JP2022149827A - Bearing device for wheel - Google Patents

Abstract

To provide a bearing device for wheel which improves rigidity of a hub ring.SOLUTION: In a bearing device for wheel, a protruded part 33 which is elongated in an axis direction is formed on either one of a hub ring 1 and a stem part 30 of an outer side coupling member 24 while a recessed part 40 formed by cutting according to press-fitting of the protruded part 33 is formed on the other of these. An axial force of a screw fastening structure N is set as a size which permits the cutting according to press-fitting of the protruded part 33. A reception member 50 which fits an inner circumferential surface of a shaft hole 35 is arranged on the shaft hole 35 of the hub ring 1 and the inner circumferential surface of the shaft hole 35 and an outer circumferential surface of the reception member 50 are formed in tapered surface-shaped states which are brought into surface contact with each other in the screw fastening structure N.SELECTED DRAWING: Figure 1

Description

The present invention relates to a wheel bearing device that rotatably supports drive wheels (front wheels of FF vehicles, rear wheels of FR vehicles, all wheels of 4WD vehicles) with respect to, for example, a suspension system of an automobile.

An example of a drive shaft that transmits power from an automobile engine to wheels is described in Patent Document 1 below. As shown in FIG. 7, this drive shaft 121 is generally placed on the engine side (inboard side) because it is necessary to accommodate angular displacement and axial displacement due to changes in the relative positional relationship between the engine and the wheels. A sliding constant velocity universal joint 151 and a fixed constant velocity universal joint 106 are arranged on the wheel side (outboard side), respectively, and both constant velocity universal joints 151 and 106 are connected by an intermediate shaft 122. .

A fixed constant velocity universal joint 106 on the outboard side of the drive shaft 121 is mounted with a wheel bearing 120 composed of a double-row angular contact ball bearing. The wheel bearing 120 supports the wheel rotatably with respect to the vehicle body. The outer ring 105 is fixed to the knuckle 152 extending from the vehicle body side using the bolt 153, and the hub wheel 101 is attached to the wheel via the hub bolt 110. be done.

As shown in FIG. 8, the fixed constant velocity universal joint 106 is provided at one end of an intermediate shaft 122 and includes an outer joint member 124 having a track groove 123 formed on the inner peripheral surface thereof, and a track groove of the outer joint member 124. An inner joint member 126 having a track groove 125 opposite to 123 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. A cage 128 interposed between the inner peripheral surface of the member 124 and the outer peripheral surface of the inner joint member 126 holds the balls 127 .

The outer joint member 124 has a mouth portion 129 containing internal parts consisting of the inner joint member 126, the balls 127, and the cage 128, and a stem portion 130 integrally extending from the mouth portion 129 in the axial direction. The inner joint member 126 is coupled to the intermediate shaft 122 so as to transmit torque by spline fitting with the intermediate shaft 122 inserted into the inner periphery thereof.

Between the outer joint member 124 and the intermediate shaft 122, a bellows-shaped boot 131 made of resin or rubber is provided to prevent leakage of lubricant such as grease sealed inside the joint and to prevent foreign matter from entering from the outside of the joint. is installed. As a result, the opening on one axial side of the outer joint member 124 is closed by the boot 131 .

In order to couple the wheel bearing 120 and the fixed constant velocity universal joint 106 without backlash in the circumferential direction, a protrusion and a A concave-convex fitting structure is provided in which the entire area of fitting contact with the recess is in close contact. In this concavo-convex fitting structure, a male spline having a plurality of axially extending convex portions 133 is formed on the outer peripheral surface of the stem portion 130 on the outboard side. A female spline (press spline) having a plurality of recesses 137 having an interference with respect to the protrusion 133 is formed on the outboard side inner peripheral surface of the shaft hole 135 of the hub wheel 101 .

