TRIPOD ROLLER AND TRIPOD JOINT ASSEMBLY
20230417290 ยท 2023-12-28
Inventors
Cpc classification
F16D2003/2026
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
Abstract
A tripod roller for a tripod joint assembly including an outer ring with an annular running surface on its outer circumference for rolling in a tripod housing as well as an inner peripheral surface. An inner ring includes an annular running surface on its inner circumference for mounting on a pin of a tripod star and an outer circumferential surface and opposite end faces. Rolling elements may be arranged in an annular space between the inner circumferential surface of the outer ring and the outer peripheral surface of the inner ring, and via which the outer ring is rotatably mounted. Axial locking rings may be fixed to the outer ring and secure the outer ring axially relative to the inner ring. The inner ring includes recesses opening into the annular space for receiving lubricant on end faces and/or the axial locking rings via the rolling elements.
Claims
1. A tripod roller for a tripod joint, comprising: an outer ring comprising an outer ring circumference annular running surface, for rolling in a tripod housing, and an inner circumferential surface; an inner ring comprising an inner ring circumference annular running surface for mounting on a pin of a tripod star and with an outer circumferential surface and end faces; rolling elements configured in an annular space between the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring, wherein the outer ring is rotatably mounted on the outer circumferential surface of the inner ring; axial locking rings, configured to be fixed to the outer ring to secure the outer ring axially relative to the inner ring, wherein the inner ring comprises recesses on at least one of the end faces for receiving lubricant, and wherein the recesses on the outer peripheral surface of the inner ring are configured to open into the annular space of the rolling elements to supply the rolling elements with lubricant.
2. The tripod roller of claim 1, wherein a bearing length of the rolling elements in an axial direction is smaller than a length of the inner ring on its outer peripheral surface, and wherein a depression of the recesses in at least one of the end faces at their respective opening into the annular space is smaller than the difference between the length of the inner ring and the bearing length.
3. The tripod roller of claim 1, wherein the end faces of the inner ring comprise recesses, a bearing length of the rolling elements is smaller in an axial direction than the length of the outer circumferential surface in the axial direction, and wherein a depression of the recesses on the end faces at their respective opening into the annular space is in each case smaller than half the difference between a length of the inner ring and the bearing length.
4. The tripod roller of claim 1, wherein the end faces of the inner ring comprise recesses opening into the inner ring circumference annular running surface.
5. The tripod roller of claim 4, wherein the recesses are configured as grooves with a constant cross-section in the longitudinal direction of each respective groove.
6. The tripod roller of claim 4, wherein the recesses are configured to be deeper in an end face of the inner ring at their opening into the annular space than at their opening into the inner ring circumference annular running surface.
7. The tripod roller of claim 4, wherein the recesses are configured as grooves, and wherein the grooves are configured to be deeper in an end face of the inner ring circumference annular running surface than at their opening into the annular space.
8. The tripod roller of claim 4, wherein the recesses are configured as grooves, and wherein a width of the grooves decreases from the opening into the inner ring circumference annular running surface to an opening into the annular space.
9. The tripod roller of claim 4, wherein the recesses on an end face of the inner ring are configured as pockets extending into the annular space.
10. The tripod roller of claim 4, wherein the recesses are configured as grooves connecting the annular space to the inner ring circumference annular running surface, wherein the grooves are curved in an arc to a radial direction of the inner ring.
11. The tripod roller of claim 10, wherein the curvature of the grooves on the opposing end faces is opposite to one another.
12. The tripod roller of claim 1, wherein the axial locking rings comprise recesses for receiving lubricant, wherein the recesses on the axial locking ring are formed on one of the inner rings facing an inner side.
13. The tripod roller of claim 12, wherein the recesses on the axial locking ring comprise radial grooves extending radially from an inner edge of the axial locking ring at least up to the level of the annular space.
14. The tripod roller of claim 12, wherein the recesses on the axial locking ring comprise axial grooves opening into the annular space and are formed obliquely or axially on an inner edge of the axial locking ring.
