JP2016118233A - Tripod type constant velocity joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tripod type constant velocity joint capable of reducing slide resistance between a raceway groove of an outer ring and a roller unit on an anti-torque transmission side.SOLUTION: On a bottom part 12 of a raceway groove 11, formed is a support surface 12a that contacts with a roller unit 30 obliquely moving with torque transmission of a constant velocity joint 2, on an anti-torque transmission side, and supports the roller unit 30. On the support surface 12a, formed is a holding part 15 holding grease stored in an outer ring 10.SELECTED DRAWING: Figure 3A

Description

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

  There exists a thing disclosed by patent document 1 as a tripod type | mold constant velocity joint. The constant velocity joint disclosed in Patent Document 1 includes a double roller type roller unit that is supported by three shaft portions provided in a tripod and includes an outer roller and an inner roller. When torque is transmitted in a state where a constant velocity joint having such a double roller type roller unit is given a joint angle, the roller unit reciprocates along the raceway groove of the outer ring, and the inner peripheral surface of the roller unit and the tripod The contact position with the shaft portion reciprocates in the radial direction of the tripod.

JP 2014-055621 A

  As described above, when the tripod shaft portion moves relative to the roller unit, the roller unit may tilt in the axial direction of the outer ring, and may contact the raceway groove of the outer ring on the counter-torque transmission side. The resistance due to the contact may become a sliding resistance when the roller unit reciprocates in the raceway groove of the outer ring.

  This invention is made in view of such a situation, and provides the tripod type constant velocity joint which can reduce the sliding resistance of the raceway groove | channel of an outer ring | wheel and a roller unit in an anti-torque transmission side. Objective.

(Claim 1) A tripod constant velocity joint according to the present invention includes an outer ring having a plurality of raceway grooves having an opening on one end side in the axial direction and extending in the axial direction, and a tripod having three shaft parts, A plurality of roller units that are formed in an annular shape, are rotatably supported on each of the three shaft portions, and roll on each of the plurality of raceway grooves.
When the outer ring rotates in the groove width direction of the raceway groove, a side opposite to the side where torque is transmitted between the raceway groove and the roller unit is defined as an anti-torque transmission side. A support surface for supporting the roller unit is formed on the bottom of the raceway groove so as to come into contact with the roller unit tilting with the torque transmission of the constant velocity joint on the side opposite to the torque transmission side. The support surface is formed with a holding portion for holding the grease accommodated in the outer ring.

  According to the first aspect of the invention, since the holding portion holds the grease accommodated in the outer ring, the contact portion between the end surface of the roller unit and the support surface of the raceway groove is suitably lubricated. As a result, when the constant velocity joint transmits torque, it is possible to reduce the sliding resistance of the outer ring raceway groove and the roller unit on the counter-torque transmission side.

It is an axial sectional view of a constant velocity joint assembly including a tripod type constant velocity joint in the embodiment. It is sectional drawing seen from the opening part side of the outer ring | wheel in FIG. It is a figure which shows the 1st aspect of the holding | maintenance part formed in the support surface. It is a figure which shows the 2nd aspect of the holding | maintenance part formed in the support surface. It is a figure which shows the 3rd aspect of the holding | maintenance part formed in the support surface. It is a figure which shows the 4th aspect of the holding | maintenance part formed in the support surface. It is sectional drawing which shows the radial direction position of the boundary part in the internal peripheral surface of an outer ring | wheel. It is sectional drawing which expands and shows the torque transmission side in the width direction of a track groove. It is sectional drawing which expands and shows the anti-torque transmission side in the width direction of a track groove. It is a top view of the roller unit in the deformation | transformation aspect of embodiment.

<Embodiment>
(1. Overall configuration of constant velocity joint assembly 1)
The constant velocity joint assembly 1 will be described with reference to FIG. The constant velocity joint assembly 1 is used for a power transmission shaft of a vehicle, for example. The constant velocity joint assembly 1 is used at a connection portion between a differential (not shown) and a wheel (not shown).

  As shown in FIG. 1, the constant velocity joint assembly 1 includes a tripod type constant velocity joint 2 (hereinafter referred to as “constant velocity joint”), a shaft 3, and a boot 4. The constant velocity joint 2 includes an outer ring 10, a tripod 20, and three roller units 30. The tripod 20 can move with respect to the outer ring 10 in the outer ring axial direction (left and right direction in FIG. 1) and can tilt.

