JP4361402B2 - Unit cover / joint assembly and drive wheel bearing assembly comprising the same - Google Patents

Description

  The present invention relates to a constant velocity universal joint equipped with a unit cover, a unit cover / joint assembly including a drive shaft connected to the constant velocity universal joint, and a drive wheel bearing device total assembly including the unit cover / fitting assembly.

  A power transmission device that transmits engine power of a vehicle such as an automobile to a wheel transmits power from the engine to the wheel, and also causes radial or axial displacement from the wheel that occurs when the vehicle bounces or turns when traveling on a rough road. For example, as shown in FIG. 7, one end of the drive shaft 100 interposed between the engine side and the drive wheel side is connected to a sliding type constant velocity universal joint 101. The other end is connected to a wheel 105 via a drive wheel bearing device 104 including a fixed type constant velocity universal joint 103.

  Such a drive wheel bearing device 104 includes a wheel bearing 106 referred to as a third generation, and a fixed type constant velocity universal joint 103 detachably connected to the wheel bearing 106. In recent years, the drive wheel bearing device 104 tends to shift to a so-called fourth generation structure in which the wheel bearing 106 and the fixed type constant velocity universal joint 103 are unitized for further light weight and compactness. .

  A typical example of such a drive wheel bearing device will be described with reference to FIG. 2 showing a first embodiment of the present invention. In the following description, the side closer to the outer side of the vehicle when assembled to the vehicle is referred to as the outboard side (left side in the drawing), and the side closer to the center is referred to as the inboard side (right side in the drawing).

  This drive wheel bearing device is configured by unitizing a hub wheel 1, a double row rolling bearing 2, and a constant velocity universal joint 3. The hub wheel 1 is made of medium carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and a wheel mounting flange 4 for mounting a wheel (not shown) to the end on the outboard side is integrated. And hub bolts 6 are implanted at equal circumferential positions. Concave and convex portions 5 are formed on the inner peripheral surface of the hub wheel 1, and a hardened layer is formed with a surface hardness in the range of 54 to 64 HRC by heat treatment. As the heat treatment, local heating is preferable, and quenching by high-frequency induction heating that can set the hardened layer depth relatively easily is preferable.

  In addition, the uneven part 5 is formed in the shape of an iris knurl, and a cross groove formed by a plurality of annular grooves formed independently by turning or the like and a plurality of axial grooves formed by broaching or the like substantially orthogonal to each other. Alternatively, it consists of a cross groove composed of spiral grooves inclined with respect to each other. Further, in order to ensure good biting property, the tip of the concavo-convex portion 5 is formed in a spire shape such as a triangular shape.

  The double-row rolling bearing 2 includes an outer member 7, an inner member 8, and double-row rolling elements (balls) 9 and 9. The outer member 7 is formed of a medium carbon steel containing carbon 0.40 to 0.80 wt% such as S53C, and integrally includes a vehicle body mounting flange 7b for mounting on a knuckle N constituting a suspension device on the outer periphery. Double rows of outer rolling surfaces 7a, 7a are formed on the inner periphery. On the other hand, the inner member 8 refers to the hub wheel 1 and an outer joint member 14 (described later) that is fitted into the in-row portion 13 of the hub wheel 1 in abutting state, and the outer rolling surface 7a of the outer member 7; An inner rolling surface 1 a on the outboard side facing 7 a is formed on the outer periphery of the hub wheel 1, and an inner rolling surface 14 a on the inboard side is formed on the outer periphery of the outer joint member 14. Double-row rolling elements 9 and 9 are accommodated between the rolling surfaces 7a and 1a and 7a and 14a, respectively, and are held by the cages 10 and 10 so as to be freely rollable. Seals 11 and 12 are attached to the ends of the double row rolling bearing 2 to prevent leakage of lubricating grease sealed inside the bearing and intrusion of rainwater and dust from the outside into the bearing. .

