JP2007255486A - Joint assembly and axle module provided with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a joint assembly protecting a pair of constant velocity universal joints and boots and preventing the constant velocity universal joint from tilting, and an axle module provided with the same. <P>SOLUTION: In the axle module provided with the fourth generation structure wheel bearing device rotatably supporting a wheel and the joint assembly 32 connected to the same, a unit cover 5 is externally fitted on outer joint members 7, 25 of the pair of constant velocity universal joints 1, 2, and boots 17, 31 installed on the same, is formed dividedly in a radial direction by injection molding of elastomer and is provided with cup parts 33, 34 having a shape following an outer shell shape and a cylinder part 35 installed on a drive shaft 4. Since an outer diameter Da of a fitting surface 10d of an external member 10 is formed larger than an outer diameter Db of the unit cover 5, assembly of the axle module on a knuckle is facilitated and assembly workability to a vehicle is improved. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a joint assembly including a pair of constant velocity universal joints and a drive shaft connected to these constant velocity universal joints, and outboard side constant velocity universal joints and wheel bearings of the pair of constant velocity universal joints. And a wheel bearing assembly (hereinafter referred to as an axle module).

  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 wheel side is connected to a sliding type constant velocity universal joint 101. The other end is connected to a wheel 105 via a wheel bearing device 104 including a fixed type constant velocity universal joint 103.

  Such a 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, this 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 wheel bearing device of such a fourth generation structure, a constant velocity universal joint constituting the wheel bearing device, and a drive shaft connected to a pair of constant velocity universal joints including the constant velocity universal joint A known axle module is provided with a unit cover that improves the assembly workability to the vehicle and protects the boot of the constant velocity universal joint during assembly and transportation. As shown in FIG. 8, in this axle module, a vehicle body mounting flange 50b to be attached to the knuckle N on the outer periphery and a fitting surface 50c to be fitted into the knuckle N are integrally formed, and a double row is formed on the inner periphery. The outer member 50 is formed with outer rolling surfaces 50a, 50a, and the outer member 50 is inserted through the double-row balls 51, 51 to attach a wheel (not shown) to one end. And a hub wheel 53 in which one inner rolling surface 53a facing the double row outer rolling surfaces 50a, 50a is formed on the outer periphery, and the hub wheel 53 is fitted into the outer periphery. A wheel bearing device composed of an inner member 55 composed of an outer joint member 54 in which the other inner rolling surface 54a facing the double row outer rolling surfaces 50a, 50a is formed, and the wheel bearing device. Fittings connected to And the outer diameter Da of the fitting surface 50c is formed larger than the maximum outer diameter Db of the constant velocity universal joint 56, and is formed in a cylindrical shape so as to cover the outer periphery of the joint assembly JA. Elastomer unit covers 57 having reduced diameter portions 57a and 57b are attached to both ends. Here, the joint assembly JA includes a pair of constant velocity universal joints 56 and 58 including a constant velocity universal joint 56 and a drive shaft 59 connected to the constant velocity universal joints 56 and 58.

Thus, the joint assembly JA is protected by covering the outer periphery of the joint assembly JA with the unit cover 57. Further, since the diameter-reduced portions 57a and 57b are formed at the end of the unit cover 57, the unit cover 57 can be elastically attached to the outer joint member 54 of the constant velocity universal joint 56 with one touch, and the unit cover 57 can be removed. Can be prevented. Therefore, it is possible to provide an axle module that improves the assembly workability to the vehicle and stabilizes the quality of the device.
JP 2005-256938 A

  However, in this conventional axle module, the constant velocity universal joints 56 and 58 are inclined by their own weight, so that the constant velocity universal joints 56 and 58 are inclined by such a unit cover 57 and are difficult to be incorporated into the knuckle N. In addition, when the constant velocity universal joint 58 on the inboard side is assembled into a differential (not shown), there is a problem that the unit cover 57 interferes with the workability. Moreover, the problem that the attitude | positions of the constant velocity universal joints 56 and 58 were not stabilized at the time of packing or during conveyance, and handling became difficult was also inherent.

  The present invention has been made in view of such circumstances, and includes a joint assembly that protects a pair of constant velocity universal joints and boots thereof, and prevents the constant velocity universal joint from being inclined by its own weight, and the same. It aims to provide an axle module.

  Furthermore, another object of the present invention is to provide an axle module that improves assembly workability to a vehicle and simplifies assembly and transportation.

