JP2016161053A - Sliding constant velocity joint - Google Patents

Abstract

Provided is a slide type constant velocity joint capable of suppressing tilting of a cage that holds rolling elements and thereby reducing forcing and vibration.
A constant velocity joint 1 includes an outer ring 2 in which three raceway grooves 211 having a pair of raceway surfaces 211a and 211b and a groove bottom surface 211c are formed, and a plurality of tripod shafts 32 respectively inserted into the raceway grooves 211. , A plurality of raceway rolling elements 5 that roll on a pair of raceway surfaces 211a and 211b, a cage 6 that holds the plurality of raceway rolling elements 5 in a circulatory manner, and a tripod shaft 32. The intermediate member 4 interposed between the plurality of raceway surface rolling elements 5 and the groove bottom surface rolling element 7 that is rotatably supported by the cage 6 and can roll the groove bottom surface 211c. The contact between the groove bottom rolling element 7 and the groove bottom surface 211c restricts the inclination of the outer ring 2 with respect to the central axis.
[Selection] Figure 1

Description

  The present invention relates to a slide type constant velocity joint.

  As a conventional constant velocity joint, it has a bottomed cylindrical outer ring in which three track grooves extending in the central axis direction are formed on the inner peripheral surface, and three tripod shaft portions respectively inserted into the track grooves of the outer ring. There is a slide-type constant velocity joint including a tripod member and a plurality of rolling elements interposed between the outer peripheral surface of the tripod shaft and the inner surface of the raceway groove (see Patent Document 1).

  The constant velocity joint described in Patent Document 1 includes a roller unit having a plurality of rolling elements between the tripod shaft and the inner surface of the raceway groove. The roller unit includes an intermediate member disposed so as to be swingable with respect to the tripod shaft portion, a plurality of rolling elements disposed between the inner surface of the raceway groove and the power transmission surface of the intermediate member, and the plurality of rolling members. And a cage that holds the moving body so that the outer periphery of the intermediate member can be circulated. A cage | basket consists of a pair of circulation path formation member facing and connected so that each axial direction both ends of a some rolling element may be hold | maintained. The pair of circulation path forming members are connected by a pair of connecting portions that sandwich the intermediate member in the central axis direction of the outer ring.

  The constant velocity joint can transmit torque between the outer ring and a shaft connected to the tripod member. When the shaft and the outer ring rotate while the shaft is inclined with respect to the outer ring, the roller unit slides in the direction of the central axis of the outer ring due to the rolling of the rolling elements. Torque input to the outer ring is transmitted to the shaft through a plurality of rolling elements, intermediate members, and tripod members.

JP 2010-169250 A

  When the shaft is tilted with respect to the outer ring, the tripod member is tilted with respect to the outer ring together with the shaft. And the force which inclines a roller unit with respect to an outer ring | wheel generate | occur | produces with the frictional force in the contact surface of the tripod shaft part of a tripod member and an intermediate member. When the roller unit cage is tilted with respect to the outer ring, the rotating shaft of the rolling element is tilted with respect to the radial direction perpendicular to the center axis of the outer ring, and the circumferential direction (rolling direction) of the rolling element is the extending direction of the raceway groove. Therefore, sliding friction occurs when the roller unit slides in the direction of the central axis of the outer ring. The sliding friction generated by the inclination of the cage is a cause of generation of forcing force (induced thrust force).

  Further, when the inclination of the cage with respect to the outer ring increases, the rolling elements that circulate around the outer periphery of the intermediate member come into contact with each other so as to ride on the step portion between the raceway surface and the portion other than the raceway surface on the inner surface of the outer ring. It has been confirmed by the present inventors that such contact of the rolling elements becomes a cause of generation of a forcing force and a factor of generation of vibration.

  Therefore, an object of the present invention is to provide a slide type constant velocity joint capable of suppressing the tilt of the cage and thereby reducing the forcing force and the vibration.

