JOINT ASSEMBLY WITH RESTRICTION FEATURE

Abstract

A joint assembly comprising a hollow outer joint member including a wall forming an open end and a closed end, the outer joint member having a plurality of tracks in its inner surface. An inner joint member received in the outer joint member and plurality of torque-transmitting elements, whereby the plurality of torque-transmitting elements rotationally engage with the inner joint member and the tracks of the outer joint member. Each track comprises two opposing side walls and a torque-transmitting element engages these side walls of the outer joint member and is configured to move in an axial direction along the side walls. Furthermore, a boot covering the open end of the outer joint member and at least one restrictor configured to engage at least one of the plurality of torque-transmitting elements to militate against undesired displacement of the inner joint member with respect to the outer joint member.

Claims

1. A joint assembly comprising: a hollow outer joint member including a wall forming an open end and a closed end, the outer joint member having a plurality of tracks in its inner surface; an inner joint member received in the outer joint member; a plurality of torque-transmitting elements, the plurality of torque-transmitting elements rotationally engaging with the inner joint member and the plurality of tracks of the outer joint member, wherein each track comprises two opposing side walls and the plurality of torque-transmitting elements engage these side walls of the outer joint member and is configured to move in an axial direction along the side walls; a boot covering the open end of the outer joint member; at least one restrictor configured to engage at least one of the plurality of torque-transmitting elements to militate against undesired displacement of the inner joint member with respect to the outer joint member, wherein the at least one restrictor is part of the boot and extends through the open end of the outer joint member into the at least one of the plurality of tracks in the outer joint member along the side walls, and a surface of the restrictor in an area of a first side wall points to the opposite side wall of the track, and said surface runs at an angle α to the first side wall, wherein the angle α opens to the open end of the outer joint member, wherein the angle α is between 0 and 35°.

2. The joint assembly according to claim 1, wherein the restrictor is made in one piece with the boot.

3. The joint assembly according to claim 1, wherein the at least one restrictor is a leaf running along the side wall of the track.

4. The joint assembly according to claim 1, wherein two restrictors extend into each track and run along both side walls of the track.

5. The joint assembly according to claim 1, wherein the restrictor is in contact with the side wall of the track.

6. The joint assembly according to claim 1, wherein the restrictor is arranged in a distance to the side wall of the track.

7. (canceled)

8. (canceled)

9. The joint assembly according to claim 1, wherein the restrictor is made of an elastic material.

10. The joint assembly according to claim 1, wherein the plurality of torque-transmitting elements are roller assemblies or balls that engage with the side walls of the track.

11. The joint assembly according to claim 1, wherein the angle α is between 0 and 20°.

12. The joint assembly according to claim 1, wherein the angle α is between 0 and 10°.

Description

[0025] The various embodiments will be explained in greater detail below based on the attached figures. These must be viewed only as examples, and are not intended to limit the disclosed embodiments to the depicted embodiments. Shown on:

[0026] FIG. 1: a first longitudinal section through an embodiment of a joint assembly with an inner joint member in a moving position;

[0027] FIG. 2: the joint assembly of FIG. 1 with the inner joint member in an almost blocked position;

[0028] FIG. 3: a partial insight into the joint assembly of FIG. 1;

[0029] FIG. 4: an enlarged view A of the partial insight of FIG. 3;

[0030] FIG. 5: a second longitudinal section through the joint assembly of FIG. 1 with the inner joint member in a blocked position;

[0031] FIG. 6: a three-dimensional view of a boot for use in the embodiment;

[0032] FIG. 7: another three-dimensional view of the boot of FIG. 6;

[0033] FIG. 8: an enlarged view B of the boot of FIG. 6;

[0034] FIG. 9: a schematic illustration of a roller assembly in a moving position and in a position contacting two restrictors with restrictors adjacent to the side walls;

[0035] FIG. 10: a schematic illustration of a roller assembly in a moving position and in a position contacting two restrictors with restrictors spaced apart from the side walls;

[0036] FIG. 11: an enlarged view of a roller assembly deforming and displacing the leaf of a boot; and

[0037] FIG. 12: an enlarged extracted view of a ball-type joint assembly.

[0038] The following detailed description and appended drawings describe and illustrate various exemplary embodiments of the disclosed embodiments. The description and drawings serve to enable one skilled in the art to make and use the disclosed embodiments, and are not intended to limit the scope of the disclosed embodiments in any manner. In respect of methods disclosed, the steps presented are exemplary in nature, and thus, the order of the steps is not necessary or critical.

[0039] The present technology relates to joint assemblies, such as constant velocity joints, used in motor vehicles. However, the present disclosure can apply to other types of joint assemblies used in motor vehicles or in other applications. Joint assemblies according to the disclosure are configured to facilitate a transmission of rotational forces and torque to components of a motor vehicle such as the wheels, for example.

