JP5372364B2 - Tripod type constant velocity universal joint - Google Patents

Abstract

A tripod type constant velocity universal joint has an outer ring (10) having three axially extending track grooves (12) formed on the inner peripheral surface of the outer ring with each track groove (12) having axially extending roller guide surfaces (14) arranged on both sides of the track groove (12) of the outer ring (10), a tripod member (20) having three radially projecting leg shafts (24), rollers (30) rotatably supported by the leg shafts (24) of the tripod member (20), rollably inserted in the track grooves (12), and guided along the roller guide surfaces (14), and needle-like rollers (40) arranged between each leg shaft (24) and each roller (30). Each leg shaft (24) has a circumferential groove (23) formed on the outer peripheral surface of the leg shaft and receiving needle-like rollers (40), and the groove (23) has a bottom surface (23a) functioning as the rolling surface for the needle-like rollers (40). Each groove (23) has an inner flange (25) formed at the radial base end of the groove and also has an outer flange (27) formed at the radial head end of the groove. Flange surfaces (25a, 27a) formed between the bottom surface (23a) of the groove (23) and the inner and outer flanges (25, 27) are tapered, and the angle of the tapering defined as the angle of opening of the groove (23) relative to the bottom surface (23a) is set greater than 90 degrees and not greater than 140 degrees.

Description

  The present invention is used in power transmission systems such as automobiles, airplanes, ships, and various industrial machines, and is incorporated in drive shafts and propeller shafts used in, for example, 4WD vehicles and FR vehicles. The present invention relates to a tripod type constant velocity universal joint which is a kind of sliding type constant velocity universal joint that allows axial displacement and angular displacement between two axes.

  For example, there is a tripod type constant velocity universal joint as one of constant velocity universal joints used as means for transmitting rotational force from an automobile engine to wheels at a constant speed (see, for example, Patent Document 1). This tripod type constant velocity universal joint connects two shafts on the drive side and the driven side, transmits rotational torque at a constant speed even if the two shafts take an operating angle, and also allows relative displacement in the axial direction. It has a structure that can

  7 and 8 show the structure of the tripod type constant velocity universal joint disclosed in Patent Document 1. FIG. FIG. 7 shows a transverse section with respect to the axis of the joint, and FIG. 8 shows a longitudinal section with respect to the axis of the joint.

  The tripod type constant velocity universal joint shown in the figure is composed of an outer ring 110 as an outer joint member, a tripod member 120 as an inner joint member, and a roller 130 as a rolling element. One shaft (drive shaft) of the drive side and the driven side to be connected extends integrally from the bottom of the outer ring 110, and the other shaft (not shown) is coupled to the tripod member 120.

  The outer ring 110 has a bottomed cylindrical shape with one end opened, and three track grooves 112 extending in the axial direction are formed at equal intervals in the circumferential direction on the inner circumference thereof. The tripod member 120 has three leg shafts 124 projecting radially outward from the cylindrical boss portion 122, and these leg shafts 124 are inserted into the track grooves 112 of the outer ring 110 and engaged with the track grooves 112. Torque transmission. A roller 130 is rotatably fitted on the leg shaft 124 via a needle roller 140, and the roller 130 rolls along a pair of roller guide surfaces 114 facing each other in the track groove 112, thereby connecting two shafts. Smooth the angular displacement and axial displacement between.

  FIG. 9 is a partially enlarged view of FIG. 7 and shows the leg shaft 124, the needle rollers 140, and the rollers 130. The outer circumferential surface of the leg shaft 124 constitutes the inner rolling surface of the needle roller 140, and the inner circumferential surface of the roller 130 constitutes the outer rolling surface of the needle roller 140. The plurality of needle rollers 140 are disposed between the outer peripheral surface of the leg shaft 124 and the inner peripheral surface of the roller 130 in a full roller state.

These needle rollers 140 are in contact with the inner washer 150 fitted to the base of the leg shaft 124 inward in the radial direction, and are radially outward with the outer washer 160 fitted in the tip of the leg shaft 124. It touches. The outer washer 160 is prevented from coming off by fitting a retaining ring 170 such as a circlip into an annular groove 126 formed at the tip of the leg shaft 124, and the retaining ring 170 causes the needle roller 140 to move in the radial direction. Movement is restricted.
Japanese Patent No. 3615987

  By the way, in the tripod type constant velocity universal joint disclosed in the above-mentioned Patent Document 1, the leg shaft 124 of the tripod member 120 moves in the radial direction relative to the roller 130 with the rotation of the joint with the operating angle taken. Therefore, it is necessary to regulate the position of the needle roller 140 interposed between the roller 130 and the leg shaft 124 in the radial direction.