  In order to achieve the object, the invention described in claim 1 of the present invention is a joint assembly including a pair of constant velocity universal joints and a drive shaft connected to the constant velocity universal joints. The constant velocity universal joint on the outboard side of the constant velocity universal joint is an outer joint member in which a plurality of track grooves extending in the axial direction having curved portions are formed on the inner periphery, and the outer peripheral portion on the opening side of the outer joint member And a boot mounted between the drive shafts, and a shaft to which the in-board constant velocity universal joint of the pair of constant velocity universal joints is differentially connected. And a sliding member provided with an outer joint member formed with a plurality of track grooves extending in the axial direction on the inner periphery, and a boot mounted between the outer periphery of the outer joint member and the drive shaft. In the joint assembly comprising the constant velocity universal joints, a unit cover is fitted on the outer joint member and the boot of the pair of constant velocity universal joints, and the unit cover is formed by dividing the elastomer in the radial direction by injection molding. The unit cover includes a cup portion formed in a shape following the outer shape of the outer joint member and the boot, and a cylindrical portion attached to the drive shaft.

  Thus, in a joint assembly including a pair of constant velocity universal joints and a drive shaft connected to these constant velocity universal joints, the unit cover is fitted on the outer joint member and the boot of the pair of constant velocity universal joints. The unit cover is formed by dividing the elastomer in the radial direction by injection molding, and the unit cover is mounted on the drive shaft and the cup portion formed in a shape following the outer joint member and the outer shape of the boot. This prevents and protects the joint assembly from contamination and scratches and prevents the constant velocity universal joint from tilting due to its own weight. Handling during transportation can be made easier.

  Moreover, if the protrusion which engages with the pleat of the boot of the said outboard side is formed in the inner periphery of the said cup part like invention of Claim 2, a constant velocity universal joint will incline with its own weight. Can be reliably prevented, and the unit cover can be prevented from moving in the axial direction with respect to the constant velocity universal joint.

  Further, as in the invention described in claim 3, a locking groove is formed on the outer periphery of the outer joint member in the constant velocity universal joint on the inboard side, and the locking groove is formed on the inner periphery of the cup portion. If the engaging protrusion is formed, it is possible to reliably prevent the constant velocity universal joint from being inclined by its own weight and to restrict the outer joint member from sliding relative to the drive shaft. .

  Further, the invention described in claim 4 of the present invention has a vehicle body mounting flange and a fitting surface for mounting on a knuckle constituting a suspension device on the outer periphery, and a double row outer rolling surface on the inner periphery. The formed outer member, a wheel mounting flange for mounting the wheel at one end, and one inner rolling surface facing the double row outer rolling surface on the outer periphery, and this inner rolling A hub wheel formed with a cylindrical small-diameter step portion extending in the axial direction from the surface, and a hollow shaft portion fitted to the hub wheel are integrally formed on the outer periphery of the double row outer rolling surface. An inner member composed of an outer joint member of a constant velocity universal joint formed with the other inner rolling surface facing each other, and a plurality of rolling members accommodated between the inner member and the outer member. A hardened uneven portion is formed on the inner periphery of the hub wheel, and the shaft portion is expanded in diameter. A wheel bearing device in which the hub wheel and the outer joint member are integrally plastically coupled by biting into the convex portion, a drive shaft having one end connected to the constant velocity universal joint, and the other end of the drive shaft An axle module comprising a sliding type constant velocity universal joint connected to the outer joint member of the pair of constant velocity universal joints, and a unit cover is externally fitted to the boots attached to these outer joint members, The unit cover is formed by dividing an elastomer in a radial direction by injection molding, a cup portion formed in a shape following the outer shape of the outer joint member and the boot, and a cylindrical portion mounted on the drive shaft, And the outer diameter of the fitting surface of the outer member is larger than the outer diameter of the unit cover.

  Thus, in the axle module including the wheel bearing device of the fourth generation structure for rotatably supporting the wheel and the joint assembly connected to the wheel bearing device, the outer joint in the pair of constant velocity universal joints A unit cover is externally fitted to the member and the boots attached to these outer joint members, and this unit cover is formed by dividing the elastomer in the radial direction by injection molding, following the outer shape of the outer joint member and the boot. Since it has a cup part formed in a shape and a cylindrical part attached to the drive shaft, the outer diameter of the fitting surface of the outer member is formed larger than the outer diameter of the unit cover, In addition to light weight and compactness, the axle module can be easily assembled to the knuckle, further improving the assembly workability to the vehicle.

