JP6261847B2 - Wheel bearing device and method for manufacturing wheel bearing device - Google Patents

Description

The present invention provides, for example, a wheel bearing device that rotatably supports driving wheels (front wheels of FF vehicles, rear wheels of FR vehicles, and all wheels of 4WD vehicles) with respect to a suspension device of an automobile, and a method of manufacturing the wheel bearing device. About.

  For example, there has been proposed a wheel bearing device that can be separated from a hub wheel of a wheel bearing and an outer joint member of a constant velocity universal joint and has excellent maintainability (see, for example, Patent Document 1). As shown in FIG. 11, the wheel bearing device disclosed in Patent Document 1 includes a wheel bearing 120 including a hub ring 101, an inner ring 102, double row rolling elements 103 and 104, and an outer ring 105, and a fixed constant velocity. The main part is composed of the universal joint 106.

  The hub wheel 101 has an inner raceway surface 107 on the outboard side formed on the outer peripheral surface thereof, and a wheel mounting flange 109 for mounting a wheel (not shown). Hub bolts 110 for fixing the wheel disc are implanted at equal intervals in the circumferential direction of the wheel mounting flange 109. An inner ring 102 is fitted to a small diameter step portion 112 formed on the inboard side outer peripheral surface of the hub wheel 101, and an inner raceway surface 108 on the inboard side is formed on the outer peripheral surface of the inner ring 102.

  The inner ring 102 is press-fitted with an appropriate tightening margin to prevent creep. An outboard-side inner raceway surface 107 formed on the outer peripheral surface of the hub wheel 101 and an inboard-side inner raceway surface 108 formed on the outer peripheral surface of the inner ring 102 constitute a double-row raceway surface. The inner ring 102 is press-fitted into the small-diameter step portion 112 of the hub wheel 101, and the end portion of the small-diameter step portion 112 is crimped to the outside, so that the inner ring 102 is prevented from coming off by the crimping portion 111 and integrated with the hub wheel 101. The preload is applied to the wheel bearing 120.

  The outer ring 105 has double rows of outer raceway surfaces 113 and 114 facing the inner raceway surfaces 107 and 108 of the hub ring 101 and the inner ring 102 on the inner circumferential surface. The wheel bearing device is attached to the vehicle body by fitting and fixing the outer peripheral surface of the outer ring 105 to a knuckle extending from a suspension device (not shown) of the vehicle body.

  The wheel bearing 120 has a double-row angular contact ball bearing structure, and has inner raceway surfaces 107 and 108 formed on the outer peripheral surfaces of the hub wheel 101 and the inner ring 102, and an outer raceway surface 113 formed on the inner peripheral surface of the outer ring 105. The rolling elements 103 and 104 are interposed between the rolling elements 103 and 104, and the rolling elements 103 and 104 in each row are supported by the cages 115 and 116 at equal intervals in the circumferential direction.

  A pair of seals 117, 118 that seal the annular space between the outer ring 105, the hub ring 101, and the inner ring 102 are provided at both end openings of the wheel bearing 120 so as to be in sliding contact with the outer peripheral surfaces of the hub ring 101 and the inner ring 102. 105 is fitted to the inner diameters at both ends, and prevents leakage of grease filled in the inside and intrusion of water and foreign matters from the outside.

  The constant velocity universal joint 106 is provided at one end of an intermediate shaft 122 that constitutes the drive shaft 121, and is opposed to the outer joint member 124 in which the track groove 123 is formed on the inner peripheral surface, and the track groove 123 of the outer joint member 124. An inner joint member 126 having a track groove 125 formed on the outer peripheral surface, a ball 127 incorporated between the track groove 123 of the outer joint member 124 and the track groove 125 of the inner joint member 126, and the outer joint member 124. The cage 128 is interposed between the inner peripheral surface and the outer peripheral surface of the inner joint member 126 and holds the ball 127.

  The outer joint member 124 includes a mouth portion 129 that accommodates inner parts including the inner joint member 126, the ball 127, and the cage 128, and a stem portion 130 that extends integrally from the mouth portion 129 in the axial direction. The inner joint member 126 is coupled so that torque can be transmitted by spline fitting with the shaft end of the intermediate shaft 122 press-fitted.

  Between the outer joint member 124 of the constant velocity universal joint 106 and the intermediate shaft 122, a resin bellows for preventing leakage of a lubricant such as grease sealed inside the joint and preventing foreign matter from entering from the outside of the joint. The boots 131 are attached and the opening of the outer joint member 124 is closed.

  The boot 131 includes a large-diameter end portion 133 fastened and fixed to the outer peripheral surface of the outer joint member 124 by a boot band 132, a small-diameter end portion 135 fastened and fixed to the outer peripheral surface of the intermediate shaft 122 by a boot band 134, The diameter end portion 133 and the small diameter end portion 135 are connected to each other, and a flexible bellows portion 136 having a diameter reduced from the large diameter end portion 133 toward the small diameter end portion 135 is formed.

  FIG. 12 shows a state before the stem portion 130 of the outer joint member 124 is press-fitted into the shaft hole 138 of the hub wheel 101. As shown in the figure, the stem portion 130 of the outer joint member 124 has a male spline formed of a plurality of convex portions 137 extending in the axial direction on the outer peripheral surface thereof. On the other hand, the shaft hole 138 of the hub wheel 101 forms a simple cylindrical portion 139 in which a female spline is not formed on the inner peripheral surface thereof.

  FIG. 13 shows a state after the stem portion 130 of the outer joint member 124 is press-fitted into the shaft hole 138 of the hub wheel 101. The stem portion 130 of the outer joint member 124 is press-fitted into the shaft hole 138 of the hub wheel 101, and the convex portion 137 of the stem portion 130 is transferred to the inner peripheral surface of the cylindrical portion 139 of the shaft hole 138 of the hub wheel 101. As shown in the figure, a concave portion 140 is formed on the inner peripheral surface of the shaft hole 138 of the hub wheel 101 so as to be in close contact with the convex portion 137 and tightening margin, and this convex portion 137 and the concave portion 140 are fitted over the entire contact area. The outer joint member 124 and the hub wheel 101 are coupled so as to be able to transmit torque by forming an uneven fitting structure that is in close contact.

