WO2016206851A1

WO2016206851A1 - Vibration absorber

Info

Publication number: WO2016206851A1
Application number: PCT/EP2016/060370
Authority: WO
Inventors: Peter Frohs; Anton SOKOLOW
Original assignee: Voith Patent Gmbh
Priority date: 2015-06-24
Filing date: 2016-05-10
Publication date: 2016-12-29
Also published as: DE102015211649A1

Abstract

The invention relates to a vibration absorber (1) for damping rotational vibrations, comprising a spring element (3) and an absorber mass (30), wherein the absorber mass (30) is operatively connected to the spring element (3). At least one leg spring (10) comprising a first leg (12) and a second leg (14) is provided as the spring element (3). The first leg (12) is non-rotatably joined to the absorber mass (30) . Torsional vibrations acting on the second leg (14) can be transmitted by means of the leg spring (10) to the absorber mass (30).

Description

vibration absorber

The invention relates to a vibration damper. The vibration damper has an absorber mass and a Tilgerfederelement. As a vibration damper special types of vibration dampers are referred to. A vibration absorber is not attached between two objects, but only attached to an object. The vibrations of this object should be damped. The natural frequency of the vibration absorber is tuned to the resonant frequency of the object to be eliminated. At this frequency, the object performs only minor movements. From DE 10 2004 006 030 B3 a vibration damper is known, which has a base plate. With the base plate, a spring body is firmly connected. As a spring body, an element made of an elastomeric material is provided. With the spring body a damping mass is firmly connected. The absorber mass is thus connected via the spring body with the base plate. By means of a fastening element, the vibration damper can be firmly connected to a structure / element, wherein vibrations of this structure / element are to be damped. This vibration damper builds up in the axial direction, because over the axial extent of the spring element, the permissible angle of rotation are determined. The higher the elasticity of the elastomer and the higher the axial extension, the greater the rotations in the direction of rotation are permissible, without damaging the elastomere existing spring element.

From DE 10 2008 052 902 A1 a device for reducing torsional vibrations in a rotating shaft is known. The device comprises a primary part, a secondary part and movable mass elements as well as elastic means. The elastic means couple the primary part and the secondary part with each other. At least one of the parts is so connected to the shaft that it rotated with the shaft. In the embodiment shown, the mass elements are arranged so that they increasingly act with increasing speed on the elastic means and so change the coupling between the primary part and the secondary part, in particular reinforce. The device can be used as a vibration absorber or as an elastic coupling.

The life of spring elements made of an elastomeric material are dependent on the temperature at the site. Especially at high temperatures elastomers age strongly and become brittle. Furthermore, elastomeric material components are sensitive to elongation. The torsion of a spring element is limited by the height in the axial direction and the elasticity of the elastomer.

From DE10 2006 057 481 A1 a decoupling element for vibration decoupling is known. The decoupling element counteracts the transmission of torsional vibrations between a drive component and a rotationally driven component thereof. The drive component and the driven component are connected to each other via a torsion spring. The decoupling element is not a vibration damper, since the decoupling element is arranged between a driving and driven element. The decoupling element is arranged in contrast to the vibration damper in the power transmission path. From DE 197 28 241 A1 a torsional vibration damper for the drive train is known. A rotatably arranged input part is coupled via a spring device torsionally elastic with an output part. The torsional vibration damper is arranged in the power transmission path and is therefore not a vibration damper. The invention is therefore based on the object to provide a vibration damper, in which the aforementioned disadvantages are eliminated.

The invention was based, in particular, on the object of providing a vibration damper which is short in the axial direction. Furthermore, the invention was based on the object to provide a vibration damper, which is particularly suitable for a frequency range of 10-160 Hz.

