JP2009248720A - Bearing apparatus for driving wheel and axle module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-cost wheel bearing apparatus for a driving wheel with which the number of man-hours and assembly steps can be reduced, and with which component replacement fees and repair costs can be reduced. <P>SOLUTION: This bearing apparatus for a driving wheel includes an external member 25 fitted with a vehicle knuckle hole by a predetermined joining, an internal member composed of a hub ring 1 having a flange 21 for fixing the wheel and an inner ring 24 fitted with the hub ring 1, double-row rolling elements 30 rollably interposed between the external member 25 and the internal members 1, 24, and an outside joint member 5 of a constant velocity universal joint integral with the hub ring 1 via a projection-recess fitting structure M formed by press-fitting. An annular groove is formed in both an outer peripheral surface 25a of the external member 25 and an inner peripheral surface of the knuckle hole, and a retaining ring 130 is engaged in both annular grooves. The external member 25 is prevented from coming off of the knuckle, and the external member 25 can be separated from the knuckle only as a result of deformation or breakage of the retaining ring 130. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a drive wheel bearing device and an axle module for rotatably supporting a drive wheel of a vehicle such as an automobile with respect to a vehicle body.

  A power transmission device for an automobile needs to transmit power from an engine to wheels, and to allow radial and axial displacements and moment displacements of the wheels during vertical movement and turning of the suspension. For this reason, the inboard side end of the drive shaft interposed between the engine and the drive wheel is connected to the differential through a sliding constant velocity universal joint, and the fixed end of the constant velocity universal joint is connected to the outboard side end. Via a drive wheel. In the following description, when the term “drive shaft” is used, the entire shaft including the constant velocity universal joints at both ends of the shaft is referred to as a drive shaft. Here, the side closer to the center of the vehicle in the state assembled to the vehicle is referred to as the inboard side, and the side closer to the outer side is referred to as the outboard side.

  The drive wheel bearing device includes a hub wheel having a flange for mounting the drive wheel, an outer joint member of an outboard side constant velocity universal joint coupled to the hub wheel so as to be able to transmit torque, and rotatably supports these members. A rolling bearing is unitized. The combination of the drive shaft and the drive wheel bearing device is called an axle module. The drive shaft and the drive wheel bearing device use the outer joint member of the outboard side constant velocity universal joint as a common component.

  The wheel bearing device has evolved from a structure in which a double-row rolling bearing called a first generation is used alone to a second generation in which a vehicle body mounting flange is integrated with an outer member. 3rd generation, which forms one inner raceway (inner race) of a double row rolling bearing on the outer periphery of the hub wheel that has an integral, and the hub wheel and the constant velocity universal joint are integrated, this constant velocity free Up to the fourth generation, in which the other inner race (inner race) of the double row rolling bearing is formed on the outer periphery of the outer joint member constituting the joint, has been developed.

  Patent Document 1 describes a third-generation wheel bearing device. As shown in FIG. 16, the wheel bearing device includes a hub wheel 152 having a flange 151 extending in the outer diameter direction, a constant velocity universal joint 154 in which an outer joint member 153 is fixed to the hub wheel 152, and a hub wheel 152. And an outer member 155 disposed on the outer peripheral side.

  The constant velocity universal joint 154 includes a ball interposed between the outer joint member 153, the inner joint member 158 housed in the bowl-shaped portion 157 of the outer joint member 153, and the outer joint member 153 and the inner joint member 158. 159 and a holder 160 for holding the ball 159. A spline (or serration; the same applies hereinafter) 161 is formed in the center hole of the inner joint member 158, and is splined with a spline shaft of a shaft (not shown).

  The hub wheel 152 includes the flange 151 and a cylindrical portion 163, and a short cylindrical pilot portion for mounting a wheel and a brake rotor (not shown) on the outer end surface (end surface on the opposite joint side) 164 of the flange 151. 165 is formed. The pilot unit 165 includes a large-diameter brake pilot 165a and a small-diameter wheel pilot 165b, and the brake pilot 165a is fitted with a brake rotor, and the wheel pilot 165b is fitted with a wheel.

A small-diameter portion 166 is provided at an end portion of the cylindrical portion 163 on the flange-shaped portion 157 side, and an inner ring 167 is fitted to the small-diameter portion 166. A first inner race (inner race) 168 is formed in the vicinity of the flange on the outer peripheral surface of the cylindrical portion 163 of the hub wheel 152, and a second inner race (inner race) 169 is formed on the outer peripheral surface of the inner ring 167. . The flange 151 of the hub wheel 152 has a bolt mounting hole 162, and the wheel and brake rotor are fixed to the flange 151 by a hub bolt (not shown) implanted in the bolt mounting hole 162.

  The outer member 155 has two rows of outer races (outer races) 170 and 171 formed on the inner periphery, and a flange (vehicle body mounting flange) 182 formed on the outer periphery. The first inner track 168 of the hub ring 152 and the first outer track 170 of the outer member 155 are opposed to each other, and the second inner track 169 of the inner ring 167 and the second outer track 171 of the outer member 155 are opposed to each other. Two rows of rolling elements 172 are interposed between the two.

  A spline portion 176 is formed on the inner peripheral surface of the cylindrical portion 163 of the hub wheel 152. The shaft portion 173 has a threaded portion 174 formed at the tip, and a spline portion 175 is formed between the threaded portion 174 and the hook-shaped portion 157. Then, the shaft portion 173 of the outer joint member 153 is inserted into the tube portion 163 of the hub wheel 152, and the spline portion 175 of the shaft portion 173 and the spline portion 176 of the hub wheel 152 are engaged with each other, thereby The member 153 can be coupled to transmit torque.

When the nut 177 is attached and tightened to the threaded portion 174 of the shaft portion 173 protruding from the cylindrical portion 163, the seat surface 178 of the nut 177 and the outer end surface 179 of the cylindrical portion 163 are brought into close contact with each other. The end surface 180 and the outer end surface 181 of the inner ring 167 are in close contact with each other. That is, by tightening the nut 177, the hub wheel 152 is sandwiched between the nut 177 and the hook-shaped part 157 via the inner ring 167.
JP 2004340403 A

  Conventionally, as described above, the spline portion 175 of the shaft portion 173 and the spline portion 176 of the hub wheel 152 are engaged to obtain a coupling structure capable of transmitting torque. For this reason, both the shaft portion 173 and the hub wheel 152 need to be splined, which not only increases the cost, but also the unevenness between the spline portion 175 of the shaft portion 173 and the spline portion 176 of the hub wheel 152 during press-fitting. It is necessary to match. Furthermore, if the teeth are pressed together by matching the tooth surfaces, the uneven teeth may be damaged (peeled). Moreover, if it press-fits by matching the large diameter of an uneven | corrugated tooth | gear, without matching a tooth surface, the play of a circumferential direction will arise easily. If there is a backlash in the circumferential direction, the transmission performance of the rotational torque is inferior and abnormal noise may be generated. Thus, in the case of spline fitting, it has been difficult to remove both the damage to the uneven teeth and the play in the circumferential direction at the same time.

  Further, since the nut 177 is attached to the threaded portion 174 of the shaft portion 173 protruding from the cylindrical portion 163 and tightened, it is necessary to cut the screw at the tip of the shaft portion 173 of the outer joint member 153. When assembling, the work of attaching and tightening the nut 177 is indispensable. Therefore, the workability is inferior, the number of parts is large, and the parts manageability is also inferior.

Therefore, the present applicant can first suppress the backlash in the circumferential direction, and can separate and reassemble the hub wheel and the outer joint member of the constant velocity universal joint. A wheel bearing device that can be easily assembled with a joint member has been proposed (Japanese Patent Application No. 2007-274065).
However, since the outer member corresponding to the bearing outer ring is inserted into the knuckle hole of the vehicle and the steel retaining ring is used to prevent the outer member from coming off, there is the following problem. That is, when repairing or the like, it is not easy to remove the outer member from the knuckle, and it must be disassembled by applying a large pulling load. As a result, the retaining ring groove of the knuckle is destroyed, so that it is necessary to replace the knuckle, and the repair cost increases.

  An object of the present invention is to provide a low-cost bearing device for a drive wheel that eliminates the above-mentioned problems, reduces the number of processing steps and assembly steps, and suppresses the cost of parts replacement at the time of repair.