  In this way, after the stem portion 130 of the outer joint member 124 is press-fitted into the shaft hole 138 of the hub wheel 101, as shown in FIG. 11, the female screw formed at the shaft end of the stem portion 130 of the outer joint member 124. The constant velocity universal joint 106 is fixed to the hub wheel 101 by screwing the bolt 142 to 141 and tightening the bolt 142 in a state where the bolt 142 is locked to the end surface of the hub wheel 101.

JP 2009-97557 A

  By the way, in the wheel bearing device described above, the fixed constant velocity universal joint 106 coupled to the wheel bearing 120 including the hub wheel 101, the inner ring 102, the double row rolling elements 103 and 104, and the outer ring 105 is provided on the drive shaft 121. Part of it. As shown in FIG. 14, a drive shaft 121 that transmits power from an automobile engine to a wheel needs to cope with an angular displacement and an axial displacement due to a change in the relative positional relationship between the engine and the wheel. Are equipped with a sliding type constant velocity universal joint 151 on the engine side (inboard side) and a fixed type constant velocity universal joint 106 on the wheel side (outboard side), respectively. A structure connected by a shaft 122 is provided.

  Here, in the conventional wheel bearing device, as shown in FIG. 12, the inner peripheral surface of the shaft hole 138 of the hub wheel 101 forms a simple cylindrical portion 139 in which no female spline is formed. When the stem portion 130 of 124 is press-fitted into the shaft hole 138 of the hub wheel 101, workability is poor because a large press-fitting load is required to transfer the convex portion 137 of the stem portion 130 to the inner peripheral surface of the shaft hole 138. It was necessary to use a press machine. Therefore, the current situation is that the wheel bearing device must be assembled to the vehicle body with the constant velocity universal joint 106 of the drive shaft 121 assembled to the wheel bearing 120.

  As a result, when the vehicle is assembled by an automobile manufacturer, the wheel bearing 120 and the constant velocity universal joint 106 of the drive shaft 121 are coupled, that is, the two constant velocity universal joints 106 of the wheel bearing 120 and the drive shaft 121 are combined. , 151 are integrated with each other. Since the minimum inner diameter of the knuckle 152 (see FIG. 14) extending from the suspension device of the vehicle body is larger than the maximum outer diameter of the constant velocity universal joints 106 and 151, the assembly to the vehicle body is shown in FIGS. 15, the sliding constant velocity universal joint 151 and the fixed constant velocity universal joint 106 of the drive shaft 121 are sequentially passed through the knuckle 152 extending from the suspension device of the vehicle body, and then the outer ring of the wheel bearing 120. 105 is fitted to the knuckle 152 and fixed.

  Since the drive shaft 121 is a long assembly body that connects the wheel side and the engine side, as described above, the sliding constant velocity universal joint 151 and the fixed constant velocity universal joint 106 of the drive shaft 121 are knuckled. The assembling method to the vehicle body that is sequentially passed through 152 is inferior in workability, and there is a possibility that parts constituting the drive shaft 121 may be damaged during the assembling.

  Accordingly, the present invention has been proposed in view of the above-mentioned problems, and the object of the present invention is to improve the workability in assembling the vehicle body and prevent damage to the components during the assembly. It is to provide a bearing device for use.

  A wheel bearing device according to the present invention includes an outer member having a double-row outer raceway formed on the inner periphery, and a double-row inner raceway facing the outer raceway on the outer periphery. And a bearing for a wheel comprising a double row rolling element interposed between the outer raceway surface of the outer member and the inner raceway surface of the inner member, and the like to the inner diameter of the hub wheel By fitting the stem portion of the outer joint member of the quick universal joint, the structure is such that the constant velocity universal joint is separably coupled to the wheel bearing by a screw tightening structure. As described above, the wheel bearing device includes the wheel bearing and the constant velocity universal joint.

  The former wheel bearing has an outer member having a double-row outer raceway formed on the inner periphery, and a double-row inner raceway facing the outer raceway on the outer periphery. And a double row rolling element interposed between the outer raceway surface of the outer member and the inner raceway surface of the inner member, and the outer joint member of the constant velocity universal joint is provided on the inner diameter of the hub ring. By fitting the stem portion, the constant velocity universal joint is detachably coupled by the screw tightening structure.

  The latter constant velocity universal joint includes an outer joint member having a stem portion and an inner joint member that transmits torque while allowing angular displacement between the outer joint member and the outer joint member via the torque transmission member. The wheel bearing is separably coupled by the screw tightening structure by fitting the stem portion to the inner diameter of the hub ring of the wheel bearing.

As a technical means for achieving the above-described object, the wheel bearing device according to the present invention extends in the axial direction to one of the hub wheel 1 and the stem portion 30 of the outer joint member 24. A plurality of convex portions 37 are formed, a concave portion 40 in which the shape of the convex portion 37 is transferred is formed on the other member, the convex portion 37 is press-fitted into the concave portion 40, and the diameter of the convex portion 37 is formed. There is a gap p between the directional tip 44 and the recess 40, and the other member is provided with a chip 66 formed by cutting with the press-fitted protrusion 37, and the chip 66 is formed by the protrusion. 37 has a concave-convex fitting structure M that is formed only at a position corresponding to the circumferential side wall portion 43 of the concave portion 37 and the fitting contact region X of the convex portion 37 and the concave portion 40 is in close contact with each other. The ratio of the pitch circle diameter to the fitting length at 2.0 to 3. Characterized in that defined in the range of.