  The constant velocity universal joint 3 includes an outer joint member 14, a joint inner ring 15, a cage 16 and a torque transmission ball 17. The outer joint member 14 is formed of medium carbon steel containing carbon 0.40 to 0.80 wt% such as S53C, and has a cup-shaped mouth portion 18 and a shoulder portion 19 that forms the bottom of the mouth portion 18. A hollow shaft portion 20 extending in the axial direction from the shoulder portion 19 is provided. On the outer periphery of the shaft portion 20, there are formed a small diameter step portion 20a fitted in the inrow portion 13 and a fitting portion 20b extending in the axial direction from the small diameter step portion 20a.

  In addition, eight curved track grooves 18 a extending in the axial direction are formed on the inner periphery of the mouse portion 18, and eight track grooves 15 a facing the track grooves 18 a are formed on the outer periphery of the joint inner ring 15. Has been. A torque transmission ball 17 is accommodated between the track grooves 18a and 15a. In the outer joint member 14, a predetermined hardened layer is formed on the surfaces of the track groove 18a, the shoulder portion 19 and the shaft portion 20 by induction hardening or the like.

  Then, the shaft portion 20 of the outer joint member 14 is fitted into the hub wheel 1, a diameter expanding jig such as a mandrel is pushed into the shaft portion 20 to expand the fitting portion 20 b, and the fitting portion 20 b is connected to the hub wheel. 1, the hub wheel 1 and the outer joint member 14 are integrally plastically joined. As a result, it is not necessary to control the preload by tightening firmly with a nut or the like as in the prior art, so that the weight and size can be reduced and the strength and durability of the hub wheel 1 can be improved and long. The amount of preload can be maintained for a period. Furthermore, it has the feature that it can be easily incorporated into a vehicle.

  On the outer periphery of the hub wheel 1, a hardened layer is formed by induction hardening on the surfaces of the seal land portion, the inner rolling surface 1a, and the in-row portion 13 with which the seal lip of the seal 11 on the outboard side slides. Further, the fitting portion 20b to be expanded is an unquenched portion with a material surface hardness of 24 HRC or less after forging, and the hardness difference between the surface hardness 54 to 64 HRC of the uneven portion 5 of the hub wheel 1 is 30 HRC or more. It is preferable to set to. Thereby, the fitting part 20b can bite into the uneven | corrugated | grooved part 5 easily and deeply, and both can be firmly plastic-bonded without the front-end | tip of the uneven | corrugated | grooved part 5 being crushed.

Here, the outer diameter of the fitting surface 7c of the outer member 7 fitted to the inner diameter of the knuckle N is Da, and the maximum outer diameter of the constant velocity universal joint 3, here, the outer periphery of the mouse portion 18 is mounted. When the outer diameter of the boot 21 is Db, Da ≧ Db is set. As a result, the double row rolling bearing 2 and the constant velocity universal joint 3 can be assembled in advance and then assembled to the knuckle N, further improving the workability of the assembly to the vehicle, and work such as inspection and repair. Also improves.
JP 2001-171308 A

  However, in such a conventional drive wheel bearing device, the outer diameter Da of the fitting surface 7c of the outer member 7 is made larger than the maximum outer diameter Db of the constant velocity universal joint 3, whereby the double row rolling bearing 2 and Although the drive wheel bearing device integrated with the constant velocity universal joint 3 can pass through the knuckle N, in order to improve the workability, the outer diameter Da of the fitting surface 7c of the outer member 7 is improved. And the maximum outer diameter Db of the constant velocity universal joint 3 increase the weight of the knuckle N as well as the outer member 7 and halve the effect as a lightweight and compact device. It is not preferable. On the other hand, if the gap is small, the outer joint member 14 or the boot 21 may be damaged, and a careful assembling work is forced from the viewpoint of quality. As a result, not only skill is required for the assembling work but also the assembling work takes time and the cost increases.

  The present invention has been made in view of such circumstances, and has improved a unit cover / joint assembly that improves the assembly workability to a vehicle and stabilizes the quality, and a drive wheel bearing device total assembly including the unit cover / joint assembly. It is intended to provide.

