JP6752633B2 - Constant velocity universal joint - Google Patents

Description

The present invention relates to a constant velocity universal joint, and more particularly to a constant velocity universal joint applied as a power transmission mechanism of an automobile and various industrial machines.

Constant velocity universal joints (fixed constant velocity universal joints) applied as a power transmission mechanism for automobiles and various industrial machines generally have a seal structure using bellows-shaped boots in many cases. That is, in a constant velocity universal joint, rubber or resin boots are generally attached as a sealing member for preventing foreign matter from entering from the outside and grease from leaking from the inside (Patent Documents). 1).

Then, in the case of low-angle high-speed rotation such as that used for propeller shafts in automobiles and direct connection to motors in industrial machines, metal ring boots (see FIG. 5) that are advantageous for rotational expansion are applied. By the way, in recent years, in order to improve production efficiency in industrial machinery and equipment, the speeding up is accelerating, and there is a need for a device capable of higher speed rotation.

In the constant velocity universal joint shown in FIG. 5, an outer joint member 3 having a track groove 2 formed on the inner diameter surface 1 and a track groove 5 paired with the track groove 2 of the outer joint member 3 are formed on the outer diameter surface 4. A ball 7 that is interposed between the inner joint member 6 and the track groove 2 of the outer joint member 3 and the track groove 5 of the inner joint member 6 to transmit torque, and the inner diameter surface 1 of the outer joint member 3 and the inner joint. A cage 8 for holding the ball 7 is provided between the member 6 and the outer diameter surface 4.

The center of curvature O1 of the track groove 2 of the outer joint member 3 and the center of curvature O2 of the track groove 5 of the inner joint member 6 are equidistant from the joint center O on the opposite side in the axial direction. In this case, the center of curvature O2 of the track groove 5 of the inner joint member 6 is arranged on the adapter side described later from the joint center O, and the center of curvature O1 of the track groove 2 of the outer joint member 3 is arranged on the anti-adapter side. To.

A female spline 10 is formed on the inner diameter surface of the axial core hole of the inner joint member 6, and a male spline 12 at the tip of the stub shaft 11 is fitted into the axial core hole. As a result, the female spline 10 and the male spline 12 mesh with each other. Stop rings 13 and 14 to prevent the male spline 12 from coming off are attached to the tip end portion and the base end portion, respectively. That is, a circumferential groove 12a is formed at the tip of the male spline 12, a circumferential groove 12b is formed at the base end of the male spline 12, and retaining rings 13 and 14 are attached to the circumferential grooves 12a and 12b. ..

At this time, the retaining ring 13 comes into contact with one end surface 6a (the end surface on the adapter side described later) of the inner joint member 6, and the retaining ring 14 is the inner diameter of the other end surface 6b (the end surface on the anti-adapter side) of the inner joint member 6. It is fitted in a notch 15 provided in the portion. Therefore, the shaft 11 is restricted from moving in the axial direction with respect to the inner joint member 6.

A pipe member 16 is continuously provided on the base end side of the stub shaft 11. That is, a boss portion 11b is formed at the base end portion of the stub shaft 11, and the pipe material 16 is connected to the boss portion 11b. In this case, a fitting portion 17 is formed in the boss portion 11b, the fitting portion 17 is internally fitted in the opening of the pipe material 16, and the large diameter portion 18 of the boss portion 11b and the pipe material 16 are welded. Etc. are joined.

The outer joint member 3 is a disc type, and the adapter 20 is mounted on one end face 3a side, and the boot fixing plate 21 is mounted on the other end face 3b side. That is, the adapter 20 is made of a tubular body having a key groove 20a formed on the inner diameter surface, and a fitting recess 20b into which the end surface of the outer joint member 3 on the adapter 20 side is fitted is formed on the end surface on the joint body side. A packing 9a is attached between the end face 3a and the end surface 3a. Further, the boot fixing plate 21 is made of a flat plate ring body, and the end surface on the joint body side is provided with a fitting recess 21a into which the end portion on the opposite side of the outer joint member 3 is fitted, and is provided with the end surface 3b. A packing 9b is attached between them. The packings 9a and 9b are molded from a synthetic material of paper + resin. In addition, metal (iron, stainless steel, aluminum, etc.) or liquid gasket can be applied to the packing depending on the usage conditions and environment.