  The drive wheel bearing device of the present invention has an outer member having a double row outer track formed on the inner periphery and a flange for fixing the wheel, and one of the double row inner tracks formed on the outer periphery. An inner member comprising a hub ring and an inner ring that fits with the hub ring and forms the other of the double-row inner raceway on the outer periphery, and between the outer raceway of the outer member and the inner raceway of the inner member A bearing device for a drive wheel having a double row rolling element interposed so as to roll freely and an outer joint member of a constant velocity universal joint integrated with the hub ring by press-fitting, wherein the hub wheel and the outer side The joint member forms a concave-convex fitting structure, and the concave-convex fitting structure extends in the axial direction on either the outer diameter surface of the shaft portion of the outer joint member or the inner diameter surface of the hole portion of the hub wheel. By providing a convex part and press-fitting the shaft part of the outer joint member into the hole part of the hub wheel, A concave-convex fitting structure in which a concave portion that closely fits with the convex portion is formed by the convex portion, and the entire fitting contact portion between the convex portion and the concave portion is in close contact, and the outer member is attached to a vehicle knuckle. The knuckle is fitted into the hole with a predetermined fit, and an annular groove is formed in each of the outer peripheral surface of the outer member and the inner peripheral surface of the hole of the knuckle. The outer member is prevented from coming off, and the outer member can be separated from the knuckle only by deformation or breaking of the retaining ring.

  A convex portion extending in the axial direction provided on one of the inner peripheral surface of the hole of the hub wheel and the outer peripheral surface of the shaft portion of the outer joint member is press-fitted into the other along the axial direction, and the convex portion is Thus, a concave / convex fitting structure in which the entire fitting contact portion between the convex portion and the concave portion is in close contact with each other can be formed.

A convex portion of the concave-convex fitting structure is provided on the shaft portion of the outer joint member of the constant velocity universal joint, and at least the hardness of the axial end portion of the convex portion is higher than the inner diameter portion of the hole portion of the hub wheel, By pressing the shaft portion into the hole portion of the hub wheel from the axial end portion side of the convex portion, a concave portion that closely fits the convex portion is formed on the inner diameter surface of the hole portion of the hub wheel at the convex portion. An uneven fitting structure may be configured (claim 2). At this time, the convex part bites into the concave part forming surface on the other side (the inner diameter surface of the hole part of the hub wheel), so that the hole part is slightly expanded in diameter and the axial movement of the convex part is allowed. However, if the movement in the axial direction stops, the diameter of the hole portion is reduced to return to the original diameter. Thereby, the whole recessed part fitting part of a convex part closely_contact | adheres to the corresponding recessed part.

Further, a convex portion of the concave-convex fitting structure is provided on the inner diameter surface of the hole portion of the hub wheel, and at least the hardness of the axial end portion of the convex portion is set to the outer diameter portion of the shaft portion of the outer joint member of the constant velocity universal joint. The convex portion on the hub wheel side is press-fitted into the shaft portion of the outer joint member from the axial end portion side, thereby projecting to the outer diameter surface of the shaft portion of the outer joint member. The concave-convex fitting structure may be formed by forming a concave portion that closely fits to the portion. If the convex portion bites into the outer diameter surface of the shaft portion, the hole portion is slightly expanded in diameter, allowing the convex portion to move in the axial direction and stopping the axial movement. The part is reduced in diameter to return to the original diameter. As a result, the entire fitting contact region between the convex portion and the concave portion (outer diameter surface of the shaft) of the mating member fitted into the concave portion is in close contact.

To illustrate the configuration of the bearing, when the bearing type is a double-row angular ball bearing, an outer member having two rows of outer races, an inner member having two rows of inner races, an outer race and an inner race, And rolling elements (in this case, balls) interposed between the two. The inner member corresponding to the bearing inner ring includes a hub ring and an inner ring each having a row of inner races, and can be fixed by fitting the inner ring to the hub ring and caulking the end of the hub ring. it can. Various types of caulking are known, and an example is swing caulking. By caulking the end of the hub wheel, the distance between the two rows of inner races is reduced and bearing preload is applied. The outer member corresponding to the bearing outer ring has a fitting relationship with the knuckle hole.

  The outer joint member includes the shaft portion and a mouth portion that accommodates the inner joint member and the torque transmission element therein, and a boot is attached to the open end portion of the outer joint member. Generally, the maximum outer diameter of the boot band that tightens the boot from the outside is the maximum outer diameter of the drive shaft. Therefore, by setting the outer diameter of the outer member to be larger than the maximum outer diameter, the entire drive shaft can be taken out from the knuckle hole to the outboard side.

  Here, the drive shaft includes an outboard side constant velocity universal joint, a shaft, and an inboard side constant velocity universal joint, and functions to transmit torque from the engine to the wheel. The inboard side constant velocity universal joint is coupled to the output shaft of the transmission so as to be able to transmit torque and to be movable in the axial direction by a slide spline. The outboard side constant velocity universal joint transmits torque to the wheel via the hub wheel.

  The outer member can be attached to and removed from the knuckle. By fitting the fit between the outer member and the hole of the knuckle into a tight fit, it is possible to prevent the shaft from coming off to some extent. However, since it is not possible to make an excessive tightening allowance, a retaining ring is also used in order to prevent failing reliably and to take measures against fail-safe and unexpectedly high loads. Retaining ring grooves are formed on the outer peripheral surface of the outer member and the inner peripheral surface of the knuckle hole, and the retaining ring is attached to the outer peripheral surface of the outer member and inserted into the knuckle hole in a state of being reduced in diameter by elastic deformation. When the retaining ring is moved in the axial direction, as soon as the retaining ring reaches the position of the retaining ring groove of the knuckle hole, the diameter of the retaining ring expands elastically and expands into the hole of the knuckle, and engages with both retaining ring grooves. . As compared with the case where the flange of the outer member is fastened to the knuckle with a bolt as in the conventional example shown in FIG. 16, attachment and removal are easier.

  In removing the outer member from the knuckle, the retaining ring is positively deformed. Here, deformation includes destruction. Then, a retaining ring made of a material having a shear stress smaller than that of the knuckle and the outer member is used so as not to break the knuckle and the outer member. Specifically, the shear stress of the retaining ring is preferably in the range of 5 to 150 MPa (Claim 5). An example of such a retaining ring material is a thermoplastic synthetic resin.

  In order to facilitate the work of press-fitting the outer member into the hole of the knuckle, the outer diameter side ridge line portion of the retaining ring may be chamfered (Claim 7). This is a case where the retaining ring has a rectangular cross-sectional shape, but the same effect can be obtained even if a retaining ring having a circular cross-sectional shape is employed. That is, by adopting a retaining ring made of a wire having a circular cross section, the press-fitting operation into the knuckle hole is facilitated.

  The edge on the outboard side of the knuckle hole may be chamfered (claim 9). The outboard side of the knuckle hole is the outer side of the vehicle when it is attached to the vehicle, and serves as an inlet when the outer member is press-fitted. The outer member can be smoothly inserted into the knuckle hole by reducing the diameter and facilitating sinking into the retaining ring groove of the outer member.

An axle module of the present invention includes a drive wheel bearing device according to any one of claims 1 to 9, an outboard side constant velocity universal joint including the outer joint member, a shaft, and an inboard side constant velocity universal joint. The maximum outer diameter of the outboard side constant velocity universal joint and the inboard side constant velocity universal joint is smaller than the outer diameter of the outer member.

  According to the present invention, in the concave-convex fitting structure, no gap that causes play in the radial direction and the circumferential direction is formed, so that all of the fitting parts contribute to torque transmission and stable torque transmission is possible. In addition, no abnormal noise is generated. Furthermore, since the contact is made without any clearance, the strength of the torque transmitting portion is improved. For this reason, the wheel bearing device can be made lightweight and compact.

  Further, the convex portion provided on either the outer peripheral surface of the shaft portion of the outer joint member or the inner peripheral surface of the hole portion of the hub wheel is pressed into the other along the axial direction so as to be in close contact with the convex portion. A recessed portion to be fitted can be formed. For this reason, an uneven | corrugated fitting structure can be formed reliably. Moreover, it is not necessary to form splines or the like on the member on the side where the concave portion is formed (reduction of processing man-hours), and it is not necessary to align the phases of the splines during assembly (reduction of assembly man-hours). In addition, damage to the tooth surface during press-fitting can be avoided, and a stable fitting state can be maintained.

  Furthermore, since the shearing stress of the retaining ring is smaller than that of the knuckle or the outer member, there is no fear of damaging the knuckle when the outer member is removed from the knuckle during repair or the like. Therefore, parts replacement at the time of repair or the like can be suppressed to the minimum necessary, and a drive wheel bearing device that is low in cost can be provided as a whole.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an example of an axle module. This axle module can be roughly divided into a wheel bearing device portion and a drive shaft portion. The wheel bearing device is obtained by unitizing the outer joint member of the outboard side constant velocity universal joint T1, the hub wheel 1, and the rolling bearing 2. The drive shaft includes a shaft 10, an outboard-side constant velocity universal joint T1 attached to both ends thereof, and an inboard-side constant velocity universal joint T2. As described above, the wheel bearing device and the drive shaft have the outboard side constant velocity universal joint T1 (the outer joint member thereof) as a common component.