15. A method for forming a tripod roller for a tripod joint, comprising: providing an outer ring comprising an outer ring circumference annular running surface, for rolling in a tripod housing, and an inner circumferential surface; an inner ring comprising an inner ring circumference annular running surface for mounting on a pin of a tripod star and with an outer circumferential surface and end faces, wherein the end faces comprise recesses opening into the inner ring circumference annular running surface; rolling elements configured in an annular space between the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring, wherein the outer ring is rotatably mounted on the outer circumferential surface of the inner ring; axial locking rings, configured to be fixed to the outer ring to secure the outer ring axially relative to the inner ring, wherein the inner ring comprises recesses on at least one of the end faces for receiving lubricant, and wherein the recesses on the outer peripheral surface of the inner ring are configured to open into the annular space of the rolling elements to supply the rolling elements with lubricant.
16. The tripod roller of claim 4, wherein the recesses are configured as grooves with a constant cross-section in the longitudinal direction of each respective groove.
17. The tripod roller of claim 4, wherein the recesses are configured to be deeper in an end face of the inner ring at their opening into the annular space than at their opening into the inner ring circumference annular running surface.
18. The tripod roller of claim 4, wherein the recesses are configured as grooves, and wherein the grooves are configured to be deeper in an end face of the inner ring circumference annular running surface than at their opening into the annular space.
19. The tripod roller of claim 4, wherein the recesses are configured as grooves, and wherein a width of the grooves decreases from the opening into the inner ring circumference annular running surface to an opening into the annular space.
20. A tripod joint assembly, comprising: a tripod star comprising radially projecting pins; a tripod roller, mounted on each pin, the tripod roller comprising: an outer ring comprising an outer ring circumference annular running surface, for rolling in a tripod housing, and an inner circumferential surface, an inner ring comprising an inner ring circumference annular running surface for mounting on a pin of a tripod star and with an outer circumferential surface and end faces, rolling elements configured in an annular space between the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring, wherein the outer ring is rotatably mounted on the outer circumferential surface of the inner ring; axial locking rings, configured to be fixed to the outer ring to secure the outer ring axially relative to the inner ring, wherein the inner ring comprises recesses on at least one of the end faces for receiving lubricant, and wherein the recesses on the outer peripheral surface of the inner ring are configured to open into the annular space of the rolling elements to supply the rolling elements with lubricant, and a tripod housing comprising a pair of tracks for each tripod roller for guiding the annular running surface of the outer ring of a respective tripod roller.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The present disclosure is explained in more detail below using an embodiment illustrated in the drawing and further modifications. The drawing shows in:
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[0023]
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[0032]
DETAILED DESCRIPTION
[0033] For a better understanding of the principles of the present disclosure, embodiments of the present disclosure will be explained in more detail below with reference to the figures. It is to be understood that the present disclosure is not limited to these embodiments and that the features described may be combined or modified without departing from the scope of the present disclosure as defined in the appended claims.
[0034] In some examples disclosed herein, the bearing length of the rolling elements in the axial direction is smaller than the length of the inner ring on its outer peripheral surface in the axial direction. In addition, the depth of the recesses on the end face at their respective opening into the annular space can be smaller than the difference between the length of the inner ring and the bearing length. As a result, the strength and acoustic properties of the tripod roller remain largely unaffected by the recesses.
[0035] If the axially opposite end faces of the inner ring are each provided with recesses, it may be advantageous to select the depth of the recesses on the end face at their respective opening into the annular space such that it is less than half the difference between the length of the inner ring and the bearing length.
[0036] In some examples, the recesses on the end face of the inner ring open into the inner peripheral surface of the inner ring, as a result of which a channel for transporting the lubricant is provided over the entire end face. The recesses on the end face of the inner ring may be configured as grooves with a constant cross-section in the longitudinal direction of the respective groove.
[0037] In some examples, the recesses on the end face of the inner ring may be deeper on the end face at their opening into the annular space than at their opening into the inner peripheral surface of the inner ring. Also, the recesses on the end face of the inner ring can be configured as grooves which are deeper at their opening into the inner peripheral surface of the inner ring than at their opening into the annular space. Furthermore, the width of the grooves may decrease from the opening into the inner peripheral surface of the inner ring to the opening into the annular space.
[0038] In some examples, the recesses on the end face of the inner ring may be configured as pockets that only open into the annular space, which means that they have no opening into the inner peripheral surface of the inner ring. The pockets preferably extend radially inwardly from the outer peripheral surface of the inner ring to only half or up to two-thirds of the inner ring thickness.