  In the present invention, a plurality of convex portions extending in the axial direction are formed on one of the hub portion and the stem portion of the outer joint member, and a concave portion having a tightening margin with respect to the convex portion is formed in advance on the other side. . By pressing any one of the hub wheel and the stem portion of the outer joint member into the other, an uneven fitting structure in which the entire fitting contact portion between the convex portion and the concave portion is in close contact is configured. Here, the convex part in this invention is provided in the stem part of an outer joint member, and the structure in which the recessed part was provided in the hub ring | wheel is desirable. In this way, by pressing the stem portion of the outer joint member into the hub wheel, it is possible to easily configure the concave-convex fitting structure in which the entire fitting contact portion between the convex portion and the concave portion is in close contact.

  At the time of the press-fitting described above, the shape of the convex portion is transferred to the concave portion forming surface on the other side while the convex portion is accompanied by a slight plastic deformation and cutting. At this time, the convex portion bites into the concave-part forming surface on the other side, so that the inner diameter of the hub wheel is slightly expanded, and relative movement in the axial direction of the convex portion is allowed. When the axial relative movement of the convex portion stops, the inner diameter of the hub wheel is reduced to return to the original diameter. Thereby, it can closely_contact | adhere in the fitting contact site | part whole area | region of a convex part and a recessed part, and an outer joint member and a hub ring can be combined firmly.

  Here, since the concave portion is formed in advance with respect to the convex portion, the convex portion and the concave portion are brought into close contact with each other as compared with the conventional case where the convex portion is transferred to a simple cylindrical portion. Therefore, it is easy to press the outer joint member into the hub wheel of the wheel bearing and to connect the constant velocity universal joint to the wheel bearing after the wheel bearing is attached to the vehicle body. Therefore, workability can be improved.

  Further, by defining the ratio of the pitch circle diameter to the fitting length in the concave-convex fitting structure in the range of 2.0 to 3.0, either one of the hub wheel and the stem portion of the outer joint member is used as the other. The press-fitting load during press-fitting into the wheel can be reliably reduced, and the constant velocity universal joint can be easily coupled to the wheel bearing, thereby improving workability. Moreover, the shear strength of the convex portion can be increased, and sufficient strength can be secured in the concave-convex fitting structure.

  The concave portion in the present invention preferably has a structure having a tightening margin only for the circumferential side wall portion of the convex portion. Here, “only the circumferential side wall portion of the convex portion” means a portion excluding the radial front end portion of the convex portion. Since the radial tip end portion of the convex portion does not have a recess and a fastening margin, the shape of the radial tip end portion of the convex portion is not transferred to the recess forming surface on the counterpart side. Thus, since it is set so as to have a tightening margin only for the circumferential side wall portion of the convex portion, it is further more than the case where the concave portion and the tightening margin are set over the entire convex portion. Since the press-fitting load can be reduced, the press-fitting work for coupling the constant velocity universal joint to the wheel bearing is further facilitated.

  In the present invention, it is desirable to make the surface hardness of the convex portion larger than the surface hardness of the concave portion. In this way, when one of the hub wheel and the stem portion of the outer joint member is press-fitted into the other, the shape of the convex portion is easily transferred to the concave portion forming surface on the other side by plastic deformation and cutting. can do.

  In the present invention, it is desirable that the outer joint member can be press-fitted into the hub wheel with an axial force generated by the screw tightening structure or less. In this way, when the outer joint member is press-fitted into the hub wheel of the wheel bearing after the wheel bearing is attached to the vehicle body, there is no need to prepare a dedicated jig, and the wheel bearing device is configured. The constant velocity universal joint can be easily coupled to the wheel bearing with a screw tightening structure as a part.

  The screw tightening structure according to the present invention includes a female screw portion formed at the shaft end of the stem portion of the outer joint member, and a male screw portion that is engaged with the female screw portion and locked to the hub wheel. Is possible. In this structure, the constant-velocity universal joint is fixed to the hub wheel by screwing the male screw part into the female screw part of the stem part and tightening the male screw part in a state where the male screw part is locked to the hub wheel.

  The screw tightening structure according to the present invention has a structure composed of a male screw portion formed at the shaft end of the stem portion of the outer joint member and a female screw portion that is engaged with the male screw portion and locked to the hub wheel. Is possible. In this structure, the constant-velocity universal joint is fixed to the hub wheel by screwing the female screw portion into the male screw portion of the stem portion and tightening the female screw portion while being locked to the hub wheel.

  According to the present invention, a plurality of convex portions formed in any one of the hub wheel and the stem portion of the outer joint member and extending in the axial direction are formed into a plurality of concave portions having an allowance for the convex portion. By press-fitting into the other side and transferring the shape of the convex part to the other side, a concavity and convexity fitting structure is formed in which the whole contact area of the convex part and the concave part is in close contact with each other. Since the press-fit load for making it adhere in the fitting contact part whole region of a convex part and a recessed part can be lowered | hung, since it has previously formed the recessed part which has a wheel bearing after attaching a wheel bearing to a vehicle body It is easy to press-fit the outer joint member into the hub wheel and to connect the constant velocity universal joint to the wheel bearing, improve the workability in assembling to the vehicle body, and prevent the parts from being damaged during the assembling. be able to.

  Further, by defining the ratio of the pitch circle diameter to the fitting length in the concave-convex fitting structure in the range of 2.0 to 3.0, either one of the hub wheel and the stem portion of the outer joint member is used as the other. The press-fitting load during press-fitting into the wheel can be reliably reduced, and the constant velocity universal joint can be easily coupled to the wheel bearing, thereby improving workability. Moreover, the shear strength of the convex portion can be increased, and sufficient strength can be secured in the concave-convex fitting structure.