  The outer ring 10 is formed in a cylindrical shape having an opening on one end side in the axial direction. The outer ring 10 is formed in a bottomed cylindrical shape in the present embodiment, but may be formed in a cylindrical shape that penetrates. In the present embodiment, the outer bottom surface of the outer ring 10 is differentially connected. As shown in FIG. 1, three race grooves 11 extending in the axial direction of the outer ring 10 from the opening of the outer ring 10 toward the back side (left side in FIG. 1) are provided on the inner peripheral surface of the outer ring 10 in the circumferential direction. Are formed at equal intervals.

  The tripod 20 includes a boss 21 and three shaft portions 22 (hereinafter referred to as “tripod shaft portions”) extending radially outward from the boss 21. The outer peripheral surface of each tripod shaft part 22 is formed in a spherical convex shape. That is, the axial cross-sectional shape of the outer peripheral surface of the tripod shaft portion 22 is formed in a circular arc shape.

  Each of the three roller units 30 is formed in an annular shape as a whole. Each of the three roller units 30 is rotatable to the outer peripheral side of each of the three tripod shaft portions 22, is slidable in the axial direction of each tripod shaft portion 22, and the tripod shaft portion 22. It is supported so that it can tilt with respect to each. Further, each of the three roller units 30 is arranged to roll along the raceway groove 11. The three roller units 30 roll while maintaining their postures with respect to the three raceway grooves 11.

  The roller unit 30 is engaged with the outer roller 31, the inner roller 32, the needle 33 sandwiched between the outer roller 31 and the inner roller 32 in the radial direction, and the inner peripheral surface of the outer roller 31. And a retaining ring 34 for preventing the needle 33 from coming off. The roller unit 30 having such a configuration is a double roller type in which two rollers (an outer roller 31 and an inner roller 32) are stacked in the radial direction.

  The shaft 3 is connected to the boss 21 of the tripod 20. That is, torque is transmitted between the members via the tripod 20 and the roller unit 30 with the shaft 3 and the outer ring 10 provided with an angle. Hereinafter, the angle formed by the shaft 3 and the outer ring 10 is also referred to as “joint angle” of the constant velocity joint 2.

  The boot 4 is formed in a bellows cylinder shape that can be expanded and contracted in the axial direction and that can bend the axial center. One end of the boot 4 is attached to the opening side of the outer peripheral surface of the outer ring 10, and the other end of the boot 4 is attached to the outer peripheral surface of the shaft 3. In this way, the boot 4 closes the opening side of the outer ring 10. Grease is accommodated in the inner region of the outer ring 10, and the boot 4 seals the grease so that it does not leak from the opening of the outer ring 10.

(2. Detailed configuration of the outer ring 10 and the roller unit 30)
(2-1. Tilt of the roller unit 30 during torque transmission)
In the raceway groove 11 of the outer ring 10, the groove side surface 13 located on both sides in the groove width direction (left and right direction in FIG. 2) with respect to the bottom 12 has an outer peripheral surface of the roller unit 30 (corresponding to the outer peripheral surface 41 of the outer roller 31). The transmission surface 13a for transmitting torque is formed. The cross-sectional shape of the transmission surface 13a is formed in a concave shape in which a predetermined curvature or a plurality of curvatures are combined.

  As shown in FIG. 2, the roller unit 30 is disposed so that the outer peripheral surface 41 of the roller unit 30 is fitted into the two transmission surfaces 13a. When the outer ring 10 rotates, the roller unit 30 contacts one of the two transmission surfaces 13a of the raceway groove 11 according to the rotation direction, and transmits torque to and from the outer ring 10. That is, when the rotation direction of the outer ring 10 is reversed, the roller unit 30 contacts the other of the two transmission surfaces 13a and transmits torque to and from the outer ring 10.

  Here, when the outer ring 10 rotates in the groove width direction of the raceway groove 11, the direction of torque transmission between the raceway groove 11 and the roller unit 30 is defined as “torque transmission side”. In addition, the side opposite to the torque transmission side and opposite to the direction in which torque is transmitted between the raceway groove 11 and the roller unit 30 is defined as an “anti-torque transmission side”.

  In a state where the center in the groove width direction of the raceway groove 11 and the rotation axis of the roller unit 30 coincide with each other, a slight gap is formed between the outer peripheral surface 41 of the roller unit 30 and each transmission surface 13a facing the outer peripheral surface 41. Provided. Therefore, when torque transmission is performed with the outer ring 10, the roller unit 30 is slightly displaced from the above state to the torque transmission side, and the outer peripheral surface 41 is separated from the transmission surface 13a on the counter-torque transmission side. It will be in the state.