In this wheel bearing device, the stem portion 130 of the outer joint member 124 is press-fitted into the shaft hole 135 of the hub wheel 101, and at that time, the male spline convex portion 133 of the stem portion 130 is fitted into the female spline concave portion 137 of the hub wheel. Press in. By cutting the concave portion 137 with the press-fitted convex portion 133, a concave portion is formed by transferring the shape of the convex portion 33 to the shaft hole 135 of the hub wheel 101, and the entire area of fitting contact between the convex portion 133 and the concave portion is brought into close contact. This constitutes a concave-convex fitting structure M (see FIG. 7).

This wheel bearing device has a screw tightening structure. As shown in FIGS. 7 and 8, the screw tightening structure includes a female threaded portion 141 formed at the shaft end of the stem portion 130 of the outer joint member 124, and the hub wheel 101 engaged with the female threaded portion 141 in a screwed state. It is composed of a bolt 142 which is a male threaded portion to be fastened. In this structure, the stem portion 130 of the outer joint member 124 is attached to the hub by screwing the bolt 142 onto the female thread portion 141 of the stem portion 130 and tightening the bolt 142 while engaging the end face of the hub wheel 101 . The concave-convex fitting structure M is formed by pulling it into the inner circumference of the ring 101 and cutting the wall surface of the concave portion 137 with the convex portion 133 .

In the wheel bearing device shown in FIG. 8, an inner wall 1 that engages with a bolt 142 is provided at the outboard side end of the shaft hole 135 of the hub wheel 101 so as to protrude radially inward. On the other hand, in Patent Document 2 below, as shown in FIG. It has also been proposed to omit the inner wall 150 .

JP 2013-079063 A JP 2014-111425 A

In the concave-convex fitting structure of Patent Document 1, it is necessary to accurately and efficiently form the female spline having the concave portion 137 on the inner circumference of the hub wheel. From this point of view, it is desired to form the female spline by broaching, but an inner wall 150 is formed in the opening on the outboard side of the hub wheel to engage with the bolt bearing surface, and this inner wall 150 is formed during broaching. 150 interferes with the broach for broaching. Therefore, it is difficult to form press splines by broaching.

If the shaft hole 135 of the hub wheel 101 is formed in a straight shape without an inner wall as in Patent Document 2, interference between the broach and the hub wheel does not occur during broaching. It can be formed by broaching. However, in such a configuration, since an annular gap C is formed between the inner peripheral surface of the hub wheel 101 on the outboard side and the outer peripheral surface of the bolt 142, it has been found that the rigidity of the hub wheel 101 is insufficient. rice field.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a wheel bearing device in which the rigidity of a hub wheel is increased.

As a technical means for achieving the above object, the present invention provides an outer member having a double-row outer raceway surface formed on its inner circumference and a double-row inner raceway surface facing the outer raceway surface on its outer circumference. and comprising an inner member having a hub ring and an inner ring, and double-row rolling elements interposed between the outer raceway surface of the outer member and the inner raceway surface of the inner member A shaft hole is formed in the inner circumference of the hub wheel, a stem portion of an outer joint member of a constant velocity universal joint is fitted into the shaft hole, and the stem portion of the outer joint member is fitted to the hub wheel One of the hub ring and the stem portion of the outer joint member is separably coupled by a screw tightening structure, and a protrusion extending in the axial direction is formed on one of the hub wheel and the stem portion of the outer joint member, and the other is formed by cutting by press-fitting the protrusion. In the wheel bearing device in which a recessed portion is formed with a recessed portion, and the axial force of the screw tightening structure is set to a magnitude that enables cutting by press-fitting the protruded portion, the shaft hole The inner peripheral surface of the shaft hole and the outer peripheral surface of the receiving member are tapered so that they come into surface contact with each other under the axial force of the screw tightening structure. characterized by being

In this way, by arranging the receiving member in the shaft hole of the hub wheel to fit the inner peripheral surface of the shaft hole, in the region where the receiving member is arranged, the inner peripheral surface of the shaft hole of the hub wheel and the stem portion are separated. An annular gap is not formed with the outer peripheral surface. Therefore, the rigidity of the hub wheel 1 can be increased, and the rigidity of the wheel bearing device can be improved.