The boot fixing plate 21 and the outer joint member 3 are provided with through holes 22 and 23, and the adapter 20 is provided with screw holes 24. Therefore, the end of the outer joint member 3 on the adapter side is fitted into the fitting recess 20b of the adapter 20, and the end of the outer joint member 3 on the non-adapter side is fitted into the fitting recess 21a of the boot fixing plate 21. Match. In this state, the bolt member 25 is fitted into the through hole 22 of the boot fixing plate 21 and the through hole 23 of the outer joint member 3, and the screw portion 25a of the bolt member 25 is screwed into the screw hole 24 of the adapter 20. For example, the boot fixing plate 21, the outer joint member 3, and the adapter 20 are integrated.

Further, the opening on the shaft side of the constant velocity universal joint is sealed by the sealing device 30. In this case, the sealing device is flexible with a U-shaped cross section that connects the metal inner diameter side cylinder portion 30a, the metal outer diameter side cylinder portion 30b, the inner diameter side cylinder portion 30a, and the outer diameter side cylinder portion 30b. It is composed of a bent portion 30c made of a sex material.

The inner diameter side cylinder portion 30a is fitted onto the shaft 11, and the outer diameter side cylinder portion 30b is fixed to the outer joint member 3 via the boot fixing plate 21. That is, a flange portion 26 extending in the outer diameter direction is provided at the end portion of the outer diameter side tubular portion 30b on the joint side, and the flange portion 26 is formed on the inner diameter portion of the end surface of the boot fixing plate 21 on the joint side. It is fitted in the directional recess 27.

Further, a grease nipple 28 for replenishing grease is arranged on the boot fixing plate 21. That is, the grease nipple 28 is in a state of communicating with the inside of the joint body.

In a fixed constant velocity universal joint having a track offset as shown in FIG. 5, the track groove 2 of the outer joint member 3 and the track groove 5 of the inner joint member 6 facing the track groove 2 are formed by this offset. A wedge angle is formed on the ball track to be formed, and a force for holding the ball 7 and the cage 8 on the bisected surface of the operating angle acts. This wedge angle is in the direction of opening toward the sealing device side in all ball tracks when the operating angle is normally 0 °.

JP-A-2007-247768

In the fixed constant velocity universal joint having a track offset as shown in FIG. 5, the sealing device includes a metal inner diameter side cylinder portion 30a, a metal outer diameter side cylinder portion 30b, and an inner diameter side cylinder portion. Since it is composed of a bent portion 30c made of a flexible material having a U-shaped cross section that connects the 30a and the outer diameter side cylinder portion 30b, low-angle high-speed rotation conditions (operating angle is 10 ° or less, rotation speed is 1000 rpm). The above is supported.

However, in the fixed constant velocity universal joint shown in FIG. 5, the wedge angle is in the direction of opening toward the sealing device side in all ball tracks, and if such a joint is bent at a high angle, the joint Grease inside the main body tends to flow out to the sealing device side. If the grease flows out to the sealing device side in this way, the grease inside the joint body is reduced and the lubrication function is deteriorated. Further, if the grease flows out to the sealing device side, the grease in the sealing device deforms the sealing device (particularly the bent portion) due to the centrifugal force during rotation, which causes a limiting factor of the allowable rotation speed. become.

Therefore, the present invention prevents the outflow of grease to the sealing device side, does not deteriorate the lubrication function inside the joint body, maintains stable sealing performance, and is capable of high-speed universal joints. I will provide a.