  Further, as described above, the roller unit 30 is supported so as to be tiltable with respect to the tripod shaft portion 22, and is fitted into the two transmission surfaces 13 a of the raceway groove 11 of the outer ring 10. Therefore, the roller unit 30 rolls on the raceway groove 11 while maintaining the posture during torque transmission. However, since the outer peripheral surface 41 of the roller unit 30 is separated from the transmission surface 13a on the counter-torque transmission side, the roller unit 30 may have a tripod shaft depending on the contact position between the outer ring 10 and the tripod shaft portion 22 and the direction of the load. It tilts around an axis parallel to the rotation axis of the outer ring 10 with respect to the portion 22.

  As described above, when the roller unit 30 tilts with the torque transmission of the constant velocity joint 2, the roller unit 30 contacts any part of the inner peripheral surface of the outer ring 10 on the counter-torque transmission side. In the present embodiment, in the roller unit 30, the radially outer end face 42 located on the counter-torque transmission side contacts the bottom 12 of the raceway groove 11 by setting the shapes of the transmission surface 13 a and the outer peripheral surface 41 ( (See FIG. 6). The details of the setting of the shape of the transmission surface 13a and the outer peripheral surface 41 will be described later.

(2-2. Holding of grease at the bottom 12 of the raceway groove 11)
A support surface 12 a that supports the roller unit 30 is formed on the bottom 12 of the raceway groove 11 in contact with the roller unit 30 that tilts with the torque transmission of the constant velocity joint 2 on the counter-torque transmission side. The support surface 12a faces the end surface 42 of the roller unit 30 and is designed to preferentially contact other parts when the roller unit 30 tilts.

  Here, when the roller unit 30 reciprocates in the axial direction of the outer ring 10 in a state where the end surface 42 of the roller unit 30 is in contact with the bottom 12 of the raceway groove 11, the frictional force at the contact portion becomes a sliding resistance. The support surface 12a of the bottom portion 12 is lubricated by the grease accommodated in the inner region of the outer ring 10, and the above-described sliding resistance is reduced. For the purpose of further reducing this sliding resistance, a holding portion for holding the grease accommodated in the outer ring 10 is formed on the support surface 12a. In the present embodiment, the “holding portion” is an oil groove 15 that causes grease to flow in a predetermined direction.

  Here, an application example of the oil groove 15 as the holding portion will be described with reference to FIGS. 3A to 3D. 3A to 3D are views of the bottom portion 12 of the raceway groove 11 as viewed from the front, and the outer roller 31 of the roller unit 30 to be seen through is indicated by a broken line. As shown in FIG. 2 and FIGS. 3A to 3D, the bottom 12 of the raceway groove 11 is located closer to the center side in the groove width direction of the raceway groove 11 than the support surface 12a, and more or less than the support surface 12a. The groove 11 has a retracting surface 12b that is located on the deep side in the groove depth direction (the upper side in FIG. 2) and is not in contact with the roller unit 30.

  As a first aspect of the oil groove 15, as shown in FIG. 3A, the oil groove 15 has a groove shape that allows grease to flow in the axial direction of the outer ring 10. In the first embodiment, two oil grooves 15 are formed. As a second mode of the oil groove 15, as shown in FIG. 3B, the oil groove 15 has a groove shape that allows grease to flow in the rotation direction of the outer ring 10. The oil groove 15 of the second aspect has an opening 15a that extends to the connecting portion between the support surface 12a and the retracting surface 12b and opens at the end of the support surface 12a on the retracting surface 12b side. The opening 15 a functions to promote the inflow of grease into the oil groove 15 from the center side in the groove width direction of the raceway groove 11. In the second aspect, the plurality of oil grooves 15 are arranged at equal intervals in the axial direction of the outer ring 10.

  As a third aspect of the oil groove 15, as shown in FIG. 3C, the oil groove 15 has a groove shape that allows grease to flow in the axial direction and the rotational direction of the outer ring 10. Further, as a fourth aspect of the oil groove 15, as shown in FIG. 3D, the oil groove 15 is inclined with respect to the axial direction of the outer ring 10 and has a groove shape that allows grease to flow in the axial direction and the rotational direction of the outer ring 10. Become. The oil groove 15 of the third aspect and the fourth aspect has a lattice shape as a whole, and has an opening 15a that opens at the end of the support surface 12a on the retracting surface 12b side.

