DE102015219464A1 - Tripod joint and longitudinal shaft with such - Google Patents

Abstract

A tripod joint (10), in particular for motor vehicle longitudinal shafts, comprises an inner joint part (11) with a shaft section (12) and rolling elements (13) mounted thereon, and an outer joint part (21) with an engagement section (22) for the rolling elements (13), which forms on its inner periphery running surfaces (23) which are in engagement with the rolling elements (13) of the inner joint part. The outer joint part (21) has a pipe section (24) axially adjoining the engagement section (22), in which at least the shaft section (12) of the inner joint part (11) is axially displaceable in the installed position.

Description

The invention relates to a tripod joint, comprising an inner joint part with radially projecting pins and rolling elements mounted thereon, and an outer joint part with an engaging portion for the rolling elements, which forms on its inner periphery running surfaces, which are in engagement with the rolling elements of the inner joint part.

Such Tripodegelenke come for example in side or longitudinal shafts of motor vehicles used. A propshaft with a tripod joint of the type mentioned is, for example, in DE 10 2008 026 063 A1 described.

The present invention is based on the object of further developing suitable tripod joints for such longitudinal shafts.

For this purpose, a tripod joint with the features of claim 1 is proposed. The tripod joint according to the invention is characterized in particular by the fact that the outer joint part has an axially adjoining the engagement portion pipe section in which the inner joint part is axially displaceable in the installed position.

As a result, a propeller shaft equipped with such a tripod joint can be selectively pushed together axially in order to prevent the transmission of any axial forces. This results in an axial overload protection, with the crash safety can be further increased, for example, on a motor vehicle.

Advantageous embodiments of the invention are the subject of further claims.

Thus, for example, a cover can be arranged between the engagement section and the pipe section, which seals the engagement section relative to the pipe section and can be released when a predetermined minimum force in the axial direction is exceeded by the inner joint part. As a result, the tripod joint is protected against the ingress of dirt and moisture and against the loss of lubricant.

The lid can for example be very easily pressed, glued or welded to a weld of the pipe section.

In a further embodiment variant, the cover may be formed as a bottom of the engagement portion, which is configured to break out when exceeding a predetermined minimum force in the axial direction through the inner joint part. For this purpose, if appropriate, the soil for breaking out additionally weakened, for example by machining and / or forging. This makes it possible to produce the engagement portion with the lid, for example, as a forged part to which the pipe section is attached.

Furthermore, the running surfaces of the engagement portion may be configured such that the axial displacement force of the tripod joint increases toward the tube portion-side cover-side end thereof, in order to effect an energy dissipation of the introduced axial force. Preferably, this increase in the required displacement force is limited to a region which lies outside the intended operating range of the tripod joint, so that the desired energy consumption only occurs when telescoping the joint beyond this intended operating range. If necessary, a further increase in the axial displacement force can be effected by the lid. As a result, deceleration peaks are reduced.

According to a further advantageous embodiment, the inner joint part for initiating or discharging a torque on a shaft. This shaft is preferably configured such that it can be displaced axially at least in sections, together with the inner joint part, into the pipe section. As a result, a particularly large insertion path is achieved via which a transfer of axial forces is practically prevented.

Furthermore, on the shaft, a rolling bearing for supporting the same may be arranged on a tripod joint supporting structure, wherein the outer diameter of the rolling bearing is dimensioned such that this roller bearing is axially displaceable in the engagement portion of the outer joint part to increase the aforementioned insertion path.

According to a further advantageous embodiment of the invention, the engagement portion to the pipe section on a down to the area of the treads extending constriction to form an abutment for the rolling elements in an axial displacement of the shaft portion in the pipe section. As a result, the rolling elements are retained in the engagement portion in an example crash-related displacement of the inner joint part relative to the outer joint part, whereby additional impact energy can be absorbed.

In addition, in this case, the rolling elements bearing pins can be selectively sheared to absorb more impact energy.

An optionally existing cover can be provided in the region of the constriction relief opening through which the Shaft section is guided, close for normal operation.