Further, with the above configuration, the axial force of the screw tightening structure can be received by the taper fitting of the receiving member and the hub wheel. When the receiving member is formed in a cylindrical shape that is straight in the axial direction, the receiving member is formed in a cylindrical shape with a flange that protrudes radially outward in order to receive the axial force of the screw tightening structure. It is necessary to axially engage the flange portion with the end face of the hub wheel on the outboard side while inserting the portion into the shaft hole of the hub wheel 1 . However, the cylindrical receiving member with a collar requires a large amount of machining allowance when it is manufactured by machining such as turning, so there is a problem that the processing cost of the receiving member rises. By taper-fitting the receiving member and the hub wheel as described above, the machining allowance for machining the receiving member can be reduced, and the manufacturing cost of the receiving member can be reduced.

It is preferable that the cutting by press-fitting the projection is performed on a small recess formed on the other side and having an interference with respect to the projection. As a result, the cutting allowance when cutting the small concave portion with the press-fitted convex portion is small, so that the press-fitting load when the convex portion is press-fitted can be reduced. Therefore, it is possible to construct a concavo-convex fitting structure by drawing the stem portion into the inner periphery of the hub wheel with the axial force of a general screw tightening structure using bolts and nuts.

It is preferable that the receiving member is arranged at the outboard side end of the shaft hole of the hub wheel. This arrangement makes it possible to stably increase the rigidity of the hub wheel.

The inner peripheral surface of the shaft hole of the hub wheel is on the outboard side of the recess, and is larger than the maximum diameter of the protrusion or the maximum diameter of the recess formed in the inner peripheral surface of the shaft hole of the hub wheel. It is preferably formed to diameter. This makes it possible to improve workability when forming splines (press splines) on the inner circumference of the hub wheel by broaching.

ADVANTAGE OF THE INVENTION According to this invention, the wheel bearing apparatus which improved the rigidity of a hub wheel can be provided.

FIG. 2 is a cross-sectional view of the wheel bearing device according to the present embodiment, showing a state after the constant velocity universal joint is attached to the wheel bearing; (A) is an enlarged cross-sectional view of essential parts showing a state before the stem portion of the outer joint member is press-fitted into the hub ring of the wheel bearing, and (B) is a cross-sectional view taken along line AA of (A). (A) is an enlarged cross-sectional view of a main portion showing a state in which the stem portion of the outer joint member is being press-fitted into the hub ring of the wheel bearing, and (B) is a cross-sectional view taken along line BB of (A). 2 is a cross-sectional view showing an enlarged region A in FIG. 1; FIG. FIG. 4 is a cross-sectional view showing the wheel bearing device during broaching; FIG. 5 is a cross-sectional view of a wheel bearing device according to another embodiment; and FIG. 10 is a cross-sectional view showing a conventional wheel bearing device to which a drive shaft is assembled. FIG. 10 is a cross-sectional view showing a state before a constant velocity universal joint is attached to a conventional wheel bearing; FIG. 10 is a cross-sectional view showing another example of a conventional wheel bearing device to which a drive shaft is assembled;

An embodiment of a wheel bearing device according to the present invention will be described in detail below. The wheel bearing device shown in FIG. 1 is mainly composed of a wheel bearing 20 and a constant velocity universal joint 6 . In the following description, when assembled to the vehicle body, the side closer to the outside of the vehicle body is called the outboard side (left side in the drawing), and the side closer to the center is called the inboard side (right side in the drawing).

A wheel bearing 20 has a hub wheel 1 and an inner ring 2 which are inner members, double-row rolling elements 3 and 4 , and an outer ring 5 .

The hub wheel 1 has an outboard side inner raceway surface 7 formed on its outer peripheral surface, and a wheel mounting flange 9 for mounting a wheel. Hub bolts 10 for fixing the wheel disc are implanted at equal intervals in the circumferential direction of the wheel mounting flange 9 . An inner ring 2 having an inboard-side inner raceway surface 8 on its outer peripheral surface is fixed to a small-diameter stepped portion 12 formed on the inboard-side outer peripheral surface of the hub wheel 1 .

