut out portions defined along the associated common transverse plane.

8. A rotary fluid flow machine as claimed in claim 2 wherein said axial member is provided with longitudinal, external, splines and the interior cylindrical surface of said sleeve is provided with complementary interfitting splines to allow relative axial sliding of these parts but to substantially preclude relative rotation between them, there being provided, on either or both of the axial member and sleeve, roller members disposed between side adjacent surfaces of splines of the axial member and sleeve, each of these rollers being engaged by the adjacent spline surface and being rotatable about axes generally radial of said axial member.

9. A rotary fluid flow machine as claimed in claim 1 wherein said outer cylindrical wall is defined by an in terior surface of said axial member and said inner cylindrical wall is defined by the external surface of an axially extending hollow cylindrical section of the body said sleeve being axially slidingly engaged within said axial member and said annular member comprising a radially inwardly extending skirt within said sleeve.

10. A rotary fluid flow machine as claimed in claim 9 wherein the planes containing the roots of the undulating surfaces of the said annular member are separated by a continuous inner peripheral surface of said annular member, the said port means including further ports in a side wall of the said cylindrical section of said body and extending from said inner circumferential surface, the said further ports being disposed so that, at opposite extremes of reciprocating movement of the annular member, the further ports communicate respectively with the chambers to an associated end of the machine.

11. A rotary fluid flow machine as claimed in claim 9 wherein said continuous inner peripheral surface is provided with one or more circumferential sealing strips which engage the said inner cylindrical surface.

12. A rotary fluid flow machine as claimed in claim 9 wherein there are provided a pair of cylindrical sealing strips, said body being provided with a pair of axial cylindrical bosses at the opposite axial ends thereof and upon which the said axial member is engaged, said sealing strips being disposed either towards respective opposite axial ends of the axial member and on the inner surface thereof or one upon the outer surface of each boss, the said extensions each separately being engageable, at the respective opposite extremes of movement of the annular member, in the respective spaces between the outer surfaces of the bosses and the inner surface of said axial member, said sealing strips sealing the spaces between the outer surfaces of the bosses and the inner surface of said axial member at said extremes of movement, each end edge of the sleeve separately and alternately disengaging from its associated boss at the respective extreme of reciprocatory movement of the annular member to allow said communication between the associated chambers and first and second sets of ports.

13. A rotary fluid flow machine as claimed in claim 9 wherein said roots are progressively enlarged, towards the inner periphery of the annular member, by cut out portions defined along the said planes.

14. A rotary fluid flow machine as claimed in claim 9 wherein said axial member has a first set of circumferentially arranged ports extending through the side wall thereof and a second set of circumferentially arranged ports extending through the side wall thereof and axially displaced from said first set, said first set of ports being disposed to be axially aligned substantially at the common transverse plane containing root portions of one undulating surface on said body and the other set is aligned substantially at a common transverse plane containing root portions of the other undulating surface on said body, the said root portions on said body being progressively enlarged towards the outer edges thereof by cut out portions defined along the associated common transverse plane.

15. A rotary fluid flow machine as claimed in claim 9 wherein said axial member is provided with longitudinal, internal, splines and the exterior cylindrical surface of said sleeve is provided with complementary interfitting splines to allow relative axial sliding of these parts but to substantially preclude relative rotation between them, there being provided, on either or both of the axial member and sleeve, roller members disposed between adjacent side 7 surfaces of splines of the shaft and sleeve, each of these rollers being engaged by the adjacent spline surface and being rotatable about axes generally radial of said axial member.

16. A rotary fluid flow machine as claimed .in claim 1 1 2 wherein said first ports comprise inlet ports and said further ports comprise exhaust ports, said machine including compressor means for compressing working fluid prior to admission to said inlet ports.

17. A rotary fluid flow machine as claimed in claim 1 wherein crest portions of the undulating surfaces on said body are provided with generally conical roller bearing members which extend generally radially and are arranged with the wider portions radially outermost, the said undulating surfaces on the annular member engaging these roller bearings.

18. A rotary fluid flow machine as claimed in claim 2 wherein said axial member comprises a shaft rotatable in said body.

19. A rotary fluid flow machine as claimed in claim 2 wherein said axial member comprises a shaft upon which said body, in use of the machine rotates. I i

20. A rotary fluid flow machine as claimed in claim 1 wherein said first ports comprise exhaust ports and said further ports comprise inlet ports, said machine also ineluding compressor means for compressing working fluid prior to admission to said inlet ports. I

21. A rotary fluid flow machine as claimed in claim 9 wherein said axial member comprises a shaft rotatable in said body.

22. A rotary fluid machine as claimed in claim 9 wherein said body comprises a shaft rotatable in said axial member.

References Cited UNITED STATES PATENTS 112,853 3/1871 *Ruggles 418-68 205,868 7/1878 Huston et al. 418- 8 908,916 1/1909 Weinat 418-68 2,896,590 7/1959 Bush et al. 418-68 FOREIGN PATENTS v 274,940 6/1914 Germany 418-68 13,677 8/1916 Great Britain 123-45 A 514,628 11/1939 Great Britain 418-68 ALLAN 1). HERRMANN, Primary Examiner