In embodiment of the wheel bearing apparatus which concerns on this invention, it is a longitudinal cross-sectional view which shows the state before attaching a constant velocity universal joint to the wheel bearing. It is a longitudinal cross-sectional view which shows the state after attaching the constant velocity universal joint to the wheel bearing of FIG. It is sectional drawing which shows the state before attaching the constant velocity universal joint of a drive shaft to the wheel bearing with which the knuckle was mounted | worn. It is sectional drawing which shows the state in the middle of assembling the constant velocity universal joint of a drive shaft to the wheel bearing with which the knuckle was mounted | worn. It is sectional drawing which shows the state after attaching the constant velocity universal joint of a drive shaft to the wheel bearing with which the knuckle was mounted | worn. (A) is a principal part expanded sectional view which shows the state before pressing the stem part of an outer joint member in the hub ring of a wheel bearing, (B) is sectional drawing which follows the AA line of (A). (A) is a principal part expanded sectional view which shows the state in the middle of press-fitting the stem part of an outer joint member to the hub ring of a wheel bearing, (B) is sectional drawing which follows the BB line of (A). (A) is a principal part expanded sectional view which shows the state after press-fitting the stem part of an outer joint member in the hub ring of a wheel bearing, (B) is sectional drawing which follows the CC line of (A). FIG. 2 is a cross-sectional view showing a hub wheel and a stem portion after assembling a constant velocity universal joint to the wheel bearing of FIG. 1. It is sectional drawing which shows the state after assembling | attaching the constant velocity universal joint of a drive shaft to the wheel bearing attached to the knuckle in other embodiment of the wheel bearing apparatus which concerns on this invention. It is a longitudinal cross-sectional view which shows the whole structure of the conventional wheel bearing apparatus. FIG. 12 is an enlarged vertical cross-sectional view of a main part showing a state before the stem portion of the outer joint member is press-fitted into the shaft hole of the hub wheel in the wheel bearing device of FIG. 11. In the wheel bearing device of FIG. 11, it is a principal part expanded horizontal sectional view which shows the state after pressing the stem part of an outer joint member in the axial hole of a hub ring. It is sectional drawing which shows the state before mounting | wearing the knuckle with the wheel bearing apparatus with which the drive shaft was assembled | attached. It is sectional drawing which shows the state after mounting | wearing the knuckle with the wheel bearing apparatus with which the drive shaft was assembled | attached.

  An embodiment of a wheel bearing device according to the present invention will be described in detail below. The wheel bearing device shown in FIGS. 1 and 2 includes a hub wheel 1 and an inner ring 2 which are inner members, double-row rolling elements 3 and 4, a wheel bearing 20 including an outer ring 5 and a constant velocity universal joint 6. The main part is composed. FIG. 1 shows a state before the constant velocity universal joint 6 is assembled to the wheel bearing 20, and FIG. 2 shows a state after the constant velocity universal joint 6 is assembled to the wheel bearing 20. In the following description, the side closer to the outer side of the vehicle body is called the outboard side (left side of the drawing) and the side closer to the center is called the inboard side (right side of the drawing).

  The hub wheel 1 has an inner raceway surface 7 on the outboard side formed on the outer peripheral surface thereof, and includes a wheel mounting flange 9 for mounting a wheel (not shown). Hub bolts 10 for fixing the wheel disc are implanted at equal intervals in the circumferential direction of the wheel mounting flange 9. The inner ring 2 is fitted to the small-diameter step portion 12 formed on the inboard side outer peripheral surface of the hub wheel 1, and the inboard-side inner raceway surface 8 is formed on the outer peripheral surface of the inner ring 2.

  The inner ring 2 is press-fitted with an appropriate tightening margin to prevent creep. The outboard side inner raceway surface 7 formed on the outer peripheral surface of the hub wheel 1 and the inboard side inner raceway surface 8 formed on the outer peripheral surface of the inner ring 2 constitute a double row raceway surface. The inner ring 2 is press-fitted into the small-diameter step portion 12 of the hub wheel 1, and the end portion of the small-diameter step portion 12 is crimped outward by swing caulking to prevent the inner ring 2 from coming off with the caulking portion 11. It is integrated with the hub wheel 1 and preload is applied to the wheel bearing 20.

  The outer ring 5 has double-row outer raceways 13 and 14 that are opposed to the raceways 7 and 8 of the hub wheel 1 and the inner race 2 on the inner circumferential surface, and is attached to a knuckle extending from a suspension device of a vehicle body (not shown). A vehicle body mounting flange 19 is provided. As will be described later, the vehicle body mounting flange 19 is fitted to the knuckle 52 and fixed by a bolt 63 (see FIG. 3).

  The wheel bearing 20 has a double-row angular ball bearing structure, and has inner raceway surfaces 7 and 8 formed on the outer peripheral surfaces of the hub wheel 1 and the inner ring 2 and an outer raceway surface 13 formed on the inner peripheral surface of the outer ring 5. 14, the rolling elements 3 and 4 are interposed, and the rolling elements 3 and 4 in each row are supported by the cages 15 and 16 at equal intervals in the circumferential direction.

  A pair of seals 17 and 18 that seal the annular space between the outer ring 5, the hub ring 1, and the inner ring 2 are provided at both ends of the wheel bearing 20 so as to be in sliding contact with the outer peripheral surfaces of the hub ring 1 and the inner ring 2. 5 is fitted to the inner diameters of both end portions to prevent leakage of grease filled inside and entry of water and foreign matters from the outside.

  The constant velocity universal joint 6 is provided at one end of an intermediate shaft 22 constituting the drive shaft 21 and is opposed to the outer joint member 24 having a track groove 23 formed on the inner peripheral surface thereof and the track groove 23 of the outer joint member 24. An inner joint member 26 having track grooves 25 formed on the outer peripheral surface thereof, balls 27 incorporated between the track grooves 23 of the outer joint member 24 and the track grooves 25 of the inner joint member 26, and the outer joint member 24. The cage 28 is interposed between the inner peripheral surface and the outer peripheral surface of the inner joint member 26 and holds the balls 27.

