CONSTANT VELOCITY JOINT

Abstract

A constant velocity joint includes an outer part having an opening and a plurality of axially extending race grooves in the opening, an inner part at least partially located in the opening and having an outer surface with a plurality of axially extending race grooves, and a plurality of balls located between in inner and outer parts in the grooves. A first subset of the race grooves in the outer part and/or a first subset the race grooves in the inner part includes a section that follows a curved path in the axial direction.

Claims

1. A constant velocity joint, comprising: a joint outer part having a connecting side configured to connect to a first shaft and an opening side having an opening and a plurality of axially extending race grooves in the opening; a joint inner part at least partially located in the opening, the joint inner part including an outer surface having a plurality of axially extending race grooves; and a plurality of balls between the joint inner part and the joint outer part, each of the plurality of balls being located partly in one of the plurality of race grooves of the joint outer part and partly in one of the plurality of race grooves of the joint inner part, wherein a first subset of the plurality of race grooves of the joint outer part and/or a first subset the plurality of race grooves of the joint inner part includes a first section that follows a first curved path in the axial direction.

2. The constant velocity joint according to claim 1, wherein the first subset of the plurality of race grooves of the joint outer part and the first subset the plurality of race grooves of the joint inner part include the first section that follows a first curved path in the axial direction.

3. The constant velocity joint according to claim 2, wherein the first subset of the plurality of race grooves of the joint outer part and the first subset of the plurality of raceways of the joint inner part include a second section that follows a second curved path in the axial direction, and wherein the first curved path has a first curvature and the second curved path has a second curvature opposite the first curvature.

4. The constant velocity joint according to claim 3, wherein the first subset of the plurality of race grooves of the joint outer part and the first subset of the plurality of race grooves of the joint inner part include a linear third section.

5. The constant velocity joint according to claim 4, wherein the first section is located between the second section and the third section.

6. The constant velocity joint according to claim 4, wherein the third section is located between the first section and the second section.

7. The constant velocity joint according to claim 3, wherein a curvature change from the first section to the second section is +/−5° about a working angle of 0°.

8. The constant velocity joint according to claim 3, wherein a greatest difference between a tangent of the first curved path and a tangent of the second curved path is less than or equal to 10°.

9. The constant velocity joint according to claim 8, wherein a greatest difference between the tangent of the first curved path and an edge of the linear third section is +/−5°.

10. The constant velocity joint according to claim 3, wherein the first path is mirror inverted relative to the second path.

11. The constant velocity joint according to claim 3, wherein the first curvature is complementary to the second curvature.

12. The constant velocity joint according to claim 3, wherein a second subset of the plurality of race grooves of the joint outer part and/or a second subset of the plurality of race grooves of the joint inner part are entirely linear.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG. 1 is a sectional view of a constant velocity joint according to an embodiment of the present disclosure.

[0023] FIG. 2 is a perspective view of a joint inner part of the constant velocity joint of FIG. 1.

[0024] FIG. 3 is a plan view of the joint inner part of FIG. 2.

[0025] FIG. 4 is a perspective view of a part of the joint outer part of the constant velocity joint of FIG. 1.

[0026] FIG. 5 is a plan view of the joint outer part of FIG. 4.

DETAILED DESCRIPTION

[0027] In the following, identical or functionally equivalent elements are designated by the same reference numbers.

[0028] FIG. 1 shows a constant velocity joint 1 including a joint outer part 2 and a joint inner part 4. The joint outer part 2 can be connected by a connecting side 6 to a first shaft (not shown). An opening in a side 8 of the joint outer part 2 receives the joint inner part 4. The joint inner part 4 can be connected to a second shaft (not shown).

[0029] The joint outer part 2 includes a plurality of axially extending grooves 10, and the joint inner part 4 also includes a plurality of axially extending grooves 12. As shown in FIG. 2, the joint inner part 4 can be viewed as a star-shaped ring that has a plurality of axially extending grooves 12 and a central bore 18.

[0030] In order to transmit force and torque between the joint outer part 2 and the joint inner part 4, balls 14 are provided that are guided by a cage 16. Each outer race groove 10 and inner race groove 12 form a raceway, and a ball 14 is disposed in each of the raceways. The axially extending grooves 10, 12, allow the two joint parts 2, 4 to be tilted relative to each other. With rotating shafts, such a tilting leads to a movement of the balls 14 in the raceways.