[0039] In some examples, the recesses can be designed as grooves connecting the annular space with the inner peripheral surface of the inner ring, which are curved in an arc shape in relation to a radial direction of the inner ring. Such an approximately paddle-wheel-shaped configuration leads to a rotary movement of the rollers and results in an active conveying effect of the lubricant and thus a good supply of the lubricant to the rolling elements. When a motor vehicle is being driven, the tripod rollers perform a continuous oscillating rolling motion. A relative rotating movement takes place between the outer ring and the inner ring, which results in the conveying effect. Furthermore, the curvatures of the grooves on the opposing end faces may be opposite each other. Depending on the direction of rotation, such an inverse design means that lubricant is supplied on one side and used lubricant is discharged or pumped out of the rolling element contact on the other side.
[0040] In some examples, recesses for accommodating lubricant are formed on the axial locking ring on an inner side facing towards the inner ring, in order to convey lubricant more effectively to the rolling elements. The recesses on the axial locking ring can, for example, include radial grooves that extend radially from an inner edge of the axial locking ring at least up to the level of the annular space. For example, these radial grooves can extend continuously over the entire end face of the axial lock or as a pocket only up to the middle or the last third of the ring height.
[0041] Furthermore, the recesses may include axial grooves on the axial locking ring, which open into the annular space and are formed obliquely or axially running on the inner edge of the axial locking ring. The radial grooves and the axial grooves may be provided together on an axial locking ring and can preferably, but not necessarily, be connected to one another.
[0042] The tripod roller may be configured for a tripod joint assembly that includes a tripod star with radially projecting pins, with a tripod roller of the type explained above being mounted on each pin, and a tripod housing with a pair of tracks for each tripod roller to guide the annular running surface of the outer ring of the respective tripod roller.
[0043] Such a tripod joint is characterized by a compact design and a long service life. It is particularly suitable for the high torques and alternating loads that occur in electric vehicle drives.
[0044]
[0045] The tripod joint assembly 1 may include an inner joint part in the form of a tripod star 10 with an axis of rotation A and an outer joint part in the form of a tripod housing 20 with an axis of rotation B. Pairs of tracks 21 are formed on the inside of the outer joint part, in which the inner joint part is guided axially, i.e., in the direction of the axis of rotation B. When the tripod joint assembly 1 is extended, the axes of rotation A and B are aligned with one another. If the tripod joint assembly 1 is bent during operation, however, the axes of rotation form a bending angle that is not equal to 0, as is shown in
[0046] The tripod star 10 may be configured with a central shaft portion 11 and a plurality of, preferably three, pins 12 protruding from the shaft portion 11. The central shaft portion 11 can be designed as a ring body that can be coupled to a shaft.
[0047] The pins 12 may be configured in the circumferential direction at the same distance from one another about the axis of rotation A of the inner joint part or tripod star 10. Their longitudinal axes Z run substantially radially to the axis of rotation A and preferably lie in a common plane, as shown in the embodiment illustrated in
[0048] Furthermore, the tripod joint assembly 1 may include a tripod roller 30 on the tripod star 10 for each pin 12 that is rotatably mounted on the associated pin 12 of the tripod star 10 about the longitudinal axis Z of the pin 12.
[0049] In some examples, the pins 12 each have a profiled surface 13 for mounting the tripod rollers 30, which is explained in more detail below.
[0050] Each tripod roller 30 may include an outer ring 31 and an inner ring 32 as well as rolling elements 33 arranged between them, so that the outer ring 31 and the inner ring 32 can be rotated in relation to one another.
[0051] The outer ring 31 and the inner ring 32 are preferably designed as rotationally symmetrical components.
[0052] For example, the outer ring 31 has an annular running surface 31a on its outer circumference for rolling on a pair of tracks 21 of the tripod housing 20, and also an inner peripheral surface 31b.
[0053] On its inner circumference, the inner ring 32 has an annular running surface 32a to be placed on the pin 12 of the tripod star 10, as well as an outer circumferential surface 32b and opposite end faces 32c and 32d.
[0054] The rolling elements 33, which are preferably designed as needles or rollers, are arranged in an annular space 34 between the inner peripheral surface 31b of the outer ring 31 and the outer peripheral surface 32b of the inner ring 32. The annular space 34 extends around the pin 12. The inner peripheral surface 31b of the outer ring 31 is rotatably mounted on the outer peripheral surface 32b of the inner ring 32 via the rolling elements 33. Preferably, the rolling elements 33 each have a line contact with the inner peripheral surface 31b of the outer ring 31 and with the outer peripheral surface 32b of the inner ring 32.