The solution according to the invention is characterized by the features of the independent claims. By using a leg spring, the vibration absorber according to the invention has the advantage that the space required in the axial direction is small. The leg spring has a first and a second leg. The vibrations to be damped, in particular torsional vibrations, can be introduced via the second leg into the vibration damper. The first leg is rotatably connected to the absorber mass. As a result, initiated rotational movements are transferable to the absorber mass. By acting on the second leg torsional vibrations, a deflection of the absorber mass can be achieved. The vibrations acting on the second leg are transmitted to the first leg as a function of the frequency and the spring characteristic. The absorber mass then oscillates out of phase to the introduced torsional vibration, whereby a vibration damping is achieved. Such an arrangement, in which by the introduced moment a mass, here absorber mass, phase-shifted to perform a rotational movement can be freely excited, is referred to as a cantilever. The transmission of the torsional vibrations depends on the elasticity of the leg spring and on the frequency of the vibration.

Preferably, the natural frequency of the vibration absorber is tuned to the vibrations to be damped. Preferably, the mass of the absorber is 10% of the total weight of the drive train. The natural frequency results from the mass m and the spring constant, which is also referred to as spring stiffness. In a preferred embodiment, it is provided that the rigidity of the spring element of the absorber deviates a maximum of 15% from the rigidity of a damper, which would oscillate at the natural frequency of the overall drive train.

In a preferred embodiment, the leg spring is made of metal, preferably spring steel. This makes the vibration damper insensitive to high temperatures. In one embodiment, a leg spring is provided with at least one turn. The winding runs around a winding center axis. At least one of the legs, preferably both legs is / are arranged tangentially to the winding center axis. As a result, the legs act as a lever arm in the conversion of the rotational movement in an elastic deformation of the leg spring.

In one embodiment, it is provided that the absorber mass coaxial with

Windungsmittenachse is arranged and is preferably formed in the form of a disc. Due to the design of the absorber mass in the form of a disk, the required installation space in the axial direction can be minimized.

In one embodiment, it is provided that the absorber mass is supported by a bearing rotatable about the winding center axis. It can be provided that with the absorber mass a shaft is firmly connected, which is preferably rotatably mounted on both sides of the absorber mass. In such an arrangement, the turns of the leg spring may be coaxial with the shaft. This allows a particularly compact design can be achieved. An advantageous development of this embodiment is to provide the bearing of the shaft in a housing surrounding the vibration damper.

Furthermore, it can be provided to mount the absorber mass rotatably on a shaft, wherein the shaft is part of the object. By the vibration damper, the vibrations of the object should be eradicated. The object may be a system of multiple components that are interconnected or act as a single component. In this case, the shaft of the object protrude into a housing surrounding the vibration damper.

In one embodiment of the invention, an attenuation for damping the movement of the absorber mass is provided. Preferably, a viscous damping is provided. When viscous damping increases at higher speeds, the friction of the viscous damping and is thus speed-dependent.

In particular, it has proven to be advantageous to provide the damping on the radial outer circumference of the absorber mass. In a further development, the damping is arranged coaxially to the at least one leg spring. As a result, a particularly compact design is achieved in the axial direction.

In an advantageous embodiment, a friction damping is provided as damping. In a friction damping is a damping with a constant force regardless of the speed. In one embodiment of the invention it is provided that the vibration damper has a further leg spring. The further leg spring has a first and a second leg. The first leg is rotatably connected to the absorber mass. About the second leg torsional vibrations can be introduced into the vibration damper. By introduced torsional vibrations, a deflection of the absorber mass can be achieved. The Tilgermasse is free-swinging and then oscillates out of phase to the initiated torsional vibration, whereby a vibration damping is achieved.

The use of at least two torsion springs makes it possible, on the one hand, to convert larger acting forces in the direction of rotation by the two torsion springs into elastic deformation of the two torsion springs. The individual torsion springs can be made smaller.

The further advantage lies in the fact that the tilting moments introduced by both torsion springs can be compensated. When offset in the axial direction of the first and second legs of the at least one leg spring acting on the absorber mass tilting moment is generated. This tilting moment can be compensated by the other leg spring by an opposing tilting moment.

In a preferred embodiment it is provided that the further leg spring is opposite to the first leg spring. It should be understood in opposite directions that the winding direction of the turns of the leg spring is opposite to the winding direction of the other leg spring. If the turns of the first leg spring are wound in a clockwise direction, then the turns of the other leg spring are wound in a counterclockwise direction.

