DE102009031800A1 - Freewheel device with damping and crank-CVT transmission with a freewheel device - Google Patents

Abstract

A freewheel device includes an outer ring, an inner ring, a plurality of rolling bodies arranged between the outer ring and the inner ring and a damping device arranged between adjacent rolling bodies in the circumferential direction. The damper includes a base biasing means for biasing a rolling body in a first circumferential direction and a damping mechanism for damping movement of the rolling body in a second circumferential direction.

Description

The Invention relates to a freewheel device with a damping, in particular for use in a crank-CVT transmission, and a Crank CVT transmission with such a freewheel device with damping.

A crank-CVT transmission is for example from the EP 1 650 071 A2 known. On an input shaft driven by a motor which forms a driving shaft with respect to the gear, there is provided an eccentric eccentric drive assembly having eccentric members connected to a driven shaft via connecting rod-like connecting members forming an output or output shaft with respect to the gearbox , By transmitting the stroke of the connecting elements by means of freewheel devices on the driven shaft, this is driven, wherein the freewheel devices between the connecting rod-like connecting elements and the driven shaft are provided. The driving crankshaft and the output shaft or driven shaft are aligned parallel to one another and in each case rotatably mounted in a transmission housing. Torque is introduced into the crankshaft from an internal combustion engine and transmitted to the output shaft through the crank CVT transmission. Depending on the position of the Exzenterbauteile with respect to the axis of rotation of the drive shaft, the eccentricity of the Exzenterbauteile and thus their axis of rotation relative to the drive shaft is changed, whereby the transmitted from the connecting rod connecting elements on the output shaft hub and thus the ratio of the transmission can be adjusted. On the output shaft, the torque can be tapped for example for driving wheels of a vehicle.

In usually in a crank-CVT transmission in the axial direction of the Crankshaft arranged one behind the other several eccentric units, at each of which connecting rod-like connecting elements are attached and those with a corresponding number of freewheel units the output side of the transmission are in communication.

The Freewheel units can be considered non-switchable or reversible Freewheeling be provided. In the former case is in a Relative rotation direction of an outer ring of a freewheel unit and the output shaft or a permanently connected inner ring achieved a blocking effect and in the other direction of relative rotation no blocking effect achieved. With reversible freewheels are provided two blocking positions, in which the two components in one block first or second relative direction of rotation and thus be twisted together in the first and second directions of rotation. As a result, the direction of rotation of the output shaft can be changed be, so that by means of the switchable freewheels, for example a reverse gear can be realized.

A such freewheel device usually has an outer ring concentric around a polygonal profile of the output shaft is provided. Between the polygonal profile and the outer ring rolling or clamping body are provided with respect to the inner ring, which has the polygonal-like profile, and the outer ring at least two positions in the circumferential direction, namely a first position in which they twist the inner ring and block the outer ring to each other, and a second position, in which the inner ring and the outer ring relative to each other can be freely rotated (freewheel). The first position will be hereinafter also referred to as clamping or locking position.

At one in the EP 1 650 071 A2 described freewheel device are for pressing and damping of the rollers on the inner or outer ring V-shaped leaf springs, which are mounted on a pin provided with which the freewheel rollers or clamp body are pressed against the inner ring with the polygonal profile or the outer ring. The provision of the V-shaped spring avoids self-motions and vibrations of the idlers, so that the rollers are always ideally pressed against the gap and conditions are avoided in which slip occurs when the rollers do not engage the outer ring. The V-shaped leaf spring is supported in each case with its two legs on a roller and thus on two opposite or adjacent rollers. Thus, two force components are exerted on each roller since two adjacent leaf springs act on one roller. The resulting force is chosen to be close to the self-locking of the rollers to achieve high frictional force without pinching the roller. Alternatively, the contact pressure near the self-locking limit in the in the EP 1 650 071 A2 described embodiment also done by means of a single-acting spring. When using the freewheeling damping, which operates in the vicinity of the self-locking limit, but there is a risk that at high friction, the role or the clamping body gets stuck in the braking device and thus is not moved back to the freewheeling position of the freewheel. At low coefficient of friction, it is possible that the total attenuation is insufficient.

From that Based on the object of the invention, a freewheel with a Provide damping device in which the risk of Self-locking is minimized and thus works reliably.