The first constant velocity universal joint of the present invention includes an outer joint member having a plurality of track grooves formed on the inner diameter surface, an inner joint member having a plurality of track grooves formed on the outer diameter surface, and the outer joint member. A plurality of torque transmission balls arranged between the track groove and the corresponding track groove of the inner joint member, and balls interposed between the inner diameter surface of the outer joint member and the outer diameter surface of the inner joint member. and a cage for holding a sheet Yafuto is fitted to the inner joint member, the center of curvature of the track grooves of the outer joint member the center of curvature and the inner joint member of the track grooves of axially opposite with respect to the joint center It is a constant velocity universal joint that is offset to the side by an equal distance, and the center of curvature of the track groove of the outer joint member is offset to the opposite shaft side from the joint center, and the center of curvature of the track groove of the inner joint member is jointed. The joint opening on the shaft fitting side is sealed by a sealing device so as to be offset to the shaft side from the center , and the sealing device includes an inner diameter side cylinder portion outerly fitted to the shaft and at least one grease shield. The grease shielding lip is provided with a lip, the outer diameter side thereof is attached to the outer joint member, and the inner diameter side cylinder portion is fitted in the center hole in a loose fit shape.
The second constant velocity universal joint of the present invention includes an outer joint member having a plurality of track grooves formed on the inner diameter surface, an inner joint member having a plurality of track grooves formed on the outer diameter surface, and the outer joint member. A plurality of torque transmission balls arranged between the track groove and the corresponding track groove of the inner joint member, and balls interposed between the inner diameter surface of the outer joint member and the outer diameter surface of the inner joint member. The shaft is fitted into the inner joint member, and the center of curvature of the track groove of the outer joint member and the center of curvature of the track groove of the inner joint member are opposite to the joint center in the axial direction. It is a constant velocity universal joint that is offset by an equal distance, and the center of curvature of the track groove of the outer joint member is offset to the side opposite to the shaft from the center of the joint, and the center of curvature of the track groove of the inner joint member is offset from the center of the joint. Is also offset to the shaft side, and the joint opening on the shaft fitting side is sealed by a sealing device, and an end plate that prevents the outflow of grease is placed on the joint opening side opposite to the sealing device. A conical trapezoidal convex portion that bulges toward the inside of the joint body is provided at the center of the end plate .

Since the center of curvature of the track groove of the outer joint member is offset to the side opposite to the shaft from the center of the joint, and the center of curvature of the track groove of the inner joint member is offset to the shaft side from the center of the joint, the wedge angle is ball track. It is in the direction of opening toward the anti-sealing device side. Therefore, even if the joint is bent at a high angle, the grease inside the joint body tends to be difficult to flow out to the sealing device side.

The sealing device includes a metal inner diameter side cylinder into which a shaft is fitted, a metal outer diameter side cylinder whose inner diameter is larger than the outer diameter of the metal inner diameter side cylinder, and a metal inner diameter side cylinder. The bent portion having a U-shaped cross section made of a flexible member connecting the portion and the metal outer diameter side cylinder portion is formed, and the boot fixing plate attached to the end surface of the outer joint member on the shaft fitting side is used. It is preferable that the sealing device is fixed to the outer joint member. By using such a sealing device, it is advantageous for rotational expansion in the case of low-angle high-speed rotation.

The bent portion of the sealing device may be one in which the inner side of the joint body is convex or one in which the outer side of the joint body is convex. In particular, when the outer side of the joint body is convex, the connection portion between the inner diameter side cylinder portion and the bent portion and the connection portion between the outer diameter side cylinder portion and the bent portion are torque transmission between the outer joint member and the inner joint member. It is arranged on the joint body side consisting of a ball and a cage. Therefore, when the working angle is taken, the connection part on which the tensile force acts is on the joint body side, the tensile force is small, damage such as cracks in the bent portion can be prevented, and the life of the sealing device is improved. Can be planned. Moreover, the reversal phenomenon due to deformation due to rotational expansion can be prevented, and high speed can be achieved.