  Therefore, as described above, the needle roller 140 is popped out and dropped by preventing the needle roller 140 from coming off by the retaining ring 170 fitted to the tip end portion of the leg shaft 124 and the outer washer 160. I try to prevent it.

  However, in this retaining structure using the retaining ring 170 and the outer washer 160, in addition to the components such as the needle roller 140 and the roller 130, additional parts for the retaining ring 170 and the outer washer 160 are required. Increase the cost of the product.

  Further, when the needle roller 140 is assembled between the leg shaft 124 and the roller 130, the outer washer 160 is externally fitted to the distal end portion of the leg shaft 124, and the retaining ring 170 is fitted to the annular groove 126 of the leg shaft 124. It is necessary to prevent the needle rollers 140 to be detached, and it is difficult to improve the assembling workability.

  Therefore, the present invention has been proposed in view of the above-described problems, and an object of the present invention is to provide a tripod type constant velocity universal joint capable of reducing the number of parts and improving assembly workability. There is.

As a technical means for achieving the above-mentioned object, the tripod type constant velocity universal joint according to the present invention is formed with three track grooves extending in the axial direction on the inner peripheral surface, and shafts on both sides of each track groove. The outer joint member having a roller guide surface extending in the direction, the tripod member having three leg shafts projecting in the radial direction, and rotatably supported by the leg shaft of the tripod member and being transferred to the track groove of the outer joint member. A roller that is movably inserted and guided along the roller guide surface; and a plurality of needle rollers disposed between the leg shaft and the roller, and the needle rollers are provided on the outer peripheral surface of the leg shaft. A concave groove portion is formed in the circumferential direction that is accommodated and the bottom surface becomes the rolling surface of the needle roller, and an inner flange portion is provided on the radially proximal end side of the concave groove portion and an outer flange portion is provided on the radially distal end side. Formed between the heel and outer ridges and the bottom of the groove The rib face is tapered which is greater than 90 ° with opening angle of the taper angle from the bottom surface of the recessed groove portion, and 140 ° or less, the radial dimension of the recessed groove portion of the trunnion, one needle roller The sum of the gap between the contact point between the end of the inner flange and the tapered surface of the inner flange and the contact point between the other end of the needle roller and the tapered surface of the outer flange is the normal operating angle of the joint. The leg shaft is set to be larger than the maximum movement amount when moving in the radial direction of the outer joint member .

  In the present invention, on the outer peripheral surface of the leg shaft, a concave groove portion is formed in the circumferential direction in which the needle roller is accommodated and the bottom surface becomes the rolling surface of the needle roller, and the inner flange is formed on the radial base end side of the concave groove portion. By providing the outer flange on the distal end side in the radial direction, the needle rollers housed in the concave groove can be removed from the inner flange and the outer without requiring a retaining ring and an outer washer as in the prior art. The position can be restricted in the radial direction with the collar.

  In this way, the number of parts can be reduced and the assembly workability can be improved. Even if the leg shaft moves in the radial direction relative to the roller in a state where the joint has an operating angle, the radius of the leg shaft can be reduced. The needle roller can be prevented from jumping out of the groove and falling off by the outer flange provided on the tip side in the direction, and the needle roller can stably roll between the outer peripheral surface of the leg shaft and the inner peripheral surface of the roller. Is possible. Even in this case, the inner flange functions as a means for restricting the position of the needle rollers inward in the radial direction.

Further, the flange surface formed between the inner flange portion and the outer flange portion and the bottom surface of the groove portion is tapered, and the taper angle is larger than 90 ° by an opening angle from the bottom surface of the groove portion, and 140 °. When compared with a configuration in which the flange surface extends in a direction orthogonal to the bottom surface of the concave groove portion, the needle roller moves when the needle roller moves in the radial direction between the inner flange portion and the outer flange portion. The contact area between the inner collar part of the inner collar part and the tapered collar surface of the outer collar part becomes smaller, and the contact between the inner collar part or outer collar part and the needle roller from the bottom surface of the concave groove part. The distance to the point is reduced. As a result, since the force to fall the needle rollers in the rolling direction is reduced when the needle rollers roll along the circumferential direction of the leg shaft, the needle rollers can be smoothly rolled. it can.