  The oil groove 15 in the above aspect is appropriately set in consideration of the characteristics of grease, the magnitude of torque to be transmitted, and the like, including the shape including the groove depth and groove width, and the interval between adjacent oil grooves 15. The oil groove 15 contacts the end face 42 of the rotating roller unit 30, thereby causing the grease to flow in the rotating direction of the roller unit 30 and the extending direction of the oil groove 15 and holding the grease in the groove portion. Thereby, it will be in the state by which the grease was applied to the support surface 12a, and the suitable lubricating state of the support surface 12a will be maintained.

  Further, in the second to fourth aspects, the oil groove 15 is formed over the entire region of the support surface 12a in the rotation direction of the outer ring 10 (the left-right direction in FIGS. 3B to 3D). That is, on the counter-torque transmission side, the range in which the end surface 42 of the outer roller 31 can contact is limited, but the oil groove 15 is formed to a range exceeding this range. With this configuration, the grease is held over the entire area of the support surface 12a in the rotation direction of the outer ring 10. Further, the grease deposited on the portion of the support surface 12a that does not come into contact with the end surface 42 of the roller unit 30 is scraped out by the roller unit 30 in the case where the rotation direction of the constant velocity joint 2 is reversed. Circulate.

(2-3. Relationship between bottom 12 and groove side surface 13)
The groove side surface 13 of the raceway groove 11 is in contact with the outer peripheral surface 41 of the roller unit 30 to form a transmission surface 13 a that transmits torque to and from the roller unit 30. On the other hand, the bottom 12 of the raceway groove 11 is not a part that contributes to torque transmission, but the roller unit 30 is tilted and brought into contact with the torque transmission of the constant velocity joint 2, so that the end surface 42 of the roller unit 30 A support surface 12a is provided for contacting and supporting.

  Here, as shown in FIG. 4, the boundary portion 14 between the groove side surface 13 of the raceway groove 11 and the support surface 12 a is located at the outermost radial direction of the outer ring 10 on the inner peripheral surface of the outer ring 10. That is, the distance D1 from the rotation axis of the outer ring 10 to the boundary portion 14 is larger than any of the distances at which the portion excluding the other boundary portion 14 on the inner peripheral surface of the outer ring 10 is separated from the rotation axis. For example, the distance D <b> 1 of the boundary portion 14 is larger than the distance D <b> 2 where the corner portion in the groove width direction of the retracting surface 12 b at the bottom portion 12 of the raceway groove 11 is separated from the rotation axis of the outer ring 10.

  When the outer ring 10 or the like rotates with the torque transmission of the constant velocity joint 2, the grease accommodated in the outer ring 10 flows outward in the radial direction of the outer ring 10 by the centrifugal force generated by the rotation. Further, the grease that has flowed to the inner peripheral surface of the outer ring 10 flows and accumulates along the inner peripheral surface up to the radially outermost position depending on the shape of the inner peripheral surface of the outer ring 10. For this reason, the flow of grease to the boundary portion 14 located at the outermost position in the radial direction is promoted by the configuration as described above.

(2-4. Groove side surface 13 of raceway groove 11 and outer peripheral surface 41 of roller unit 30)
In the present embodiment, the shape of the groove side surface 13 of the raceway groove 11 and the outer peripheral surface 41 of the roller unit 30 is set so as to be in the following contact state. That is, as shown in FIG. 5, the groove side surface 13 (transmission surface 13 a) of the raceway groove 11 and the outer peripheral surface 41 of the roller unit 30 are two contact sites (first contact site T <b> 1, second contact site T <b> 1, second contact). Contact is made at the contact site T2).

  As described above, when the constant velocity joint 2 transmits torque, the torque transmission side has a first contact portion T1 and a second contact portion T2 positioned radially inward in the axial direction view. The outer peripheral surface 41 of the roller unit 30 contacts the transmission surface 13a at a location. At this time, a straight line passing through the first contact site T1 and having a contact angle at the first contact site T1 is defined as a first contact line L1.

  A straight line having a contact angle at the second contact site T2 passing through the second contact site T2 is defined as a second contact line L2. The first contact line L1 and the second contact line L2 intersect at the intersection point Pn. The contact angle is the contact surface at the contact site (T1, T2) when the X axis is the axis orthogonal to the central axis of the tripod shaft portion 22 and the rotation axis of the outer ring 10 at a joint angle of 0 °. The acute angle between the normal and the X axis.

  In addition, when the constant velocity joint 2 performs torque transmission in a state where the joint angle is given, the position Tc where the inner peripheral surface 43 of the roller unit 30 and the tripod shaft portion 22 contact each other is two contact sites (T1). , T2), and is radially outward of the outer ring 10 from the intersection Pn of the two contact lines (L1, L2) having the respective contact angles corresponding to the contact portions (T1, T2).