The sealing device preferably comprises at least one grease shielding lip. When such a grease shielding lip is provided, it is possible to stably prevent the grease from flowing out to the sealing device, and it is possible to extend the life of the sealing device and improve the rotation performance.

By arranging a grease nipple for replenishing grease on the side opposite to the sealing device, it is possible to replenish grease and extend the life of the joint body.

An end plate that prevents grease from flowing out is placed on the joint opening side opposite to the sealing device, and a conical trapezoidal convex portion that bulges toward the inside of the joint body is provided at the center of the end plate. It may be. By the way, in this constant velocity universal joint, the wedge angle is in the direction of opening toward the anti-sealing device side by the ball track, so that the grease is spread to the joint opening side opposite to the sealing device by the so-called wedge effect. Although it tries to flow out, the end plate can effectively prevent the outflow from the joint body. In particular, since the conical trapezoidal convex portion that bulges toward the inside of the joint main body is provided in the central portion of the end plate, it is guided by the inclined surface of the convex portion and returns to the joint main body.

In the present invention, even if the joint is bent at a high angle, the grease inside the joint body tends to be difficult to flow out to the sealing device side, so that damage to the sealing device due to centrifugal force can be effectively prevented. Therefore, it is possible to support high speed while maintaining stable sealing performance without losing the lubrication function inside the joint body for a long period of time.

It is sectional drawing of the constant velocity universal joint which shows 1st Embodiment of this invention. FIG. 3 is an enlarged cross-sectional view of a main part of the constant velocity universal joint shown in FIG. It is sectional drawing of the constant velocity universal joint which shows the 2nd Embodiment of this invention. It is sectional drawing of the constant velocity universal joint which shows the 3rd Embodiment of this invention. It is sectional drawing of the conventional constant velocity universal joint.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 4. 1 and 2 show the constant velocity universal joint of the first embodiment, and the constant velocity universal joint has an outer joint member 33 having a track groove 32 formed on an inner diameter surface 31 and an outer joint member on an outer diameter surface 34. The torque is transmitted by interposing between the inner joint member 36 in which the track groove 35 paired with the track groove 32 of 33 is formed, and the track groove 32 of the outer joint member 33 and the track groove 35 of the inner joint member 36. The ball 37 is provided with a cage 38 that is interposed between the inner diameter surface 31 of the outer joint member 33 and the outer diameter surface 34 of the inner joint member 36 to hold the ball 37.

The center of curvature O1 of the track groove 32 of the outer joint member 33 and the center of curvature O2 of the track groove 35 of the inner joint member 36 are equidistant from the joint center O on the opposite side in the axial direction. In this case, the center of curvature O1 of the track groove 32 of the outer joint member 33 is arranged on the adapter side described later from the joint center O, and the center of curvature O2 of the track groove 35 of the inner joint member 36 is arranged on the anti-adapter side. To.

A female spline 40 is formed on the inner diameter surface of the axial core hole of the inner joint member 36, and the male spline 42 at the tip of the stub shaft 41 is fitted into the axial core hole. As a result, the female spline 40 and the male spline 42 mesh with each other. Retaining rings 43 and 44 are attached to the tip and base ends of the male spline 42, respectively. That is, a circumferential groove 42a is formed at the tip of the male spline 42, a circumferential groove 42b is formed at the base end of the male spline 42, and retaining rings 43 and 44 are attached to the circumferential grooves 42a and 42b. ..

At this time, the retaining ring 43 is fitted into the circumferential notch 45 provided on one end surface 36a (the end face on the adapter side described later) of the inner joint member 36, and the radial notch end surface of the circumferential notch 45 is fitted. It is in contact with 45a. Further, the retaining ring 44 is in contact with the other end surface 36b (end surface on the anti-adapter side) of the inner joint member 36. Therefore, the shaft 41 is restricted from moving in the axial direction with respect to the inner joint member 36.