In order to achieve the object, the invention according to claim 1 of the present invention is such that an outer joint member having a plurality of axially extending track grooves having curved portions on the inner periphery and an outer periphery facing the track grooves are provided. A joint inner ring formed with a track groove, a torque transmission ball respectively accommodated in a ball track formed by the both track grooves, a cage for rotatably holding the torque transmission ball, and one end of the joint inner ring , A fixed type constant velocity universal joint composed of the drive shaft and a boot attached to the outer peripheral portion of the outer joint member on the opening side, and the opening of the drive shaft and the outer joint member Fitting assembly comprising a sliding type constant velocity universal joint composed of a boot attached to the side outer peripheral portion, and the outer peripheral portion of the joint assembly Is formed in a cylindrical shape so as to cover, elastomeric unit cover having a reduced diameter portion is resiliently mounted to the joint assembly at both ends, the reduced diameter portion of the at least inboard side of the reduced diameter portion is tapered In addition, a configuration was adopted in which a plurality of slits were formed in the circumferential direction in the reduced diameter portion on the outboard side .

In this way, by covering the outer periphery of the joint assembly with the unit cover, it is possible to prevent one of the pair of constant velocity universal joints from bending and sagging, protecting the joint assembly and handling such as transportation. It becomes easier. Further, a reduced diameter portion is formed at the end of the unit cover, and at least the reduced diameter portion on the inboard side of the reduced diameter portion is formed in a tapered shape, and a plurality of reduced diameter portions on the outboard side are circumferentially arranged. Since the slit is formed, it can be elastically attached to the outer joint member of the constant velocity universal joint with one touch, and the unit cover can be prevented from falling off. Therefore, it is possible to provide a unit cover / joint assembly that improves the assembly workability to the vehicle and stabilizes the quality of the apparatus.

Further, the unit cover may be integrally formed in a cylindrical shape as in the invention described in claim 2 , or the unit cover is formed in a curved shape as in the invention described in claim 3 . It may be made of a single sheet-like synthetic resin and may be formed into a cylindrical shape by polymerizing the end portions along the longitudinal direction.

In the invention according to claim 4 of the present invention, the body mounting flange and the fitting surface of the knuckle constituting the suspension device are integrally formed on the outer periphery, and the double row outer rolling surface is formed on the inner periphery. An outer member that is rotatably supported by the outer member via a plurality of rolling elements, a wheel mounting flange on the outer periphery, and a double-row inner rolling surface facing the double-row outer rolling surface, The inner rolling surface of the double row forms one inner rolling surface on the outer periphery of the hub wheel, and the other inner rolling surface forms the constant velocity universal joint. Each of the outer joint members is formed on the outer periphery, and a hollow shaft portion formed in the outer joint member is fitted into the hub wheel, and an uneven portion cured on the inner diameter of the hub wheel is formed. The hub ring is formed by expanding the diameter of the fitting portion formed on the concave and convex portions into the uneven portion. And the outer joint member and a joint assembly according to any one of claims 1 to 3 connected the bearing drive wheel that is plastically bonded together, and the driving wheel bearing, fitting of the outer member A configuration was adopted in which the outer diameter of the mating surface was larger than the maximum outer diameter of the joint assembly.

  In this way, the drive wheel bearing and the joint assembly connected to the drive wheel bearing are provided, and the outer diameter of the fitting surface of the outer member is formed larger than the maximum outer diameter of the joint assembly, Elastomer unit covers that are formed in a cylindrical shape to cover the outer periphery of the joint assembly and have reduced diameter portions at both ends are attached, so the knuckle can be easily extrapolated without damaging the joint assembly. The joint assembly can be easily assembled into a knuckle. In addition, it is possible to prevent contamination and damage to the drive wheel bearing assembly as a whole, and it is possible to install the corner module and vehicle assembly of the suspension as it is, not only handling such as transportation but also assembly work Property can be further improved.