This object is achieved with a freewheel device with the features of claim 1. Be Preferred embodiments are given in the dependent claims. A crank CVT transmission with a freewheel device is defined by claim 12.

Of the Invention is based on the idea, in addition to a damping device a separately formed basic biasing device in the Provide damping device, with the rolling body in a first circumferential direction, namely the reverse direction of the freewheel, is biased and direction nip of the freewheel device is pressed. The damping device has further a separately formed damping mechanism on, only then or strengthened on the rolling body acts when the rolling elements from the blocking position of the freewheel be moved into the freewheeling position, and thereby the movement of the Rolling body dampens. Thus, the pressure must be through the damping mechanism and / or the base biasing device not near the self-inhibition limit, but is rather according to the actually occurring Adjusted forces in the respective operating state.

Especially Thus, a freewheel device is provided, which has an outer ring, an inner ring and several between the outer ring and having the inner ring arranged rolling body. The inner ring is preferably provided with a polygonal-like profile, so that the rolling elements between the outer ring and the Inner ring a freewheel device lock position and a freewheeling position can take. Next is between adjacent rolling elements (in the circumferential direction) arranged a damping device, wherein the damping device is a basic bias device for preloading a rolling body in a first circumferential direction (Reverse direction of the freewheel) and a damping mechanism for damping the movement of the rolling body in one second circumferential direction (movement from the locked position to the free-running position) having. Thus, the base bias voltage is over the base biasing means generated, and acts on the rolling body, such as a Role that this always in a contact position between the outer ring and inner ring is held. At the moment of solving the Locking position of the rolling body creates a differential speed between the rolling body and the inner ring with the polygonal Profile. This differential speed, which leads to a swinging of the Can roll body is damped away by the damping mechanism, so that the rolling body at the next intervention in the gap of the freewheel (blocking position) calms before the gap, d. H. in a defined starting position lies. Thus ensures the damping mechanism for making the kinetic Differential energy between the rolling body and the polygonal Profile of the inner ring is absorbed, z. B. by putting in friction energy (Heat) is converted and dissipated.

preferred Way is between each pair of circumferentially adjacent Roll bodies provided a damping device. This can be a damping device on each rolling body act and be dampened every rolling body. This ensures a smooth operation the freewheel device. In this case, all damping devices are preferred the same design, but in principle within a freewheel Various damping devices are used may or only part of the rolling elements dampened can be.

To In a preferred embodiment, the base biasing means becomes formed by a spring device, which either directly or indirectly via presses an intermediate element on the rolling body. By the spring means thus each rolling body with a suitable spring force (for example, about 5 to 30 times the roll weight at tangential force) in the gap (Clamping gap) between outer ring and inner ring of the freewheel device be pressed. It can, depending on the training the contact between the rolling body and the spring means Coil springs, leaf springs or the like as the basic bias spring be used.

To a preferred embodiment, the damping mechanism a friction device, which is preferably in turn spring loaded. In particular, by the friction device, the kinetic energy, which needs to be quenched, in frictional energy (heat) converted and thus damped the movement of the rolling body. For example, a spring device (damping spring) be in frictional contact with the rolling body, wherein, for example a lever provided on a coil spring, a leaf spring portion or the like can be used therefor. Depending on the configuration, the pressing element and so that the friction element on the rolling body the same or a be another, also for applying the basic prestressing on the rolling body with this procedure is.

Preferably, the damping spring is mounted on a freewheel device, such as idlers, so that it does not block or obstruct the movement of the rolling body in a rotational or movement direction and rubs in the other direction against the rolling body to apply the damping effect. Thus, by the freewheel device in this case, the damping spring can be held in a first position in which it dampens the movement of the rolling elements, or be held in a second position in which it is at least as far mobile that the rolling elements not damped and no force is applied to them.

alternative is the damper spring with the damping freewheel device interacting in such a way that, for example, a brake lever an inner ring of a damping freewheel device firmly attached is while the damper spring with an outer ring the damping freewheel device via a friction body is in frictional contact. During the movement of the rolling body from the locked position to the freewheeling position becomes the brake lever pivoted in a rotational direction in which the damping freewheel device blocked, leaving the inner ring and outer ring of the damping freewheel device twisted together and thus the damping effect the friction device on the outer ring of the damping freewheel device acts, is used. In the other direction of rotation, the inner and the outer ring of the damping freewheel device relative to each other, so that by the basic bias means on the brake lever without damping by the friction device the basic bias force can be applied because of the Friction body in frictional contact outer ring of Damping freewheel device with a rotation of the inner ring not rotated.