  Further, as in the invention according to claim 5, the pitch circle diameter of the rolling element row on the inboard side of the double row rolling elements is set to be larger than the pitch circle diameter of the rolling element row on the outboard side. In addition, the outer diameter of the rolling elements in the double row is the same, and the number of rolling elements in the rolling element row on the inboard side is set larger than the number of rolling elements in the rolling body row on the outboard side. As a result, it is possible to reduce the weight and size, increase the bearing rigidity, and extend the life of the bearing.

  A joint assembly according to the present invention is a joint assembly including a pair of constant velocity universal joints and a drive shaft connected to these constant velocity universal joints, and is provided on the outboard side of the pair of constant velocity universal joints. The constant velocity universal joint has an outer joint member formed with a plurality of axially extending track grooves having a curved portion on the inner periphery, a boot mounted between the outer peripheral portion of the outer joint member and the drive shaft. Of the pair of constant velocity universal joints, a constant velocity universal joint on the inboard side of the pair of constant velocity universal joints, and a plurality of shaft portions that are connected to the differential, and a plurality of axially extending inner circumferences A sliding type constant velocity universal joint provided with an outer joint member in which a track groove is formed, and an opening-side outer peripheral portion of the outer joint member and a boot mounted between the drive shaft. In the joint assembly, a unit cover is externally fitted to the outer joint member and the boot of the pair of constant velocity universal joints, and the unit cover is formed by dividing the elastomer in the radial direction by injection molding. The outer joint member and the cup formed in a shape that follows the outer shape of the boot and the cylindrical portion that is attached to the drive shaft prevent contamination and damage to the joint assembly. In addition to protecting this, it is possible to prevent the constant velocity universal joint from being inclined due to its own weight, which makes handling easier during assembly and transportation.

  Further, the axle module according to the present invention has a vehicle body mounting flange and a fitting surface to be attached to the knuckle constituting the suspension device on the outer periphery, and an outer side in which a double row outer rolling surface is formed on the inner periphery. A member and a wheel mounting flange for mounting a wheel at one end, and one inner rolling surface facing the outer rolling surface of the double row on the outer periphery, and from the inner rolling surface in the axial direction A hub wheel formed with an extending cylindrical small-diameter step portion, and a hollow shaft portion fitted to the hub wheel are integrally formed, and the other inner side facing the double row outer rolling surface on the outer periphery An inner member composed of an outer joint member of a constant velocity universal joint formed with a rolling surface, and a plurality of rolling elements accommodated so as to roll between the inner member and the outer member, A hardened uneven portion is formed on the inner periphery of the hub wheel, and the shaft portion is expanded in diameter. The hub wheel and the outer joint member are integrally plastically joined by biting into the portion, a drive shaft having one end connected to the constant velocity universal joint, and the other end of the drive shaft. In an axle module composed of a connected sliding type constant velocity universal joint, a unit cover is externally fitted to an outer joint member of the pair of constant velocity universal joints and a boot attached to these outer joint members. A unit cover is formed by dividing an elastomer in a radial direction by injection molding, a cup portion formed in a shape following the outer shape of the outer joint member and the boot, and a cylindrical portion mounted on the drive shaft. In addition, the outer diameter of the fitting surface of the outer member is formed larger than the outer diameter of the unit cover. Both, it is easy to assemble the axle module to the knuckle, the assembling workability to the vehicle is further improved.