A unit cover / joint assembly according to the present invention includes an outer joint member having a plurality of axially extending track grooves having a curved portion on the inner periphery, and a joint having a track groove facing the track grooves on the outer periphery. An inner ring, a torque transmission ball accommodated in each of the ball tracks formed by the both track grooves, a cage for holding the torque transmission ball in a rollable manner, a drive shaft having one end connected to the joint inner ring, A fixed type constant velocity universal joint composed of the drive shaft and a boot mounted on the opening side outer peripheral portion of the outer joint member, and a boot mounted on the opening side outer peripheral portion of the drive shaft and the outer joint member And a joint assembly including a sliding type constant velocity universal joint configured by the above and an outer peripheral portion of the joint assembly. An elastomer unit cover that is formed in a cylindrical shape and has reduced diameter portions at both ends is elastically attached to the joint assembly, preventing one of the pair of constant velocity universal joints from bending and sagging. In addition to protecting the joint assembly, handling such as transportation is further facilitated. Further, a reduced diameter portion is formed at the end of the unit cover, and at least the reduced diameter portion on the inboard side is formed in a tapered shape among the reduced diameter portions, and a plurality of reduced diameter portions on the outboard side are provided in the circumferential direction. Since the slit is formed , the outer joint member of the constant velocity universal joint can be elastically attached with one touch, and the unit cover can be prevented from falling off. Therefore, it is possible to provide a unit cover / joint assembly that improves the assembly workability to the vehicle and stabilizes the quality of the apparatus.

Further, the drive wheel bearing device total assembly equipped with the unit cover according to the present invention is formed integrally with the body mounting flange on the outer periphery and the fitting surface of the knuckle constituting the suspension device, and has a double row on the inner periphery. An outer member on which an outer rolling surface is formed, and a double row that is rotatably supported by the outer member via a plurality of rolling elements, and that is opposed to a wheel mounting flange and the outer rolling surface of the double row on the outer periphery. And an inner member formed with one inner rolling surface of the double row inner rolling surface on the outer periphery of the hub wheel, and the other inner rolling surface with the inner rolling surface. A concave and convex portion formed on the outer periphery of the outer joint member constituting the speed universal joint, fitted into the hub ring with a hollow shaft portion formed on the outer joint member, and hardened to the inner diameter of the hub ring. Formed and the fitting portion formed on the shaft portion is expanded in diameter to form the concave portion. By cutting into parts, the according to the hub wheel and the outer joint member and has one claims 1 to 3 connected the bearing drive wheel that is plastically bonded together, and the driving wheel bearing Since the outer diameter of the fitting surface of the outer member is larger than the maximum outer diameter of the joint assembly, the knuckle can be easily extrapolated without damaging the joint assembly. The joint assembly can be easily assembled into a knuckle. In addition, it is possible to prevent contamination and damage to the drive wheel bearing assembly as a whole, and it is possible to install the corner module and vehicle assembly of the suspension as it is, not only handling such as transportation but also assembly work Property can be further improved.

An outer member having a body mounting flange on the outer periphery and a fitting surface of a knuckle that constitutes a suspension device are formed integrally, and an outer member having a double row outer rolling surface formed on the inner periphery, and a plurality of rolling members on the outer member. is rotatably supported by a moving object, the inner raceway surface opposite to the wheel mounting flange outer rolling surface of the double row is constituted by an inner member formed on the outer periphery, an inner rolling of the double row One inner rolling surface of the running surface is formed on the outer periphery of the hub wheel, and the other inner rolling surface is formed on the outer periphery of the outer joint member constituting the constant velocity universal joint, and the outer joint member is formed on the hub wheel. The hollow shaft portion formed on the inner ring is internally fitted, and a hardened uneven portion is formed on the inner diameter of the hub wheel, and the fitting portion formed on the shaft portion is expanded in diameter so that the uneven portion is bitten. by, drive vehicle the hub wheel and the outer joint member is plastically bonded together And a joint assembly coupled to the drive wheel bearing, the outer surface of the fitting surface of the outer member being formed with a larger outer diameter than the maximum outer diameter of the joint assembly, and the joint An elastomer unit cover, which is formed in a cylindrical shape so as to cover the outer periphery of the assembly and has reduced diameter portions at both ends, is elastically attached to the joint assembly, and at least the inboard side of the reduced diameter portion is reduced. A drive wheel bearing assembly total assembly in which a diameter portion is formed in a tapered shape and a plurality of slits are formed in a circumferential direction in a reduced diameter portion on the outboard side .

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing a first embodiment of a drive wheel bearing device total assembly equipped with a unit cover according to the present invention, and FIG. 2 is an enlarged view of a main part of FIG.