To In another preferred embodiment, the damping device formed by a hydraulic device. This is the entire freewheel device filled with hydraulic fluid. In particular, it is preferable the rolling body of the freewheel device in a roller cage stored, in turn, a piston of a hydraulic device is formed and biased by the basic bias means. The piston increases or decreases an oil chamber by its piston movement, which coincides with the movement of the rolling body goes along with a reduction in the volume of the oil space Hydraulic fluid, which is located in the oil chamber over An aperture can be removed and thus the movement of the piston and the rolling body is damped. To produce the hydraulic circuit is preferably to the aperture connected in parallel, a check valve provided so that achieves directional damping becomes. If the piston with the rolling body in the direction of clamping gap, d. H. Locking position of the freewheel, moved, so is the check valve open and thus the damping off. With a movement in the other direction, the check valve is closed and thus the damping is switched on.

The Damping device can be fixed to one with the inner ring connected or integrally formed therewith sliding bearing body be educated. The plain bearing body can on the inner surface slide the outer ring.

following the invention will be described by way of example with reference to the attached Figures described in which:

1 a sectional view perpendicular to the axial direction by a first embodiment of the freewheel device;

2 a section from 1 shows, wherein the rolling bodies are in a locking position;

3 the cutout 2 shows, wherein the rolling bodies are in a movement from the locking position to the freewheeling position;

4 a second embodiment of the freewheel device in a view accordingly 1 is;

5 a section of the freewheel device according to 4 is, wherein the rolling bodies are in a locking position;

6 the clipping off 5 is, wherein the rolling bodies are in a movement position between the locking position and the free-running position;

7 a third embodiment of the freewheel device in a view accordingly 1 is;

8th a section from 7 shows, wherein the rolling bodies are in a locking position; and

9 the cutout 8th shows, wherein the rolling bodies are in a freewheeling position.

1 shows in a view in section perpendicular to the axial direction of an output shaft of a crank-CVT transmission, a first embodiment of a freewheel device 10 , The freewheel device includes an outer ring 12 on which a connecting rod eye 14 for articulating connecting rod-like connecting elements (not shown) for producing a transmission mechanism from the input shaft of the transmission to an output shaft. The outer ring 12 has a substantially cylindrical (circular cylindrical) inner surface 13 on.

Concentric to the outer ring 12 is an inner ring 16 provided, which may be formed integrally with the output shaft of a transmission, for example, or forms by clamping or bracing several freewheel units, the output shaft of the transmission. The inner ring 16 has on its outer circumference a polygonal-like profile 17 on. Between the inner ring 16 and the outer ring 12 are several (six in this embodiment) rolling elements 18 provided, which can be held and guided in a common cage. The rolling bodies 18 are with the inner surface 13 of the outer ring 12 and the polygonal surface 17 of the inner ring 16 in abutment and can along the polygonal surfaces of the inner ring 16 be shifted relative to it in the circumferential direction by rolling on the inner or outer ring so that they have a locking position between the outer ring 12 and the inner ring 16 or a release position between the outer ring 12 and the inner ring 16 Provide so that the inner ring 16 and the outer ring 12 can only be rotated together or in a freewheeling position in which they are rotatable relative to each other.

The inner ring 16 is also in each case in the areas between two adjacent rolling bodies 18 in the circumferential direction with a plain bearing body 20 Mistake. The plain bearing body 20 is in the 1 illustrated embodiment in one piece with the inner ring 16 designed and extends from the polygonal profile 17 of the inner ring 16 radially outward. The plain bearing body 20 centers the outer ring 12 with respect to the inner ring 16 , In the plain bearing body 20 is also a damping device (generally with 22 referred to) for the rolling body 18 brought in. The damping device 22 in turn, includes both a base biasing device 24 with which the rolling bodies 18 in the nip between the outer ring 12 and the inner ring 16 be preloaded (in the figures counterclockwise), and a damping mechanism 26 which determines the movement of the rolling elements 18 when they are moved out of the nip in the freewheeling position, dampens.