In a preferred embodiment it is provided that the leg spring and the other leg spring are arranged on different sides of the absorber mass.

In one embodiment, it is provided that leg spring and the other leg spring have the same number of turns. In a preferred embodiment, it is provided to use two torsion springs with identical spring characteristics as leg spring and other leg spring. In each case, the second leg of the two leg springs are spaced from each other to Tilgernnasse. The first leg of the leg spring and the other leg spring are rotatably connected to the absorber mass. It has proven to be advantageous that the first leg and the second leg of the leg spring are arranged with an axial offset and are arranged by the second leg spring of the first leg and the second leg with an axial offset. In this case, the first axial offset of the leg spring and the axial offset of the second leg spring is arranged in the opposite direction in the axial direction. This ensures that due to the offset resulting tilting moments of the leg spring and the other leg spring compensate each other. The complete compensation is only achieved if the characteristics of the leg spring are identical and the amount of the axial distance is identical. If different leg springs are used with different characteristics, then the tilting moments occurring compensate at least partially. Due to the compensation of the tilting moments, the bearing of the absorber mass must be able to absorb lower forces. This allows a more compact design can be achieved.

It has proven to be advantageous to use identical torsion springs as leg spring and other leg spring. It has proven to be advantageous that the turns of the first leg spring and the other leg spring are wound in different winding direction. As a result, it is achieved in the installed state that upon initiation of a torsional vibration in the direction of increasing the turns of the first leg spring, the second leg spring is also elastically deformed in the direction of increasing the turns. The absorber according to the invention is particularly suitable for use at a resonant frequency of the consumer of 10-160 Hz. Furthermore, the absorber according to the invention is suitable for use with an object in a speed range of 200-3000 rpm, preferably in a speed range of 300 rpm. 2500 revolutions per minute.

The invention will be described in more detail below with reference to exemplary embodiments. The embodiments are shown schematically in the figures. The embodiments may include independent inventive aspects, wherein the invention is not limited to the embodiments to understand.

It shows:

Figure 1 vibration absorber

1 is a sectional view of the vibration absorber of FIG. 1 along B-B; FIG. 4 shows an alternative embodiment of a vibration damper with a disk-shaped absorber mass

Figure 5: enlarged view of the absorber of FIG. 4 with the

Torsion springs

Figure 6: Schematic representation of a drive train

FIG. 1 shows a vibration damper 1. The vibration damper 1 is surrounded by a housing 40. A housing cover 42 is shown in plan view with a partial elevation. In the middle of the housing 40, a receptacle 6 for a shaft of a consumer 8 can be seen. The housing is firmly connected to the receptacle 6. The elevation shows a second leg 14 of a first leg spring 10. FIG. 2 shows the section along AA through this vibration damper 1. FIG. 3 shows the section along BB through this vibration damper 1. With reference to Figure 2, the structure of the vibration absorber 1 will be described in detail below. The vibration damper 1 is surrounded by a housing 40. The housing consists of two housing cover 42. Through the housing cover 42, the housing 40 is closed in the axial direction. Furthermore, the housing 40 comprises a sleeve-shaped housing wall 41st By the housing 41, the housing is limited and completed in the radial direction. The housing wall 41 is designed in two parts in this embodiment. The two parts of the housing 41 are connected to each other via a flange connection. The housing 41 is arranged coaxially with the shaft of the consumer 8. The shaft of the consumer 8 is connected to a receptacle 6 at least rotationally fixed, preferably fixed. The receptacle 6 is in turn connected to a housing cover 42 of the housing fixed via a flange connection. The receptacle could also be formed integrally with the housing cover 42. The receptacle 6 protrudes into the volume defined by the housing 40. The receptacle 6 comprises a wave-shaped portion which is arranged within the volume of the housing 40. This wave-shaped portion is arranged coaxially with the axis of rotation D of the shaft of the consumer 8. On the wave-shaped portion of the receptacle 6, the absorber mass 30 is rotatably supported by means of a bearing 31. However, it could also be provided that the receptacle produces only a rotationally fixed connection between housing and consumer / object and protrudes the shaft of the consumer / object into the housing 40 and then stored the absorber mass 30 by a bearing directly on the shaft of the consumer / object is.