  Here, since the roller unit 30 is in angular contact with the transmission surface 13a of the raceway groove 11 as described above, the inner peripheral surface 43 is located at the position shifted in the radial direction of the outer ring 10 with respect to the intersection Pn. When the torque is transmitted between the two, a load to be tilted about the intersection Pn is received. At this time, in the present embodiment, the contact position Tc between the inner peripheral surface 43 of the roller unit 30 and the tripod shaft portion 22 is located radially outward of the outer ring 10 from the intersection Pn.

  Therefore, when the roller unit 30 tilts with the torque transmission of the constant velocity joint 2, the roller unit 30 has the end face 42 of the roller unit 30 on the side opposite to the torque transmission side as shown in FIG. It rotates in the direction approaching the support surface 12a (the direction indicated by the arrow in FIG. 6). That is, the roller unit 30 is configured such that the transmission surface 13a on the counter-torque transmission side and the outer peripheral surface 41 of the roller unit 30 are not in contact with each other. When the tilting angle of the roller unit 30 reaches a certain level, the support surface 12a lubricated by the action of the oil groove 15 and the end surface 42 of the roller unit 30 come into contact with each other.

(3. Effects of the configuration of the embodiment)
In the embodiment, the support surface 12 a of the raceway groove 11 is formed with a holding portion (oil groove 15) that holds the grease accommodated in the outer ring 10. According to such a configuration, since the holding portion holds the grease accommodated in the outer ring 10, the contact portion between the end surface 42 of the roller unit 30 and the support surface 12a of the raceway groove 11 is suitably lubricated. Thereby, when the constant velocity joint 2 transmits torque, the sliding resistance between the raceway groove 11 of the outer ring 10 and the roller unit 30 can be reduced on the counter-torque transmission side.

  The oil groove 15 is formed on the support surface 12 a of the raceway groove 11. According to such a configuration, the grease is held in the oil groove 15 on the support surface 12 a of the raceway groove 11. Therefore, the sliding resistance when the roller unit 30 rotating at the time of torque transmission of the constant velocity joint 2 is lubricated by the grease held on the side of the raceway groove 11 to cause contact is reduced.

  Further, the holding portion (oil groove 15) has a groove shape that allows grease to flow in the axial direction of the outer ring 10 in the first aspect, the third aspect, and the fourth aspect of the oil groove 15. According to such a configuration, the grease can be held by the oil groove 15 formed corresponding to the moving direction with respect to the roller unit 30 that reciprocates in the raceway groove 11 during torque transmission. Thereby, the end surface 42 of the roller unit 30 can be efficiently lubricated while being in contact with the support surface 12a.

  Further, the bottom 12 of the raceway groove 11 is located on the center side in the groove width direction of the raceway groove 11 with respect to the support surface 12a, and is located on the radially outer side of the outer ring 10 with respect to the support surface 12a. It has a retracting surface 12b that is non-contact. In the second to fourth aspects of the oil groove 15, the holding part (the oil groove 15) opens at the end of the support surface 12 a on the side of the retracting surface 12 b, and has a groove shape that allows grease to flow in the rotational direction of the outer ring 10. This is the oil groove 15. According to such a configuration, the inflow of grease can be promoted from the opening of the oil groove 15. In particular, when grease stays at the end of the support surface 12a on the retracting surface 12b side, the grease can be flowed in the groove side surface direction through the oil groove 15, so that the lubricity can be improved.

  In addition, the boundary portion 14 between the groove side surface 13 of the raceway groove 11 and the support surface 12 a is located on the outermost radial surface of the outer ring 10 on the inner peripheral surface 43 of the outer ring 10. According to such a configuration, since the boundary portion 14 between the groove side surface 13 of the raceway groove 11 and the support surface 12a is located on the outermost surface of the inner peripheral surface 43 of the outer ring 10, the grease is caused by the centrifugal force accompanying the rotation of the outer ring 10. Accumulated at the boundary 14. Thereby, the contact site | part of the support surface 12a located between the said boundary part 14 and the groove bottom center part (site | part with the retracting surface 12b) and the end surface 42 of the roller unit 30 is lubricated suitably.

  The oil groove 15 is formed over the entire area of the support surface 12a in the rotation direction of the outer ring 10. According to such a configuration, the grease can be held over the entire area of the support surface 12a in the rotation direction of the outer ring 10, so that contact between the support surface 12a and the end surface 42 of the roller unit 30 occurs in any part. In addition, sliding resistance can be reduced.