When the taper angle is 90 ° or less from the bottom surface of the groove portion, the distance from the bottom surface of the groove portion to the contact point between the inner flange portion or the outer flange portion and the needle roller is increased. Smooth rolling of the roller is prevented. On the other hand, when the taper angle is larger than 140 ° as the opening angle from the bottom surface of the groove portion, the holding ability of the needle rollers is reduced. Therefore, the taper angle is defined to be larger than 90 ° and 140 ° or less in terms of the opening angle from the bottom surface of the concave groove portion, so that the needle roller is securely held in the concave groove portion and the needle roller is legged. This is effective in that it rolls smoothly in the axial direction of the shaft.
Further, the radial dimension of the concave groove portion of the leg shaft is determined so that the total gap existing between the both end portions of the needle rollers and the inner flange portion and the outer flange portion is the leg shaft of the outer joint member at the normal operating angle of the joint. By setting it to be larger than the maximum movement amount when moving in the radial direction, the amount that the needle roller can move in the radial direction is the same as that when the leg shaft moves in the radial direction at the normal operating angle of the joint. Since it becomes larger than the maximum travel distance, the number of times the end of the needle roller contacts the inner collar part or the outer collar part can be reduced. As a result, the rotational behavior of the needle roller is stabilized, so this constant speed is freely adjustable. This contributes to the improvement of NVH (Noise Vibration Harshness) performance of automobiles equipped with joints.

  In the present invention, it is desirable that at least the bottom surface of the concave groove portion of the leg shaft is formed by quenching steel cutting or total shape grinding. Since the bottom surface of the concave groove part of the leg shaft becomes the rolling surface of the needle roller, if the bottom surface is formed by quenching steel cutting or general grinding, the bottom surface of the concave groove part should be formed with high accuracy. And a good rolling surface of the needle roller can be secured.

  In the present invention, it is desirable that the leg shaft has a forged skin except for the groove portion. Here, the leg shaft of the tripod member is manufactured by forging, and it is a concave groove portion that requires dimensional accuracy with the leg shaft, and a portion other than the concave groove portion does not require so high dimensional accuracy. Therefore, if the surface of the portion excluding the concave groove portion of the leg shaft is left as the forged skin, it is not necessary to perform a process such as a curing process, so that the manufacturing cost can be reduced.

  In the present invention, the leg shaft preferably has a structure in which a hardened surface layer is formed at a site including at least the recessed groove portion and the inner flange portion. Here, “a part including at least the concave groove part and the inner collar part” means that the concave groove part and the inner collar part are included as necessary, and a part other than the concave groove part and the inner collar part in the leg shaft is also included. If a hardened surface layer is formed in the concave groove, the rolling fatigue strength with the needle roller in the concave groove can be improved. In addition, if a hardened surface layer is formed on the inner flange, it is possible to ensure strength against bending stress applied to the leg shaft.

  In the present invention, when the common operating angle of the joint is large (for example, larger than 6 °), the radial center position of the concave groove portion of the leg shaft has a radius that is larger than the radial center position of the roller guide surface of the outer joint member. A structure offset in the outward direction is desirable. On the other hand, when the common operating angle of the joint is small (for example, 6 ° or less), the radial center position of the concave groove portion of the leg shaft is made to coincide with the radial center position of the roller guide surface of the outer joint member. A structure is desirable.

  This is based on the following reason. In a state where the joint takes an operating angle, the leg shaft moves in the radial direction relative to the roller as the joint rotates. At this time, the movement amount of the leg shaft is greater in the movement amount in the radial direction than in the radial direction, and the movement amount in the radial direction is larger in proportion to the operating angle. Become.

  Therefore, when the common operating angle of the joint is large, the movement amount of the leg shaft inward in the radial direction is large. Therefore, the radial center position of the concave groove portion of the leg shaft is set in the radial direction of the roller guide surface of the outer joint member. It is preferable to offset outward in the radial direction from the center position. Also, when the common operating angle of the joint is small, the radial center position of the concave groove portion of the leg shaft and the radial center position of the roller guide surface of the outer joint member are used to prevent uneven wear of the concave groove portion of the leg shaft. Is preferably matched.