  Although the constant velocity universal joint T1 on the outboard side is shown as an example of a Rzeppa type here, other fixed type constant velocity universal joints such as an undercut free type having a linear portion at the bottom of the ball groove are adopted. You can also. The constant velocity universal joint T1 includes a joint outer ring 5 as an outer joint member, a joint inner ring 6 as an inner joint member, a plurality of balls 7 as torque transmitting elements, and a cage 8 that holds the balls 7. Include as.

  The joint outer ring 5 is made of medium carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and is composed of a mouse part 11 and a stem part 12, and as shown in FIG. 11a is formed. The mouse portion 11 has a bowl shape opened at one end, and a plurality of ball grooves 14 extending in the axial direction are formed at equal intervals in the circumferential direction on the spherical inner peripheral surface (inner spherical surface) 13. As shown by cross hatching, the shaft portion 12 of the joint outer ring 5 is formed with a predetermined hardened layer H having a surface hardness of 58 to 64 HRC (Rockwell hardness C scale) from the back face 11a to the shaft portion. In addition, the front-end | tip of the axial part 12 is left raw without performing a surface hardening process.

The joint inner ring 6 is made of medium carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C,
By connecting the spline shaft 10a at the end of the shaft 10 through the spline hole 6a in the shaft center portion, the shaft 10 is coupled to the shaft 10 so that torque can be transmitted. The shaft 10 is prevented from coming off from the joint inner ring 6 by a retaining ring 9 attached to the end 10 a of the shaft 10. The joint inner ring 6 has a spherical outer peripheral surface (outer spherical surface) 15, and a plurality of ball grooves 16 extending in the axial direction are formed at equal intervals in the circumferential direction.

  The ball groove 14 of the joint outer ring 5 and the ball groove 16 of the joint inner ring 6 form a pair, and one ball 7 is incorporated in a ball track formed by each pair of ball grooves 14 and 16 so as to roll. . The ball 7 is interposed between the ball groove 14 of the joint outer ring 5 and the ball groove 16 of the joint inner ring 6 to transmit torque. All balls 7 are held in the same plane by the cage 8. The cage 8 is interposed between the joint outer ring 5 and the joint inner ring 6 in a spherical contact state, is in contact with the inner spherical surface 13 of the joint outer ring 5 at the spherical outer peripheral surface, and is connected to the joint inner ring 6 at the spherical inner peripheral surface. It contacts the outer spherical surface 15.

  In order to prevent leakage of the lubricant filled in the inside and prevent foreign matter from entering from the outside, the opening of the mouse portion 11 is closed with a boot 60. The boot 60 includes a large-diameter portion 60a, a small-diameter portion 60b, and a bellows portion 60c that connects the large-diameter portion 60a and the small-diameter portion 60b. The large diameter part 60 a is attached to the opening of the mouse part 11 and fastened with a boot band 61. The small diameter portion 60 b is attached to the boot mounting portion 10 b of the shaft 10 and fastened with a boot band 62.

  Although the example of the tripod type is shown here as the constant velocity universal joint T2 on the inboard side, other sliding type constant velocity universal joints such as a double offset type can also be adopted. The constant velocity universal joint T2 includes a joint outer ring 131 as an outer joint member, a tripod 132 as an inner joint member, and a roller 133 as a torque transmission element as main components.

  The joint outer ring 131 is made of medium carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and includes a mouse portion 131a and a stem portion 131b. The stem portion 131b and a differential output shaft and torque transmission. It is designed to be connected as possible. The mouse portion 131a has a cup shape opened at one end, and a track groove 136 extending in the axial direction is formed at a position of the inner circumference in the circumferential direction. For this reason, the cross-sectional shape of the mouse | mouth part 131a exhibits a corolla shape. A predetermined hardened layer having a surface hardness in the range of 58 to 64 HRC is formed on the outer periphery of the track groove 136 and the stem portion 131b by induction hardening.

  The tripod 132 includes a boss 138 and a leg shaft 139, and is coupled to an end spline 10c of the shaft 10 through a spline hole 138a of the boss 138 so that torque can be transmitted. The leg shaft 139 protrudes in the radial direction from the circumferentially divided position of the boss 138. A roller 133 is rotatably supported on each leg shaft 139.

  Again, the boot 140 is attached to close the opening of the joint outer ring 131. This prevents leakage of the lubricant filled in the interior and prevents foreign matter from entering from the outside. The boot 140 includes a large diameter portion 140a, a small diameter portion 140b, and a bellows portion 140c between the large diameter portion 140a and the small diameter portion 140b. The large diameter portion 140a is attached to the open end of the mouse portion 131a. The band 141 is tightened, and the small-diameter portion 140b is attached to the boot mounting portion 10d of the shaft 10 and is tightened with the boot band 141.

Next, the hub wheel 1 is made of medium carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and as can be seen from FIGS. 2 and 5, the cylindrical portion 20 and the anti-joint side of the cylindrical portion 20 And a flange 21 provided at the end of each. A bolt mounting hole 32 is provided in the flange 21 of the hub wheel 1, and the wheel and brake rotor are fixed to the flange 21 by a hub bolt 33 planted in the bolt mounting hole 32. A small-diameter portion 23 is formed at the end of the tubular portion 20 on the joint side, and an inner ring 24 is fitted therein. Then, the end portion of the small diameter portion 23 is caulked outward in the radial direction, and the caulking portion 31 is applied to the end surface of the inner ring 24 to fix the inner ring 24 to the hub wheel 1 and simultaneously apply a preload to the bearing.

  The cylinder part 20 has a hole 22 (FIG. 5) penetrating the axial center part. The hole 22 includes a tapered portion 22b located on the opposite side of the fitting portion 22a at the axially intermediate portion and a large-diameter portion 22c on the joint side. In the fitting portion 22a, the shaft portion 12 of the joint outer ring 5 of the constant velocity universal joint T1 and the hub wheel 1 are coupled to each other through an uneven fitting structure M described later. Moreover, the fitting part 22a and the large diameter part 22c are connected by the taper hole 22d. The tapered hole 22d is reduced in diameter in the press-fitting direction when the hub wheel 1 and the shaft portion 12 of the joint outer ring 5 are coupled. The angle θ1 (FIG. 5) of the tapered hole 22d is, for example, 15 ° to 75 °.

  As shown by cross hatching in FIG. 5, the hub wheel 1 has a surface hardness by induction hardening from the inner race 28 to the seal land portion where the seal lip of the seal S <b> 1 on the outboard side is in sliding contact with a part of the small diameter portion 23. A predetermined hardened layer H1 in the range of 58 to 64 HRC is formed. Thereby, not only the wear resistance of the seal land portion is improved, but also the strength of the hub wheel 1 itself against a moment load or the like is increased and the durability is improved. Moreover, it is preferable that the part which should be plastically deformed to be the caulking part 31 is an unquenched part of the material surface hardness after forging.

  The rolling bearing 2 includes, as main components, an outer member 25 corresponding to a bearing outer ring, inner members (1, 24) corresponding to a bearing inner ring, and balls 30 as rolling elements. The outer member 25 is made of a high carbon chrome bearing steel such as SUJ2, has an outer peripheral surface of a cylindrical shape, and has two rows of outer races (outer races) 26 and 27 on the inner periphery. Here, the inner member is constituted by the hub wheel 1 and the inner ring 24. That is, a first inner race (inner race) 28 is formed near the flange 21 of the cylindrical portion 20 of the hub wheel 1, and the second inner race is formed on the outer periphery of the inner ring 24 fitted to the small diameter portion 23 of the hub wheel 1. (Inner race) 29 is formed. A hardened layer having a surface hardness of 58 to 64 HRC is formed on the track 28 by induction hardening. The inner ring 24 is made of a high carbon chromium bearing steel such as SUJ2, and a hardened layer having a surface hardness in the range of 58 to 64 HRC is formed on the raceway 29 by quenching. The first outer track 26 and the first inner track 28 face each other, the second outer track 27 and the second inner track 29 face each other, and a ball 30 is interposed therebetween. The balls 30 in each row are held at a predetermined interval by a cage.

  Seal members S1 and S2 are attached to the opening portions at both ends of the outer member 25 in order to prevent leakage of the lubricant filled inside and to prevent foreign substances from entering from the outside. As will be described later, the outer member 25 is fitted in a hole 34a of a knuckle 34 (see FIG. 9) extending from the suspension device of the vehicle body.