  Further, the groove side surface 13 of the raceway groove 11 and the outer peripheral surface 41 of the roller unit 30 are in contact with each other at two contact sites (first contact site T1 and second contact site T2) serving as an angular contact. When the constant velocity joint 2 performs torque transmission in a state where the joint angle is given, the position Tc where the inner peripheral surface 43 of the roller unit 30 and the shaft portion 22 of the tripod 20 contact each other is two contact sites (T1 , T2) and the radial direction of the outer ring 10 from the intersection Pn of two contact lines (first contact line L1, second contact line L2) having respective contact angles corresponding to the respective contact sites (T1, T2). Is outward.

  According to such a configuration, when the roller unit 30 tilts with torque transmission of the constant velocity joint 2, the roller unit 30 is prevented from tilting radially inward of the outer ring 10 on the counter-torque transmission side. it can. As a result, when the roller unit 30 tilts, the roller unit 30 tilts toward the support surface 12a of the raceway groove 11. Since the support surface 12a is suitably lubricated by the grease held in the oil groove 15, the sliding resistance when the roller unit 30 tilts can be reliably reduced.

<Modification of Embodiment>
In the embodiment, the oil groove 15 having a groove shape is formed on the support surface 12a of the raceway groove 11 as a holding portion for holding the grease. On the other hand, in addition to the groove shape, the holding portion may be appropriately provided with a recess. According to such a configuration, the grease circulating in the outer ring 10 is accumulated and held in the recess. By appropriately setting the position, size, shape, and the like of the recess, the same effects as in the embodiment can be obtained.

  In the embodiment, the oil groove 15 that is a holding portion that holds the grease is disposed on the support surface 12 a of the raceway groove 11. On the other hand, it is good also as a structure by which the holding part is formed in the end surface 42 of the roller unit 30 facing the said support surface 12a instead of the support surface 12a or in addition to the support surface 12a. Specifically, as shown in FIG. 7, in the roller unit 130, an oil groove 145 is formed on the end surface 42 of the outer roller 31 as a holding portion.

  According to such a configuration, the grease is held in the oil grooves 15 and 145 on the end surface 42 of the roller unit 30. Therefore, the grease adhering to the roller unit 30 rotating in the torque transmission of the constant velocity joint 2 is moved to a range where the support surface 12a is located in the raceway groove 11. Thereby, the end surface 42 of the roller unit 30 and the support surface 12a are lubricated, and the sliding resistance when contact occurs is reduced.

<Appendix>
The tripod type constant velocity joint 2 includes an outer ring 10 having a plurality of raceway grooves 11 having an opening on one end side in the axial direction and extending in the axial direction, and a tripod 20 having three shaft parts (tripod shaft part 22). And a plurality of roller units 30 that are formed in an annular shape, are rotatably supported on each of the three shaft portions (22), and roll on each of the plurality of raceway grooves 11.
When the outer ring 10 rotates in the groove width direction of the raceway groove 11, the side opposite to the side where torque is transmitted between the raceway groove 11 and the roller unit 30 is defined as the counter-torque transmission side.
A support surface 12 a that supports the roller unit 30 is formed on the bottom 12 of the raceway groove 11 in contact with the roller unit 30 that tilts with the torque transmission of the constant velocity joint 2 on the counter-torque transmission side. A holding portion (oil groove 15) that holds the grease accommodated in the outer ring 10 is formed on the support surface 12a.

  According to such a configuration, since the holding part (oil groove 15) holds the grease accommodated in the outer ring 10, the contact portion between the end surface 42 of the roller unit 30 and the support surface 12a of the raceway groove 11 is preferably lubricated. Is done. Thereby, when the constant velocity joint 2 transmits torque, the sliding resistance between the raceway groove 11 of the outer ring 10 and the roller unit 30 can be reduced on the counter-torque transmission side. Further, the holding portion (oil groove 15) is formed on the support surface 12 a of the raceway groove 11. According to such a configuration, the grease is held by the holding portion (oil groove 15) on the support surface 12a of the raceway groove 11. Therefore, the sliding resistance when the roller unit 30 rotating at the time of torque transmission of the constant velocity joint 2 is lubricated by the grease held on the side of the raceway groove 11 to cause contact is reduced.