Furthermore, the pipe section may have a clear width which is greater than the maximum diameter of a circle enclosing the inner joint part about its axis of rotation to ensure a reliable displacement of the inner joint part in the pipe section without colliding with it or at least with only a slight resistance. If the engagement section has the constriction, the inside width of the pipe section can also be reduced to the maximum outside diameter of the shaft section of the inner joint part.

As already mentioned, the above-described tripod joint is particularly suitable for arrangement on a longitudinal shaft of a motor vehicle for the purpose of improving crash safety.

Accordingly, it is advantageous if the engagement portion of the outer joint part is arranged in the forward direction of travel of the motor vehicle in front of the pipe section, whereby the longitudinal shaft can be rotatably supported on the vehicle body on a component rotatably connected to the inner joint part.

Furthermore, as already mentioned above, the inner joint part have a shaft which extends from this in the forward direction and against the forward direction of travel is inserted axially into the pipe section of the outer joint part.

If the bearing of the longitudinal shaft on the vehicle body on the outer joint part, a reverse installation is possible.

The invention will be explained in more detail with reference to embodiments shown in the drawing. The drawing shows in:

1 a cross-sectional view of a first embodiment of a tripod joint,

2 a longitudinal sectional view of an embodiment of a longitudinal shaft with a tripod joint according to the first embodiment in the installed state,

3 a longitudinal sectional view of the longitudinal shaft 1 in a collapsed state after the overload protection function of the tripod joint according to the first embodiment has responded,

4 a longitudinal sectional view of another embodiment of a longitudinal shaft with a tripod joint according to another embodiment in the installed state, and in

5 a longitudinal sectional view of the longitudinal shaft 4 in a collapsed state after the overload protection function has responded.

1 shows a first embodiment of a tripod joint 10 , This includes an inner joint part 11 in the form of a tripod star with a wave gating 12 as well as from the shaft section 12 projecting pins 12a , The cones 12a are equidistant in the circumferential direction. Their longitudinal axes Z extend substantially radially to the axis of rotation A of the inner joint part 11 and lie in the illustrated embodiment in a common plane.

Furthermore, the tripod joint comprises 10 at the inner joint part 11 three rolling elements 13 , each with an inner peripheral surface 14 on one of the cones 12a are stored and at its outer periphery profiled treads 15 form. The number of rolling elements 13 can also be smaller or larger than shown. Every rolling element 13 can have an outer ring 16 and an inner ring 17 have, over rolling elements 18 are rotatable relative to each other. The inner peripheral surface 14 of the inner ring 17 may be formed substantially cylindrical and with a spherical outer peripheral surface 19 of the pin 12a engaged, so that at a diffraction of the tripod joint 10 the inner ring 17 relative to the longitudinal axis Z of the associated pin 12a can be tilted. In addition, an axial displaceability in the direction of the longitudinal axis Z of the pin 12a given. The construction of the illustrated tripod joint is merely exemplary in nature. The functions of turning about the pins, the tilting and a radial displacement can also be realized in other ways. In the 1 embodiment shown represents only one possibility for this, for the purpose of illustrating the function of such a tripod joint 10 is specified.

The tripod joint 10 further comprises an outer joint part 21 with an engaging portion 22 for the rolling elements 13 , The engaging section 22 is sleeve-shaped and may have a constant cross-sectional profile over its axial length. In particular, the engagement section 22 on its inner circumference parallel to the axis of rotation B of the outer joint part 21 running track pairs with each other in the circumferential direction opposite treads 23 on. These treads 23 stand with the treads 15 the rolling elements 13 engaged, depending on the direction of rotation and operating conditions, one of the treads 23 load carrying and the opposite tread 23 is essentially relieved. The treads 23 at the outer joint part 21 run each parallel to the axis of rotation B of the outer joint part 21 , By profiling both the treads 23 at the outer joint part 21 as well as the treads 15 on the rolling elements 13 will cause a rotation of the joint 10 under diffraction of the component axes A and B to each other, the rolling elements 13 axially parallel to the axis of rotation B of the outer joint part 21 be moved back and forth. The required pivoting degree of freedom, for example, between the pin 12 and the bearing inner rings 17 the rolling elements 13 to be provided.