  The hub wheel 1 and the shaft portion 12 of the joint outer ring 5 of the constant velocity universal joint T <b> 1 are coupled via the concave / convex fitting structure M. As shown in FIG. 3, the concave-convex fitting structure M includes, for example, a convex portion 35 provided at the end of the shaft portion 12 and an inner diameter surface of the hole 22 of the hub wheel 1 (in this case, the shaft portion fitting). It consists of a recess 36 formed in the inner diameter surface 37) of the joint portion 22a, and the entire fitting contact portion 38 between the projection 35 and the recess 36 fitted into the projection 35 is in close contact. That is, a plurality of convex portions 35 are arranged at a predetermined pitch in the circumferential direction on the outer peripheral surface of the shaft portion 12 on the side opposite to the mouse portion, and convex portions on the inner diameter surface 37 of the fitting portion 22a of the hole 22 of the hub wheel 1 A plurality of recesses 36 into which 35 is fitted are formed along the circumferential direction. That is, the convex part 35 and the concave part 36 fitted to this are tight-fitted over the entire circumference in the circumferential direction.

In this case, each convex portion 35 has a triangular shape (mountain shape) having a convex arcuate cross section, and the concave portion fitting portion of each convex portion 35 is within a range A shown in FIG. Yes, it is the range from the middle of the mountain in the cross section to the summit. Further, between the adjacent convex portions 35 in the circumferential direction,
A clearance 40 is formed on the inner diameter side of the inner diameter surface 37 of the hub wheel 1.

  As described above, since the bearing preload is applied by caulking the end portion of the hub wheel 1 on the joint side and applying the caulking portion 31 to the end surface of the inner ring 24, the back face 11a of the mouth portion 11 of the joint outer ring 5 is provided. There is no need to contact the inner ring 24, and a non-contact structure in which the mouse part 11 is not brought into contact with the end part of the hub wheel 1 (in this case, the caulking part 31) can be achieved. For this reason, as shown in FIG. 2, a clearance 98 exists between the caulking portion 31 of the hub wheel 1 and the back face 11 a of the mouse portion 11. If there is no problem of abnormal noise, a structure in which the mouse part 11 and the caulking part 31 are in contact with each other can be used.

  The joint side (inboard side, that is, the inner side of the vehicle when attached to the vehicle) than the concave-convex fitting structure M and the anti-joint side (outboard side, that is, the state attached to the vehicle) The foreign matter intrusion prevention means W to the concave-convex fitting structure M is provided on the outer side of the vehicle). That is, as shown in an enlarged view in FIG. 6, the inboard-side foreign matter intrusion preventing means W1 (the inboard side foreign matter intrusion preventing means W1 (by the seal member 99 disposed in the gap 98 between the caulking portion 31 of the hub wheel 1 and the back face 11a of the mouth portion 11) FIG. 2) is formed. In this case, the clearance 98 includes a radial portion between the caulking portion 31 of the hub wheel 1 and the back face 11 a of the mouth portion 11, and an axial portion between the large diameter portion 22 c and the shaft portion 12. The seal member 99 is disposed in the vicinity of the corner where the radial portion and the axial portion of the clearance 98 meet. The sealing member 99 may be an O-ring or the like as shown in FIG. 6A, or a gasket or the like as shown in FIG. 6B.

  As shown in FIGS. 2 and 4, the outboard-side foreign matter intrusion prevention means W2 includes a sealing material (not shown) interposed between the tapered locking piece 65 as an engaging portion and the inner diameter surface of the tapered portion 22b. (Not shown). In this case, the sealing material is applied to the tapered locking piece 65. That is, it is only necessary to apply sealing materials (sealing agents) made of various resins that are cured after application and can exhibit sealing performance between the tapered locking piece 65 and the inner diameter surface of the tapered portion 22b. In addition, as this sealing material, the thing which does not deteriorate in the atmosphere where this wheel bearing apparatus is used is selected.

  A shaft portion retaining structure M <b> 1 is provided between the end portion of the shaft portion 12 of the joint outer ring 5 and the inner diameter surface 37 of the hub wheel 1. The shaft portion retaining structure M1 includes the tapered locking piece 65 that extends from the end of the shaft portion 12 of the joint outer ring 5 to the anti-joint side and locks to the taper portion 22b. That is, the tapered locking piece 65 is formed of a ring-shaped body whose diameter increases from the joint side toward the anti-joint side, and at least a part of the outer peripheral surface 65a is in pressure contact with or in contact with the tapered portion 22b.

  When assembling the wheel bearing device, as will be described later, the shaft portion 12 of the joint outer ring 5 is press-fitted into the hub wheel 1, and the concave portion 36 is formed by the convex portion 35. At this time, as the press-fitting progresses, the material protrudes from the concave portion 36 formed by the convex portion 35 to form the protruding portion 45 (see FIG. 4). The protruding portion 45 is the material of the capacity of the concave portion 36 into which the concave portion fitting portion of the convex portion 35 is fitted (fitted), and is pushed out from the formed concave portion 36 or to form the concave portion 36. It is comprised from what was cut | disconnected by this, or what was extruded and what was cut. For this reason, a pocket portion (storage portion) 50 for storing the protruding portion 45 is provided in the shaft portion 12.

  Here, a pocket portion (housing portion) 50 is formed by providing a circumferential groove 51 at the shaft end edge of the spline 41 of the shaft portion 12. A tapered locking piece 65 that constitutes the above-described shaft portion retaining structure M1 is located on the side opposite to the spline from the circumferential groove 51.

Next, how to make the uneven fitting structure M will be described. In this case, as shown in FIG.
A surface hardening process is performed on the outer diameter portion of the, and a spline 41 including a convex portion 41a and a concave portion 41b extending in the axial direction is formed in the hardened layer H. For this reason, the convex part 41a of the spline 41 is hardened, and the convex part 41a becomes the convex part 35 of the concave-convex fitting structure M. In addition, the range of the hardened layer H here is from the outer end edge of the spline 41 to a part of the back face 11a of the joint outer ring 5 as shown by cross hatching. As the surface hardening treatment, various heat treatments such as induction hardening and carburizing and quenching can be employed. Induction hardening is a hardening method that applies the principle of heating a conductive object by placing a portion necessary for hardening in a coil through which high-frequency current flows and generating Joule heat by electromagnetic induction. Carburizing and quenching is a method in which carbon is infiltrated / diffused from the surface of a low carbon material and then quenched.

  Further, a hardened layer H1 is formed on the outer diameter side of the hub wheel 1 by induction hardening, and the inner diameter side of the hub wheel 1 is left unfired. The range of the hardened layer H1 here is from the root portion of the flange 21 to the vicinity of the caulking portion of the small diameter portion 23 to which the inner ring 24 is fitted, as shown by cross hatching. If induction hardening is performed, the surface is hard and the inside can be kept as it is, so that the inner diameter side of the hub wheel 1 can be kept unfired. The hardness difference between the hardened layer H of the shaft portion 12 of the joint outer ring 5 and the uncured portion of the hub wheel 1 is 20 points or more in HRC. If a specific example is given, the hardness of the hardened layer H shall be about 50 HRC to 65 HRC, and the hardness of an unhardened part shall be about 10 HRC to about 30 HRC.

  At this time, the intermediate portion in the protruding direction of the convex portion 35 corresponds to the position of the concave portion forming surface (in this case, the inner diameter surface 37 of the hole 22 of the hub wheel 1) before the concave portion is formed. That is, as shown in FIG. 5, the inner diameter dimension D of the inner diameter surface 37 of the hole 22 is set to the maximum outer diameter of the protrusion 35, that is, the maximum diameter dimension of a circle connecting the vertices of the protrusion 35 that is the protrusion 41 a of the spline 41. It is set smaller than (circumferential circle diameter) D1 and larger than the outer diameter size of the shaft outer diameter surface between the convex portions, that is, the maximum diameter size D2 of the circle connecting the bottoms of the concave portions 41b of the spline 41. That is, a dimensional relationship represented by D2 <D <D1.

  The configuration and processing method of splines are well known (see JIS B 0006: 1993). That is, it can be formed by various processing methods such as rolling, cutting, pressing, and drawing. As the surface hardening treatment, various heat treatments such as induction hardening and carburizing and quenching can be employed.

  A short cylindrical portion 66 for forming a tapered locking piece 65 (FIGS. 2 and 4) is protruded in the axial direction from the outer peripheral edge portion of the end surface of the shaft portion 12. The outer diameter D4 of the short cylindrical portion 66 is set smaller than the inner diameter D of the fitting portion 22a of the hole 22. Thus, the short cylindrical portion 66 performs a centering action when the shaft portion 12 is press-fitted into the hole 22 of the hub wheel 1 as will be described later.