[0031] The joint inner part 4 and the joint outer part 2 are described in more detail hereinafter with reference to FIGS. 2 to 5.

[0032] In order for the constant velocity joint to both transmit a high torque and achieve a high efficiency for large working angles, i.e., a large tilting of the two joint parts 2, 4 with respect to each other, the axially extending race grooves 10, 12 of a raceway have, at least sectionally, a curvature in the axial course. The race grooves 10, 12 of a raceway therefore do not extend linearly in the axial direction, but rather have, in the axial course, an arc-shaped deviation from the axial linear course. At the same time, due to the arc-shaped design of the race grooves 10, 12 of a raceway, the efficiency is increased with large working angles. In comparison to raceways with linear course displaced in the circumferential direction, the force that is exerted on the cage 16 is reduced, whereby the service life of the cage 16 is extended.

[0033] As is shown in FIGS. 2 to 5, the race grooves 10, 12 can in particular have two curvature changes with a linear section between the two curvature changes. Preferably the ends of the linear section are not offset in the circumferential direction.

[0034] The race groove 12-1 of the joint inner part 4 will now be described, but this description also applies to the remaining race grooves of the joint inner part 4. As is shown in FIGS. 2 and 3, the race groove 12-1 includes a first section 20 that is curved. After a curvature change 21, a second section 22 connects to this first section 20; the second section 22 extends axially and linearly and the ends of the second section are not offset in the circumferential direction. After a curvature change 23, a third section 24 connects thereto which is also curved. For this purpose the race groove 10-1 of the joint outer part 2 (see FIGS. 4 and 5) includes sections 26 to 30 complementary to the aforementioned sections of the joint inner part 4. The two sections 26 and 30 are curved and include an axial linear section 28 the ends of which are not offset in the circumferential direction between the curvature changes 27 and 29. Such a design has the advantage that when the ball is located in the axial linear section 22, 28, a high torque can be transmitted between the two joint parts 2, 4. Due to the curved sections 20, 24, 26, 30, 8, a high efficiency can be achieved simultaneously with large working angles.

[0035] Two adjacent raceways with their race grooves (e.g., 12-1 and 12-2, as well as 10-1 and 10-2) are preferably mirror-inverted with respect to each other. Here the respective circumferential race grooves 12-1, 12-2 and 10-1, 10-2 each converge at one end and diverge at the other.

[0036] In summary, due to the constant velocity joint described here, a high efficiency is achieved with a large working angle, wherein a high torque can be transmitted simultaneously with small working angles, which is comparable to the transmissible torque of a usual constant velocity joint with axially linearly extending raceways.

[0037] Representative, non-limiting examples of the present invention were described above in detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Furthermore, each of the additional features and teachings disclosed above may be utilized separately or in conjunction with other features and teachings to provide improved constant velocity joints.

[0038] Moreover, combinations of features and steps disclosed in the above detailed description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative examples of the invention. Furthermore, various features of the above-described representative examples, as well as the various independent and dependent claims below, may be combined in ways that are not specifically and explicitly enumerated in order to provide additional useful embodiments of the present teachings.

[0039] All features disclosed in the description and/or the claims are intended to be disclosed separately and independently from each other for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter, independent of the compositions of the features in the embodiments and/or the claims. In addition, all value ranges or indications of groups of entities are intended to disclose every possible intermediate value or intermediate entity for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter.

REFERENCE NUMBER LIST

[0040] 1 Constant velocity joint [0041] 2 Joint outer part [0042] 4 Joint inner part [0043] 6 Connecting side [0044] 8 Opening side [0045] 10 Outer race grooves [0046] 12 Inner race grooves [0047] 14 Ball [0048] 16 Cage [0049] 18 Bore [0050] 20 Curvature section [0051] 21 Curvature change [0052] 22 Linear section [0053] 23 Curvature change [0054] 24 Curvature section [0055] 26 Curvature section [0056] 27 Curvature change [0057] 28 Linear section [0058] 29 Curvature change [0059] 30 Curvature section