The basic bias device 24 points in the in 1 to 3 illustrated embodiment, a coil spring as a basic biasing spring 28 on that in a recess 29 on the plain bearing body 20 is stored. The basic bias spring 28 acts in a substantially radial direction against the rolling body 18 In the illustrated embodiment, there is no transfer or intermediate element between the base biasing spring 28 and the rolling body 18 is provided. If required, such a transmission element can be interposed. For each of the rolling bodies 18 is a basic bias spring 28 intended.

The damping mechanism 26 the damping device 22 has a leaf spring 30 as a damping spring which, in a recess of the plain bearing body 20 is held loose and by a freewheel roller assembly 32 in a tense, ie not loose movable position can be brought. The leaf spring 30 has a friction surface 31 on, with which they rest against one of the rolling elements 18 is or can be brought. The friction surface 31 forms a friction device. Instead of as in the 1 to 3 illustrated embodiment, this leaf spring 30 each form as an element between adjacent rolling bodies 18 arranged, the leaf springs can 30 also in one piece by a cage for the rolling elements 18 be formed.

The damping has an angle until the rolling body 18 the leaf springs 30 tense when they are moved from their locked position to the freewheeling position, and abut the stop. From then on, the leaf spring rubs 30 each on the associated rolling body 18 and destroys the kinetic energy of the rolling body 18 ,

The clearance angle, ie the angle of the rolling bodies 18 without attenuation, will be in the in 1 to 3 illustrated embodiment on the mounting of the leaf spring 30 by means of freewheel rollers 32 reached. As in 3 represented, a rolling body passes 18 in contact with the contact surface 31 the leaf spring 30 in the movement from the gap in the freewheeling position and thus gets into friction. At the same time, the freewheel rollers of the freewheel roller assembly 32 , which forms a damping freewheel device, in recesses in the plain bearing body 20 moved until they are in a blocking position and thus the leaf spring 30 can not move or change their situation. Thus, the leaf spring rubs 30 on the rolling elements 18 , When there is a rolling body 18 away from the rubbing position with the leaf spring 30 moves (counterclockwise in 1 to 3 ), get the freewheel rollers 32 in a freewheeling position, the damping freewheel device is effective and the biasing force of the leaf spring 30 breaks down. 2 shows the position in which the damping freewheel device by means of freewheel rollers 32 in the freewheeling position.

To form the damping freewheel device, the freewheel rollers 32 in corresponding recesses in the plain bearing body 20 stored. In the illustrated embodiment, three U-shaped, the leaf spring 30 between them receiving freewheel rollers 32 intended.

In 4 to 6 is another embodiment of the freewheel device 10 shown. Only those components that differ from those of the first embodiment will be described. The other components are essentially the same and functionally identical.

In particular, in the in 4 to 6 illustrated embodiment of the sliding bearing body 20 with the inner ring 16 not formed in one piece but separately formed and firmly connected. In the plain bearing body 20 is again a damping device 22 integrated, which is a basic biasing device 24 and a damping mechanism 26 contains. However, some components of both the basic biasing device 24 as well as the damping device 26 shared.

In particular, the basic bias device 24 from one to an inner ring 41 a damping freewheel device 40 rotatably mounted lever 42 formed by a basic bias spring 43 , which are on the plain bearing body 20 supports, in contact with the rolling body 18 is preloaded. The basic bias spring 43 is designed for example as a helical spring. The lever 42 thus has a contact surface against the rolling body 18 and presses it with the force of the basic bias spring 43 in the direction of the inner ring 16 and nips. The tangential portion of the spring force is for example 5 to 30 times the weight of the rolling body 18 ,

The damping freewheel device 40 also has an outer ring 44 and between the inner ring 41 and the outer ring 44 attached clamp body 45 on. A twisting of the lever 42 and thus the inner ring 41 the damping freewheel device 40 counterclockwise in 4 to 6 corresponds to the freewheeling direction of the damping freewheel device 40 and is thus without common rotation of the inner ring 41 and the outer ring 44 possible; rather, the inner ring 41 relative to the outer ring 44 twisted or pivoted. The outer ring 44 is in contact with a friction device 48 made from a spring 49 and a contact element 50 to the outer ring 44 the damping freewheel device 40 consists. The contact element 50 constantly pushes against the outer ring 44 the damping freewheel device 40 , so that at a rotation of the outer ring 44 the rotational movement of the outer ring 44 and optionally the inner ring rotated together therewith 41 be steamed.