The holding portion (oil groove 15) has a groove shape that allows grease to flow in the axial direction of the outer ring 10.
According to such a configuration, the grease can be held by the holding portion (oil groove 15) formed corresponding to the moving direction with respect to the roller unit 30 that reciprocates in the raceway groove 11 during torque transmission. Thereby, the end surface 42 of the roller unit 30 can be efficiently lubricated while being in contact with the support surface 12a.

The bottom portion 12 of the raceway groove 11 is located on the center side in the groove width direction of the raceway groove 11 with respect to the support surface 12a, and is located on the radially outer side of the outer ring 10 with respect to the support surface 12a and is not in contact with the roller unit 30. It has a retracting surface 12b. The holding portion (oil groove 15) has an opening at the end of the support surface 12a on the retracting surface 12b side, and has a groove shape that allows grease to flow in the rotation direction of the outer ring 10.
According to such a configuration, the inflow of grease can be promoted from the opening of the holding portion (oil groove 15). In particular, when grease stays at the end of the support surface 12a on the retracting surface 12b side, the grease can be flowed in the groove side surface direction through the holding portion (oil groove 15), thereby improving lubricity. it can.

The boundary portion 14 between the groove side surface of the raceway groove 11 and the support surface 12 a is located on the outermost surface in the radial direction of the outer ring 10 on the inner peripheral surface 43 of the outer ring 10.
According to such a configuration, since the boundary portion 14 between the groove side surface 13 of the raceway groove 11 and the support surface 12a is located on the outermost surface of the inner peripheral surface 43 of the outer ring 10, the grease is caused by the centrifugal force accompanying the rotation of the outer ring 10. Accumulated at the boundary 14. Thereby, the contact site | part of the support surface 12a located between the said boundary part 14 and the groove bottom center part (site | part with the retracting surface 12b) and the end surface 42 of the roller unit 30 is lubricated suitably.

The holding portion (oil groove 15) is formed over the entire area of the support surface 12a in the rotation direction of the outer ring 10.
According to such a configuration, the grease can be held over the entire area of the support surface 12a in the rotation direction of the outer ring 10, so that contact between the support surface 12a and the end surface 42 of the roller unit 30 occurs in any part. In addition, sliding resistance can be reduced.

A holding portion (oil groove 145) for holding the grease accommodated in the outer ring 10 is formed on the end surface 42 of the roller unit 30 facing the support surface 12a.
According to such a configuration, the grease is held in the holding portion (oil groove 145) on the end surface 42 of the roller unit 30. Therefore, the grease adhering to the roller unit 30 rotating in the torque transmission of the constant velocity joint 2 is moved to a range where the support surface 12a is located in the raceway groove 11. Thereby, the end surface 42 of the roller unit 30 and the support surface 12a are lubricated, and the sliding resistance when contact occurs is reduced.

The tripod type constant velocity joint 2 includes an outer ring 10 having a plurality of raceway grooves 11 having an opening on one end side in the axial direction and extending in the axial direction, and a tripod 20 having three shaft parts (tripod shaft part 22). And a plurality of roller units 30 that are formed in an annular shape, are rotatably supported on each of the three shaft portions (22), and roll on each of the plurality of raceway grooves 11.
When the outer ring 10 rotates in the groove width direction of the raceway groove 11, the side opposite to the side where torque is transmitted between the raceway groove 11 and the roller unit 30 is defined as the counter-torque transmission side.
A support surface 12 a that supports the roller unit 30 is formed on the bottom 12 of the raceway groove 11 in contact with the roller unit 30 that tilts with the torque transmission of the constant velocity joint 2 on the counter-torque transmission side. A holding portion (oil groove 145) for holding the grease accommodated in the outer ring 10 is formed on the end surface 42 of the roller unit 30 facing the support surface 12a.

  According to such a configuration, the grease is held in the holding portion (oil groove 145) on the end surface 42 of the roller unit 30. Therefore, the grease adhering to the roller unit 30 rotating in the torque transmission of the constant velocity joint 2 is moved to a range where the support surface 12a is located in the raceway groove 11. Thereby, the end surface 42 of the roller unit 30 and the support surface 12a are lubricated, and the sliding resistance when contact occurs is reduced.