  According to the present invention, on the outer peripheral surface of the leg shaft, the concave groove portion that accommodates the needle roller and the bottom surface becomes the rolling surface of the needle roller is formed in the circumferential direction, and the radial groove proximal end side of the concave groove portion is formed. By providing the inner flange and the outer flange on the distal end side in the radial direction, the needle roller accommodated in the concave groove can be moved into the inner flange without the need for a retaining ring or an outer washer. The position can be regulated in the radial direction by the outer flange portion.

  In this way, the number of parts can be reduced and the assembly workability can be improved. Even if the leg shaft moves in the radial direction relative to the roller in a state where the joint has an operating angle, the radius of the leg shaft can be reduced. The needle roller can be prevented from jumping out of the groove and falling off by the outer flange provided on the tip side in the direction, and the needle roller can stably roll between the outer peripheral surface of the leg shaft and the inner peripheral surface of the roller. Is possible.

  As a result, it is possible to provide a tripod type constant velocity universal joint that secures stable operability while reducing the number of parts and improving assembly workability.

  1 and 2 show an embodiment of a tripod type constant velocity universal joint according to the present invention. 1 shows a transverse section with respect to the axis of the joint, and FIG. 2 shows a longitudinal section with respect to the axis of the joint. The tripod type constant velocity universal joint according to this embodiment includes an outer ring 10 that is an outer joint member, a tripod member 20 that is an inner joint member, and a roller 30 that is a rolling element.

  The outer ring 10 has a bottomed cylindrical shape with one end opened, and a rotating shaft (for example, a driving shaft) integrally extends from the center of the bottom. Three track grooves 12 extending in the axial direction are formed on the inner peripheral surface of the outer ring 10 at equal intervals in the circumferential direction. Each track groove 12 has a pair of roller guide surfaces 14 facing each other on both sides thereof. The roller guide surface 14 has an arc-shaped cross section and extends linearly in the axial direction of the outer ring 10. The outer ring 10 has a recess 18 formed in the axial direction by reducing the thickness of a portion corresponding to the space between the track grooves 12 in order to reduce the weight.

  The tripod member 20 is formed by integrally forming three leg shafts 24 protruding outward in the radial direction on the outer peripheral surface of a cylindrical boss portion 22 at equal intervals in the circumferential direction (120 ° intervals). A shaft end of a rotating shaft (not shown) (not shown) is connected to the shaft hole of the boss 22 by spline fitting. The tip of each leg shaft 24 extends outward in the radial direction and extends to the vicinity of the bottom surface of the track groove 12, and the outer peripheral surface thereof is generally a cylindrical surface.

  A roller 30 is rotatably disposed via a needle roller 40 between the roller guide surface 14 of the track groove 12 of the outer ring 10 and the outer peripheral surface of the leg shaft 24. The outer peripheral surface of the roller 30 has an arc shape in vertical section, and may contact with the roller guide surface 14 at two locations by angular contact or contact at one location by circular contact. On the other hand, the inner peripheral surface of the roller 30 is formed in a cylindrical shape.

  A roller 30 rotatably mounted on the leg shaft 24 of the tripod member 20 via a needle roller 40 is inserted into and engaged with the track groove 12 of the outer ring 10, and a pair of track grooves 12 facing each other. By rolling along the roller guide surface 14, torque is transmitted while allowing angular displacement and axial displacement between the two connecting shafts (drive shaft and driven shaft).

  FIG. 3 is a partially enlarged view of FIG. 1 and shows the leg shaft 24, the needle rollers 40, and the rollers 30. The outer circumferential surface of the leg shaft 24 constitutes the inner rolling surface of the needle roller 40, and the inner circumferential surface of the roller 30 constitutes the outer rolling surface of the needle roller 40. A plurality of needle rollers 40 are disposed between the inner peripheral surface of the roller 30 and the outer peripheral surface of the leg shaft 24 in a single row full roller state.