  In order to achieve the above object, the present invention provides an outer part having a cylindrical portion in which a plurality of raceway grooves having a pair of raceway surfaces extending in the central axis direction and facing each other and a groove bottom surface between the pair of raceway surfaces are formed. And a plurality of leg shafts that are erected so as to extend radially outward of the boss portion from the outer peripheral surface of the boss portion and are inserted into the raceway grooves, respectively. A plurality of members that roll on any one of the pair of raceway surfaces in accordance with a rotation direction of the outer member and a torque transmission direction between the outer member and the shaft. Raceway surface rolling elements, a cage that holds the plurality of rolling elements in a circulating manner around the leg shaft, an intermediate member interposed between the leg shaft and the plurality of rolling elements, and the cage The bottom surface of the groove can be rotated on the bottom surface of the groove. And a body, said retainer by contact with the groove bottom surface and the groove bottom surface rolling elements, the slope is restricted with respect to the center axis of the outer member to provide a sliding type constant velocity joint.

  According to the present invention, it is possible to suppress the tilt of the cage and reduce the forcing force and vibration.

It is a whole view which fractures | ruptures and shows a part of slide-type constant velocity joint. It is the top view which looked at the outer ring | wheel of the slide-type constant velocity joint from the rotating shaft direction. It is a disassembled perspective view which shows a tripod member with a roller unit. A roller unit is shown, (a) is a front view, (b) is sectional drawing.

[Embodiment]
Hereinafter, a slide type constant velocity joint according to an embodiment of the present invention will be described with reference to FIGS. 1 to 4. Each of the embodiments described below is shown as a preferred specific example for carrying out the present invention, and there are portions that specifically illustrate various technical matters that are technically preferable. However, the technical scope of the present invention is not limited to this specific embodiment.

FIG. 1 is an overall view in which a part of a slide type constant velocity joint according to an embodiment is broken. 2, the outer ring of the sliding type constant velocity joint is a plan view seen from the rotation axis O ₁ direction. The cross section shown in FIG. 1 is a cross section taken along line AA in FIG. Hereinafter, this slide type constant velocity joint is simply referred to as “constant velocity joint”.

  The constant velocity joint 1 is disposed between a side gear (not shown) that is an output member of a differential device of a vehicle and a shaft (an intermediate shaft of a drive shaft) 8 and transmits a driving force for rotating a wheel to the shaft 8. The constant velocity joint 1 is also referred to as a tripod type constant velocity joint, and includes an outer ring 2 as an outer member, a tripod member 3 as an inner member, and three roller units 10 (one roller unit in FIG. 1). 10 is shown). The outer ring 2 is connected to rotate integrally with the side gear of the differential device, and the tripod member 3 is connected to rotate integrally with the shaft 8. The roller unit 10 is fitted to a tripod shaft portion 32 as a leg shaft of a tripod member 3 described later. Hereinafter, the configuration of each of these members will be described in detail.

(Configuration of outer ring 2)
The outer ring 2 includes a cylindrical portion 21 in which a plurality of (three) track grooves 211 extending in the central axis direction are formed on the inner peripheral surface, a bottom portion 22 that closes one end portion of the cylindrical portion 21, and a central portion of the bottom portion 22. It has an axial stem portion 23 that protrudes on the opposite side to the cylindrical portion 21. The cylindrical portion 21 and the bottom portion 22 have a bottomed cylindrical shape, and an accommodating space 20 for accommodating the tripod member 3 and the three roller units 10 is formed inside the cylindrical portion 21. Note that the central axis of the cylinder portion 21 coincides with the rotation axis O ₁ of the outer ring 2. In Figure 1, the rotation axis O ₂ of the rotary shaft O ₁ and the shaft 8 of the outer ring 2 is matched, the joint angle is shown the state of zero.