  The outer joint member 24 includes a mouth portion 29 that accommodates an inner part composed of the inner joint member 26, a ball 27, and a cage 28, and a stem portion 30 that extends integrally from the mouth portion 29 in the axial direction. The inner joint member 26 is coupled so that torque can be transmitted by fitting the shaft end of the intermediate shaft 22 by spline fitting.

  Between the outer joint member 24 of the constant velocity universal joint 6 and the intermediate shaft 22, a resin bellows for preventing leakage of a lubricant such as grease enclosed in the joint and preventing foreign matter from entering from the outside of the joint. The boot 31 is attached and the opening of the outer joint member 24 is closed.

  The boot 31 includes a large-diameter end portion 33 fastened and fixed to the outer peripheral surface of the outer joint member 24 by a boot band 32, a small-diameter end portion 35 fastened and fixed to the outer peripheral surface of the intermediate shaft 22 by a boot band 34, The diameter end portion 33 and the small diameter end portion 35 are connected to each other, and a flexible bellows portion 36 having a diameter reduced from the large diameter end portion 33 toward the small diameter end portion 35 is formed.

The wheel bearing device has a cylindrical fitting surface 61 formed on the outer peripheral surface of the inboard side of the stem portion 30 of the outer joint member 24, and a plurality of axially extending surfaces on the outer peripheral surface of the stem portion 30 on the outboard side. A male spline composed of the convex portions 37 is formed. On the other hand, a cylindrical fitting surface 62 is formed on the inboard side inner peripheral surface of the shaft hole 38 of the hub wheel 1, and the convex portion 37 is formed on the outboard side inner peripheral surface of the shaft hole 38. A plurality of concave portions 39 (small concave portions) having a tightening margin n are formed only on the circumferential side wall portion 43 [see FIG. 7B]. In addition, although the above-mentioned convex part 37 is made into the trapezoidal tooth shape of a cross section, an involute tooth shape may be sufficient.

  In this wheel bearing device, the stem portion 30 of the outer joint member 24 is press-fitted into the shaft hole 38 of the hub wheel 1, and the circumferential side wall of the convex portion 37 is inserted into the shaft hole 38 of the hub wheel 1, which is a recess forming surface on the other side. The concave portion 40 is formed by transferring the shape of only the portion 43 (see FIG. 8B), and the concave-convex fitting structure M is formed in which the entire fitting contact region X between the convex portion 37 and the concave portion 40 is in close contact (see FIG. (See FIG. 2). As the material of the outer joint member 24 and the hub wheel 1, medium carbon steel for machine structure represented by S53C and the like is suitable.

  This wheel bearing device includes a screw tightening structure N (see FIG. 2) as follows. The screw tightening structure N includes a female screw portion 41 formed at the shaft end of the stem portion 30 of the outer joint member 24 and a bolt that is a male screw portion that is engaged with the female screw portion 41 and is locked to the hub wheel 1. 42. In this structure, the constant velocity universal joint 6 is fixed to the hub wheel 1 by screwing the bolt 42 into the female screw portion 41 of the stem portion 30 and tightening the bolt 42 in a state where the bolt 42 is locked to the hub wheel 1. . The wheel bearing 20 has a structure in which the inner ring 2 is prevented from coming off by the caulking portion 11 and is integrated with the hub wheel 1, so that it can be separated from the outer joint member 24 of the constant velocity universal joint 6. It has become.

  By the way, in this wheel bearing device, the caulking portion 11 of the hub wheel 1 of the wheel bearing 20 and the shoulder portion 45 of the outer joint member 24 are in contact with each other. There is a possibility that a stick-slip sound, commonly referred to as a cuckling noise, is generated between the caulking portion 11 of the wheel 1 and the shoulder portion 45 of the outer joint member 24. This stick-slip noise is generated when the rotational torque is applied from the outer joint member 24 of the constant velocity universal joint 6 to the hub wheel 1 of the wheel bearing 20 in a stationary state when the vehicle starts. The rotational torque is transmitted to the wheel 1, but the caulking portion 11 and the outer joint member 24 of the hub wheel 1 are caused by the transmission torque fluctuation between the outer joint member 24 and the wheel bearing 20 and the torsion of the outer joint member 24. Abrupt slip occurs on the contact surface with the shoulder 45 of the head. This sudden slip causes stick-slip noise.

  In the screw tightening structure N described above, as a means for preventing the stick-slip noise, the tightening torque is set lower than the tightening torque when the outer joint member 24 is pressed into the hub wheel 1. That is, after the outer joint member 24 is press-fitted into the hub wheel 1, the screw tightening state is once loosened, and the tightening torque is set lower than the tightening torque at the time of the press-fitting. As a result, the surface pressure generated on the contact surface between the caulking portion 11 of the hub wheel 1 and the shoulder portion 45 of the outer joint member 24 can be managed optimally, and stick slip caused by a sudden slip on the contact surface. Generation of sound can be prevented beforehand.

  In this wheel bearing device, a fixed type constant velocity universal joint 6 coupled to a wheel bearing 20 comprising a hub wheel 1, an inner ring 2, double row rolling elements 3, 4 and an outer ring 5 is part of a drive shaft 21. It is composed. As shown in FIG. 3, the drive shaft 21 that transmits power from the engine of the automobile to the wheels needs to cope with angular displacement and axial displacement due to a change in the relative positional relationship between the engine and the wheels. Is equipped with a sliding type constant velocity universal joint 51 on the engine side (inboard side) and a fixed type constant velocity universal joint 6 on the wheel side (outboard side). A structure connected by a shaft 22 is provided.