  In the tripod type constant velocity universal joint in this embodiment, as shown in the figure, the concave groove portion in which the needle roller 40 is accommodated on the outer peripheral surface of the leg shaft 24 and the bottom surface 23 a becomes the rolling surface of the needle roller 40. 23 is formed in the circumferential direction, and an inner flange portion 25 is provided on the radially proximal end side of the concave groove portion 23 and an outer flange portion 27 is provided on the distal end side in the radial direction. In order to smoothly move the needle rollers 40 in the radial direction between the bottom surface 23a of the groove 23 and the flange surfaces 25a, 27a, a relief 29 recessed so as to retreat from the bottom 23a of the groove 23 is provided. (Nusumi) is formed.

  In the tripod type constant velocity universal joint in this embodiment, the concave groove portion 23 in which the needle roller 40 is accommodated on the outer peripheral surface of the leg shaft 24 and the bottom surface 23a becomes the rolling surface of the needle roller 40 is formed in the circumferential direction. By providing the inner flange 25 on the proximal end side in the radial direction of the concave groove 23 and the outer flange 27 on the distal end side in the radial direction, a conventional retaining ring 170 and outer washer 160 (see FIGS. 9), the position of the needle roller 40 accommodated in the recessed groove portion 23 can be restricted in the radial direction by the inner flange portion 25 and the outer flange portion 27. In particular, in this embodiment, the end of the needle roller 40 abuts on the flange surface 25a of the inner flange portion 25 and the flange surface 27a of the outer flange portion 27, so that the radial movement of the needle roller 40 is restricted. The

  In this way, the number of parts can be reduced and the assembly workability can be improved, and even if the leg shaft 24 moves in the radial direction relative to the roller 30 in a state where the joint takes an operating angle, the leg shaft It is possible to prevent the needle roller 40 from jumping out of the groove 23 and falling off by the outer flange 27 provided on the distal end side in the radial direction of 24, and between the outer peripheral surface of the leg shaft 24 and the inner peripheral surface of the roller 30. The needle roller 40 can be stably rolled. In this case as well, the inner flange 25 functions as a means for restricting the position of the needle rollers 40 inward in the radial direction.

In this embodiment, the inner flange portion 25 and the outer flange portion 27 have a structure having tapered flange surfaces 25 a and 27 a that are reduced in diameter toward the bottom surface 23 a of the recessed groove portion 23. The inner flange portion side flange surface 25a, the outer flange portion side flange surface 27a, and the bottom surface 23a of the recessed groove portion 23 form taper angles α ₁ and α ₂ . In this embodiment, the case where the angles α ₁ and α ₂ are the same size is illustrated, but may be different sizes.

  As described above, since the flange surfaces 25a and 27a of the inner flange portion 25 and the outer flange portion 27 are tapered, the needle rollers 40 are radially disposed between the inner flange portion 25 and the outer flange portion 27. When moving, the end of the needle roller 40 comes into contact with the tapered flange surface 25a of the inner flange portion 25 or the tapered flange surface 27a of the outer flange portion 27, so that the radial movement of the needle roller 40 is restricted. Is done.

  4A shows an embodiment in which the flange surface 25a of the inner flange portion 25 is tapered, and FIG. 4B shows an embodiment in which the flange surface 28a of the inner flange portion 28 is orthogonal to the bottom surface 26a of the recessed groove portion 26. The comparative form extended in a direction is shown. As shown in FIGS. 4A and 4B, the embodiment has a smaller area in which the end of the needle roller 40 contacts the tapered flange surface 25a of the inner flange portion 25 than the comparative embodiment, and is recessed. The distance from the bottom surface 23a of the groove 23 to the contact point becomes small (a <b). As a result, since the force to fall the needle roller 40 in the rolling direction is reduced when the needle roller 40 rolls in the circumferential direction of the leg shaft 24, the needle roller 40 rolls smoothly. Can be made. Although not shown, this is the same for the tapered flange surface 27a of the outer flange portion 27.

The taper angles α ₁ and α ₂ are defined to be an opening angle from the bottom surface 23a of the groove 23 greater than 90 ° and 140 ° or less, preferably 130 °. When the taper angles α ₁ and α ₂ are 90 ° or less, the distance from the bottom surface of the concave groove portion to the contact point between the inner flange portion or the outer flange portion and the needle roller increases, and the needle roller smoothly rotates. Movement is hindered. On the contrary, when it becomes larger than 140 °, the holding ability of the needle rollers becomes small. Therefore, when the taper angles α ₁ and α ₂ are defined to be larger than 90 ° and 140 ° or less, the needle rollers are securely held in the groove and the needle rollers are circumferential in the leg axis direction. It is effective in that it rolls smoothly.