As shown in FIG. 2, the three track grooves 211 are formed so as to be recessed outward from the central portion of the cylindrical portion 21 at equal intervals along the circumferential direction of the cylindrical portion 21. The three roller units 10 are accommodated in the three raceway grooves 211, respectively. Each raceway groove 211 on its inner surface, facing each other and extend in the central axis direction of the cylindrical portion 21 (the rotation axis _{O 1} and parallel to the direction) pair of raceway surfaces 211a, 211b, and a pair of raceway surfaces 211a, between 211b The groove bottom surface 211c is provided. The pair of raceway surfaces 211a and 211b are flat surfaces and face each other in parallel. The groove bottom surface 211c is a flat surface perpendicular to the pair of track surfaces 211a and 211b. In the following description, when it is necessary to distinguish each of the pair of raceway surfaces 211a and 211b, a raceway on which a plurality of raceway rolling elements 5 (described later) of the roller unit 10 roll during forward acceleration of the vehicle. The surface is referred to as a first track surface 211a, and the other track surface is referred to as a second track surface 211b.

  The stem portion 23 is formed with a spline fitting portion 231 that is spline fitted to the side gear of the differential device. In addition, a ring-shaped stopper (not shown) such as a snap ring is provided at the end of the stem portion 23 on the distal end side (opposite the base end portion on the bottom 22 side) of the spline fitting portion 231. An annular groove 232 for holding is formed.

(Configuration of tripod member 3)
FIG. 3 is an exploded perspective view showing the tripod member 3 together with the roller unit 10 combined with one tripod shaft portion 32. 4A and 4B show the roller unit 10, in which FIG. 4A is a front view, and FIG. 4B is a sectional view taken along line BB in FIG.

  The tripod member 3 is erected so as to extend from the outer peripheral surface 31a of the boss 31 to the outer side in the radial direction of the boss 31 by being connected to the shaft 8, and is respectively provided in the raceway groove 211 of the outer ring 2. A plurality of (three) tripod shaft portions 32 are inserted. The boss 31 is formed with an insertion hole 30 through which the shaft 8 is inserted in the center, and is fitted to a spline fitting portion 81 (see FIG. 1) formed at the end of the shaft 8 so as not to be relatively rotatable. Further, the tripod member 3 is prevented from coming off by a snap ring 80 (see FIG. 1) fitted to the shaft 8. A plurality of spline protrusions are formed on the inner peripheral surface of the insertion hole 30 of the boss portion 31, but the illustration of these spline protrusions is omitted in FIG. 3.

  The three tripod shaft portions 32 are provided at equal intervals along the circumferential direction of the boss portion 31, and the tip portions thereof are formed in a partial spherical shape. More specifically, each tripod shaft portion 32 has a neck portion 321 on the boss portion 31 side, and a head portion 322 having a convex spherical outer peripheral surface 322a having an outer diameter larger than that of the neck portion 321. The portion 322 is provided closer to the distal end side of the tripod shaft portion 32 than the neck portion 321. The roller unit 10 is fitted to each head portion 322 of the three tripod shaft portions 32 so as to be swingable.

(Configuration of roller unit 10)
The roller unit 10 includes an intermediate member 4 composed of a pair of split members 41 and 41 arranged so as to sandwich the head 322 of the tripod shaft portion 32, the rotational direction of the outer ring 2, and the outer ring 2 and the shaft 8. The plurality of raceway rolling elements 5 that roll on any one of the pair of raceway surfaces 211a and 211b in the raceway groove 211 and the plurality of raceway rolling elements 5 are tripod shafts according to the torque transmission direction between them. A cage 6 that is circulated around the portion 32 and a groove bottom surface rolling member 7 that is rotatably supported by the cage 6 and can roll the groove bottom surface 211c of the outer ring 2 are provided.

  The pair of split members 41, 41 of the intermediate member 4 are interposed between the head 322 of the tripod shaft portion 32 and the plurality of raceway rolling elements 5. One of the divided members 41 is disposed between the tripod shaft portion 32 and the first raceway surface 211a, and the other divided member 41 is disposed between the tripod shaft portion 32 and the second raceway surface 211b. Has been.