To the engagement section 22 axially closes a pipe section 24 in which the inner joint part 11 in the in 2 shown installation position virtually collision-free, ie in particular without significant collision resistance through the outer joint part 21 is axially displaceable. The axially displaced state is in 3 shown. Here are both the shaft section 12 attached to this pin 12a and the rolling elements 13 inside the pipe element 24 added.

The pipe section 24 can be carried out in the manner of a hollow shaft, via which a torque from or to the engagement portion is transferable. Its clear width is greater than the maximum diameter of the inner joint part 11 enclosing circle. Be the rolling elements 13 in the pipe section 24 shifted, these are free and can no longer transmit torque. The cross-sectional profile of the pipe section 24 can be adapted to the respective installation situation, as long as its interior is suitable, the inner joint part 11 at an axial displacement of the in 2 shown installation position without noticeable axial resistance, so that the axial forces are very low when pushed axially together or virtually zero.

In the illustrated embodiment is between the engagement portion 22 and the pipe section 24 a lid 25 intended. The lid 25 seals the engagement section 22 opposite the pipe section 24 from. The lid 25 is configured such that it exceeds a predetermined minimum force in the axial direction through the inner joint part 11 is solvable, so this is the in 3 can reach shown location. The lid 25 is preferably in the engaging portion 22 arranged, but can also be in the pipe section 24 to be placed.

The lid 25 For example, it can be pressed or glued. It is also possible to use the lid 25 with a weld of the pipe section 24 to weld.

In a modification of the illustrated embodiment, the lid 25 especially as the bottom of the engaging portion 22 be educated. So can the engagement section 22 and the lid 25 be made for example as a one-piece forging, where the pipe section 24 is attached. In order to ensure a desired breaking out of the cover when a predetermined minimum force in the axial direction is exceeded, the bottom of the engagement section can have weakened sections which are formed, for example, by a machining operation and / or a forging machining. After overcoming the lid 25 can also here the inner joint part 11 without appreciable axial resistance in the pipe section 24 be inserted.

Furthermore, it is possible the treads 23 of the engaging portion 22 of the outer joint part 21 in such a way that the axial displacement force of the tripod joint increases towards its cover-side end, in order to ensure energy absorption of the introduced axial force even before reaching the cover 25 to effect and thereby reduce decelerating peaks when telecopying the tripod joint. Through the lid 25 a further increase of the axial displacement force can be effected.

In the opposite direction is the tripod joint 10 through an elastic bellows 30 sealed against the ingress of dirt and moisture. The bellows 30 is at a peripheral portion of the outer joint part 21 attached and seals against a shaft 40 from. This wave 40 serves to initiate or dissipate a drive torque in the inner joint part 11 and is accordingly attached to the same or possibly also formed integrally with the tripod esters. Also the wave 40 is at least partially up to the pipe section 24 relocatable, as in 3 can be seen. It usually has a larger outer diameter than the shaft portion 12 on.

At the wave 40 can be a rolling bearing 50 for supporting the shaft 40 at one the tripod joint 10 carrying structure 60 be arranged. The support on the supporting structure 60 can do this via an elastic recording 51 be made. Here, the outer diameter of the bearing 50 be sized so that this optionally axially with minimal resistance in the engaging portion 22 of the outer joint part 21 or even in the pipe section 24 can be relocated. The clear width of the engagement section 22 is larger than the outer diameter of the rolling bearing 50 ,

The rolling bearing 50 can on the shaft 40 an axial shoulder 41 be upstream, which an axial pressing out of the rolling bearing 50 from its inclusion 51 can support. This shoulder 41 can turn axially a hollow shaft section 42 be upstream, which also by the admission 51 through in the outer joint part 21 is axially inserted.

The support via the rolling bearing 50 is merely exemplary in nature. A support of the shaft 40 at one the tripod joint 10 carrying structure 60 can also be made in other ways than shown in the figures. The same applies analogously to the axial displacement of the rolling bearing 50 in the engaging section 22 or pipe section 24 ,

The tripod joint explained above 10 can be in a propshaft 70 a motor vehicle to be installed, which extends for example between a vehicle transmission and a differential in the vehicle longitudinal direction and transmits a drive torque of the vehicle engine. The torque transmission takes place between the shaft 40 and the pipe section 24 , which may be part of another shaft not shown or connected to such.