Will the rolling body 18 from the nip between inner ring 16 and outer ring 12 moved, he presses the lever 42 in the clockwise direction in 4 to 6 and thus in the reverse direction of the damping freewheel device 40 , so that next to the lever 42 firmly connected inner ring 41 the outer ring 44 is rotated, which in turn in frictional contact with the friction device 48 is. This will release the lock of the freewheel 10 occurring differential speed between the inner ring 16 and the outer ring 12 through the friction device 48 , in particular the damping of the rotation of the lever 42 , dampened.

Will the braked rolling body 18 again through the basic biasing device 24 against the gap (counterclockwise in 4 to 6 ), a small force is sufficient, since the damping freewheel device 40 free in this direction.

A further embodiment of the freewheel device according to the invention 10 is in 7 to 9 shown. Again, only those components will be described which differ from those of the previous embodiments.

At the in 7 to 9 illustrated embodiment, the sliding bearing body 20 again in one piece with the inner ring 16 designed. The plain bearing body 20 has a recess that serves as an oil chamber 60 serves. In this recess is a piston-like formed extension 62 a roll cage 61 in which one of the rolling bodies 18 is mounted, used, which is movable or displaceable in the recess, that the piston-like extension 62 through its movement the volume of the oil space can increase or decrease (movement to the left in 8th and 9 : Enlargement, movement to the right: reduction). The oil room 60 also has an aperture 64 with the adjacent space for receiving the rolling elements 18 , which is also an oil room 69 makes contact. Parallel to the recess 60 and aperture 64 is in the plain bearing body 20 a recess 65 provided with a stopper 66 is closed and in which a check valve 67 is used. The recess 65 stands over a passage 68 with the oil room 60 in connection. This is between the oil room 60 and the oil room 69 on the one hand over the aperture 64 and on the other hand via the check valve 67 and the passage 68 each made a connection. Is the pressure in the oil room 60 relatively low, so opens the check valve 67 and hydraulic fluid can from the oil room 69 (Space of the adjacent rolling body 18 ) flow through the check valve into the oil chamber. Takes the pressure in the oil room 60 To, so can hydraulic fluid from the oil chamber 60 only over the aperture 64 be dissipated. The check valve 67 is closed.

In the recess, the oil room 60 is also a basic bias spring 70 provided, which is the basic biasing device 24 forms by putting on the roller cage 61 and thus the rolling body 18 press and push (in the counterclockwise direction) into the nip between the inner ring 16 and outer ring 12 suppressed.

In the 9 the state is shown in which the rolling body 18 is released from the clamping position. The rolling body moves 18 in the clockwise direction with the roller cage 61 so that the piston-like extension 62 of the roll cage 61 is moved in the recess and the oil chamber 60 reduced. This will cause the pressure of the hydraulic fluid in the oil space 60 Increased and the hydraulic fluid is through the aperture 64 in the adjacent oil room 69 that the adjacent rolling body 18 surrounds, pressed. The check valve 67 is due to the increased oil pressure in the oil room 60 closed. Thus, a directional damping of the movement of the rolling body 18 reached. Will the piston-like extension 62 with the rolling body 18 Directed gap, so is the check valve 67 open and thus the damping off. In this embodiment, the freewheeling space is completely filled with hydraulic fluid or oil.

By the illustrated embodiments, thus, a direction-dependent damping during movement of the rolling body 18 be generated away from the gap. The damping takes place either with Coulomb friction or through fluid damping, ie by providing a hydraulic device. The damping can be applied to every single rolling element 18 act, so that each individual rolling body can be damped, or act together on a roller cage for the rolling elements, if they are provided in a cage. Parallel to the damping, a basic prestressing for the rolling elements (the roller cage) is provided.