  An outer member having a body mounting flange and a fitting surface to be attached to a knuckle that constitutes a suspension device on the outer periphery, a double row outer rolling surface formed on the inner periphery, and a wheel on one end The wheel mounting flange is integrally formed, and one inner rolling surface facing the outer rolling surface of the double row is formed on the outer periphery, and a cylindrical small diameter step portion extending in the axial direction from the inner rolling surface is formed. And a hollow shaft portion that is fitted to the hub wheel, and the other inner rolling surface facing the outer rolling surface of the double row is formed on the outer periphery. An inner member made of an outer joint member of the joint, and a plurality of rolling elements housed in a freely rollable manner between the inner member and the outer member, and the inboard of the double row rolling elements The pitch circle diameter of the rolling element row on the side is larger than the pitch circle diameter of the rolling element row on the outboard side The outer diameter of the rolling elements in the double row is the same, and the number of rolling elements in the rolling element row on the inboard side is set larger than the number of rolling elements in the rolling element row on the outboard side. For the wheel in which a hardened uneven portion is formed on the inner periphery of the hub wheel, and the hub wheel and the outer joint member are integrally plastically bonded by expanding the shaft portion and biting into the uneven portion. In the axle module comprising a bearing device, a drive shaft having one end connected to the constant velocity universal joint, and a sliding type constant velocity universal joint connected to the other end of the drive shaft, the pair of constant velocity universal A unit cover is externally fitted to the outer joint member of the joint and the boots attached to these outer joint members, and this unit cover is formed by dividing the elastomer in the radial direction by injection molding. A cup portion formed in a shape following the outer shape of the member and the boot, and a cylindrical portion attached to the drive shaft, and the outer diameter of the fitting surface of the outer member is outside the unit cover. The diameter is larger than the diameter.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 is a longitudinal sectional view showing a first embodiment of an axle module according to the present invention, FIG. 2 is an enlarged view of a main part showing a wheel bearing device of FIG. 1, and FIG. 3 is a view of a unit cover of FIG. FIG. 4 is an explanatory view showing an assembly method, and FIG. 4 is an explanatory view showing an assembly method of the axle module and the knuckle of FIG. 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).

  As shown in FIG. 1, the axle module includes a pair of constant velocity universal joints 1 and 2, and the constant velocity universal joint 1 on the outboard side of the pair of constant velocity universal joints 1 and 2 and a double row rolling bearing. 3 is a unitized wheel bearing device, a drive shaft 4 connected to the pair of constant velocity universal joints 1 and 2, and a unit cover 5 that protects the pair of constant velocity universal joints 1 and 2 and the drive shaft 4. And. The wheel bearing device rotatably supports a wheel (not shown) with respect to a knuckle (not shown) constituting the suspension device.

  As shown in FIG. 2, the double row rolling bearing 3 constituting the wheel bearing device includes an inner member 8 including a hub wheel 6 and an outer joint member 7 of the constant velocity universal joint 1, and the inner member. 8 is composed of an outer member 10 extrapolated via double-row rolling elements (balls) 9 and 9, and has a configuration called a so-called fourth generation. The hub wheel 6 is formed of medium carbon steel containing carbon of 0.40 to 0.80 wt% such as S53C, and integrally includes a wheel mounting flange 11 for mounting the wheel to the end portion on the outboard side, One (outboard side) inner rolling surface 6a and a cylindrical small diameter step portion 6b extending in the axial direction from the inner rolling surface 6a are formed. In addition, an uneven portion 12 is formed on the inner periphery of the hub wheel 6 by a heat treatment to a surface hardness 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. Hub bolts 13 are implanted in the circumferentially equidistant positions of the wheel mounting flange 11.

  The concave and convex portion 12 is formed in the shape of an iris knurl, and is 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 12 is formed in a spire shape such as a triangular shape.

  The outer member 10 is formed of medium carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and integrally includes a vehicle body mounting flange 10c for mounting to a knuckle (not shown) on the outer periphery. Double row outer raceway surfaces 10a and 10b are formed. And the predetermined | prescribed hardened layer is formed in the range whose surface hardness is 58-64HRC by the induction hardening of these double row outer side rolling surfaces 10a and 10b.

  The constant velocity universal joint 1 includes an outer joint member 7, a joint inner ring 14, a cage 15, and a torque transmission ball 16. This outer joint member 7 is formed of medium carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and a cup-like mouth portion 18 in which a resin boot 17 is mounted on the outer periphery on the opening side, A shoulder portion 19, which forms the bottom of the mouse portion 18 and has the other (inboard side) inner rolling surface 7 a formed on the outer periphery, and a hollow shaft portion 20 extending in the axial direction from the shoulder portion 19 are integrally provided. is doing. On the outer periphery of the shaft portion 20, an inrow portion 20a fitted into the small diameter step portion 6b of the hub wheel 6 via a predetermined radial clearance and a fitting portion 20b extending in the axial direction from the inrow portion 20a are integrally formed. Is formed. An end cap 21 is attached to the inner periphery of the shoulder portion 19 to prevent leakage of grease enclosed in the mouse portion 18 together with the boot 17 and preventing rainwater and dust from entering the joint from the outside. Yes.