  In the tripod member 20 of this embodiment, the bottom surface 23a of the concave groove portion 23 of the leg shaft 24 is formed by quenching steel cutting or total grinding. Since the bottom surface 23a of the concave groove portion 23 of the leg shaft 24 is a rolling surface of the needle roller 40, the bottom surface of the concave groove portion 23 is formed by forming the bottom surface 23a by quenching steel cutting or general grinding. 23a can be formed with high accuracy, and a good rolling surface of the needle roller 40 can be secured.

  Further, the leg shaft 24 has a forged skin except for the concave groove 23. Here, the leg shaft 24 of the tripod member 20 is manufactured by forging, and it is the groove 23 that requires dimensional accuracy in the leg shaft 24. For this reason, as described above, it is an effective means to form the bottom surface 23a of the concave groove portion 23 of the leg shaft 24 by quenching steel cutting or total shape grinding.

  On the other hand, the portions other than the concave groove portion 23 do not require so high dimensional accuracy. Therefore, if the surface of the part of the leg shaft 24 excluding the recessed groove portion 23 is left as a forged skin, it is not necessary to perform a hardened steel cutting process or a total form grinding process, so that the manufacturing cost can be reduced.

  Further, as shown in FIG. 5, a hardened surface layer n is formed in the concave groove portion 23 and the inner flange portion 25 of the leg shaft 24. By forming the surface hardened layer n in the concave groove 23, the rolling fatigue strength with the needle roller 40 in the concave groove 23 can be improved. Further, by forming the surface hardened layer n on the inner flange portion 25 which is the base portion of the leg shaft 24, it is possible to ensure the strength against the bending stress applied to the leg shaft 24. It should be noted that a hardened surface layer may be formed on the leg shaft 24 at other portions than the concave groove portion 23 and the inner flange portion 25.

  The leg shaft 24 moves in the radial direction relative to the roller 30 as the joint rotates while the joint takes an operating angle. At this time, the movement amount of the leg shaft 24 is larger in the movement amount in the radial direction than in the radial direction, and the movement amount in the radial direction is proportional to the operating angle. growing.

Therefore, when the common operating angle of the joint is large (for example, larger than 6 °), the amount of movement of the leg shaft 24 in the radial direction is large as shown in FIG. The radial center position P ₂ of the concave grooves 26 and 23 may be offset radially outward from the radial center position P of the roller guide surface 14 of the outer ring 10 (offset amount f ₂ ).

On the other hand, when the common operating angle of the joint is small (for example, 6 ° or less), as shown in FIG. 3, the radial center position P ₂ of the concave groove 23 of the leg shaft 24 and the roller guide surface of the outer ring 10 are used. 14 radial center positions P may be made coincident with each other. If it does in this way, it will become possible to prevent the partial wear of the ditch | groove part 23 of the leg axis | shaft 24. FIG.

  Further, the radial dimension of the concave groove portion 23 of the leg shaft 24 is such that the total gap existing between the both end portions of the needle roller 40 and the inner flange portion 25 and the outer flange portion 27 corresponds to the leg shaft at the normal operating angle of the joint. 24 is set to be larger than the maximum movement amount when moving in the radial direction.

  In this way, the amount of movement of the needle roller 40 in the radial direction is larger than the maximum movement amount when the leg shaft 24 moves in the radial direction at the normal operating angle of the joint. The number of times that the end of 40 contacts the inner flange 25 or the outer flange 27 can be reduced. As a result, the rotational behavior of the needle roller 40 is stabilized. Vibration Harshness) Contributes to improved performance.

In the case of this embodiment, the total gap existing between the both end portions of the needle roller 40 and the inner flange portion 25 and the outer flange portion 27 is as shown in FIG. The gap S ₃ between the one end of the needle roller 40 and the contact point between the tapered surface 25 a of the inner flange 25 and the needle roller 40 in a state where the concave groove 23 of the leg shaft 24 is at the center position in the radial direction. It means the sum of the gaps S ₄ between the other end and the contact point between the outer flange 27 and the tapered surface 27a.