  This drive wheel bearing device transmits power from the engine to the wheels, and rotatably supports the wheels of the automobile with respect to the suspension device. The basic configuration of the drive wheel bearing device has been described with reference to FIG. 2 as an example of the above-described conventional drive wheel bearing device. Therefore, the detailed description is omitted, and the characteristic portion of the present invention is mainly used. Explained. This drive wheel bearing device has a so-called fourth generation configuration in which the hub wheel 1, the double row rolling bearing 2 and the constant velocity universal joint 3 are unitized.

  The outer joint member 14 of the constant velocity universal joint 3 on the outboard side that is a fixed type includes a cup-shaped mouth portion 18, a shoulder portion 19 that forms the bottom of the mouth portion 18, and an axial direction extending from the shoulder portion 19. It has a hollow shaft portion 20. Eight track grooves 18 a extending in the axial direction are formed on the inner periphery of the mouse portion 18, and eight track grooves 15 a facing the track grooves 18 a are formed on the outer periphery of the joint inner ring 15. Yes. A torque transmission ball 17 is accommodated between the track grooves 18a and 15a. A resin boot 21 is mounted on the outer periphery of the mouth portion 18 on the opening side to prevent leakage of grease sealed in the mouse portion 18 and intrusion of rainwater or dust from the outside into the joint. .

  Here, the compact type constant velocity universal joint 3 having eight balls is illustrated, but not limited to this, the maximum outer diameter of the constant velocity universal joint 3, that is, the outer diameter Db of the boot 21 in the present embodiment is As long as it is set to be equal to or smaller than the outer diameter Da of the fitting surface 7c of the side member 7, a constant velocity universal joint composed of six general balls may be used. Furthermore, the constant velocity universal joint may be a fixed type, and the track groove is not limited to a curved shape, and may be a constant velocity universal joint such as a track groove having a straight portion, a so-called undercut free type.

  As shown in FIG. 1, one end of the drive shaft 100 is fitted into the inner ring 15 of the constant velocity universal joint 3 via a serration 15b, and the other end is connected to a differential (not shown), which will be described later. A constant velocity universal joint 22 serving as a mold is fitted into a tripod member 24 via a serration 24b.

  This inboard side constant velocity universal joint 22 which is a sliding type includes an outer joint member 23, a tripod member 24 having three leg shafts 24a projecting from the outer periphery at equal intervals, and these leg shafts 24a. And a roller 26 that is rotatably inserted through a needle roller bearing 25. The outer joint member 23 is formed of a medium carbon steel containing carbon of 0.40 to 0.80 wt% such as S53C, and a cylindrical outer tube portion 27 having an outer periphery formed in a flower shape, and a bottom portion of the outer tube portion 27 And a shaft portion 28 extending in the axial direction. A serration 28a is formed at the end of the shaft portion 28 so as to be fitted into the differential.

  Further, three linear track grooves 27a extending in the axial direction are formed on the inner periphery of the outer cylindrical portion 27, and the roller 26 rolls on the track grooves 27a. In the outer joint member 23, a predetermined hardened layer is formed on the surfaces of the track groove 27a and the shaft portion 28 by induction hardening or the like. A boot 29 made of synthetic rubber or the like is attached to the outer periphery on the opening side of the outer cylinder portion 27 to prevent leakage of grease sealed in the outer cylinder portion 27 and rainwater or dust from entering the joint from the outside. It is preventing.

  The outer joint members 14 and 23 of the constant velocity universal joints 3 and 22 include cylindrical unit covers 30 that cover the outer peripheral portions of the constant velocity universal joints 3 and 22 and the drive shaft 100 (hereinafter referred to as a joint assembly JA). Is installed. The unit cover 30 is formed by injection molding an elastomer such as PA66, and has reduced diameter portions 30a and 30b that are elastically fitted to the outer joint member 14 and the boot 29 at both ends. Further, a slit (not shown) is formed in the reduced diameter portion 30a so that elastic deformation is easy. The reduced diameter portion 30b is formed in a gently tapered shape so as to cover the entire outer joint member 23. The unit cover 30 is not limited to being made of synthetic resin, but may be any material that is elastically deformed from the viewpoint of wearability, and may be formed of an elastic member such as synthetic rubber having a predetermined rigidity.