  Each split member 41 is formed with a contact surface 41a with which the head portion 322 of the tripod shaft portion 32 contacts as a concave surface having a partial spherical shape. A surface of the split member 41 opposite to the contact surface 41a is formed as a flat rolling surface 41b on which the plurality of raceway rolling elements 5 roll.

  The raceway rolling element 5 has an axial shape including a cylindrical body 51 and a pair of needle-like protrusions 52 and 52 erected on both end surfaces of the body 51 in the axial direction. In the present embodiment, 18 raceway rolling elements 5 are arranged on the outer periphery of the intermediate member 4. However, the number of raceway rolling elements 5 can be changed as appropriate according to the torque transmission capacity of the constant velocity joint 1. In FIG. 3, one of the 18 raceway surface rolling elements 5 is illustrated outside the cage 6.

  The plurality of raceway rolling elements 5 roll on the first raceway surface 211a during forward acceleration of the vehicle on which the constant velocity joint 1 is mounted, and torque is generated between the outer ring 2 and the intermediate member 4 (divided member 41). To communicate. At this time, a slight gap is formed between the plurality of raceway rolling elements 5 and the second raceway surface 211b. In addition, when the vehicle is decelerated in the forward state or accelerated in the reverse state, the plurality of raceway rolling elements 5 roll on the second raceway surface 211b, and the plurality of raceway surface rolling elements 5 and the first raceway surface. A slight gap is formed between 211a.

The cage 6 is formed by connecting a pair of circulation path forming members 61 and 62 sandwiching a plurality of raceway rolling elements 5 in the axial direction thereof, and has a rectangular shape with a rounded corner when viewed from the radial direction of the outer ring 2. (Rounded rectangular shape). In the following description, a pair of circulating path forming members 61 and 62, the outer circulation passage forming member one of the circulation path forming member disposed farther radially outward from the rotation axis O ₁ in receiving space 20 of the outer ring 2 The other circulation path forming member is referred to as an inner circulation path forming member 62. The outer circulation path forming member 61 and the inner circulation path forming member 62 are formed by pressing a material made of a plate-like metal.

  As shown in FIG. 4B, the cage 6 includes a groove-shaped outer circulation path 611 that engages with one needle-like protrusion 52 of the plurality of raceway rolling elements 5, and a plurality of raceway rolling elements 5. It has a groove-shaped inner circulation path 621 with which the other needle-like protrusion 52 is engaged. The outer circulation path 611 is formed in the outer circulation path forming member 61, and the inner circulation path 621 is formed in the inner circulation path forming member 62. In the plurality of raceway rolling elements 5, one needle-like protrusion 52 is guided to the outer circulation path 611 and the other needle-like protrusion 52 is guided to the inner circulation path 621.

  In addition, the outer circulation path forming member 61 and the inner circulation path forming member 62 are connected to the cage 6 by a pair of connecting portions 60 and 60. The pair of connecting portions 60, 60 are formed on the inner side of the outer circulation path 611 and the inner circulation path 621, that is, on the inner side (the tripod shaft part 32 side) of the movement track of the raceway rolling element 5. It is lined up along the axial direction. Each connecting portion 60 includes an outer connecting piece 612 extending from the outer circuit forming member 61 toward the inner circuit forming member 62, and an inner connecting piece 622 extending from the inner circuit forming member 62 toward the outer circuit forming member 61. And the outer connecting piece 612 and the inner connecting piece 622 are caulked.

  A pair of support portions 601 and 601 project from each connecting portion 60 so as to hold the groove bottom surface rolling element 7 so that it can rotate and cannot move relative to the cage 6 in the central axis direction of the cylindrical portion 21. . The pair of support portions 601 and 601 protrude from the connecting portion 60 toward the groove bottom surface 211c. In the present embodiment, the support portion 601 is formed by cutting and raising a part of the upper surface 60a of the connecting portion 60 (the surface facing the groove bottom surface 211c). Each support portion 601 is formed with a through-hole 601a through which a needle-like protrusion 72 serving as a supported portion of the groove bottom surface rolling element 7 is inserted.