[0055] Furthermore, axial locking rings 40 are provided, which are fixed to the outer ring 31 and which axially secure the outer ring 31 relative to the inner ring 32. The axial locking rings 40 are radially slotted for assembly and have, for example, a rectangular cross section. They are fitted into corresponding grooves on the inner peripheral surface 31b of the outer ring 31.
[0056] In some examples, annular space 34 is closed by the inner sides 40a of the axial locking rings 40 arranged axially on both sides of the annular space 34. The axial locking rings 40 also ensure that the rolling elements 33 cannot migrate sideways out of the annular space 34.
[0057] As shown in the examples of
[0058] As a result, the contact length 1.sub.W of the rolling elements 33 is smaller in the axial direction than the length 1.sub.IR of the inner ring 32 on its outer peripheral surface 32b in the axial direction.
[0059] Each tripod roller 30 can roll with the annular running surface 31a of its outer ring 31 along a pair of tracks 21 of the outer joint part or tripod housing 20. For this purpose, the profile of the ring-shaped running surface 31a can be convexly curved outwards in the cross-section. The tracks of the pair of tracks 21 can correspondingly have a concave cross-sectional profile, as can be seen in
[0060] Due to the convex configuration of the surface 13 of the pin 12 with which the inner peripheral surface 32a of the inner ring 32 is in contact, the inner ring 32 can be tilted relative to the longitudinal axis Z of the associated pin 12 when the tripod joint assembly 1 is tilted. In addition, there is an axial displaceability in the direction of the longitudinal axis Z of the pin 12.
[0061] The functions of the rotation about the pins 12, the tilting as well as the axial displacement can also be realized in other ways. The embodiment of a rotatable bearing in a plurality of directions shown in
[0062] The outer joint part or tripod housing 20 has its own engagement portion for each tripod roller 30. The engagement portion is designed, for example, like a sleeve and can have a constant cross-sectional profile over its axial length.
[0063] In the embodiment illustrated in
[0064] The profiling of both the tracks 21 on the tripod housing 20 and the annular running surfaces 31a of the outer rings 31 of the tripod rollers 30 have the effect that, when the joint 1 rotates and the component axes A and B bend towards one another, the tripod rollers 30 are moved back and forth parallel to the axis of rotation B of the tripod housing 20. As has already been explained above, the degree of pivoting freedom required for this can be provided, for example, between the pins 12 and the inner rings 32 of the tripod rollers 30.
[0065] To improve the service life of the tripod rollers 30, as shown in
[0066] In further variants, as shown by way of example in
[0067] Both measures, namely recesses 35 on the inner ring side and recesses 41 on the axial locking ring side, can be combined with one another. In the present case, the recesses 35 and 41 are preferably depressions in the respective surfaces 32c, 32d and 40a and 43.
[0068] Particularly suitable embodiment variants in this respect will be explained in more detail below, without the present disclosure being restricted to these specific variants. In particular, combinations of the following design variants can also be implemented, so that recesses 35 or 41 of different design variants are provided on an inner ring 32 and/or an axial locking ring 40.
[0069]
[0070] As can be seen in particular from
[0071] As a modification of this, the depression t of the recesses 35 in the end face 32c, 32d at their respective opening into the annular space 34 can also be selected, particularly if only one end face 32c, 32d is to be provided with recesses 35, but also in general, such that it is smaller than the difference between the length 1.sub.IR of the inner ring 32 and the bearing length 1.sub.W.
[0072] It is also possible to make the depressions t of the recesses 35 even deeper than mentioned above and to thereby accept a locally reduced contact length between the inner ring 32 and the rolling elements 33. The effective bearing length 1.sub.W of the rolling elements 33 is restricted by the deeper depression. This is acceptable as long as, in terms of the service life, the advantage of an improved supply of lubricant outweighs the disadvantage of the reduced bearing length.
[0073]
[0074] The recesses 35 can, for example, be deeper at their opening into the inner peripheral surface 32a of the inner ring 32 than at their opening into the annular space 34. As can be seen in particular in
[0075] In a modification of this, the recesses 35 on the end face 32c, 32d of the inner ring 32 can be deeper on the end face 32c, 32d at their opening into the annular space 34 than at their opening into the inner peripheral surface 32a of the inner ring 32. In this case, t.sub.1 is greater than t.sub.2.