  The unit cover 30 is formed to have a predetermined thickness so that the unit cover 30 can be easily attached to the joint assembly JA and is not damaged during handling. In the present embodiment, it is set in the range of 0.5 to 3.0 mm in consideration of durability during transportation or reuse. In the present embodiment, the tripod type is exemplified for the constant velocity universal joint 22 on the inboard side. However, the present invention is not limited to this, and a sliding type constant velocity universal joint may be used. A double offset type constant velocity universal joint (DOJ) using a ball may be used.

Next, a procedure for assembling the drive wheel bearing device including the joint assembly JA (hereinafter referred to as drive wheel bearing device total assembly) into the knuckle N constituting the suspension device of the vehicle will be described.
1. The reduced diameter portion 30a of the unit cover 30 is elastically deformed to pass through the boot 29 of the constant velocity universal joint 22 on the inboard side, and the outer peripheral portion of the joint assembly JA is covered, and the constant velocity universal joint 3 on the outboard side is covered. The outer joint member 14 is attached.
2. In a state where the unit cover 30 is covered by the outer peripheral portion of the joint assembly JA, the knuckle N is sequentially provided from the reduced diameter portion 30b side of the unit cover 30 along the outer peripheral surface of the unit cover 30 to the vehicle body mounting flange 7b of the outer member 7. It is extrapolated until it contacts.
3. Thereafter, the outer member 7 and the knuckle N are fastened with a knuckle bolt (not shown).

  In the present embodiment, the outer periphery of the joint assembly JA is covered with the unit cover 30, and at least the reduced diameter portion 30b on the inboard side is formed in a tapered shape, so that one of the pair of constant velocity universal joints 3 and 22 is It can be prevented from bending and sagging, and the joint assembly JA is protected and handling such as transportation is further facilitated. Further, since the reduced diameter portion 30a is formed in the unit cover 30, it can be elastically attached to the outer joint member 14 with one touch, and the unit cover 30 can be prevented from falling off.

  Further, the outer diameter Da of the fitting surface 7c of the outer member 7 is formed larger than the maximum outer diameter Db of the constant velocity universal joint 3, and the reduced diameter portion 30b of the unit cover 30 has a gentle taper shape. Thus, the knuckle N can be easily extrapolated without damaging the joint assembly JA, and the drive wheel bearing assembly total assembly can be easily assembled to the knuckle N. Therefore, it is possible to prevent contamination and damage to the drive wheel bearing assembly as a whole, and it is possible to install the corner module and vehicle assembly of the suspension as it is, not only handling such as transportation but also assembly work Property can be further improved.

  In the present embodiment, the drive wheel bearing device is exemplified by a fourth generation structure in which the hub wheel 1, the double row rolling bearing 2 and the constant velocity universal joint 3 are unitized. However, the unit cover 30 according to the present invention is illustrated. Is to improve the protection and handling of the joint assembly JA, so that the bearing for the drive wheel has, for example, a third generation structure in which a constant velocity universal joint is detachably connected via a serration or the like. It may be a drive wheel bearing.

  FIG. 3 is a longitudinal sectional view showing a second embodiment of a drive wheel bearing assembly total assembly to which a unit cover according to the present invention is mounted, and FIG. 4 is a cross-sectional view of the main part along line IV-IV in FIG. FIG. 5 is a sectional view taken along the line V-V in FIG. 3. In addition, the same code | symbol is attached | subjected to the site | part, the same components, or site | part which has the same function as embodiment mentioned above, and the detailed description is abbreviate | omitted.

  This drive wheel bearing device total assembly includes a hub wheel 1, a double row rolling bearing 2, and a constant velocity universal joint 3 as a unit. On the other hand, the joint assembly JA is a fixed type outboard side constant velocity universal joint 3, a sliding type inboard side constant velocity universal joint 22 fitted in a differential, and a pair of constant velocity universal joints. And a drive shaft 100 connected to the joints 3 and 22.

  The unit cover 31 according to the present embodiment is made of a single sheet-like synthetic resin that is bent and molded, and as shown in FIG. 4, the end portions 32 along the longitudinal direction are polymerized to form a cylindrical shape. Is formed. Both end portions of the unit cover 31 have reduced diameter portions 31a and 31b that are elastically fitted to the outer joint member 14 and the boot 29, respectively, as in the above-described embodiment. The reduced diameter portion 31b on the inboard side is formed in a gentle taper shape so as to cover the entire outer joint member 23.