The absorber mass 30 is a cup-shaped absorber mass 33. Within the cup-shaped absorber mass 33, a leg spring 10, hereinafter also referred to as the first leg spring, is arranged. The leg spring 10 is arranged to save space between the wave-shaped portion of the receptacle 6 within the cup-shaped absorber mass 33. A first leg 12, see FIG. 3, extends in the tangential direction with respect to the axis of rotation D. This first leg 12 is rotatably connected to the absorber mass 30 by means of a first connecting element 20. A second leg 14 is non-rotatably connected to the housing 40 by means of a second connecting element 22. The first and second legs 12, 14 extend in a tangential direction with respect to the axis of rotation D.

On the side facing away from the consumer side of the absorber mass 30 is a further leg spring 1 1, hereinafter also referred to as a second leg spring provided. This second leg spring 1 1 is also arranged coaxially to the axis of rotation of the consumer 8. The axis of rotation D thus coincides with the winding center axis of the turns 16 of the first and second leg spring 10, 1 1 together. This second leg spring 1 1 comprises a first leg 13 and a second leg 15. The two legs are only indicated in FIG. The first leg 13 is rotatably connected by means of a first connecting element 21 with the absorber mass 30. The second leg 15 of the second leg spring 1 1 is rotatably connected by means of a second connecting element 23 to the housing 40.

Between Tilgermasse 30 and housing 41, a gap 44 is formed. To seal this gap seals 52 are provided. This gap is filled with a fluid 47. Through the gap 44 with the fluid 47, a viscous damping 50 is formed. Due to the pot-shaped shape of the absorber mass 30, the absorber mass 30 extends in the axial direction 54. As a result, the effective area of the absorber mass 30, which is in operative connection with the viscous damping 50, can be maximized. By arranged radially within the absorber mass 30 first leg spring 10 a compact design is achieved. In particular, the axial space is effectively used. The first leg spring 10 and the second leg spring 1 1 have a plurality of turns 16. The windings are arranged coaxially with a winding center axis 19. Due to the windings each of the first leg 12, 13 with an axial offset to the second leg 14, 15 is arranged. The axial offset of the first leg spring is denoted by 17 and the axial offset of the second leg spring is designated by 18. If a torque is transmitted via the housing 40 to the second legs 14, 15, so by the torque, an elastic deformation of the leg springs 10, 1 1 caused. Due to the elastic deformation and the acting spring force associated with the first legs 12, 13 absorber mass 30 is set in rotation. Due to the axially offset leg acting by the first leg spring 10 a tilting moment K _a on the absorber mass 30. Furthermore, due to the axially staggered legs of the second leg spring and a tilting moment K _{b is} transmitted to the absorber mass 30. The tipping moment K _a acting on the absorber mass 30 from the first leg spring 10 is directed counter to the overturning moment K _b acting on the absorber mass 30 from the second leg spring 1. In the illustrated embodiment, leg springs 10, 1 1 are provided with identical spring characteristics. This ensures that compensate for the tilting moments acting on the absorber mass 30. Due to the reduction or compensation of the tilting moments, the rotatable mounting 31 of the absorber mass 30 can be made smaller.

The mode of operation of the vibration absorber shown in FIG. 2, also referred to as a absorber, will be described in more detail below. About the shaft of the consumer 8 torsional vibrations are transmitted to the housing 40. The second legs of the leg springs are thereby deflected in the circumferential direction. As a result, the leg springs are elastically deformed and it is a rotary motion transmitted to the first with the absorber mass rotatably connected first leg. The absorber mass is rotationally driven in a first direction of rotation. Due to the inertia and the effective restoring force of the torsion springs 10, 1 1 turns one Torsional vibration, which is directed against the initiated by the consumer torsional vibration and thereby counteracts the torsional vibration of the consumer. The amplitude of the torsional vibration of the consumer is thereby significantly reduced.