  Then, as shown in FIG. 5, the shaft portion 12 of the joint outer ring 5 is inserted (press-fitted) into the hub wheel 1 in a state where the shaft center of the hub wheel 1 and the shaft center of the joint outer ring 5 are aligned. . A seal member 99 (see FIG. 2) is fitted in advance to the base portion (mouse portion side) of the shaft portion 12 of the joint outer ring 5. At this time, since the tapered portion 22d whose diameter is reduced in the press-fitting direction is formed in the hole 22 of the hub wheel 1, the tapered portion 22d exhibits a guide action at the start of press-fitting. Further, the diameter D of the inner diameter surface 37 of the hole 22, the maximum outer diameter D1 of the convex portion 35, and the maximum outer diameter D2 of the concave portion of the spline 41 are as described above, and the convex portion 35 Is 20 points or more larger than the hardness of the inner diameter surface 37 of the hole 22, so that if the shaft portion 12 is press-fitted into the hole 22 of the hub wheel 1, the convex portion 35 is brought into the inner diameter surface 37 of the fitting portion 22 a. As a result, the convex portion 35 forms a concave portion 36 that fits into the convex portion 35 along the axial direction.

  As shown in FIG. 4, the protruding portion 45 formed with the progress of press-fitting is housed in the pocket portion 50 while curling. That is, a part of the material scraped off or pushed out from the inner diameter surface of the fitting portion 22 a enters the pocket portion 50.

  By press-fitting, as shown in FIG. 3, the entire fitting contact portion 38 between the convex portion 35 at the end of the shaft portion 12 and the concave portion 36 fitted therein is in close contact. That is, the shape of the convex portion 35 is transferred to the concave portion forming surface (in this case, the inner diameter surface 37 of the fitting portion 22a). When the convex portion 35 bites into the inner diameter surface 37 of the fitting portion 22a, the fitting portion 22a is slightly expanded in diameter, allowing the convex portion 35 to move in the axial direction, and moving in the axial direction. If stopped, the fitting portion 22a is reduced in diameter to return to the original diameter. In other words, when the convex portion 35 is press-fitted, the hub wheel 1 is elastically deformed in the radial direction, and a preload corresponding to the elastic deformation is applied to the tooth surface of the convex portion 35 (surface of the concave portion fitting portion). For this reason, the concave / convex fitting structure M in which the entire concave portion fitting portion of the convex portion 35 is in close contact with the corresponding concave portion 36 can be reliably formed.

  Further, since the seal member 99 is attached to the base part (mouse part side) of the shaft part 12 of the joint outer ring 5, in the press-fitting completion state, the caulking part 31 of the hub wheel 1 and the back face 11a of the mouse part 11 are connected. The gap 98 is closed and sealed by the seal member 99.

  When the shaft portion 12 of the joint outer ring 5 is press-fitted into the hole 22 of the hub wheel 1, a step surface G is provided on the outer diameter surface of the mouth portion 11 of the joint outer ring 5 as shown in FIG. The press-fitting jig K may be engaged with G, and a press-fitting load (axial load) may be applied from the press-fitting jig K to the step surface G. The step surfaces G may be provided over the entire circumference in the circumferential direction or may be provided at a predetermined pitch in the circumferential direction. For this reason, the press-fitting jig K to be used only needs to be able to apply an axial load corresponding to these stepped surfaces G.

  In this way, the concave / convex fitting structure M is formed, and the axial position of the concave / convex fitting structure M is a position that avoids the positions directly below the raceways 26, 27, 28, and 29 of the rolling bearing 2. desirable.

  In a state where the shaft portion 12 of the joint outer ring 5 and the hub wheel 1 are integrated through the concave-convex fitting structure M, the short cylindrical portion 66 is changed from the fitting portion 22a to the tapered portion 22b as understood from FIG. Protrudes to the side. Therefore, as shown by an imaginary line in FIG. 2, a jig 67 is used to plastically deform the short cylindrical portion 66 to expand its diameter, that is, radially outward. The jig 67 includes a columnar main body portion 68 and a truncated cone portion 69 that is connected to the tip of the main body portion 68. The truncated cone portion 69 has an inclined surface 69a whose inclination angle is substantially the same as that of the tapered portion 22b, and whose outer diameter at the tip is the same as or slightly smaller than the inner diameter of the short cylindrical portion 66. It is set to.

  Then, by applying a load in the direction of arrow α to the jig 67 and fitting the truncated cone portion 69 of the jig 67 into the short cylindrical portion 66, the short cylindrical portion 66 is expanded in the direction of arrow β. Giving power. As a result, at least a part of the short cylindrical portion 66 is pressed to the inner diameter side of the tapered portion 22b by the truncated cone portion 69 of the jig 67, and the seal constituting the foreign matter intrusion prevention means W2 is formed on the inner diameter surface of the tapered portion 22b. It will be in the state of pressure contact or contact through the material, and the shaft portion retaining structure M1 can be configured. When the load in the arrow α direction is applied to the jig 67, it is necessary to fix the wheel bearing device so that it does not move in the arrow α direction. However, the hub wheel 1, the constant velocity universal joint T1, etc. What is necessary is just to receive a part with a fixing member. If the short cylindrical portion 66 has a tapered shape in which the inner diameter surface is expanded toward the shaft end side, the inner diameter surface can be formed by forging, which leads to cost reduction.

  In order to reduce the load of the jig 67 in the direction of the arrow α, the cylindrical portion 66 may be notched, and the conical surface of the truncated cone 69 of the jig 67 is partially arranged instead of the entire circumference. May be. When a notch is made in the cylindrical portion 66, the cylindrical portion 66 can be easily expanded in diameter. In addition, when the conical surface of the truncated cone 69 of the jig 67 is partially arranged in the circumferential direction, the portion where the cylindrical portion 66 is enlarged becomes a part of the circumference, so the pushing load of the jig 67 is reduced. Can be reduced.

  As shown in FIG. 9, the axle module assembled as shown in FIG. 1 is assembled to the vehicle by fitting the outer member 25 of the rolling bearing 2 into the hole of the knuckle 34. For this purpose, the cylindrical outer peripheral surface 25a of the outer member 25 and the cylindrical inner peripheral surface 34a of the hole of the knuckle 34 are set to a predetermined fit. A retaining ring 130 is interposed between the outer peripheral surface 25 a of the outer member 25 and the inner peripheral surface 34 a of the hole of the knuckle 34. By using the retaining ring 130, the effect of preventing the outer member 25 from coming off from the knuckle 34 is enhanced. That is, an annular groove 129 (FIG. 2) is formed on the outer peripheral surface 25 a of the outer member 25, and an annular groove (not shown) is also formed on the inner peripheral surface 34 a of the hole of the knuckle 34. Then, the retaining ring 130 is engaged with both the annular groove 129 of the outer member 25 and the annular groove of the knuckle 34. That is, the inner diameter side of the retaining ring 130 is engaged with the annular groove 129 of the outer member 25, and the outer diameter side of the retaining ring 130 is engaged with the annular groove of the knuckle 34.

  As shown in FIG. 1, the outer diameter D11 of the outer member 25 is made larger than the maximum outer diameter dimension D12 of the constant velocity universal joint T1. Here, the maximum outer diameter dimension D12 of the constant velocity universal joint T1 means the maximum outer diameter dimension of the constant velocity universal joint T1 in a state including accessories such as the boot 60 and the boot band 61. The maximum outer diameter dimension D13 of the inboard side constant velocity universal joint T2 is set to be smaller than the outer diameter D11 of the outer member 25. The maximum outer diameter D13 of the inboard side constant velocity universal joint T2 is the same as that of the outboard side constant velocity universal joint T1, and the inboard side in a state including accessories such as the boot 140 and the boot band 141. It means the maximum outer diameter dimension of the quick universal joint T2.

  As shown in FIGS. 7 and 8, the axle module is assembled to the vehicle through the knuckle 34 from the constant velocity universal joint T2 on the inboard side, and then the constant velocity universal joint T1 on the outboard side. Finally, the outer member 25 of the drive wheel bearing device is press-fitted into the inner peripheral surface 34 a of the hole of the knuckle 34. As a result, as shown in FIG. 9, in the state in which the outer member 25 is press-fitted into the knuckle 34, the retaining ring 130 has an annular groove 129 on the outer peripheral surface 25 a of the outer member 25 and an annular shape of the inner peripheral surface 34 a of the knuckle 34. Engage with the groove.