A pipe material 46 is continuously provided on the base end side of the stub shaft 41. That is, a boss portion 41b is formed at the base end portion of the stub shaft 41, and the pipe material 46 is connected to the boss portion 41b. In this case, a fitting portion 47 is formed in the boss portion 41b, the fitting portion 47 is internally fitted in the opening of the pipe material 46, and the large diameter portion 48 of the boss portion 41b and the pipe material 46 are welded together. Etc. are joined.

The outer joint member 33 is a disc type, and the adapter 50 is mounted on one end face 33a side, and the boot fixing plate 51 is mounted on the other end face 33b side. That is, the adapter 50 is made of a tubular body having a key groove 50a formed on the inner diameter surface, and a fitting recess 50b into which the end surface of the outer joint member 33 on the adapter 50 side is fitted is formed on the end surface on the joint body side. A packing 39a is provided between one end surface 33a of the outer joint member 33 and the fitting recess 50b. Further, the boot fixing plate 51 is made of a flat plate ring body, and a fitting recess 51a into which the end portion of the outer joint member 33 on the opposite side of the adapter is fitted is provided on the end surface of the joint body side, and the outer joint member 33 is provided. A packing 39b is mounted between the other end surface 33b and the fitting recess 51a. The packings 51a and 51b are molded from a synthetic material of paper + resin. In addition, metal (iron, stainless steel, aluminum, etc.) or liquid gasket can be applied to the packing depending on the usage conditions and environment.

The boot fixing plate 51 and the outer joint member 33 are provided with through holes 52 and 53, and the adapter 50 is provided with screw holes 54. Therefore, the end of the outer joint member 33 on the adapter side is fitted into the fitting recess 50b of the adapter 50, and the end of the outer joint member 33 on the non-adapter side is fitted into the fitting recess 51a of the boot fixing plate 51. Match. In this state, the bolt member 55 is fitted into the through hole 52 of the boot fixing plate 51 and the through hole 53 of the outer joint member 33, and the screw portion 55a of the bolt member 55 is screwed into the screw hole 54 of the adapter 50. For example, the boot fixing plate 51, the outer joint member 33, and the adapter 50 are integrated. As the washer W used for the bolt member 25, in the example, two washers are paired, a wedge-shaped cam is provided on the meshing surface, and the wedge angle is set to be larger than the screw angle of the bolt. Therefore, the bolt member does not loosen, and the bolt tension increases due to the wedge effect. The washer W is not limited to a washer in which two pieces are paired, and may be another washer such as a disc spring washer or a spring washer.

Further, the opening on the shaft side of the constant velocity universal joint is sealed by the sealing device 60. In this case, the sealing device 60 can have a U-shaped cross section that connects the metal inner diameter side cylinder portion 60a, the metal outer diameter side cylinder portion 60b, the inner diameter side cylinder portion 60a, and the outer diameter side cylinder portion 60b. It is composed of a bent portion 60c made of a flexible material. In this case, the bent portion 60c is vulture-bonded to the metal ring of the inner diameter side cylinder portion 60a and the outer diameter side cylinder portion 60b. The metal material of the inner diameter side cylinder portion 60a and the outer diameter side cylinder portion 60b and the flexible material of the bending portion 60c can be used in an environment where this constant velocity universal joint is used. Good.

The inner diameter side cylinder portion 60a is fitted onto the shaft 41, and the outer diameter side cylinder portion 60b is fixed to the outer joint member 33 via the boot fixing plate 51. That is, a flange portion 56 extending in the outer diameter direction is provided at the end portion of the outer diameter side tubular portion 60b on the joint side, and the flange portion 56 is formed on the inner diameter portion of the end surface 51a on the joint side of the boot fixing plate 51. It is fitted in the circumferential recess 57.

The inner diameter side tubular portion 60a has an end surface 60a1 on the joint body side in contact with the retaining ring 44. That is, the retaining ring 44 is sandwiched between the inner diameter side tubular portion 60a and the other end surface 36b of the inner joint member 36.