  The groove bottom rolling element 7 has a cylindrical shape as a whole, and has a rotation axis in a direction parallel to the opposing direction of the pair of raceway surfaces 211a and 211b. The groove bottom surface rolling element 7 has a cylindrical main body 71 and a pair of needle-like protrusions 72 and 72 protruding from both end faces of the main body 71 in the rotation axis direction. It is supported by the support portion 601 of the cage 6.

  In the present embodiment, two groove bottom surface rolling elements 7 are supported by one cage 6, and these two groove bottom surface rolling elements 7 are arranged in parallel in the alignment direction along the central axis of the outer ring 2. That is, of the two groove bottom surface rolling elements 7 held by the cage 6, one groove bottom surface rolling element 7 is disposed closer to the bottom 22 of the outer ring 2 than the tripod shaft portion 32, and the other groove bottom surface rolling element 7. Is disposed closer to the opening side of the outer ring 2 than the tripod shaft portion 32.

As shown in FIG. 1, the width W _{2 in} the depth direction (vertical direction in FIG. 1) of the raceway groove 211 in the cylindrical portion 21 of the outer ring 2 is the axial direction of the outer peripheral surface of the trunk portion 51 of the raceway rolling element 5. It is formed slightly larger than the width W _1. With this configuration, the raceway rolling element 5 can smoothly roll in the raceway groove 211, while when the shaft 8 rotates while being inclined with respect to the outer ring 2, the tripod shaft 32 and the intermediate member 4 The cage 6 of the roller unit 10 is tilted with respect to the outer ring 2 together with the intermediate member 4 by the frictional force on the contact surfaces (the outer peripheral surface 322a of the head 322 and the contact surface 41a of the dividing member 41). Such tilting of the cage 6 becomes a cause of forcible force and vibration as described above.

  In the present embodiment, the inclination of the cage 6 with respect to the center axis of the outer ring 2 is restricted by the contact between the groove bottom rolling element 7 and the groove bottom surface 211 c of the raceway groove 211 of the outer ring 2. That is, as shown in FIG. 1, when the roller unit 10 is not inclined with respect to the outer ring 2, a slight gap is formed between the two groove bottom surface rolling elements 7 and the groove bottom surface 211c, and the groove bottom surface rolling is performed. Although the moving body 7 does not contact the groove bottom surface 211c, when the cage 6 tilts with respect to the outer ring 2, one of the two groove bottom surface rolling elements 7 contacts the groove bottom surface 211c. Thereby, the further tilting of the holder | retainer 6 is controlled. In this state, when the roller unit 10 slides in the raceway groove 211 in the direction of the central axis of the outer ring 2, the groove bottom surface rolling element 7 rolls on the groove bottom surface 211c.

(Effect of embodiment)
According to the embodiment described above, the following operations and effects can be obtained.

(1) Since the inclination of the cage 6 with respect to the outer ring 2 is regulated by the contact between the groove bottom surface rolling element 7 rotatably supported by the cage 6 and the groove bottom surface 211c of the raceway groove 211, the force and vibration Occurrence can be suppressed.

(2) Since the groove bottom surface rolling element 7 has a cylindrical shape having a rotation axis in a direction parallel to the opposing direction of the pair of raceway surfaces 211a and 211b, the groove bottom surface rolling element 7 is in a state of being in contact with the groove bottom surface 211c. Even if the unit 10 slides in the raceway groove 211 in the direction of the central axis of the outer ring 2, sliding friction between the groove bottom surface rolling element 7 and the groove bottom surface 211c is suppressed. Moreover, since the surface pressure of the contact portion between the groove bottom surface rolling element 7 and the raceway groove 211 is reduced as compared with the case where the groove bottom surface rolling element 7 is spherical, wear at the contact portion is suppressed.