  Thus, the axle module can be assembled to the vehicle in the assembled state as shown in FIG. Thereby, the work man-hour at the assembly work site can be reduced, and workability is enhanced. Moreover, it is possible to stabilize the quality by preventing damage to parts during disassembly / assembly.

  A retaining ring 130 is shown in FIGS. FIG. 10 shows an example of a retaining ring having a rectangular cross section, and FIG. 11 shows an example of a retaining ring having a circular cross section. In the case of the retaining ring 130 having a rectangular cross section, the outer diameter side ridge line portion is chamfered as shown in FIG. In this way, by adopting a retaining ring with a rectangular cross section chamfered on the outer diameter side ridge line part or a retaining ring with a circular cross section, when the outer member 25 is press-fitted into the hole of the knuckle 34, the retaining ring 130 is smooth. It is possible to make it easy to sink into the annular groove 129 of the outer member 25. For the same purpose, it is also preferable to chamfer the end of the knuckle 34 on the outboard side. This is because the outboard side end of the hole of the knuckle 34 serves as an inlet when the outer member 25 is press-fitted, so that the press-fitting is started smoothly.

  As the material of the retaining ring 130, a material having a shear stress smaller than that of the outer member 25 and the knuckle 34 is adopted. There are various types of materials for the knuckle 34, and in general, cast iron, aluminum alloy die casting, aluminum alloy casting, and the like are used. Further, the allowable shear stress varies depending on the material, shape, thickness, etc., but if exemplified as a temporary guide, it is 200 MPa or less in the case of aluminum alloy die casting.

On the other hand, in the case of a 1500 cc class vehicle, a proof stress of about 5.7 kN (580 kgf) is required. The yield strength of 5.7 kN means that the retaining ring is not deformed or damaged even when 5.7 kN is applied to the retaining ring as a thrust load. The shear stress in this case is about 10 MPa (5 to 15 MPa) although it depends on the dimensions of the retaining ring 130. Accordingly, the shear stress that the material of the retaining ring 130 should have is preferably in the range of 5 MPa to 150 MPa.

  An example of such a material is a thermoplastic synthetic resin. Specific examples include polypropylene, acrylic resin, ABS resin (acrylonitrile butadiene styrene resin) and the like. Resin retaining rings can be mass-produced at a relatively low cost by injection molding. Therefore, the outer member 25 can be pulled out from the knuckle 34 by applying a pulling force exceeding the shear stress of the retaining ring 130 at the time of disassembly. At this time, since the retaining ring 130 is deformed or broken to allow disassembly, the outer member 25 and the knuckle 34 are prevented from being damaged. When reassembling, replace the deformed or damaged retaining ring with a new one.

  Since the hub wheel 1 is not provided with a pilot portion, the hub wheel 1 has a shape that can be easily cold forged, and thus contributes to an improvement in productivity. In this case, a member having a pilot portion that is separate from the hub wheel 1 may be attached to the hub wheel 1. FIG. 12 shows an example where such a member is the brake rotor 142. That is, the pilot portion 144 is provided in the brake rotor 142, and the outer peripheral surface 21a of the flange 21 of the hub wheel 1 is used as a brake pilot. In this case, by not providing the wheel pilot portion, the hub wheel 1 has a simple shape, and forging becomes easy. Therefore, the hub wheel 1 can be manufactured at low cost by cold forging.

  Of course, it is also possible to provide a pilot portion on the hub wheel as in the conventional example already described with reference to FIG. For example, as shown in FIG. 13, a pilot portion 146 including a brake pilot 148 a and a wheel pilot 148 b is provided on the end face on the opposite side of the flange 21 of the hub wheel 1.

The effect of the embodiment described here and illustrated will be described.
In the wheel bearing device, the concave / convex fitting structure M has the entire fitting contact portion 38 between the convex portion 35 and the concave portion 36 in close contact with each other. No gap is formed. For this reason, all of the fitting parts contribute to rotational torque transmission, stable torque transmission is possible, and no abnormal noise is generated.

  The member in which the recess 36 is formed (in this case, the hub wheel 1) is excellent in productivity because it is not necessary to form a spline portion or the like, and is easy to assemble because it does not require phase alignment between the splines. In addition to improvement, damage to the tooth surface during press-fitting can be avoided, and a stable fitting state can be maintained.

  Since the tapered portion 22d can constitute a guide at the start of press-fitting, the shaft portion 12 of the joint outer ring 5 can be press-fitted into the hole 22 of the hub wheel 1 without causing a deviation, and a stable torque can be obtained. Communication is possible. Furthermore, since the outer diameter D4 of the cylindrical portion 66 is set to be smaller than the inner diameter D of the fitting hole 22a of the hole 22, the short cylindrical portion 66 exhibits a centering effect and prevents misalignment. The portion can be press-fitted into the hub wheel, and more stable press-fitting is possible.

  By arranging the concave-convex fitting structure M so as not to be directly under the raceway surface of the rolling bearing 2, generation of hoop stress on the bearing raceway surface is suppressed. As a result, it is possible to prevent a bearing failure such as a decrease in rolling fatigue life, occurrence of cracks, and stress corrosion cracking, and a high-quality bearing can be provided.

With the shaft part retaining structure M1, the shaft part 12 of the joint outer ring 5 can be effectively prevented from coming out from the hole 22 of the hub wheel 1 (particularly, the axial part to the shaft side). As a result, a stable connected state can be maintained, and the quality of the wheel bearing device can be improved. Moreover, since the shaft portion retaining structure M1 is the tapered locking piece 65, conventional screw fastening can be omitted. For this reason, it is not necessary to form the screw part which protrudes from the hole 22 of the hub wheel 1 in the shaft part 12, and while being able to achieve weight reduction, a screw fastening operation | work can be abbreviate | omitted and aiming at the improvement of assembly workability | operativity. Can do. In addition, in the tapered locking piece 65, it is only necessary to increase the diameter of a part of the shaft portion 12 of the joint outer ring 5, and the shaft portion retaining structure M1 can be easily formed. In addition, the movement of the shaft portion 12 of the joint outer ring 5 in the anti-joint direction requires a pressing force in a direction in which the shaft portion 12 is further press-fitted, and the displacement of the shaft portion 12 of the joint outer ring 5 in the anti-joint direction is necessary. Even if it is misaligned in this direction, the bottom of the mouth portion 11 of the joint outer ring 5 comes into contact with the caulking portion 31 of the hub wheel 1 so that the shaft portion 12 of the outer ring 5 extends from the hub wheel 1. There is no escape.

  The hardness of the axial end of the convex portion of the shaft portion 12 of the joint outer ring 5 of the constant velocity universal joint T1 is made higher than the inner diameter surface of the hole portion of the hub wheel 1 so that the shaft portion 12 protrudes into the hole 22 of the hub wheel 1. Since it press-fits from the axial direction edge part side of the part 35, the recessed part formation to the hole inner diameter surface of the hub ring 1 becomes easy. Further, the hardness on the shaft portion side can be increased, and the torsional strength of the shaft portion 12 can be improved.

  Further, since the bearing preload is applied by crimping the end portion of the hub wheel 1 to the inner ring 24 of the rolling bearing 2, it is necessary to apply the bearing preload by applying the mouth portion 11 of the joint outer ring 5 to the inner ring 24. Disappear. For this reason, it is possible to press-fit the shaft portion 12 of the joint outer ring 5 without considering the contact with the inner ring 24, and to improve the connectivity (assembly property) between the hub wheel 1 and the joint outer ring 5. . Since the mouse part 11 is not in contact with the hub wheel 1, it is possible to prevent the generation of noise due to the contact between the mouse part 11 and the hub wheel 1.

  In addition, the convex part 35 can also be comprised with the spline normally formed in this kind of shaft, In this case, this convex part 35 can be easily formed at low cost.

  Further, when the concave portion 36 is formed by press-fitting the shaft portion 12 into the hub wheel 1, work hardening occurs on the concave portion 36 side. Here, work hardening means that when plastic deformation (plastic processing) is applied to an object, the resistance to deformation increases as the degree of deformation increases, and it becomes harder than a material that has not undergone deformation. For this reason, by plastically deforming at the time of press-fitting, the inner diameter surface 37 of the hub wheel 1 on the concave portion 36 side is hardened, and the rotational torque transmission performance can be improved.

  The inner diameter side of the hub wheel 1 is relatively soft. For this reason, the fitting property (adhesiveness) at the time of fitting the convex part 35 of the outer diameter surface of the shaft part 12 of the joint outer ring 5 to the concave part 36 of the hole inner diameter surface of the hub wheel 1 can be improved. Further, it is possible to accurately suppress the occurrence of play in the radial direction and the circumferential direction.