  The present invention is not limited to the above-described embodiments, and can of course be implemented in various forms without departing from the gist of the present invention. It includes the equivalent meanings recited in the claims and the equivalents recited in the claims, and all modifications within the scope.

1 is a cross-sectional view of a joint in an embodiment of a tripod type constant velocity universal joint according to the present invention. 1 is a longitudinal sectional view of a joint in an embodiment of a tripod type constant velocity universal joint according to the present invention. It is a principal part expanded sectional view which shows the leg shaft of FIG. 1, a needle roller, and a roller. (A) is the principal part expanded sectional view which shows embodiment of this invention which made the collar face of the inner collar part tapered in embodiment of this invention, (B) is the bottom face of a ditch | groove part, and the collar face of an inner collar part is shown. It is a principal part expanded sectional view which shows the comparative form extended in the orthogonal direction. In embodiment of this invention, it is a principal part expanded sectional view which shows the state in which the surface hardening layer was formed in the ditch | groove part and inner side collar part of a leg shaft. FIG. 4 is an enlarged cross-sectional view of a main part showing an offset state in which the radial center position of the concave groove portion of the leg shaft is offset radially outward from the radial center position of the roller guide surface of the outer ring in the embodiment of the present invention. It is an example of the conventional tripod type constant velocity universal joint, and is a cross-sectional view of the joint. It is an example of the conventional tripod type constant velocity universal joint, and is a longitudinal cross-sectional view of the joint. It is a principal part expanded sectional view which shows the leg axis | shaft of FIG. 7, a needle roller, and a roller.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Outer joint member 12 Track groove 14 Roller guide surface 20 Tripod member 23 Concave groove portion 23a Bottom surface 24 Leg shaft 25 Inner flange 25a Tapered flange 27 Outer flange 27a Tapered flange 30 Roller 40 Needle roller

Claims (6)

Three track grooves extending in the axial direction are formed on the inner peripheral surface, and an outer joint member having a roller guide surface extending in the axial direction on each side of each track groove and three leg shafts projecting in the radial direction are provided. A tripod member, a roller rotatably supported by a leg shaft of the tripod member, and a roller that is rotatably inserted into a track groove of the outer joint member and guided along the roller guide surface, and the leg shaft; In a tripod type constant velocity universal joint provided with a plurality of needle rollers arranged between the rollers,
On the outer peripheral surface of the leg shaft, a concave groove portion is formed in the circumferential direction in which the needle rollers are accommodated and the bottom surface serves as a rolling surface of the needle rollers, and an inner flange portion is provided on the radial base end side of the concave groove portion. An outer flange is provided on the radial front end side, the flange formed between the inner flange and the outer flange and the bottom surface of the groove portion is tapered, and the taper angle is changed from the bottom surface of the groove portion. The opening angle is greater than 90 ° and not more than 140 °, and the radial dimension of the concave groove portion of the leg shaft is defined as a gap between a contact point between one end of the needle roller and the tapered surface of the inner flange. The total clearance between the other end of the needle roller and the contact point between the tapered surface of the outer flange is the maximum amount of movement when the leg shaft moves in the radial direction of the outer joint member at the normal operating angle of the joint. Tripod type constant velocity universal joint, characterized in that it is set to be larger .   The tripod type constant velocity universal joint according to claim 1, wherein at least the bottom surface of the concave groove portion of the leg shaft is formed by quenching steel cutting or general grinding.   The tripod type constant velocity universal joint according to claim 1, wherein the leg shaft is a forged skin except for the recessed groove portion.   The tripod type constant velocity universal joint according to any one of claims 1 to 3, wherein the leg shaft has a surface hardened layer formed at a portion including at least a concave groove portion and an inner flange portion.   The tripod type | mold etc. as described in any one of Claims 1-4 which offset the radial direction center position of the concave groove part of the said leg shaft to the radial direction outward rather than the radial direction center position of the roller guide surface of an outer joint member. Fast universal joint.   The tripod type constant velocity universal joint according to any one of claims 1 to 4, wherein the radial center position of the concave groove portion of the leg shaft and the radial center position of the roller guide surface of the outer joint member are matched.

Images