Further, the adapter 50 is provided with a grease nipple 58 for replenishing grease. That is, a radial nipple mounting hole 59 is provided on the joint body side of the adapter 50, and the grease nipple 58 is mounted in the nipple mounting hole 59.

Further, the end plate 65 is arranged on the anti-joint body side of the nipple mounting hole 59. The end plate 65 is provided with a conical trapezoidal convex portion 66 that bulges toward the inside of the joint body at the center thereof. That is, the end plate 65 includes a disk-shaped central portion 65a, a flat plate ring-shaped outer peripheral portion 65b, and a tapered wall portion 65c in which the central portion 65a and the outer peripheral portion 65b are continuously provided. Therefore, the central portion 65a and the tapered wall portion 65c form the convex portion 66.

In this case, the hole of the adapter 50 is formed with a main body hole 61 in which the keyway 50a is formed and an opening 62 on the joint side. The opening 62 includes an opening main body 62a having a diameter larger than that of the main body hole 61, and a tapered portion 62b whose diameter increases toward the opening side. The grease nipple 58 is mounted in a nipple mounting hole 59 that opens on the inner peripheral surface of the opening main body 62a.

A circumferential concave groove 62c is provided in the opening main body 62a on the anti-joint main body side of the nipple mounting hole 59, and a retaining ring 64 is fitted in the circumferential concave groove, and the retaining ring 64 and the opening main body 62a The outer peripheral portion 65b of the end plate 65 is held in a sandwiching manner with the bottom surface, and the end plate 65 is fixed (mounted) to the adapter 50. As described above, when the end plate 65 is mounted on the adapter 50, the tapered wall portion 65c of the end plate 65 is arranged at a position facing the nipple mounting hole 59.

In the constant velocity universal joint configured as shown in FIG. 1, the center of curvature O1 of the track groove 32 of the outer joint member 33 is offset to the side opposite to the shaft from the joint center O, and the track groove 35 of the inner joint member 36 The center of curvature O2 is offset toward the shaft side from the center of the joint. Therefore, the wedge angle is in the direction of opening the ball track toward the anti-sealing device side, that is, the direction toward the adapter side.

Therefore, even if the joint is bent at a high angle, the grease inside the joint body tends to be difficult to flow out to the sealing device side, so that damage to the sealing device can be effectively prevented. In addition, high-speed response is possible while maintaining stable sealing performance without losing the lubrication function inside the joint body for a long period of time.

By arranging the grease nipple 58 for replenishing grease, it is possible to replenish grease and achieve a long life of the joint body. A plurality of grease nipples 58 can be arranged, and by using one of them, the grease can be replenished and the old grease can be replaced with a new grease. That is, regular replacement of grease contributes to prolonging the life of the joint body. At least one grease nipple 58 may be used.

Further, the end plate 65 is provided with a conical trapezoidal convex portion 66 bulging toward the inside of the joint body at the center, that is, the tapered wall portion 65c is a tapered portion whose diameter is reduced toward the inside of the joint body. Therefore, the grease inside is easily circulated, which contributes to the lubrication of the joint body.

In the sealing device 60 shown in FIG. 1, the bent portion 60c is configured so that the inner side of the joint body is convex. On the other hand, FIG. 3 shows another embodiment, and the bent portion 60c of the sealing device 60 is configured so that the inner side of the joint body is convex.

In the case where the outer side of the joint body is convex, the connection portion between the inner diameter side cylinder portion 60a and the bending portion 60c and the connection portion between the outer diameter side cylinder portion 60b and the bending portion 60c are the outer joint member 33 and the inner joint member. It is arranged on the joint body side including the 36, the torque transmission ball 37, and the cage 38. Therefore, when the working angle is taken, the connection portion on which the tensile force acts is on the joint body side, the tensile force is small, damage such as cracks in the bent portion 60c can be prevented, and the life of the sealing device 60 is extended. It can be improved. Moreover, the reversal phenomenon due to deformation due to rotational expansion can be prevented, and high speed can be achieved, that is, the rotational performance of the sealing device is improved.