  Further, eight track grooves 18a extending in the axial direction having curved portions are formed on the inner periphery of the mouse portion 18, and eight tracks extending in the axial direction having curved portions are opposed to the track grooves 18a. A groove 14 a is formed on the outer periphery of the joint inner ring 14. A torque transmission ball 16 is accommodated between the track grooves 18a and 14a. In the outer joint member 7, a predetermined hardened layer is formed in the range of 58 to 64 HRC from the shoulder 19 to the shaft 20 starting with the track groove 18 a. The fitting portion 20b of the shaft portion 20 is left unquenched raw.

  Between the double-row inner rolling surfaces 6a and 7a of the inner member 8 and the double-row outer rolling surfaces 10a and 10b of the outer member 10, double-row rolling elements 9 and 9 are accommodated, respectively. 22 and 22 are held so as to roll freely. Seals 23 and 24 are attached to the opening of the annular space formed between the outer member 10 and the hub wheel 6 and the outer joint member 7, and leakage of lubricating grease sealed inside the bearing is Prevents rainwater and dust from entering the bearing.

  The hub wheel 6 has a surface hardness of 58 to 64 HRC by induction hardening over the small diameter step portion 6b from the seal land portion where the seal lip of the seal 23 on the outboard side is in sliding contact with the inner rolling surface 6a. A predetermined hardened layer is formed. Thereby, not only the wear resistance of the seal land portion is improved, but also the strength of the hub wheel 6 itself against a moment load or the like is increased, and the durability is improved. Further, the fitting portion 20b to be expanded is an unquenched portion having a forged material surface hardness of 24 HRC or less, and the hardness difference from the surface hardness 54 to 64 HRC of the uneven portion 12 of the hub wheel 6 is 30 HRC or more. It is preferable to set to. Thereby, the fitting part 20b can bite into the uneven part 12 easily and deeply, and both can be firmly plastically bonded without collapsing the tip of the uneven part 12.

  In the assembly, the shaft portion 20 of the outer joint member 7 is fitted into the hub wheel 6 until the shoulder portion 19 of the outer joint member 7 abuts against the small-diameter step portion 6b of the hub wheel 6 to be in a butted state. By pushing a diameter expansion jig (not shown) such as a mandrel into the portion 20 to increase the diameter of the fitting portion 20b, the fitting portion 20b is bitten into the concavo-convex portion 12 of the hub wheel 6 and crimped. 6 and the outer joint member 7 are integrally plastically coupled. 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, the strength and durability of the hub wheel 6 can be improved, and the length can be increased. The amount of preload can be maintained for a period. Furthermore, incorporation into a vehicle can be simplified by unitization.

  Here, the pitch circle diameter PCDi of the 9 rolling elements on the inboard side is set larger than the pitch circle diameter PCDo of the 9 rolling elements on the outboard side. That is, the groove bottom diameter of the inner rolling surface 7a of the outer joint member 7 in the inner member 8 is the inner rolling force of the hub wheel 6 in accordance with the difference between the double row rolling elements 9 and the pitch circle diameters PCDo and PCDi of the nine rows. The diameter is larger than the groove bottom diameter of the running surface 6a. On the other hand, in the outer member 4, the groove bottom diameter of the outer rolling surface 10b on the inboard side is formed larger than the groove bottom diameter of the outer rolling surface 10a on the outboard side. The outer diameters of the double row rolling elements 9 and 9 are the same, but due to the difference in pitch circle diameters PCDo and PCDi, the number of rolling elements 9 on the inboard side is larger than the number of rolling elements 9 on the outboard side. Many are set. Accordingly, it is possible to reduce the weight and size, increase the bearing rigidity, and extend the life of the bearing.

  Further, in this embodiment, the outer diameter of the fitting surface 10d of the outer member 10 fitted to the inner diameter of the knuckle is Da, and the maximum outer diameter of the joint assembly 32 described later, here, the outer diameter of the unit cover 5 Is set to Db, the outer diameter Da of the fitting surface 10d is set larger than the outer diameter Db of the unit cover 5 (Da ≧ Db). As a result, the double row rolling bearing 3 and the constant velocity universal joint 1 can be assembled in advance and then assembled to the knuckle, further improving the workability of the assembly to the vehicle and the workability of inspection and repair. Will also improve.

  Although the compact type constant velocity universal joint 1 having eight balls is illustrated here, the outer diameter Db of the unit cover 5 attached to the constant velocity universal joint 1 is not limited to this. The constant velocity universal joint may be a general constant velocity universal joint including six balls as long as it is set to be equal to or smaller than the outer diameter Da of the fitting surface 10c.