If Sprag clutches (not shown) provided are, the damper can with the for be associated cage.

The basic bias can, as shown in the illustrated embodiments, directly on the rolling body 18 act or indirectly via the damping device, ie, be effective together with the damping mechanism. The tangential damping force is in each case a multiple of the basic bias.

at a direction-switching freewheel device, the damping finally for both turning and driving directions or intended only for forward direction be, because when reversing only small to be damped Forces occur.

10

Freewheel device

12

outer ring

13

palm

14

connecting rod

16

inner ring

17

polygon-like profile

18

roll body

20

plain bearing body

22

attenuator

24

Grundvorspannungseinrichtung

26

damping mechanism

28

Grundvorspannungsfeder

29

recess

30

leaf spring

31

friction surface

32

Idler pulley arrangement

40

Damping freewheeling device

41

inner ring

42

lever

43

Grundvorspannungsfeder

44

outer ring

45

clamping bodies

48

friction device

49

feather

50

contact element

60

oil space

61

roller cage

62

extension

64

cover

65

recess

66

Plug

67

check valve

68

passage

69

oil space

70

Grundvorspannungsfeder

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - EP 1650071 A2 [0002, 0006, 0006]

Claims (12)

Freewheel device ( 10 ) containing an outer ring ( 12 ), an inner ring ( 16 ), several between the outer ring ( 12 ) and the inner ring ( 16 ) arranged rolling bodies ( 18 ), and between adjacent rolling bodies in the circumferential direction arranged damping device ( 22 ), wherein the damping device ( 22 ) a basic bias device ( 24 ) for preloading a rolling body ( 18 ) in a first circumferential direction and a damping mechanism ( 26 ) for damping the movement of the rolling body ( 18 ) in a second circumferential direction. Freewheel device ( 10 ) according to claim 1, characterized in that between each pair of circumferentially adjacent rolling bodies ( 18 ) a damping device ( 22 ) is provided. Freewheel device ( 10 ) according to claim 1 or 2, characterized in that the basic prestressing device ( 24 ) by a spring device ( 28 . 43 . 70 ) is formed. Freewheel device ( 10 ) according to claim 3, characterized in that the damping mechanism ( 26 ) a friction device ( 31 ; 48 ), preferably a spring-loaded friction device ( 31 ; 48 ), having. Freewheel device ( 10 ) according to claim 4, characterized in that the friction device ( 31 ; 48 ) a damping spring ( 30 . 49 ), which via a damping freewheel device ( 32 . 40 ) is stored or interacting with it. Freewheel device ( 10 ) according to claim 4 or 5, characterized in that the friction device ( 31 ) as a tiltable or twistable leaf spring ( 30 ) interacting with the rolling body ( 18 ) is designed. Freewheel device ( 10 ) according to claim 5, characterized in that the friction device ( 48 ) with one on the damping freewheel device ( 40 ) provided pivotable brake lever ( 42 ) interacting with the rolling body ( 18 ) interacts. Freewheel device ( 10 ) according to claim 7, characterized in that an outer ring ( 44 ) of the damping freewheel device ( 40 ) with the friction device ( 48 ) is in frictional contact, wherein the outer ring ( 44 ) of the damping freewheel device ( 40 ) together with the brake lever ( 42 ) twisted when the rolling body ( 18 ) counter to the clamping direction of the freewheel device ( 10 ) is moved. Freewheel device ( 10 ) according to claim 3, characterized in that the damping device ( 22 ) is formed by a hydraulic device. Freewheel device ( 10 ) according to claim 9, characterized in that the hydraulic device is a diaphragm ( 64 ) and a check valve ( 67 ), which are connected in parallel, wherein the rolling body ( 18 ) in a movement opposite to the clamping direction of the freewheel ( 10 ) together with a piston ( 62 ), which has an oil space ( 60 ) and hydraulic fluid through the diaphragm ( 64 ) from the oil room ( 60 ) presses. Freewheel device ( 10 ) according to one of the preceding claims, characterized in that the damping device ( 22 ) at one with the inner ring ( 16 ) firmly connected or integral sliding bearing body ( 20 ) formed on the outer ring ( 12 ) slides. Crank CVT transmission with a freewheel device ( 10 ) according to any one of the preceding claims.