[0076] In addition, as can be seen in particular from
[0077] These two measuresdifferent depths on the one hand and different width on the othercan be implemented in combination, but also independently of one another.
[0078] Another design feature for the recesses 35 is shown in
[0079]
[0080] As can be seen in
[0081] In the viewing direction perpendicular to the end face 32c, the recesses 35 are designed in the shape of a paddle wheel. When the tripod rollers 30 rotate, this causes an active conveying effect for the lubricant. Since the tripod rollers 30 perform a continuous oscillating rolling movement when the vehicle is being driven, there is a constant relative rotating movement between the outer ring 31 and the inner ring 32, which facilitates the conveying effect for the lubricant so that lubricant can be introduced into the annular space 34 from the outside.
[0082] If the paddle-wheel-shaped recesses 35 are designed in opposite directions on an inner ring 32 on the two opposite axial end faces 32c and 32d, one side supplies lubricant and the other side removes lubricant, depending on the direction of rotation. This allows for a very good supply of lubricant to the rolling elements 32 and their contact points with the outer ring 31 and the inner ring 32.
[0083] As already mentioned, the configuration of the grooves 36, which are shown in
[0084] It is also possible, as a modification of the illustration in
[0085]
[0086] In the fifth embodiment variant, these recesses 41 are formed on a side 40a of the axial locking ring 40 pointing toward the inner ring 32 in order to effectively convey lubricant to the rolling elements 33.
[0087] In the present case, these recesses 41 on the axial locking ring 40 comprise radial grooves 42 which extend radially from an inner edge 43 of the axial locking ring 40 at least up to the level of the annular space 34.
[0088] In
[0089] However, it is also possible, as shown in a sixth embodiment variant in
[0090] Furthermore, the recesses 41 on the axial locking ring 40 can comprise axial grooves 44, as shown in a seventh embodiment variant in
[0091] The radial grooves 42 and the axial grooves 44 can be provided together on an axial locking ring 40. In this case, these can optionally be connected to one another. However, it is also possible to arrange them unconnectedly next to one another.
[0092] It has been shown that the above-described modifications to the tripod roller 30 can improve the service life of a tripod joint assembly 1 in a surprisingly significant way without increasing the weight of the component or the external dimensions. This way, compact tripod joints 1 with high loads can be realized.
[0093] Due to the improved service life properties, the tripod joints explained above are particularly suitable for motor vehicles with an electric drive and comparable drive conditions with high torques and strong alternating loads. The strength and acoustic properties of the tripod rollers 30 remain unaffected.
[0094] The modification according to the present disclosure can also be realized without undue additional technical effort.
[0095] The formation of recesses 35 on the inner ring 32, for example, can be integrated into a forging process. In this case, the additional manufacturing effort remains minimal, since only the forging tool has to be adapted.
[0096] The formation of additional recesses 41 on the axial locking ring 40 can be realized very easily with an additional step in the stamping process for the axial locking ring 40.
[0097] The present disclosure was explained in more detail above using an exemplary embodiment and further modifications. In particular, individual technical features that have been explained above in the context of other individual features can be realized independently of these and in combination with other individual features, even if this is not expressly described, as long as it is technically possible to do so. The present disclosure is therefore expressly not limited to the exemplary embodiments and modifications described, but rather includes all configurations defined by the claims.
TABLE-US-00001 List of reference signs 1 Tripod joint 10 Tripod star (inner joint part) 11 Shaft portion 12 Pin 13 Pin surface 20 Tripod housing (outer joint part) 21 Track 30 Tripod roller 31 Outer ring 31a Running surface/outer peripheral surface of the outer ring 31b Inner peripheral surface of the outer ring 32 Inner ring 32a Running surface/inner peripheral surface of the inner ring 32b Outer peripheral surface of the inner ring 32c End face of the inner ring 32d End face of the inner ring 33 Rolling elements 33a End portion 34 Annular space 35 Recess on the end face 36 Groove 37 Pocket 40 Axial locking ring 40a Inner side 41 Recess on the axial locking ring 42 Radial groove 43 Inner edge 44 Axial groove A Axis of rotation of the tripod star (inner joint part) B Axis of rotation of the tripod housing (outer joint part) Z Pin axis l.sub.w Bearing width of the rolling element l.sub.IR Length of the inner peripheral surface of the inner ring in the axial direction r Radial direction t Depression t1 Depression of the opening into the annular space t2 Depression of the opening into the inner peripheral surface of the inner ring