  As shown in FIG. 1, one end of a drive shaft 4 is coupled to a joint inner ring 14 of a constant velocity universal joint 1 on the outboard side, and the other end of the drive shaft 4 is a tripod member of the constant velocity universal joint 2 on the inboard side. 26. The constant velocity universal joint 2 forms a sliding type and is connected to a differential (not shown).

  This constant velocity universal joint 2 includes an outer joint member 25, a tripod member 26 having three leg shafts 26a projecting from the outer periphery at equal intervals, and needle roller bearings 27 on these leg shafts 26a. And a roller 28 inserted rotatably. The outer joint member 25 is formed of medium carbon steel containing carbon of 0.40 to 0.80 wt%, such as S53C, and has a cylindrical outer tube portion 29 whose outer periphery is formed in a petal shape, and a bottom portion of the outer tube portion 29. And a shaft portion 30 extending in the axial direction. A serration (or spline) 30 a that is fitted into the differential is formed at the end of the shaft portion 30.

  Further, three linear track grooves 29a extending in the axial direction are formed on the inner periphery of the outer cylindrical portion 29, and the roller 28 rolls on the track grooves 29a. In the outer joint member 25, a predetermined hardened layer is formed on the outer periphery of the track groove 29 a and the shaft portion 30 with a surface hardness of 58 to 64 HRC by induction hardening. A boot 31 made of synthetic rubber or the like is attached to the outer periphery of the outer cylinder portion 29 on the opening side, and leakage of grease sealed in the outer cylinder portion 29 and rainwater, dust, etc. enter the joint from the outside. Is preventing. Here, the tripod type is illustrated for the constant velocity universal joint 2 on the inboard side. However, the invention is not limited to this, and a sliding type constant velocity universal joint may be used. It may be a double offset type constant velocity universal joint (DOJ) using

  In the present embodiment, the outer joint members 7 and 25 of the pair of constant velocity universal joints 1 and 2 are provided with outer peripheral portions of the constant velocity universal joints 1 and 2 and the drive shaft 4 (hereinafter referred to as a joint assembly 32). A covering cylindrical unit cover 5 is attached. The unit cover 5 is formed by injection molding an elastomer such as PA (polyamide) 66, and cup parts 33, 34 formed in a shape that follows the outer shape of the outer joint members 7, 25 and the boots 17, 31. In addition, the cup portion 33, 34 is connected to the central portion, and a cylindrical portion 35 that is externally fitted to the drive shaft 4 is provided.

  As shown in FIG. 3, the unit cover 5 has a two-part structure composed of an upper cover 5a and a lower cover 5b. The unit cover 5 is fitted from the outer side in the radial direction of the joint assembly 32 and integrated by a fastening band 36. The As a result, contamination and damage to the joint assembly 32 can be prevented and protected, and handling during assembly and transportation can be made easier. Further, as shown in FIG. 4, the knuckle N can be smoothly and sequentially inserted in the direction indicated by the arrow from the outer peripheral portion of the constant velocity universal joint 2 on the inboard side to the fitting surface 10d of the outer member 10. It is possible to provide an axle module that improves the assembly workability to the vehicle and simplifies assembly and transportation. Further, the axle module can be assembled with the knuckle N fixed to the suspension device.

  In this unit cover 5, cup portions 33 (33a, 33b) and 34 (34a, 34b) covering a pair of constant velocity universal joints 1 and 2 are integrally connected by a cylindrical portion 35 (35a, 35b). The constant velocity universal joints 1 and 2 can be prevented from inclining due to their own weights. However, in the present embodiment, the protrusions 37 (37 a that engage with the folds of the boot 17 on the outboard side of the unit cover 5 are further provided. 37b) and a protrusion 38 that engages with the locking groove 29b of the outer cylindrical portion 29 is formed on the inboard side, so that the constant velocity universal joints 1 and 2 are inclined by their own weight. While being able to prevent reliably, it can prevent that the unit cover 5 moves to an axial direction with respect to the joint assembly 32, and can control that the outer joint member 25 slides with respect to the drive shaft 4. FIG.

  Examples of the material of the unit cover 5 include POM (polyacetal), PBT (polybutylene terephthalate), PET (polyethylene terephthalate), etc., in addition to the above-mentioned PA66. The material is not limited to any material as long as it is low-cost and has good moldability. For example, a synthetic rubber having a predetermined rigidity may be used.