[0040] FIGS. 1-11 show a joint assembly 5 according to an embodiment of the present disclosure. The joint assembly includes an inner joint member 20 and an outer joint member 10. The joint assembly is configured as a tripode-type constant velocity joint. However, in other embodiments, the joint assembly can be configured as a ball-type constant velocity joint. It is understood that the joint assembly can be configured as a constant velocity joint or joint assembly of any type having an inner joint member and an outer joint member, as desired. FIG. 12 shows an enlarged view of an exemplary ball-type joint assembly.

[0041] As illustrated, the inner joint member 20 of the joint assembly 5 is configured as a tripode joint including three arms 23 extending radially outwardly from the inner joint member 20. The inner joint member 20 is configured to be splined with a drive shaft 21 of the vehicle. For example, a central bore is splined and receives a splined drive shaft 21. The inner joint member 20 includes a spider 22 with three arms extending radially therefrom, whereas one arm is identified with the reference numeral 23. Each of the arms 23 includes a roller assembly engaging a distal end thereof, whereas one roller assembly is identified with the reference numeral 24.

[0042] Each roller assembly 24 includes an outer roller 25, an inner roller 26, and rolling members 27 such as rollers of a needle bearing disposed between the outer roller and the inner roller (e.g. FIG. 9). The roller assembly 24 can include retainers maintaining the rolling members 27 disposed between the inner roller 26 and the outer roller 25. The roller assembly 24 is configured to permit an axial movement and angular displacement of the inner joint member 20 with respect to the outer joint member 10 as the inner joint member 20 is moved in and out of the outer joint member 10.

[0043] The outer joint member 10 is configured as a hollow chamber having a closed end 12, an open end on the opposite side, and an annular array of recesses or tracks 11 on an inner surface of a wall forming the chamber. The outer joint member 10 has a substantially tri-lobal cross-sectional shape. The tracks 11 include a pair of longitudinally extending opposing side walls 13 and 14. Each of the tracks 11 receives one of the roller assemblies 24 of the inner joint member 20, wherein the outer roller 25 of each of the roller assemblies 24 engages the side walls 13,14 of the outer joint member 11.

[0044] A boot 30 is mounted to the open end of the outer joint member 10. The boot 30 is made of an elastic material and comprises several foldings like a bellow. The boot 30 comprises a smaller opening 32 and a larger opening 33. The drive shaft 21 runs through the smaller opening 32 and is tightly fixed to the drive shaft by means of a clamping ring 41, for example. The larger opening 33 is put over the open end of the outer joint member 10 and is tightly fixed to the outer surface of the outer joint member 10 by means of a second clamping ring 40. In addition, there is at least one circular groove 16 on the outer surface of the outer joint member 10 in the area of the open end (see FIG. 4). A circular tongue 35 on the inner surface of the boot 30 in the area of the larger opening 33 engages this groove 16.

[0045] Furthermore, the boot 30 comprises three bulges 34 in the area of the larger opening 33. These bulges 34 fit into corresponding recesses on the outer surface of the outer joint member 10 so that the boot 30 can tightly be fixed to the outer joint member 10 by means of a clamping ring 40. These recesses are due to the tri-lobal form of the outer joint member 10. Such outer joint member is also called tulip.

[0046] The boot 30 comprises several restrictors that extend into the three tracks 11 of the outer joint member 10. Each track comprises two restrictors in form of leaves that project from the boot 30 into the tracks 11. For example, the sections in FIGS. 1 to 4 show one restrictor 31 along a side wall 14 in a track 11, whereas the section of FIG. 5 shows two restrictors 31 and 31′ along two opposing side walls 13 and 14. FIGS. 1, 3 and 4 show the inner joint member 20 with the roller assemblies 24 in a moving position. FIG. 2 shows the inner joint member 20 with the roller assemblies 24 almost in a blocked position when they start to have contact to the restrictors 31, 31′. In the situation of FIG. 5, the roller assembly 24 is blocked by the restrictors 31, 31′.

[0047] FIGS. 6 and 7 show these restrictors 31, 31′ on the boot 30 in more detail. They have the form of leaves that project from the boot 30. Thereby, the foot of the restrictors has a greater thickness than the free end of the restrictors so that they are wedge-shaped. Their thickness decreases in axial direction towards the torque-transmitting elements. In addition, there are two stiffeners 50 and 51 between the two restrictors 31, 31′ that merge into the restrictors 31, 31′ with a radius. The restrictors 31, 31′ are supported against the bulges 34 by means of additional stiffeners 52, 53 and 52′, 53′. All stiffeners are formed by protruding walls

[0048] FIG. 9 schematically shows a first embodiment of restrictors 31 and 31′ that extend from a boot (not shown) into a track 11 with two opposing side walls 13 and 14. The restrictors 31, 31′ narrow the width W of the track in the area of the open end of the outer joint member. A roller assembly has an inner roller 26 fixed to an arm 23 of the inner joint member. An outer joint member 25 is rotatably held on the inner roller 26 by means of roller members 27. FIG. 9 shows this roller assembly in two positions. A first position is illustrated by dotted lines, whereas a second position is illustrated by continuous lines. The travel between these positions is indicated by double arrows. In the first position, the roller assembly can freely move along the track 11. In the second position, the roller assembly has contacted the restrictors 31, 31′ so that its free travel towards the open end of the outer joint member is prevented.