In the illustrated embodiment, the absorber mass is surrounded by the housing. But it would also be possible that the absorber mass is arranged coaxially to the shaft of the consumer or a rotatably connected to the shaft of the consumer recording and surrounds a compound of the second leg and the second leg springs with the receptacle / shaft of the consumer. The design of the absorber mass could be similar to the shape of the housing shown here in FIG. The absorber mass is rotatably mounted relative to the shaft of the consumer. In the illustrated embodiment, the two leg springs 10, 1 1 turns with opposite slope. Both the turns 16 of the first leg spring 10 and the turns 16 of the second leg spring 1 1 are inclined towards the absorber mass. The windings 16 of the first leg spring 10 are wound in the clockwise direction 27, wherein the windings 16 of the leg spring 1 1 are wound in the counterclockwise direction 28.

FIG. 3 shows a section along B-B. From this sectional view, the connection of the legs 12, 14 of the leg spring 10 with the housing 40 and the absorber mass 30 can be seen. Each leg end of a leg 12, 14 is received by a connecting element 20, 22. In the illustrated embodiment, it is provided to connect the leg end in each case by a locking element 26, here screw, with the connecting element 20, 22 fixed.

FIG. 4 shows a further exemplary embodiment. In this embodiment, the absorber mass 30 is formed in the form of a disc 32. With the disc, a shaft 34 for supporting the absorber mass 30 is firmly connected. In the illustrated embodiment, the shaft 34 is integrally formed with the disc-shaped absorber mass 32. The shaft 34 is rotatably supported by a bearing 35 in the housing 40 on both sides of the absorber mass. In the radially outer periphery of the disc 32 recesses 51 are formed in the absorber mass. This area of the disc 32 is surrounded by the housing 40 and sealed by seals 52 from the remaining volume of the housing. This area sealed by the seals 52 is filled with a fluid and represents a viscous damping 50. The recesses 51 increase the effect of the viscous damping 50.

From Figure 5, the arrangement of the leg springs 10, 1 1 is better visible. The axial direction 54 is shown by an arrow. The two torsion springs 10, 11 each have a first leg 12, 13, these first legs being connected to the absorber mass 30 by the connecting elements 20, 21. Second legs 14, 15 of the leg springs 10, 1 1 are connected to the housing 40 by the connecting elements 22, 23. The first legs 12, 13 are arranged to the second legs 14, 15 at an axial distance 17, 18. The axial distance 17, 18 from each first leg 12, 13 to each second leg 14, 15 is equal in magnitude, however, the distances 17, 18 have opposite orientation. The turns 16 of the torsion springs 10, 1 1 are inclined in the same direction. The first leg spring 10 is wound here in the clockwise direction 27 and the second leg spring 1 1 is here also wound in the clockwise direction 27.

Accordingly, upon initiation of torsional vibrations with elastic deformation of the leg spring on one side, the turns 16 are contracted and widened on the opposite side of the turns 16. When contracting the number of turns is increased at least by a fraction and the expansion of the number of turns of the respective leg spring is at least reduced by a fraction. FIG. 6 shows a use of an absorber 1 according to the invention. In Figure 6, a drive train 4 is shown schematically. The drive train has a motor 5 with a motor damping 5a. The engine is connected via a coupling 7 with a consumer 9, also referred to as object. The consumer is provided with a Tilger invention 1. As a clutch, a separation clutch or a highly elastic coupling can be provided. The absorber according to the invention is particularly suitable for use at a resonant frequency of the consumer of 10-160 Hz and / or in a speed range of 200- 3000 revolutions per minute, preferably in a speed range of 300- 2500 revolutions per minute.