Further, in the sealing device 60 shown in FIG. 3, the outer diameter dimension of the outer diameter side cylinder portion 60b can be reduced, thereby reducing the amount of grease sealed in the sealing device 60. That is, in the sealing device 60 shown in FIG. 1, the grease filling amount was 80% of the internal volume, but in the sealing device 60 shown in FIG. 3, it can be 30% of the internal volume. As a result, the speed can be increased.

In FIG. 4, the sealing device 60 includes at least one grease shielding lip 70. The grease shielding lip 70 is attached to the outer joint member 33 via the boot fixing plate 51. The grease shielding lip 70 is composed of a ring-shaped main body 70a having a dogleg-shaped cross section and an outer flange 70b extending in the outer diameter direction to the outer diameter of the main body 70a, and an inner diameter side cylinder is formed in the center hole 70c thereof. The joint body side of the portion 60a is internally fitted in a loose fit.

Then, a circumferential recess 71 is formed in the inner diameter portion of the end surface of the boot fixing plate 51 on the joint body side, and the outer flange portion 70b of the grease shielding lip 70 is fitted into the circumferential recess 71. That is, the circumferential recess 71 includes a large diameter portion 71a on the joint side and a small diameter portion 71b connected to the large diameter portion 71a. Therefore, the outer flange portion 70b of the grease shielding lip 70 is fitted to the large diameter portion 71a, and the flange portion 56 of the outer diameter side cylinder portion 60b is fitted to the small diameter portion 71b.

Therefore, by attaching the boot fixing plate 51 to the outer joint member 33, the grease shielding lip 70 and the outer diameter side cylinder portion 60b are fixed to the outer joint member 33. The grease shielding lip 70 is an elastic material, and is composed of, for example, CR (chloroprene rubber), Si (silicone rubber), AR (acrylic rubber), NBR (nitrile rubber), and has a hardness of shore hard. The hardness (unit: HS) is preferably 50 or less.

That is, in the one shown in FIG. 4, the axial length of the outer diameter side cylinder portion 60b is set shorter than the axial length of the outer diameter side cylinder portion 60b shown in FIG. 3, and the boot fixing plate 51 is provided. The inner diameter crimping groove (recessed in the circumferential direction 71) is formed into a two-stage shape (a two-stage shape of a large diameter portion 71a on the joint side and a small diameter portion 71b connected to the large diameter portion 71a), and grease flowing out from the joint body side. A grease shielding lip 70 is provided to stop the operation.

With such a configuration, the structure is such that the grease does not easily flow out to the sealing device 60, and the life of the sealing device 60 can be extended and the rotation performance can be improved as compared with the one shown in FIG.

The other configurations of FIGS. 3 and 4 are the same as those of the constant velocity universal joint shown in FIG. 1, and the same members as those of FIG. 1 are designated by the same reference numerals as those of FIG. 1 and their description is omitted. Therefore, the constant velocity universal joint shown in FIGS. 3 and 4 has the same effect as that of the constant velocity universal joint shown in FIG.

Further, the shaft 41 may be configured to allow sliding of the shaft 41 with respect to the inner joint member 36 without mounting the retaining ring 43 on the shaft 41. As described above, if the configuration allows sliding, it is excellent in assembly / separation and installability.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made, and the number of grease nipples 58 is arbitrary, and at least one is sufficient. Further, the number of fixing means (bolt members) for fixing the boot fixing plate 51 and the adapter 50 to the outer joint member may be at least three at a pitch of 120 ° along the circumferential direction, but is three or more. You may.

The grease shielding lip 70 is not limited to one, and may have two or more. Further, in FIG. 4, the grease shielding lip 70 is provided for the sealing device having the bent portion 60c in which the inner side of the joint body is convex, but as shown in FIG. 1, the bent portion 60c in which the outer side of the joint body is convex is provided. The grease shielding lip 70 may be provided on the sealing device having the above.