In the illustrated embodiment, the shaft extends 40 from the inner joint part 11 in the forward direction and is contrary to the forward direction of travel V to the pipe section 24 of the outer joint part 21 axially without substantial resistance by components of the outer joint part 21 and the pipe section 24 displaceable so that a large axial insertion path can be achieved. Even with a certain tilting between the axes of rotation A and B, axial telescoping without a large axial force resistance is possible. The engaging section 22 of the outer joint part 21 is in the forward direction of travel of the motor vehicle in front of the pipe section 24 arranged.

However, it is also possible a reverse installation. In this case, then could the longitudinal shaft 70 over the outer joint part 22 or the pipe section 24 be stored on the vehicle body, but this would lead to a larger bearing diameter because of Teleskopierfunktion.

In the 4 and 5 a further embodiment is shown, which is formed substantially in accordance with the above-described embodiment and can also be modified as explained above. In the following, therefore, only the differences will be discussed in more detail. The same components are correspondingly provided with the same reference numerals.

The tripod joint 10 according to the 4 and 5 in particular has a modified outer joint part 21 ' on which between the engaging portion 22 and the pipe section 24 ' a constriction 26 ' formed. The constriction 26 ' extends into the area of the treads 23 of the engaging portion 22 radially inwardly, at least at an axial displacement of the shaft portion 12 of the inner joint part 21 in the pipe section 24 ' a stop for the rolling elements 13 to build. As a result, for example, in a crash-induced displacement of the inner joint part 21 in the direction of the outer joint part 24 ' the rolling elements 13 in the engaging portion 22 retained, which in addition impact energy can be absorbed.

Further impact energy can be achieved by rejuvenating the treads 23 to the pipe section 24 ' be absorbed. In addition, with a corresponding displacement of the shaft section 12 of the inner joint part 11 in the pipe section 24 ' , as in 5 shown the rolling elements 13 stored cones 12a be sheared off to absorb more impact energy.

In the area of constriction 26 ' there remains a discharge opening 27 ' , which is dimensioned such that the shaft portion 12 collision-free can be passed through them. The clear width of the discharge opening 27 ' has an inner diameter which is larger than the maximum outer diameter of that portion of the shaft portion 12 of the inner joint part 11 is, which should be selectively displaced axially without collision.

In the illustrated embodiment, the constriction 26 ' integral with the treads 23 formed component having, for example, can be designed as a forging. The constriction 26 ' is exemplary here as to the engagement section 22 molded hollow section 28 ' formed, to which the pipe section 24 ' followed. Preferably, the pipe section 24 ' a separate component which on the hollow portion 28 ' is attached. This can be the end section 29 ' of the pipe section 24 ' also be designed with a diameter taper.

However, it is also possible for example, the constriction 26 ' with a stop for the rolling elements 13 together with the pipe section 24 ' to integrate into a component that is axially on an approximately 2 modeled engagement section 22 fastened without constriction.

As in the embodiment according to the 2 and 3 may present a lid 25 be provided to seal the tripod joint and to prevent the ingress of water and dirt. The lid 25 is arranged such that this in a deliberate pushing together of the inner joint part 11 and outer joint part 21 as already explained above can be overcome. Such a lid 25 For example, in the discharge opening 27 ' be arranged. However, an arrangement also elsewhere, for example in pipe section 24 ' possible to ensure the sealing function.

As in the embodiment according to the 4 and 5 only the shaft section 12 of the inner joint part 11 in the pipe section 24 ' can be relocated in a modification of 4 and 5 the clear width of the pipe section 24 ' optionally also to the maximum outer diameter of the shaft section 12 of the inner joint part 11 be reduced.

The invention has been explained in more detail above with reference to exemplary embodiments and further modifications. In particular, individual technical features, which have been explained above in the context of further individual features, can be implemented independently of these and in combination with further individual features, even if this is not expressly described, as long as this is technically possible. The invention is therefore expressly not limited to the described embodiments and modifications, but includes all embodiments defined by the claims.