  As shown in FIG. 4, prior to press-fitting the stem portion 30 of the outer joint member 24 into the shaft hole 38 of the hub wheel 1, a cylindrical fitting surface 61 is formed on the inboard-side outer peripheral surface of the stem portion 30. At the same time, the cylindrical fitting surface 62 is formed on the inboard side inner peripheral surface of the shaft hole 38 of the hub wheel 1, so that the stem portion 30 is fitted to the fitting surface 62 of the shaft hole 38 of the hub wheel 1. By fitting the mating surface 61, the axis alignment of the stem portion 30 with respect to the hub wheel 1 can be easily performed.

  6A and 6B, a guide for guiding the start of press-fitting between the fitting surface 62 located on the inboard side of the hub wheel 1 and the recess 39 located on the outboard side. A portion 64 is provided. The guide portion 64 is formed such that a concave portion 65 larger than the convex portion 37 of the stem portion 30 is continuous with the aforementioned concave portion 39 (see an enlarged portion in FIG. 1). That is, a gap m is formed between the convex portion 37 and the concave portion 65 (see FIG. 7B). When the stem portion 30 of the outer joint member 24 is press-fitted into the hub wheel 1 by the guide portion 64, the convex portion 37 of the stem portion 30 can be guided so as to be surely press-fitted into the concave portion 39 of the hub wheel 1. The phase alignment of the convex portion 37 and the concave portion 39 is easy and stable press-fitting is possible, so that misalignment or tilting of the core during press-fitting can be prevented.

  When the stem portion 30 is press-fitted into the hub wheel 1, as shown in FIGS. 7A, 7B, 8A, and 8B, the circumferential side wall portion of the convex portion 37 is formed in the shaft hole 38 of the hub wheel 1. The recess 40 is formed by transferring only the shape of 43. At this time, since the concave portion 39 is formed in advance with respect to the convex portion 37, the convex portion 37 and the concave portion 40 can be compared with the case where the convex portion 137 is transferred to the cylindrical portion 139 as in the prior art (see FIG. 12). It is possible to reduce the press-fitting load for tightly contacting the entire fitting contact region X (see FIG. 2).

  In the concave / convex fitting structure M, the circumferential dimension of the concave portion 39 is set smaller than that of the convex portion 37 so as to have a tightening margin n only with respect to the circumferential side wall portion 43 of the convex portion 37. Since the portion excluding the circumferential side wall portion 43 of the convex portion 37, that is, the radial front end portion 44 of the convex portion 37 does not have a fastening margin with the concave portion 39, its shape is not transferred to the concave portion 39. In addition, since the radial dimension of the concave portion 39 is set larger than that of the convex portion 37, the gap p is provided between the concave portion 39. Thus, since it is set so as to have a tightening margin n only for the circumferential side wall portion 43 of the convex portion 37, the concave portion 39 and the tightening margin are set over the entire convex portion 37. The press-fit load can be further reduced than the case.

  As a result, as shown in FIG. 5, the outer joint member 24 can be press-fitted into the hub wheel 1 with an axial force generated by tightening the bolt 42 or less. That is, at the time of assembling a vehicle by an automobile manufacturer, the wheel bearing 20 is attached to the knuckle 52 extending from the suspension device of the vehicle body with the bolt 63, and then the hub of the wheel bearing 20 is pulled by the pulling force by the bolt 42 of the screw tightening structure N. The stem portion 30 of the outer joint member 24 of the constant velocity universal joint 6 can be easily press-fitted into the shaft hole 38 of the wheel 1, and the constant velocity universal joint 6 of the drive shaft 21 can be easily assembled to the wheel bearing 20. This makes it possible to improve workability when assembling to the vehicle body, and prevent damage to the parts during assembling.

  Thus, when the outer joint member 24 is press-fitted into the hub wheel 1 of the wheel bearing 20 after the wheel bearing 20 is attached to the knuckle 52 of the vehicle body, it is not necessary to prepare a dedicated jig separately. The constant velocity universal joint 6 can be easily coupled to the wheel bearing 20 with the bolt 42 which is a component constituting the bearing device. In addition, since it is possible to press-fit by applying a relatively small pulling force equal to or less than the axial force generated by tightening the bolt 42, the pulling workability by the bolt 42 can be improved. Furthermore, since it is not necessary to apply a large press-fitting load, it is possible to prevent the unevenness in the concave-convex fitting structure M from being damaged (peeled), and to realize a high-quality, long-life concave-convex fitting structure M.

  When the stem portion 30 of the outer joint member 24 is press-fitted into the shaft hole 38 of the hub wheel 1, the concave portion is caused by a slight plastic deformation and cutting of the concave portion forming surface by the circumferential side wall portion 43 of the convex portion 37. The shape of the circumferential side wall 43 of the convex portion 37 is transferred to the forming surface. At this time, the circumferential side wall portion 43 of the convex portion 37 bites into the concave portion forming surface so that the inner diameter of the hub wheel 1 is slightly expanded, and relative movement in the axial direction of the convex portion 37 is allowed. Is done. When the axial relative movement of the convex portion 37 stops, the inner diameter of the hub wheel 1 is reduced to return to the original diameter. As a result, it is possible to tightly bond and integrate the outer joint member 24 and the hub wheel 1 together in the entire fitting contact region X between the convex portion 37 and the concave portion 40.

  Such a low-cost and highly reliable connection does not form gaps that cause play in the radial direction and circumferential direction of the fitting portion of the stem portion 30 and the hub wheel 1, so that the entire area X of the fitting contact portion transmits rotational torque. This contributes to stable torque transmission and can prevent harsh rattling noises over a long period of time. Since the fitting contact part whole area X is in close contact as described above, the strength of the torque transmission part is improved, so that the vehicle bearing device can be reduced in weight and size.