  By providing the foreign matter intrusion prevention means W, foreign matter can be prevented from entering the concave-convex fitting structure M. That is, the intrusion of rainwater and foreign matter is prevented by the foreign matter intrusion prevention means W, and deterioration of adhesion due to the intrusion of rainwater, foreign matter and the like into the concave-convex fitting structure M can be avoided.

In the case where the seal member 99 is disposed between the end portion of the hub wheel 1 and the bottom portion of the mouth portion 11, the gap 98 between the end portion of the hub wheel 1 and the bottom portion of the mouth portion 11 is closed by the seal member 99. Thus, intrusion of rainwater and foreign matter from the gap 98 to the concave-convex fitting structure M is prevented. As the seal member 99, any member that can be interposed between the end of the hub wheel 1 and the bottom of the mouth portion 11 may be used. For example, an existing (commercially available) O-ring can be used, and the cost is low. Foreign material intrusion prevention means can be configured, and commercially available O-rings come in a variety of materials and sizes, and foreign material intrusions that reliably perform a sealing function without the need to manufacture special ones. Prevention means can be configured.

  Engage with the inner diameter surface of the hub wheel 1 (in this case, the inner diameter surface of the tapered hole 22b) via a sealing material (seal member constituting the foreign matter intrusion prevention means W2) on the anti-joint side with respect to the concave-convex fitting structure M. By providing the engaging portion (tapered locking piece 65), it is possible to prevent foreign matter from entering from the side opposite the joint than the concave-convex fitting structure M. That is, foreign matter intrusion from the outboard side can be avoided.

  Thus, when the foreign matter intrusion prevention means W1 and W2 are provided on the joint side with respect to the concave-convex fitting structure M and the anti-joint side with respect to the concave-convex fitting structure M, foreign matters from both axial ends of the concave-convex fitting structure M are provided. Intrusion is prevented. For this reason, deterioration of adhesion can be avoided more stably over a long period of time.

  By providing the pocket portion 50 for accommodating the protruding portion 45 generated by forming the concave portion by press-fitting, the protruding portion 45 can be held (maintained) in the pocket portion 50, and the protruding portion 45 can be placed inside the vehicle outside the apparatus. There is no intrusion. That is, the protruding portion 45 can be kept stored in the pocket portion 50, and it is not necessary to perform the removal process of the protruding portion 45, the number of assembling operations can be reduced, and the assembling workability can be improved. Cost reduction can be achieved.

  In the spline 41 shown in FIG. 3, the pitch of the convex portions 41a and the pitch of the concave portions 41b are set to be the same. Therefore, as shown in FIG. 3B, the circumferential thickness L of the projecting direction intermediate portion of the convex portion 35 and the circle at a position corresponding to the intermediate portion between the convex portions 35 adjacent in the circumferential direction. The circumferential dimension L0 is substantially the same.

  On the other hand, as shown in FIG. 14A, the circumferential thickness L2 of the projecting direction intermediate portion of the convex portion 35 is a position corresponding to the intermediate portion between the convex portions 43 adjacent in the circumferential direction. It may be smaller than the circumferential dimension L1. That is, in the spline 41 formed in the shaft portion 12, the circumferential thickness (tooth thickness) L <b> 2 of the protruding portion intermediate portion of the convex portion 35 is set between the convex portions 35 on the hub wheel 1 side. It may be smaller than the circumferential thickness (tooth thickness) L1 of the intermediate portion in the protruding direction.

  For example, the total tooth thickness Σ (B1 + B2 + B3 +...) Of the convex portion 35 on the entire circumference on the shaft 12 side is replaced with the total tooth thickness Σ (A1 + A2 + A3 +...) Of the convex portion 43 (convex tooth) on the hub wheel 1 side. ) Is set smaller. As a result, the shear area of the convex portion 43 on the hub wheel 1 side can be increased, and the torsional strength can be ensured. And since the tooth thickness of the convex part 35 is small, a press-fit load can be made small and a press-fit property can be aimed at. When the sum of the circumferential thicknesses of the convex portions 35 is made smaller than the sum of the circumferential thicknesses of the convex portions 43 on the other side, the circumferential thickness L2 of all the convex portions 35 is set in the circumferential direction. It is not necessary to make it smaller than the circumferential dimension L1 between the adjacent convex portions 35. That is, even if the circumferential thickness of any projection 35 among the plurality of projections 35 is the same as the dimension in the circumferential direction between the projections adjacent in the circumferential direction, this circumferential dimension It is sufficient that the sum is smaller than the sum.

  14A is an example of a trapezoidal cross section (Mt. Fuji shape), but may have an involute tooth shape as shown in FIG. 14B.

By the way, while forming the spline 41 which comprises the convex part 35 in the axial part 12 side, it hardens | cures with respect to the spline 41 of this axial part 12, and makes the internal diameter surface of the hub wheel 1 uncured (raw material). On the other hand, as shown in FIG. 15, a spline 61 (consisting of a convex strip 61 a and a concave strip 61 b) is formed on the inner diameter surface of the hole 22 of the hub wheel 1 and the shaft portion 12. May not be subjected to a curing treatment. As is well known, the spline 61 can also be formed by various processing methods such as broaching, cutting, pressing, and drawing. Further, various heat treatments such as induction hardening and carburizing and quenching can be employed as the thermosetting treatment.

  In this case, the intermediate portion in the protruding direction of the convex portion 35 corresponds to the position of the concave portion forming surface (the outer diameter surface of the shaft portion 12) before the concave portion is formed. That is, the diameter dimension (minimum diameter dimension of the convex portion 35) D8 connecting the vertices of the convex portion 35 which is the convex portion 61a of the spline 61 is smaller than the outer diameter size D10 of the shaft portion 12, and the concave portion 61b of the spline 61 is formed. The diameter dimension (inner diameter dimension of the inner diameter surface of the fitting hole between the convex portions) D9 is set larger than the outer diameter dimension D10 of the shaft portion 12. That is, D8 <D10 <D9.

  When the shaft portion 12 is press-fitted into the hole 22 of the hub wheel 1, the concave portion 36 into which the convex portion 35 is fitted can be formed on the outer peripheral surface of the shaft portion 12 by the convex portion 35 on the hub wheel 1 side. Thereby, the whole fitting contact part 38 of the convex part 35 and the recessed part fitted to this is closely_contact | adhered.

  Here, the fitting contact portion 38 is a range B shown in FIG. 15B, and is a range from the middle of the mountain shape to the top of the mountain in the cross section of the convex portion 35. Further, a gap 62 is formed on the outer diameter side of the outer peripheral surface of the shaft portion 12 between the adjacent convex portions 35 in the circumferential direction.

  Also in this case, since the protruding portion 45 is formed by press-fitting, it is preferable to provide a storage portion for storing the protruding portion 45. Since the protruding portion 45 is formed on the mouse side of the shaft portion 12, the storage portion is provided on the hub wheel 1 side.

  In this way, in the case where the convex portion 35 of the concave-convex fitting structure M is provided on the inner diameter surface of the hole 22 of the hub wheel 1 and press-fitted, it is not necessary to perform the hardening treatment (heat treatment) on the shaft portion side, so the joint outer ring 5 There is an advantage of excellent productivity.

  Also here, the outer diameter D11 of the outer member 25 of the bearing 2 of the wheel bearing device on the outboard side is set to the maximum outer diameter dimension D12 of the constant velocity universal joint T1 and the maximum outer diameter dimension D13 of the inboard side constant velocity universal joint T2. By making the diameter larger than this, the workability of assembling the axle module to the vehicle is improved. Moreover, it is possible to stabilize the quality by preventing damage to parts during disassembly / assembly.

  As described above, the embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and various modifications can be made. As the shape, the example shown in FIG. 3 has a triangular cross section, and in the example shown in FIG. 14A, it has a trapezoidal cross section (Mt. Fuji shape), but other shapes such as semicircular, semielliptical, rectangular, etc. are adopted. Alternatively, the area, number, circumferential pitch, and the like of the convex portions 35 can be arbitrarily changed. That is, the splines 41 and 61 are formed, and the convex portions (convex teeth) 41a and 61a of the splines 41 and 61 do not need to be the convex portions 35 of the concave-convex fitting structure M. Alternatively, a curved corrugated mating surface may be formed. In short, the convex portion 35 disposed along the axial direction can be press-fitted into the mating side, and the concave portion 36 can be formed on the mating side with the convex portion 35 so as to closely fit the convex portion 35. It suffices that the entire fitting contact portion 38 between the portion 35 and the concave portion fitted thereto is in close contact, and torque can be transmitted between the hub wheel 1 and the constant velocity universal joint T1.