LIST OF REFERENCE NUMBERS

I vibration absorber

3 spring element

4 powertrain

5 engine

5a engine damping

6 recording

7 clutch

8 wave of the consumer

9 consumers / object

10 thigh spring, first leg spring

I I another leg spring, second leg spring

12 first leg of the first leg spring

13 first leg of the second / further leg spring

14 second leg of the first leg spring

15 second leg of the second / further leg spring

16 turn

17 Axial misalignment of the legs of the leg spring 10 18 Axial misalignment of the legs of the leg spring 1 1

19 winding center axis

20 first connecting element for the leg 12th

21 first connecting element for the leg 13th

22 second connecting element for the leg 14 23 second connecting element for the leg 15th

26 locking element

27 turns wrapped in a clockwise direction

Twenty-eight turns wrapped counterclockwise 30 absorber mass

31 bearings for rotatably supporting the absorber mass

32 disc pot-shaped absorber mass

Shaft for storage of the absorber mass

Bearing for bearing the shaft

casing

housing

housing cover

Connecting element / screw

gap

fluid

Viskodämpfung

Recesses in the absorber mass

poetry

axial direction

axis of rotation

Claims

claims

1 . Vibration damper (1) for damping rotational vibrations with a spring element (3) and an absorber mass (30), wherein the absorber mass (30) is operatively connected to the spring element (3),

characterized,

in that at least one leg spring (10) having a first leg (12) and a second leg (14) is provided as the spring element (3), wherein the first leg (12) is non-rotatably connected to the absorber mass (30) and wherein the second leg Leg (14) acting torsional vibrations, over the leg spring (10) on the absorber mass (30) are transferable.

2. vibration damper (1) according to claim 1,

characterized,

that the leg spring is made of metal.

3. vibration damper (1) according to claim 1 or 2,

characterized,

in that the leg spring (10) has at least one turn (16) running around a winding center axis (19) and at least one of the legs (12, 14), preferably both legs (12, 14) are arranged tangentially to the winding center axis (19).

4. vibration damper (1) according to one of the preceding claims,

characterized, in that the absorber mass (30) is arranged coaxially with the winding center axis (19) and is preferably designed in the form of a disk (32) with a radial extent or in the form of a cup-shaped absorber mass.

5. vibration damper (1) according to one of the preceding claims,

characterized,

in that the absorber mass (30) is supported by a bearing (31, 35) rotatable about the winding center axis (19) by means of a shaft (8, 34).

6. vibration damper (1) according to one of the preceding claims,

characterized,

an attenuation, preferably viscous damping (50), is provided for damping the movement of the absorber mass (30).

7. vibration damper (1) according to one of the preceding claims,

characterized,

that the vibration damper (1) comprises a further leg spring (1 1).

8. A vibration damper according to one of the preceding claims,

characterized,

in that a leg spring (10, 11) is arranged on each side of the absorber mass (30).

9. vibration damper (1) according to one of the preceding claims,

characterized,

the turns (16) of the leg spring (10) and the turns (16) of the further leg spring (11) are wound in the same direction.

10. Vibration damper according to one of the preceding claims,

characterized, that the leg spring (10) and the other leg spring (1 1) has the same number of turns (16).

A vibration damper (1) according to one of the preceding claims 1 to 8 or 10,

characterized,

the turns (16) of the leg spring (10) and the turns (16) of the further leg spring (11) are wound in the opposite direction (27, 28).

Use of a vibration damper (1) according to one of the preceding claims in a drive train (4) comprising a motor (5), in particular an internal combustion engine, and a consumer (9) and preferably a clutch (7) arranged between motor (5) and consumer (9) )

characterized,

the vibration absorber (1) is arranged as an object on the consumer (7).

Method for damping torsional vibrations of a system, preferably in a drive train (4), comprising a vibration damper (1) according to one of the preceding claims,

characterized,

that torsional vibrations of the system via the leg spring (10) and preferably via a further leg spring (1 1) are transmitted to the absorber mass (30) and the absorber mass (30) is excited by the transmitted torsional vibrations to rotate, wherein the rotational movement of the absorber mass (30 ) counteracts the torsional vibration of the system. 14. The method according to claim 1 1,

characterized, a tilting moment K _{a is} transmitted to the absorber mass (30) via a first leg spring (10) and a tilting moment K _{b is} transmitted in the opposite direction to the absorber mass (30) by the further leg spring (11).