The inner ring 2 is press-fitted onto the outer peripheral surface of the small-diameter stepped portion 12 of the hub wheel 1 with an appropriate interference to prevent creep. An outboard-side inner raceway surface 7 formed on the outer peripheral surface of the hub wheel 1 and an inboard-side inner raceway surface 8 formed on the outer peripheral surface of the inner ring 2 constitute a double-row inner raceway surface. After the inner ring 2 is press-fitted into the small-diameter stepped portion 12 of the hub wheel 1, the cylindrical inboard-side end portion of the small-diameter stepped portion 12 is plastically deformed toward the outer diameter side by swiveling caulking, thereby forming the caulked portion. 11 prevents the inner ring 2 from coming off, integrates the inner ring 2 and the hub wheel 1, and applies preload to the wheel bearing 20. - 特許庁The crimped portion 11 is in contact with the shoulder portion 31 of the outer joint member 24 .

The outer ring 5 has double-row outer raceway surfaces 13, 14 formed on its inner peripheral surface facing the inner raceway surfaces 7, 8 of the hub wheel 1 and the inner ring 2, and is attached to a knuckle extending from a suspension system of a vehicle body (not shown). A vehicle body mounting flange 19 is provided for mounting. As already described, the vehicle body mounting flange 19 is fixed to the vehicle body side knuckle 152 using bolts 153 (see FIG. 7).

The wheel bearing 20 has a double-row angular contact ball bearing structure, and includes 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, and the rolling elements 3, 4 in each row are held by cages 15, 16 at regular intervals in the circumferential direction.

Seals 17 and 18 are arranged at both end openings of the wheel bearing 20 . The seals 17 and 18 seal the annular space between the outer ring 5 and the hub ring 1 and the inner ring 2 by bringing the seal members into sliding contact with the outer peripheral surfaces of the hub ring 1 and the inner ring 2 . These seals 17 and 18 prevent leakage of grease filled in the bearing and entry of water and foreign matter from the outside.

The constant velocity universal joint 6 is attached to the outboard side end of an intermediate shaft 122 that constitutes the drive shaft 121 shown in FIG. In FIG. 1, among the components of the constant velocity universal joint 6, only the outer joint member 24 having the track grooves 23 formed on the inner peripheral surface is disclosed. The inner joint member, cage, and balls of the constant velocity universal joint 6 have a configuration corresponding to that of the fixed constant velocity universal joint 106 shown in FIG.

The outer joint member 24 is composed of a mouth portion 29 containing internal parts consisting of an inner joint member 126, balls 127 and a cage 128 shown in FIG. 8, and a stem portion 30 integrally extending from the mouth portion 29 in the axial direction. ing.

In this wheel bearing device, a first spline 34 extending in the axial direction is formed on the outer peripheral surface of the stem portion 30 of the outer joint member 24 . The first spline is formed as a male spline, and as shown in FIG. 2(B), has projections 33 extending in the axial direction at a plurality of locations in the circumferential direction. On the other hand, as shown in FIG. Two splines 38 are formed as female splines. In this embodiment, the small concave portion 37 is formed so as to have an interference n only with respect to the circumferential side wall portion 33a of the convex portion 33 (see FIG. 3B).

The second spline 38 extending in the axial direction is formed by broaching the inner peripheral surface of the shaft hole 35 of the hub wheel 1 as will be described later. The hub wheel 1 of this embodiment does not have the inner wall 150 shown in FIG. It has a shape that penetrates cylindrically. The inner diameter of the cylindrical shaft hole 35 is larger than the inner diameter of the maximum diameter portion (bottom of the recess 40) of the recess 40 after the concave-convex fitting structure M is formed.