(3) The groove bottom surface rolling element 7 is supported by a pair of support portions 601 that protrude from the connecting portion 60 that connects the outer circulation path forming member 61 and the inner circulation path formation member 62 toward the groove bottom surface 211c. Therefore, the groove bottom surface rolling element 7 can be rotatably supported by the cage 6 while suppressing an increase in the size of the cage 6.

(4) Since the two groove bottom surface rolling elements 7 are arranged in parallel in the alignment direction along the central axis of the outer ring 2 in the roller unit 10, the force with which the roller unit 10 tilts in any direction from the tripod shaft portion 32. Even if it receives, the inclination of the holder | retainer 6 is suppressed.

  As mentioned above, although the slide type constant velocity joint of this invention was demonstrated based on embodiment, this invention is not limited to these embodiment, It implements in a various aspect in the range which does not deviate from the summary. It is possible. Further, the present invention can be appropriately modified and implemented without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Constant velocity joint (sliding constant velocity joint), 10 ... Roller unit, 2 ... Outer ring (outer member), 20 ... Storage space, 21 ... Cylindrical part, 211 ... Track groove, 211a ... 1st track surface, 211b ... second raceway surface, 211c ... groove bottom surface, 22 ... bottom portion, 23 ... stem portion, 231 ... spline fitting portion, 232 ... annular groove, 3 ... tripod member (inner member), 30 ... insertion hole, 31 ... Boss part, 31a ... Outer peripheral surface, 32 ... Tripod shaft part, 321 ... Neck part, 322 ... Head, 322a ... Outer peripheral surface, 4 ... Intermediate member, 41 ... Split member, 41a ... Abutting surface, 41b ... Rolling 5, raceway rolling elements, 51, trunk, 52, needle-like projections, 6, cage, 60, connecting part, 601, support part, 601 a, through hole, 60 a, upper surface, 61, outer circulation path formation. Member, 611 ... outer circulation path, 612 ... outer connecting piece, 6 ... inner circulation path forming member, 621 ... inner circulation path, 622 ... inner connecting piece, 7 ... groove bottom rolling element, 71 ... main body, 72 ... needle projection, 8 ... shaft, 80 ... snap ring, 81 ... spline fitting Joint

Claims (4)

An outer member having a cylindrical portion in which a plurality of raceway grooves having a pair of raceway surfaces extending in the central axis direction and facing each other and a groove bottom surface between the pair of raceway surfaces are formed;
An annular boss portion connected to the shaft, and an inner side having a plurality of leg shafts that are erected so as to extend radially outward of the boss portion from the outer peripheral surface of the boss portion and are respectively inserted into the track grooves Members,
A plurality of raceway rolling elements that roll on any one of the pair of raceway surfaces according to the direction of rotation of the outer member and the direction of torque transmission between the outer member and the shaft;
A cage that holds the plurality of raceway rolling elements in a circulating manner around the leg shaft;
An intermediate member interposed between the leg shaft and the plurality of rolling elements;
A groove bottom surface rolling element that is rotatably supported by the cage and can roll the groove bottom surface;
The cage is restricted from tilting with respect to the central axis of the outer member by contact between the groove bottom surface rolling element and the groove bottom surface.
Sliding constant velocity joint. The groove bottom surface rolling element has a cylindrical shape having a rotation axis in a direction parallel to a facing direction of the pair of raceway surfaces.
The slide type constant velocity joint according to claim 1. The cage includes a pair of circulation path forming members that sandwich the plurality of raceway rolling elements, and the pair of circulation path formation members are formed on the inner side of the movement trajectories of the plurality of raceway rolling elements. Concatenated with
The groove bottom surface rolling element is supported by a support portion protruding from the connecting portion toward the groove bottom surface,
The slide type constant velocity joint according to claim 1 or 2. A plurality of the groove bottom surface rolling elements are supported by the cage, and the plurality of groove bottom surface rolling elements are arranged in parallel in a line-up direction along the central axis of the outer member.
The slide type constant velocity joint according to any one of claims 1 to 3.

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