  On the other hand, the reduced diameter portion 31a on the outboard side is bent at a substantially right angle on the inner diameter side, as shown in FIG. 5, and a plurality of slits 33 are formed in the circumferential direction on the end face. Not only does the sheet-shaped cover structure facilitate diameter expansion / reduction, but the rigidity of the unit cover 31 is increased by the diameter-reduced portion 31a, and compression / tensile generated in the diameter-reduced portion 31a during diameter expansion / reduction. It is possible to reduce the stress and improve the durability of the reduced diameter portion 31a.

  Although not shown in the drawing, a single sheet may be wound around the outer periphery of the joint assembly JA to form a unit cover. In this case, it is necessary to attach an elastic ring to the outer periphery so that the unit cover does not fall off, or to join the end portions of the sheet by some means.

  FIG. 6 is a longitudinal sectional view showing a third embodiment of a drive wheel bearing assembly total assembly to which a unit cover according to the present invention is attached. In addition, the same code | symbol is attached | subjected to the site | part, the same components, or site | part which has the same function as embodiment mentioned above, and the detailed description is abbreviate | omitted.

  The unit cover according to the present embodiment includes a first unit cover 34 that covers the outer peripheral portion of the constant velocity universal joint 3 on the outboard side, and a second unit cover that covers the outer peripheral portion of the constant velocity universal joint 22 on the inboard side. 35, each of which is formed into a cylindrical shape by injection molding a synthetic resin such as PA66.

  The first unit cover 34 has a reduced diameter portion 34 a that is elastically fitted to the outer joint member 14 at both ends and a reduced diameter portion 34 b that is tapered along the boot 21. On the other hand, the second unit cover 35 has reduced diameter portions 35 a and 35 b formed in a tapered shape along the boot 29 and the outer joint member 23 at both ends.

  The pair of unit covers 34 and 35 protect the joint assembly JA as in the above-described embodiment, and further facilitate handling such as transportation. Further, since the reduced diameter portion 35b of the second unit cover 35 is formed in a gentle taper shape, the outer joint member 23 is prevented from sagging and the knuckle N can be easily attached without damaging the joint assembly JA. The drive wheel bearing device total assembly can be easily assembled to the knuckle N.

  In addition, since the unit cover is formed as a separate body attached to each of the constant velocity universal joints 3 and 22, the attachment is improved and the handling is facilitated and the workability is improved. Furthermore, standardization can be performed according to the specifications of the constant velocity universal joint, and even if the drive shaft 100 is long, it can be handled and the cost of the unit cover can be reduced.

  The embodiment of the present invention has been described above, but the present invention is not limited to such an embodiment, and is merely an example, and various modifications can be made without departing from the scope of the present invention. Of course, the scope of the present invention is indicated by the description of the scope of claims, and further, the equivalent meanings described in the scope of claims and all modifications within the scope of the scope of the present invention are included. Including.

  A unit cover according to the present invention is mounted on a drive shaft constituting a power transmission device of an automobile or the like and a constant velocity universal joint connected thereto, and improves protection and handling of the constant velocity universal joint. Regardless of the structure and specifications of the constant velocity universal joint and the drive wheel bearing connected to the constant velocity universal joint, the present invention can be applied to any power transmission device unit.

1 is a longitudinal sectional view showing a first embodiment of a drive wheel bearing assembly total assembly to which a unit cover according to the present invention is mounted. FIG. It is a principal part enlarged view of FIG. It is a longitudinal cross-sectional view which shows 2nd Embodiment of the bearing apparatus total assembly for drive wheels with which the unit cover which concerns on this invention was mounted | worn. FIG. 4 is a cross-sectional view of a main part taken along line IV-IV in FIG. 3. It is a principal part arrow line view along the VV line of FIG. It is a longitudinal cross-sectional view which shows 3rd Embodiment of the bearing apparatus total assembly for drive wheels with which the unit cover which concerns on this invention was mounted | worn. It is a longitudinal cross-sectional view which shows an example of the power transmission device incorporating the bearing apparatus for drive wheels.