  When the stem portion 30 of the outer joint member 24 is press-fitted into the shaft hole 38 of the hub wheel 1, the surface hardness of the convex portion 37 is made larger than the surface hardness of the concave portion 39. In that case, the difference between the surface hardness of the convex portion 37 and the surface hardness of the concave portion 39 is set to 20 or more in HRC. Thereby, the shape of the circumferential side wall part 43 of the convex part 37 can be easily transcribe | transferred to the other party recessed part formation surface by the plastic deformation and cutting process at the time of press injection. The surface hardness of the convex portion 37 is preferably 50 to 65 in HRC, and the surface hardness of the concave portion 39 is preferably 10 to 30 in HRC.

Between the shaft hole 38 of the hub wheel 1 and the stem portion 30 of the outer joint member 24, there is provided an accommodating portion 67 for accommodating a protruding portion 66 (chip) generated by the transfer of the convex shape by press-fitting [ FIG. 7 (A) and FIG. 8 (A)]. Thereby, the protruding portion 66 generated by the transfer of the convex shape by press-fitting can be held in the housing portion 67, and the protruding portion 66 can be prevented from entering the vehicle outside the apparatus. By holding the protruding portion 66 in the accommodating portion 67, the removal processing of the protruding portion 66 becomes unnecessary, the work man-hours can be reduced, the workability can be improved, and the cost can be reduced. .

  In the concave-convex fitting structure M described above, as shown in FIGS. 8A and 9, the pitch circle diameter (with respect to the axial length (hereinafter simply referred to as the fitting length) of the fitting contact region X is ( (PCD) ratio is specified in the range of 2.0 to 3.0. Here, the ratio of the pitch circle diameter to the fitting length means a value (PCD / X) obtained by dividing the pitch circle diameter by the fitting length. In the conventional concave / convex fitting structure (see FIG. 12) for transferring the convex portion 137 to the cylindrical portion 139, the ratio of the pitch circle diameter to the fitting length was set to be smaller than 1.0. In the concave-convex fitting structure M in the embodiment, the ratio of the pitch circle diameter to the fitting length is specified in the range of 2.0 to 3.0.

  In this way, when the ratio of the pitch circle diameter to the fitting length is defined in the range of 2.0 to 3.0, when the stem portion 30 of the outer joint member 24 is press-fitted into the shaft hole 38 of the hub wheel 1. Therefore, the stem portion 30 of the outer joint member 24 can be easily press-fitted into the shaft hole 38 of the hub wheel 1 with the pulling force of the bolt 42 of the screw tightening structure N. Further, the shear strength of the convex portion 37 can be made higher than the breaking strength of the stem portion 30 of the outer joint member 24, and sufficient strength can be ensured in the concave-convex fitting structure M.

  If the ratio of the pitch circle diameter to the fitting length is smaller than 2.0, the fitting length becomes too large with respect to the pitch circle diameter. It becomes difficult to lower the press-fit load when the stem portion 30 of the outer joint member 24 is press-fitted into the shaft hole 38 of the hub wheel 1, and the stem portion 30 of the outer joint member 24 is press-fitted into the shaft hole 38 of the hub wheel 1. It becomes difficult. In addition, it is difficult to reduce the size and weight of the apparatus. On the contrary, if the ratio of the pitch circle diameter to the fitting length is larger than 3.0, the fitting length becomes too small with respect to the pitch circle diameter, so that the damage strength of the stem portion 30 of the outer joint member 24 is reduced. As a result, the shear strength of the convex portion 37 becomes lower, and it becomes difficult to ensure sufficient strength in the concave-convex fitting structure M.

  Moreover, in this uneven | corrugated fitting structure M, the module is prescribed | regulated in the range of 0.3-0.75. Here, as shown in FIG. 8B and FIG. 9, the module refers to the convex portion 37 formed on the outer peripheral surface of the stem portion 30 of the outer joint member 24 and the inner peripheral surface of the shaft hole 38 of the hub wheel 1. Means a value (PCD / Z) obtained by dividing the pitch circle diameter (PCD) in the fitting structure with the concave portion 40 formed by the number Z (the number of teeth) of the convex portion 37. In the conventional concavo-convex fitting structure (see FIG. 12) for transferring the convex portion 137 to the cylindrical portion 139, the module in the concavo-convex fitting structure is set to about 1.0. In the fitting structure M, the module is defined in the range of 0.3 to 0.75.

  Thus, by defining the module in the concave-convex fitting structure M in the range of 0.3 to 0.75, the convex portion 37 of the stem portion 30 of the outer joint member 24 and the concave portion 40 of the shaft hole 38 of the hub wheel 1 are provided. And the torque transmission capacity between the wheel bearing 20 and the constant velocity universal joint 6 can be sufficiently ensured. Further, the press-fitting load when the stem portion 30 of the outer joint member 24 is press-fitted into the shaft hole 38 of the hub wheel 1 can be reliably reduced, and the pull-in force of the bolt 42 of the screw tightening structure N can be used. The stem portion 30 of the outer joint member 24 can be easily press-fitted into the shaft hole 38.

  If the module in the concave-convex fitting structure M is smaller than 0.3, the fitting margin of the concave portion 39 with respect to the convex portion 37 becomes too small, so that it is sufficient between the wheel bearing 20 and the constant velocity universal joint 6. It is difficult to ensure a sufficient torque transmission capacity. On the contrary, if the module in the concave-convex fitting structure M is larger than 0.75, the fitting margin of the concave portion 39 with respect to the convex portion 37 becomes too large, so that the stem of the outer joint member 24 is inserted into the shaft hole 38 of the hub wheel 1. It is difficult to reduce the press-fitting load when the portion 30 is press-fitted, and the stem portion 30 of the outer joint member 24 can be press-fitted into the shaft hole 38 of the hub wheel 1 with the pulling force by the bolt 42 of the screw tightening structure N. It becomes difficult.