31 Inner diameter surface 32 Track groove 33 Outer joint member 34 Outer diameter surface 35 Track groove 36 Inner joint member 37 Ball 38 Cage 41 Stub shaft 58 Grease nipple 60 Sealing device 60a Inner diameter side cylinder 60b Outer diameter side cylinder 60c Bending part 65 End plate 66 Convex 70 Grease shielding lip O Joint center O1 Curvature center O2 Curvature center 39a, 39b Packing

Claims (6)

An outer joint member having a plurality of track grooves formed on the inner diameter surface, an inner joint member having a plurality of track grooves formed on the outer diameter surface, a track groove of the outer joint member, and a corresponding inner joint member. A plurality of torque transmission balls arranged between the track grooves and a cage for holding the balls between the inner diameter surface of the outer joint member and the outer diameter surface of the inner joint member are provided, and the inner joint portion is provided. Shi Yafuto is fitted to the timber, universal constant velocity of the center of curvature of the track grooves of the outer joint member the center of curvature and the inner joint member of the track grooves of are offset equidistantly in the axial direction opposite to the joint center It ’s a fitting,
The center of curvature of the track groove of the outer joint member is offset to the side opposite to the shaft from the center of the joint, and the center of curvature of the track groove of the inner joint member is offset to the shaft side from the center of the joint, so that the joint opening on the shaft fitting side is The sealing device is sealed by a sealing device , and the sealing device includes an inner diameter side cylinder portion outerly fitted to the shaft and at least one grease shielding lip, and the outer diameter side of the grease shielding lip is an outer joint. A constant-velocity universal joint that is mounted on a member and has an inner diameter side tubular portion fitted in the center hole in a loose fit . An outer joint member having a plurality of track grooves formed on the inner diameter surface, an inner joint member having a plurality of track grooves formed on the outer diameter surface, a track groove of the outer joint member, and a corresponding inner joint member. The inner joint member is provided with a plurality of torque transmission balls arranged between the track grooves and a cage that holds the balls between the inner diameter surface of the outer joint member and the outer diameter surface of the inner joint member. In a constant velocity universal joint, the shaft is fitted into the outer joint member, and the center of curvature of the track groove of the outer joint member and the center of curvature of the track groove of the inner joint member are offset by an equal distance to the opposite side of the joint center in the axial direction. There,
The center of curvature of the track groove of the outer joint member is offset to the side opposite to the shaft from the center of the joint, and the center of curvature of the track groove of the inner joint member is offset to the shaft side from the center of the joint, so that the joint opening on the shaft fitting side is It is sealed by a sealing device, and an end plate that prevents the outflow of grease is placed on the joint opening side opposite to the sealing device, and at the center of this end plate, it bulges toward the inside of the joint body. conical shape constant velocity universal joint you characterized in that a convex portion of the. The sealing device includes a metal inner diameter side cylinder into which a shaft is fitted, a metal outer diameter side cylinder whose inner diameter is larger than the outer diameter of the metal inner diameter side cylinder, and a metal inner diameter side cylinder. It is composed of a bent portion made of a flexible member having a U-shaped cross section that connects the portion and the metal outer diameter side cylinder portion, and is sealed via a boot fixing plate attached to the end surface of the outer joint member on the shaft fitting side. The constant velocity universal joint according to claim 1 or 2 , wherein the device is fixed to an outer joint member. The constant velocity universal joint according to claim 3 , wherein the bent portion of the sealing device has a convex shape on the inner side of the joint body. The constant velocity universal joint according to claim 3 , wherein the bent portion of the sealing device is convex on the outer side of the joint body. The constant velocity universal joint according to any one of claims 1 to 5 , wherein a grease nipple for replenishing grease is arranged on the side opposite to the sealing device.

Images