LIST OF REFERENCE NUMBERS

10

tripod

11

Inner race

12

shaft section

12a

spigot

13

rolling element

14

Inner circumferential surface

15

Tread on the outer circumference of the rolling element

16

Outer ring of the rolling element

17

Inner ring of the rolling element

18

Rolling elements of the rolling element

19

Outer circumferential surface

21, 21 '

Outer race

22

engaging portion

23

Tread of the outer joint part

24, 24 '

pipe section

25

cover

26 '

constriction

27 '

relief opening

28 '

hollow section

29 '

end

30

bellows

40

wave

41

shoulder

42

hollow shaft

50

roller bearing

51

admission

60

carrying structure

70

longitudinal wave

A

 Rotary axis of the inner joint part Z longitudinal axis of the pin

B

 Rotary axis of the outer joint part

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102008026063 A1 [0002]

Claims (10)

Tripod joint ( 10 ), comprising an inner joint part ( 11 ) with a shaft section ( 12 ) and on this mounted rolling elements ( 13 ), and an outer joint part ( 21 ) with an engaging portion ( 22 ) for the rolling elements ( 13 ), which on its inner circumference running surfaces ( 23 ) formed with the rolling elements ( 13 ) of the inner joint part, characterized in that the outer joint part ( 21 ) one to the engaging portion ( 22 ) axially adjoining pipe section ( 24 ; 24 ' ), in which at least the shaft portion ( 12 ) of the inner joint part ( 11 ) is axially displaceable in the installed position. Tripod joint according to claim 1, characterized in that between the engaging portion ( 22 ) and the pipe section ( 24 ; 24 ' ) a lid ( 25 ) is arranged, which the engaging portion ( 22 ) relative to the pipe section ( 24 ; 24 ' ) seals and when exceeding a predetermined minimum force in the axial direction through the inner joint part ( 11 ) is solvable. Tripod joint according to claim 2, characterized in that the cover ( 25 ), glued or glued with a weld of the pipe section ( 24 ; 24 ' ) is welded. Tripod joint according to claim 1, characterized in that between the engaging portion ( 22 ) and the pipe section ( 24 ; 24 ' ) a lid ( 25 ) is provided, the engagement section ( 22 ) relative to the pipe section ( 24 ; 24 ' ), whereby the lid ( 25 ) as the bottom of the engaging portion ( 22 ), which is configured in such a way, when a predetermined minimum force in the axial direction is exceeded by the inner joint part ( 11 ) Break out. Tripod joint according to one of claims 1 to 4, characterized in that the running surfaces ( 23 ) of the engaging section ( 22 ) are configured such that the axial displacement force of the tripod joint increases toward the end of the tube section, in order to cause an energy consumption of an introduced axial force. Tripod joint according to one of claims 1 to 5, characterized in that the inner joint part ( 11 ) for initiating or deriving a torque a shaft ( 40 ), which is axially together with the inner joint part ( 11 ) at least in sections down to the pipe section ( 24 ) is displaceable. Tripod joint according to claim 6, characterized in that on the shaft ( 40 ) a rolling bearing ( 50 ) for supporting the shaft ( 40 ) on a structure carrying the tripod joint ( 60 ), wherein the outer diameter of the rolling bearing ( 50 ) is dimensioned such that this axially in the engaging portion ( 22 ) of the outer joint part ( 21 ) is displaceable. Tripod joint according to one of claims 1 to 7, characterized in that the engaging portion ( 21 ) to the pipe section ( 24 ' ) down to the area of the treads ( 23 ) extending constriction ( 27 ' ) in order, during an axial displacement of the shaft section ( 12 ) in the pipe section ( 24 ) a stop for the rolling elements ( 13 ) to build. Longitudinal shaft ( 70 ) for a motor vehicle with a tripod joint ( 10 ) according to one of the preceding claims. Longitudinal shaft ( 70 ) according to claim 9, characterized in that the engaging portion ( 22 ) of the outer joint part ( 21 ) in the forward direction of travel of the motor vehicle in front of the pipe section ( 24 ; 24 ' ) is arranged, and / or the inner joint part ( 11 ) a wave ( 40 ) which extends from the latter in the forward direction of travel and against the forward direction of travel into the pipe section ( 24 ) is axially inserted.

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