Further, the hole 22 of the hub wheel 1 may be a deformed hole such as a polygonal hole other than a circular hole, and the cross-sectional shape of the end portion of the shaft portion 12 inserted into the hole 22 is also a polygon other than a circle or other irregular shapes. It may be. Furthermore, since only the press-fitting start end portion of the convex portion 35 needs to be harder than the portion where the concave portion 36 is formed when the shaft portion 12 is press-fitted into the hub wheel 1, it is necessary to increase the overall hardness of the convex portion 35. There is no. In FIG. 3 and the like, the clearance 40 is formed, but the gap between the convex portions 35 may be cut into the inner diameter surface 37 of the hub wheel 1. As described above, the hardness difference between the convex portion 35 side and the concave portion forming surface formed by the convex portion 35 is preferably 20 points or more by HRC, but the convex portion 35 can be press-fitted. If there is, it may be less than 20 points.

  The end surface (press-fit start end) of the convex portion 35 may be inclined at a predetermined angle with respect to the axis, in addition to a surface orthogonal to the axis. In this case, it may be inclined from the inner diameter side toward the outer diameter side toward the anti-convex portion side or inclined toward the convex portion side.

  Further, the shape of the pocket portion 50 may be any shape that can accommodate (accommodate) the protruding portion 45 that is generated, and therefore, the capacity of the pocket portion 50 only needs to be compatible with the protruding portion 45 that is generated.

  Moreover, you may provide the small recessed part in the internal diameter surface 37 of the hole 22 of the hub ring 1 with a predetermined pitch in the circumferential direction. The small recess needs to be smaller than the volume of the recess 36. Thus, by providing a small recessed part, the press-fit property of the convex part 35 can be aimed at. That is, by providing the small concave portion, the capacity of the protruding portion 45 formed when the convex portion 35 is press-fitted can be reduced, and the press-fit resistance can be reduced. Moreover, since the protrusion part 45 can be decreased, the volume of the pocket part 50 can be made small and the workability of the pocket part 50 and the improvement of the intensity | strength of the axial part 12 can be aimed at. In addition, the shape of a small recessed part can employ | adopt various things, such as a triangle, a semi-ellipse, a rectangle, and the number can also be set arbitrarily.

Moreover, although the case of the ball | bowl (ball) was illustrated as the rolling element 30 of the bearing 2, what uses a roller (roller) may be used. Furthermore, although the above description has been given by taking the case of the third generation wheel bearing device as an example, the first generation, the second generation, or the fourth generation may be used.
In addition, when press-fitting the convex portion 35, even if the side where the concave portion 36 is formed is fixed and the side where the convex portion 35 is formed is moved, the side where the convex portion 35 is formed is reversed. It may be fixed and the side where the recess 36 is formed may be moved or both may be moved.
In the constant velocity universal joint T1, the joint inner ring 6 and the shaft 10 may be integrated via the concave / convex fitting structure M.

It is a longitudinal cross-sectional view of an axle module. It is an expanded sectional view of the wheel bearing apparatus in the axle module of FIG. The uneven | corrugated fitting structure of the wheel bearing apparatus of FIG. 2 is shown, (a) is an expanded sectional view, (b) is the X section enlarged view of (a). It is the elements on larger scale of the wheel bearing apparatus of FIG. It is a longitudinal cross-sectional view which shows the state before press-fitting of the wheel bearing apparatus of FIG. It is an enlarged view of the sealing material part of the wheel bearing apparatus of FIG. 2, (a) shows the example of an O-ring, (b) shows the example of a gasket. It is a longitudinal cross-sectional view which shows the assembly | attachment process to the vehicle of the axle module of FIG. It is a longitudinal cross-sectional view which shows the assembly | attachment process to the vehicle of the axle module of FIG. It is a longitudinal cross-sectional view which shows the state which assembled | attached the axle module of FIG. 1 to the vehicle. The retaining ring of a rectangular cross section is shown, (a) is a front view and (b) is a cross-sectional view. A retaining ring with a circular cross section is shown, (a) is a front view, and (b) is a cross sectional view. It is a longitudinal cross-sectional view of the wheel bearing apparatus which shows the example which attached the brake rotor which has a pilot part to the hub wheel. It is a longitudinal cross-sectional view of the wheel bearing apparatus which shows the example which provided the pilot part in the hub ring. (A) (b) is sectional drawing similar to FIG.3 (b). (A) is sectional drawing similar to Fig.3 (a), (b) is sectional drawing similar to FIG.3 (b). It is a longitudinal cross-sectional view of the conventional wheel bearing apparatus.

Explanation of symbols

1 Hub wheel (inward member)
2 Rolling bearings 5 Joint outer ring (outer joint member)
10 Shaft 11 Mouse (Shape-shaped part)
12 Stem (shaft)
22 hole 24 inner ring (inner member)
25 Outer member 31 Caulking part 35 Protruding part 36 Concave part 98 Clearance 99 Seal member 129 Annular groove 130 Retaining ring 142 Brake rotor 144 Wheel pilot 146 Pilot part 148a Brake pilot 148b Wheel pilot M Concavity and convexity T1 Outboard side constant velocity freely Joint T2 Inboard side constant velocity universal joint

Claims (10)

An outer member having a double-row outer track formed on the inner circumference;
A hub wheel having a flange for fixing the wheel and forming one of the double-row inner tracks on the outer periphery; and an inner ring fitted with the hub wheel and forming the other of the double-row inner tracks on the outer periphery; An inner member comprising:
A double row rolling element interposed between the outer raceway of the outer member and the inner raceway of the inner member so as to roll freely;
A drive wheel bearing device having an outer joint member of a constant velocity universal joint integrated with the hub wheel by press-fitting,
The hub wheel and the outer joint member form a concave-convex fitting structure, and the concave-convex fitting structure is either an outer diameter surface of the shaft portion of the outer joint member or an inner diameter surface of the hole portion of the hub ring. A convex portion extending in the axial direction is provided on one side, and the shaft portion of the outer joint member is press-fitted into the hole of the hub wheel, so that a concave portion that closely fits the convex portion is formed on the other side by the convex portion. In addition, it is a concave-convex fitting structure in which the entire fitting contact portion between the convex portion and the concave portion is in close contact,
The outer member is fitted to a knuckle hole of the vehicle with a predetermined fit, and an annular groove is formed on each of the outer circumferential surface of the outer member and the inner circumferential surface of the knuckle hole, and both the annular grooves are engaged with each other. A drive wheel bearing device in which the outer member is prevented from coming off from the knuckle by a combined retaining ring, and the outer member can be separated from the knuckle only by deformation or breakage of the retaining ring.   By providing a convex portion of the concave-convex fitting structure on the outer diameter surface of the shaft portion of the outer joint member, and press-fitting the shaft portion into the hole portion of the hub wheel, the convex portion is closely fitted to the convex portion. The drive wheel bearing device according to claim 1, wherein a concave portion to be formed is formed on an inner diameter surface of the hole portion of the hub wheel to form the concave-convex fitting structure.   A concave portion that is closely fitted to the convex portion by the convex portion by providing a convex portion of the concave-convex fitting structure on the inner diameter surface of the hole portion of the hub wheel and press-fitting the shaft portion into the hole portion of the hub wheel. The bearing device for a drive wheel according to claim 1, wherein the concave-convex fitting structure is formed by forming the outer peripheral surface of the shaft portion.   The bearing device for a drive wheel according to claim 1, 2 or 3, wherein a shear stress of the material of the retaining ring is smaller than a shear stress of the material of the knuckle.   The drive wheel bearing device according to claim 4, wherein the retaining ring has a shear stress in the range of 5 to 150 MPa.   The bearing device for a driving wheel according to any one of claims 1 to 5, wherein the material of the retaining ring is a thermoplastic synthetic resin.   The bearing device for a drive wheel according to any one of claims 1 to 6, wherein an outer diameter side ridge line portion of the retaining ring is chamfered.   The drive wheel bearing device according to any one of claims 1 to 6, wherein the retaining ring has a circular cross-sectional shape.   The drive wheel bearing device according to any one of claims 1 to 8, wherein an outboard side edge of the knuckle hole is chamfered. The drive wheel bearing device according to any one of claims 1 to 9, an outboard side constant velocity universal joint including the outer joint member, an intermediate shaft, and an inboard side constant velocity universal joint, An axle module in which the maximum outer diameter of the outboard side constant velocity universal joint and the inboard side constant velocity universal joint is smaller than the outer diameter of the outer member.

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