The groove side surface of the track groove 11 and the outer peripheral surface 41 of the roller unit 30 are in contact with each other at two contact sites (first contact site T1 and second contact site T2) that form an angular contact. There are two positions Tc at which the inner peripheral surface 43 of the roller unit 30 and the shaft portion (tripod shaft portion 22) of the tripod 20 come into contact with each other when the constant velocity joint 2 performs torque transmission with a joint angle. Than the intersection Pn of two contact lines (first contact line L1 and second contact line L2) having a contact angle corresponding to each contact part (T1, T2) through the contact part (T1, T2) The outer ring 10 is radially outward.
According to such a configuration, when the roller unit 30 tilts with torque transmission of the constant velocity joint 2, the roller unit 30 is prevented from tilting radially inward of the outer ring 10 on the counter-torque transmission side. it can. As a result, when the roller unit 30 tilts, the roller unit 30 tilts toward the support surface 12a of the raceway groove 11. Since the support surface 12a is suitably lubricated by the grease held by the holding portions (oil grooves 15, 145), the sliding resistance when the roller unit 30 tilts can be reliably reduced.

  1: constant velocity joint assembly, 2: tripod type constant velocity joint (constant velocity joint), 10: outer ring, 11: raceway groove, 12: bottom portion, 12a: support surface, 12b: retraction surface, 13: groove side surface, 14 : Boundary portion, 15: oil groove (holding portion), 20: tripod, 22: tripod shaft portion (shaft portion), 30, 130: roller unit, 41: outer peripheral surface, 42: end surface, 43: inner peripheral surface, 145 : Oil groove, T1: First contact part, T2: Second contact part, L1: First contact line, L2: Second contact line, Pn: Intersection, Tc: Contact position

Claims (8)

An outer ring having a plurality of raceway grooves having an opening on one axial end side and extending in the axial direction;
A tripod with three shafts;
A plurality of roller units formed in an annular shape, rotatably supported on each of the three shaft portions, and rolling on each of the plurality of raceway grooves;
A tripod type constant velocity joint comprising:
When the outer ring rotates in the groove width direction of the raceway groove, the side opposite to the side where torque is transmitted between the raceway groove and the roller unit is defined as an anti-torque transmission side,
At the bottom of the raceway groove is formed a support surface that supports the roller unit in contact with the roller unit that tilts with torque transmission of the constant velocity joint on the counter-torque transmission side,
A tripod type constant velocity joint in which a holding portion for holding grease contained in the outer ring is formed on the support surface.   The tripod constant velocity joint according to claim 1, wherein the holding portion has a groove shape that allows the grease to flow in an axial direction of the outer ring. The roller unit is located at a bottom portion of the raceway groove in a center side in the groove width direction of the raceway groove with respect to the support surface, and is located on a deeper side in the groove depth direction of the raceway groove than the support surface. With a retracting surface that is non-contact with
The tripod type constant velocity joint according to claim 1 or 2, wherein the holding portion has a groove shape that opens at an end portion of the support surface on the retraction surface side and allows the grease to flow in a rotation direction of the outer ring.   The tripod type according to any one of claims 1 to 3, wherein a boundary portion between the groove side surface of the raceway groove and the support surface is positioned on an outermost surface in the radial direction of the outer ring on the inner peripheral surface of the outer ring. Constant velocity joint.   The tripod type constant velocity joint according to any one of claims 1 to 4, wherein the holding portion is formed over the entire region of the support surface in the rotation direction of the outer ring.   The tripod type constant velocity according to any one of claims 1 to 5, wherein a holding portion that holds grease contained in the outer ring is formed on an end surface of the roller unit facing the support surface. Joint. An outer ring having a plurality of raceway grooves having an opening on one axial end side and extending in the axial direction;
A tripod with three shafts;
A plurality of roller units formed in an annular shape, rotatably supported on each of the three shaft portions, and rolling on each of the plurality of raceway grooves;
A tripod type constant velocity joint comprising:
When the outer ring rotates in the groove width direction of the raceway groove, the side opposite to the side where torque is transmitted between the raceway groove and the roller unit is defined as an anti-torque transmission side,
At the bottom of the raceway groove is formed a support surface that supports the roller unit in contact with the roller unit that tilts with torque transmission of the constant velocity joint on the counter-torque transmission side,
A tripod type constant velocity joint in which a holding portion for holding grease contained in the outer ring is formed on an end surface of the roller unit facing the support surface. The groove side surface of the raceway groove and the outer peripheral surface of the roller unit are in contact with each other at two contact portions that form an angular contact,
When the constant velocity joint performs torque transmission with a joint angle, the position where the inner peripheral surface of the roller unit and the shaft portion of the tripod contact each passes through the two contact sites. The tripod type constant velocity joint as described in any one of Claims 1-7 which is a radial direction outer side of the said outer ring | wheel rather than the intersection of the two contact lines which have each contact angle corresponding to the said contact part.

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