  FIG. 5 is a longitudinal sectional view showing a second embodiment of the axle module according to the present invention, and FIG. 6 is an explanatory view showing a method of assembling the unit cover of FIG. Note that this embodiment is different from the above-described embodiment only in the configuration of the unit cover, and other parts having the same parts or the same functions are denoted by the same reference numerals and detailed description thereof is omitted.

  In the present embodiment, separate unit covers 39 and 40 that cover the outer periphery of the joint assembly 32 are mounted, respectively. These unit covers 39 and 40 are formed in a cup shape following the outer shape of the outer joint members 7 and 25 and the boots 17 and 31, respectively, by injection molding an elastomer such as PA66.

  Further, as shown in FIG. 6, these unit covers 39, 40 have a two-part structure composed of upper covers 39a, 40a and lower covers 39b, 40b, respectively. The upper cover 39a, 40a and the lower cover 39b, 40b are fitted together from the outer side in the radial direction of the joint assembly 32 and integrated by a fastening band 36.

  The unit cover 39 (39a, 39b) that protects the fixed type constant velocity universal joint 1 on the outboard side is formed with a ridge 37 that engages with the fold of the boot 17 at the opening on the large diameter side, so that the constant velocity is freely adjustable. The joint 1 is prevented from being inclined by its own weight, and the unit cover 39 is prevented from moving in the axial direction with respect to the outer joint member 7.

  On the other hand, the unit cover 40 that protects the sliding constant velocity universal joint 2 on the inboard side is formed with a protrusion 38 that engages with the locking groove 29b of the outer cylinder portion 29 at the opening on the large diameter side, The constant velocity universal joint 2 is prevented from being inclined by its own weight, the unit cover 40 is prevented from moving in the axial direction with respect to the outer joint member 25, and the outer joint member 25 slides with respect to the drive shaft 4. Is regulated.

  In the present embodiment, the unit covers 39 and 40 that cover the pair of constant velocity universal joints 1 and 2 are separately configured. Therefore, the weight can be reduced as compared with the above-described embodiment, and the constant velocity universal joints having different specifications can be used. It can be handled as appropriate and the unit cover itself can be standardized.

  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.

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

1 is a longitudinal sectional view showing a first embodiment of an axle module to which a unit cover according to the present invention is mounted. It is a principal part enlarged view which shows the wheel bearing apparatus of FIG. It is explanatory drawing which shows the assembly method of the unit cover of FIG. It is explanatory drawing which shows the assembly method of the axle module of FIG. 1, and a knuckle. It is a longitudinal cross-sectional view which shows 2nd Embodiment of the axle module with which the unit cover which concerns on this invention was mounted | worn. It is explanatory drawing which shows the assembly method of the unit cover of FIG. It is a longitudinal cross-sectional view which shows an example of the power transmission device incorporating the bearing apparatus for drive wheels. It is a longitudinal cross-sectional view which shows the axle module with which the conventional unit cover was mounted | worn.

Explanation of symbols

1, 2, ... Constant velocity universal joint 3 ... Double row rolling bearing 4 ... ..... drive shafts 5, 39, 40 ..... unit covers 5a, 39a, 40a ... upper covers 5b, 39a, 40b ...・ ・ ・ ・ ・ Lower cover 6 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Hub wheel 6a, 7a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner rolling surface 6b ・ ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Small diameter step 7, 25 ・ ・ ・ ・ ・ ・ ・ ・ Outer joint member 8 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・Inner member 9 ... rolling element 10 ... outer members 10a, 10b ... .... Outer rolling surface 10c ... 10d ・ ・ ・ ・ ・ ・ ・ ・ ・ Fitting surface 11 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Wheel mounting flange 12 ············································································································· Coupling inner rings 14a, 18a, 29a ..Track groove 15 ... Cage 16 ... Torque transmission balls 17, 31 ...・ ・ ・ ・ ・ Boots 18 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Mouse 19 ・ ・ ・ ・ ・ ・ Shoulders 20 and 30・ ・ ・ ・ ・ ・ ・ ・ ・ Shaft 20a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ In-row 20b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Fitting 21 ………… End Cap 22 ・ ・ ・ ・ ・ ・ ・ ・·········· Retainer 23, 24 ················································································・ ・ ・ ・ ・ ・ ・ Leg shaft 27 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Needle roller bearing 28 ・ ・ ・ ・ ・ ・ Roller 29 ··········································································· Serration 32 ····························· Joint assembly 33, 34 ········································ 33b, 34b ·············· Lower cup portion 35 ··········································· Upper cylindrical part 35b ......... Lower cylinder -Shaped part 36 ... tightening band 37, 38 ... ridge 37a ... ... Upper ridge 37b ... Lower ridge 50 ... Outer member 50a ...・ ・ ・ ・ ・ ・ ・ ・ Outer rolling surface 50b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Car body mounting flange 50c ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Fitting surface 51 ・・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Ball 52 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Wheel mounting flange 53 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・Hub wheel 53a, 54a ... inner rolling surface 54 ... outer joint member 55 ... .... Inward members 56, 58 ... Constant velocity universal joint 57 ... ·········· Unit covers 57a and 57b ··· Reduced diameter portions 59 and 100 ···················· Drive shaft 101 ··· ·········································································································· Differential Speed universal joint 104 ... Wheel bearing device 105 ... Wheel 106 ... ... Wheel bearings Da ... Outer diameter Db of the fitting surface of the outer member ... Fitting assembly Maximum Outer Diameter JA ・ ・ ・ ・ ・ ・ ・ ・ Fitting Assembly N ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Knuckle PCDi ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・.... Invo The pitch circle of the rolling element row of side diameter PCDo ············· pitch circle diameter of the rolling element row on the outboard side