Explanation of symbols

1 ·················· Hub wheel 1a, 16 ······························ Inner rolling surface 2 ... Double-row rolling bearings 3, 22 ... Constant velocity universal joints4 ... Wheel mounting flanges 5 ... Unevenness 6 ... Hub bolt 7 ... .... Outer member 7a ... Outer rolling surface 7b ... Car body mounting flange 7c ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Fitting surface 8 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner member 9 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・..Rolling element 10 ... Cage 11, 12, ... Seal 13 ... ·············································································· Outer joint member 15 ·············· Joint inner ring 15a, 18a Track grooves 15b, 24b, 28a ... Serration 16 ... Cage 17 ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Torque transmission ball 18 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Mouse part 19 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Shoulder parts 20, 28 ・・ ・ ・ ・ ・ ・ ・ ・ ・ Shaft 20a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Small diameter step 20b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Fitting part 21 , 29 ... Boot 24 ... Tripod member 24a ... Leg shaft 25 ... Needle roller Receptacle 26 ... Roller 27 ... Outer cylinder part 30, 31 ... .... Unit covers 30a, 30b, 31a, 31b .... Reduced diameter part 32 ... End part 33 ... Slit 34... First unit cover 34a, 34b... Reduced diameter portion 35. .... Second unit cover 35a, 35b ... Reduced diameter part 100 ... Drive shaft 101 ... ·································································································································· Joint 104 ... ················ Bearing device 105 for driving wheel ·················································・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Outer diameter Db of fitting surface of outer member ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Maximum outer diameter JA of constant velocity universal joint ・ ・ ・.... Fitting assembly

Claims (4)

An outer joint member having a plurality of curved track grooves extending in the axial direction and having a curved portion on the inner periphery, a joint inner ring having a track groove opposed to the track groove on the outer periphery, and both the track grooves A torque transmission ball housed in each formed ball track; a cage for rotatably holding the torque transmission ball; a drive shaft having one end connected to the joint inner ring; the drive shaft and the outer joint member; A fixed type constant velocity universal joint composed of a boot mounted on the outer periphery of the opening side of
And a joint assembly comprising a sliding type constant velocity universal joint composed of the drive shaft and a boot attached to the outer peripheral portion of the outer joint member on the opening side,
And an elastomer unit cover which is formed in a cylindrical shape so as to cover the outer peripheral portion of the joint assembly and which has a reduced diameter portion at both ends, is elastically attached to the joint assembly, and at least the inboard of the reduced diameter portion The unit cover / joint assembly is characterized in that the diameter-reduced portion on the side is tapered and a plurality of slits are formed in the circumferential direction on the diameter-reduced portion on the outboard side . The unit cover / joint assembly according to claim 1 , wherein the unit cover is integrally formed in a cylindrical shape . The unit cover / joint according to claim 1 , wherein the unit cover is made of a single sheet-like synthetic resin formed in a curved shape and is formed in a cylindrical shape by polymerizing ends along the longitudinal direction. Assembly. An outer member having a body mounting flange on the outer periphery and a fitting surface of a knuckle that constitutes a suspension device are formed integrally, and an outer member having a double row outer rolling surface formed on the inner periphery, and a plurality of rolling members on the outer member. An inner member which is rotatably supported via a moving body and has a wheel mounting flange and a double row inner rolling surface facing the outer rolling surface of the double row formed on an outer periphery; One inner rolling surface of the inner rolling surface is formed on the outer periphery of the hub wheel, and the other inner rolling surface is formed on the outer periphery of the outer joint member constituting the constant velocity universal joint. A hollow shaft portion formed in the outer joint member is fitted inside, and a concave and convex portion hardened on the inner diameter of the hub wheel is formed, and the fitting portion formed in the shaft portion is expanded in diameter to form the concave and convex portion. The hub wheel and the outer joint member are integrally plastically joined by biting into Dynamic wheel bearing,
And the joint assembly according to any one of claims 1 to 3 connected to the drive wheel bearing, wherein an outer diameter of a fitting surface of the outer member is larger than a maximum outer diameter of the joint assembly. A drive wheel bearing assembly as a whole.

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