  In the above embodiment, the structure in which the bolt 42 is fastened to the end surface of the hub wheel 1 by screwing the bolt 42 into the female screw portion 41 of the stem portion 30 is exemplified. However, as another screw fastening structure, 10, a male screw portion 68 formed at the shaft end of the stem portion 30 of the outer joint member 24, and a female screw portion that is locked to the end surface of the hub wheel 1 while being screwed into the male screw portion 68. It is also possible to configure with the nut 69 that is. In this structure, the constant velocity universal joint 6 is fixed to the hub wheel 1 by tightening the nut 69 in a state where the nut 69 is locked to the hub wheel 1 by screwing the nut 69 into the male screw portion 68 of the stem portion 30. become.

  Further, in the above embodiment, one of the double-row inner raceway surfaces 7 and 8 formed on the inner member composed of the hub wheel 1 and the inner ring 2, that is, the inner raceway surface 7 on the outboard side is connected to the hub wheel 1. The case of application to a drive wheel bearing device of the type (called third generation) formed on the outer periphery is illustrated, but the present invention is not limited to this, and a pair of inner rings are press-fitted into the outer periphery of the hub wheel. The outboard side raceway surface 7 is formed on the outer periphery of one inner ring, and the inboard side raceway surface 8 is formed on the outer periphery of the other inner ring (referred to as first and second generation) type of drive. The present invention can also be applied to a wheel bearing device.

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

1 Inner member (hub ring)
2 Inner member (inner ring)
3, 4 Rolling element 5 Outer member (outer ring)
6 Constant velocity universal joint 7,8 Inner raceway surface 13,14 Outer raceway surface 20 Wheel bearing 24 Outer joint member 30 Stem portion 37 Convex portion (male spline)
39, 40 Concave part 41 Female thread part 42 Male thread part (bolt)
43 Circumferential side wall portion of convex portion 68 Male thread portion 69 Female thread portion (nut)
n Tightening allowance M Concave / concave fitting structure N Screw tightening structure X Fitting contact area

Claims (6)

An outer member 5 having double-row outer raceways 13 and 14 formed on the inner periphery, and double-row inner raceways 7 and 8 facing the outer raceways 13 and 14 on the outer periphery, And an inner member composed of the inner ring 2 and a double row rolling element 3 interposed between the outer raceway surfaces 13 and 14 of the outer member 5 and the inner raceway surfaces 7 and 8 of the inner members 1 and 2. , 4, and a stem portion 30 of the outer joint member 24 of the constant velocity universal joint 6 is fitted to the inner diameter of the hub wheel 1 of the wheel bearing 20 so that the wheel bearing 20 is In the wheel bearing device in which the quick universal joint 6 is detachably coupled by the screw tightening structure N,
A plurality of convex portions 37 extending in the axial direction is formed on any one of the hub wheel 1 and the stem portion 30 of the outer joint member 24,
The other member is formed with a concave portion 40 to which the shape of the convex portion 37 is transferred,
The convex portion 37 is press-fitted into the concave portion 40,
There is a gap p between the radial tip 44 of the convex portion 37 and the concave portion 40,
The other member includes a chip 66 formed by cutting with the press-fitted convex portion 37;
The chip 66 is formed only at a position corresponding to the circumferential side wall portion 43 of the convex portion 37,
It has a concavo-convex fitting structure M in which the fitting contact region X of the convex portion 37 and the concave portion 40 is in close contact,
A wheel bearing device characterized in that a ratio of a pitch circle diameter to a fitting length in the uneven fitting structure M is defined in a range of 2.0 to 3.0.   The wheel bearing device according to claim 1, wherein the convex portion is provided in the stem portion of the outer joint member and the concave portion is provided in the hub wheel.   The wheel bearing device according to claim 1 or 2, wherein the surface hardness of the convex portion 37 is larger than the surface hardness of the concave portion 40.   The screw tightening structure N includes a female screw portion 41 formed at the shaft end of the stem portion 30 of the outer joint member 24 and a male screw portion 42 that is locked to the hub wheel 1 while being screwed into the female screw portion 41. The wheel bearing apparatus as described in any one of Claims 1-3 comprised by these.   The screw tightening structure N includes a male screw portion 42 formed at the shaft end of the stem portion 30 of the outer joint member 24 and a female screw portion 41 that is locked to the hub wheel 1 while being engaged with the male screw portion 42. The wheel bearing apparatus as described in any one of Claims 1-3 comprised by these. An outer member 5 having double-row outer raceways 13 and 14 formed on the inner periphery, and double-row inner raceways 7 and 8 facing the outer raceways 13 and 14 on the outer periphery, And an inner member composed of the inner ring 2 and a double row rolling element 3 interposed between the outer raceway surfaces 13 and 14 of the outer member 5 and the inner raceway surfaces 7 and 8 of the inner members 1 and 2. , 4, and the wheel bearing 20 by fitting the stem portion 30 of the outer joint member 24 of the constant velocity universal joint 6 to the inner diameter of the hub wheel 1 of the wheel bearing 20. A method for manufacturing a wheel bearing device in which a constant velocity universal joint 6 is detachably coupled via a screw tightening structure N,
A plurality of convex portions 37 extending in the axial direction are formed on one member of the hub wheel 1 and the stem portion 30 of the outer joint member 24, and the circumferential side wall portion of the convex portion 37 is formed on the other member. A plurality of small recesses 39 having a tightening allowance n with respect to 43 only ,
The convex portion 37 is press-fitted into the small concave portion 39 by the axial force of the screw tightening structure N, and the tightening margin n is cut only by the circumferential side wall portion 43 of the convex portion 37,
Thus, the concave portion 40 is formed in the other member to form the concave-convex fitting structure M in which the convex portion 37 and the fitting contact region X of the concave portion 40 are in close contact with each other, and the radial tip 44 of the convex portion 37 is formed. A gap p is provided between the concave portion 40 and the ratio of the pitch circle diameter of the convex portion 37 to the fitting length of the concave portion 40 is in the range of 2.0 to 3.0. Manufacturing method of wheel bearing device.

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