Claims (5)

A joint assembly comprising a pair of constant velocity universal joints and a drive shaft connected to these constant velocity universal joints,
An outer joint member in which a constant velocity universal joint on the outboard side of the pair of constant velocity universal joints is formed with a plurality of track grooves extending in the axial direction having a curved portion on the inner periphery;
It consists of a fixed type constant velocity universal joint provided with an outer peripheral portion on the opening side of the outer joint member and a boot mounted between the drive shafts,
Of the pair of constant velocity universal joints, the constant velocity universal joint on the inboard side is differentially connected to a shaft portion, and an outer joint member in which a plurality of track grooves extending in the axial direction is formed on the inner periphery,
In a joint assembly comprising a sliding type constant velocity universal joint provided with a boot mounted between the outer peripheral portion of the outer joint member and the drive shaft,
A unit cover is externally fitted to the outer joint member and the boot of the pair of constant velocity universal joints, and the unit cover is formed by dividing an elastomer in a radial direction by injection molding. A joint assembly comprising: a cup portion formed in a shape following the outer shape of the member and the boot; and a cylindrical portion attached to the drive shaft.   The joint assembly according to claim 1, wherein a protrusion that engages with a fold of the boot on the outboard side is formed on an inner periphery of the cup portion.   The locking groove is formed in the outer periphery of the outer joint member in the constant velocity universal joint on the inboard side, and the protrusion that engages with the locking groove is formed in the inner periphery of the cup portion. Or the joint assembly of 2.   An outer member having a body mounting flange and a fitting surface to be attached to a knuckle that constitutes a suspension device on the outer periphery, a double row outer rolling surface formed on the inner periphery, and a wheel on one end The wheel mounting flange is integrally formed, and one inner rolling surface facing the outer rolling surface of the double row is formed on the outer periphery, and a cylindrical small diameter step portion extending in the axial direction from the inner rolling surface is formed. And a hollow shaft portion that is fitted to the hub wheel, and the other inner rolling surface facing the outer rolling surface of the double row is formed on the outer periphery. An inner member composed of an outer joint member of a joint, and a plurality of rolling elements accommodated so as to be freely rollable between the inner member and the outer member, and an unevenness cured on the inner periphery of the hub wheel A hub portion is formed by expanding the diameter of the shaft portion and biting into the uneven portion. A wheel bearing device in which an outer joint member is integrally plastically coupled, a drive shaft having one end connected to the constant velocity universal joint, and a sliding type constant velocity universal joint connected to the other end of the drive shaft The unit cover is externally fitted to the outer joint member of the pair of constant velocity universal joints and the boots attached to the outer joint members, and the unit cover is made of elastomer by injection molding in the radial direction. The outer joint member and a cup portion formed in a shape following the outer shape of the boot, and a cylindrical portion attached to the drive shaft, and a fitting surface of the outer member The outer diameter of the axle module is formed larger than the outer diameter of the unit cover.   Among the double row rolling elements, the pitch circle diameter of the inboard side rolling element row is set larger than the pitch circle diameter of the outboard side rolling element row, and the outer diameter of the double row rolling element The axle module according to claim 4, wherein the number of rolling elements in the inboard side rolling element row is set to be larger than the number of rolling elements in the outboard side rolling element row.

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