[0049] The restrictors 31, 31′ extend along the side walls 13, 14 whereby they have contact with the surfaces of the side walls. This contact can be a loose contact or the restrictors 31, 31′ are pressed into the track 11. Preferably, the restrictors are made of an elastic material. If the inner joint member with the roller assembly moves further into the direction of the open end of the outer joint member (to the left), the outer roller 25 will deform and compress the restrictors 31, 31′. Then the roller assembly will be clamped between the two compressed restrictors 31, 31′. Thereby, an axial force F is used to generate forces F.sub.1 and F.sub.2 onto the restrictors 31, 31′ in the direction of the side walls. Form and size of the restrictors 31, 31′ are chosen adequately in order to achieve this deformation and compression. For example, the restrictors 31, 31′ should not be too thick at a contact point between restrictor and the outer roller of a roller assembly. In addition, an inclined surface 36 can help to form a wedge angle α. Angle α preferably is in the range between 0 and 35°, particularly between 0 and 20°, more particularly between 0 and 10°. The inclined surface 36 is a surface that contacts the roller assembly and provides for a ramp.

[0050] FIG. 10 shows another embodiment in a schematic illustration similar to FIG. 9. The restrictors 31, 31′ used in this embodiment do not have contact with the side walls 13 and 14. They are spaced apart from the side walls. Each restrictor 31, 31′ has a surface pointing in the direction of a side wall 13, 14 along which it runs. The distance y between these surfaces is smaller than the width W of the track 11. Even in this configuration, the restrictors 31, 31′ will not only stop the travel of the roller assembly in axial direction. When the outer roller of the roller assembly contacts the restrictors, the axial force F generates forces F.sub.1 and F.sub.2 onto the restrictors 31, 31′ in the direction of the side walls. The restrictors will bend and will be pressed between the outer roller 25 and each side wall. In this position, a wedge will be formed that clamps the roller assembly between the two restrictors.

[0051] Optionally, this clamping effect could even be used if the boot 30 is not tightly fastened to the outer hollow joint member yet. When the roller assembly contacts the restrictors, the boot might be pushed away from the outer joint member a little bit. However, as soon as the restrictors are deformed and clamped between the outer rollers and the side walls, the boot can no longer move. FIG. 11 shows an enlarged view of this situation. A leaf 31 projects from a boot 30 into a track along a side wall 14. Thereby, the boot 30 maybe has had contact to an outer edge 18 of the open end of the outer joint member, but in FIG. 11, the outer roller 25 has already pushed the boot 30 away from the edge 18 together with the restrictor 31. However, at the same time the restrictor 31 has been deformed and pressed into the space between outer roller 25 and side wall 14. Several stiffeners 50, 51, 52 and 53 on both sides of the restrictor 31 can help to keep the restrictor 31 in place. Another restrictor on the opposing side wall (not shown) has experienced the same. Therefore, the roller assembly is clamped between the two deformed restrictors. Now the boot 30 cannot be removed from the outer joint member 10 due to the friction forces between restrictor 31, side wall 14 and outer roller 25.

[0052] FIG. 12 shows an enlarged extracted view of another embodiment which is used to illustrate a restrictor according to an embodiment in a ball-type joint assembly 6 with an inner joint member 20′ and an outer joint member 10′. The torque-transmitting elements are balls. These balls 24′ engage with tracks 11′ in the outer joint member 10′ and tracks 11″ in the inner joint member 20′ and are typically held in openings within a cage 28. For ball-type joint assemblies, tracks with a semi-circular or gothic cross-section are often used. Each track also comprises two opposing side walls or sections of a wall running in axial direction. A ball engages these side walls or sections of a wall and is configured to move in an axial direction along the side walls or sections of a wall. For example, the enlarged extracted view of FIG. 11 shows that the ball 24′ engages the side wall 14′ in the track 11′ in the outer joint member 10′. A boot 30 comprises at least one restrictor 31″ that extends into the track 11′ along a side wall 14′. The boot 30 can comprise at least one restrictor 31″, in particular two restrictors, for each track. Thereby, the form of the restrictor 31″ is adapted to the shape of the track 11′.