Thus, in the wheel bearing 20 of the present embodiment, the inner wall portion 150 (see FIG. 8) protruding to the inner diameter side is not provided at the outboard side end portion of the shaft hole 35 . Therefore, as shown in FIG. 5, during broaching, the broaching tool (broach) 71 does not interfere with the inner wall portion. Therefore, the second spline 38 extending in the axial direction can be formed efficiently and accurately by broaching. Broaching of the inner circumference of the hub wheel 1 may be performed after the wheel bearing 20 is assembled as shown in FIG.

In this wheel bearing device, the stem portion 30 of the outer joint member 24 is press-fitted into the shaft hole 35 of the hub wheel 1, and the shape of the convex portion 33 is transferred to the shaft hole 35 of the hub wheel 1, which is the recess forming surface of the mating side. By doing so, a concave portion 40 is formed (see FIG. 3B), and a concave-convex fitting structure M is formed in which the entire fitting contact portion X between the convex portion 33 and the concave portion 40 is in close contact (see FIG. 1). As the material of the outer joint member 24 and the hub wheel 1, medium carbon steel for machine structure such as S53C is suitable.

As shown in FIGS. 2A and 2B, a guide portion 43 for guiding the start of press-fitting of the first spline 34 is provided on the inboard side of the hub wheel 1 relative to the second spline 38 . The guide portion 43 is formed of a concave portion having a gap with respect to the surface of the convex portion 33 of the stem portion 30 . That is, a gap m is formed over the entire area between the convex portion 33 and the guide portion 43 (see FIG. 2(B)). The recesses forming the guide portion 43 are formed on the inboard side of the small recesses 37 of the second spline 38 so as to be continuous with the small recesses 37 . When the stem portion 30 of the outer joint member 24 is press-fitted into the hub wheel 1 , the guide portion 43 guides the convex portion 33 of the stem portion 30 to be securely press-fitted into the small recessed portion 37 of the hub wheel 1 . Therefore, stable press-fitting is possible, and misalignment and inclination of the core during press-fitting can be prevented.

This wheel bearing device has a screw tightening structure N, as shown in FIG. This screw tightening structure N has a female threaded portion 41 formed at the axial end of the stem portion 30 of the outer joint member 24 and a bolt 42 having a male threaded portion 43 screwed into the female threaded portion 41 . In this screw tightening structure N, the male threaded portion 43 of the bolt 42 is screwed into the female threaded portion 41 of the stem portion 30, and the axial force generated by tightening the bolt 42 is transferred from the bolt seat surface 42a to the hub via the receiving member 50 described later. By transmitting the force to the wheel 1 , the outer joint member 24 of the constant velocity universal joint 6 is pulled toward the outboard side and fixed to the wheel hub 1 . In the wheel bearing 20, the crimping portion 11 prevents the inner ring 2 from coming off and is integrated with the hub wheel 1. The crimping portion 11 positions the hub wheel 1 and the inner ring 2 in the axial direction. The wheel bearing 20 can be separated from the outer joint member 24 by applying an axial attractive force to the concave-convex fitting structure M.

In the case of this wheel bearing device, as shown in FIG. 3(B), a small concave portion 37 having an interference n is formed in advance only on the circumferential side wall portion 33a of the convex portion 33 (see FIG. 3(B)). Therefore, the press-fitting load when press-fitting the projection 33 into the shaft hole 35 of the hub wheel 1 can be reduced as compared with the case where the projection is press-fitted into the cylindrical inner peripheral surface of the hub wheel. As a result, when an automobile manufacturer assembles a vehicle, after the wheel bearing 20 is bolted to the knuckle extending from the suspension system of the vehicle body, the axial force (pull-in force) accompanying the tightening of the bolt 42 of the screw tightening structure N The stem portion 30 of the outer joint member 24 can be press-fitted into the shaft hole 35 of the hub wheel 1 , and the constant velocity universal joint 6 can be easily assembled to the wheel bearing 20 .

In this embodiment, as shown in FIGS. 3(A) and 3(B), the small recesses 37 are arranged so that the small recesses 37 have an interference n only with respect to the circumferential side wall portion 33a of the projection 33. The circumferential dimension is set smaller than that of the convex portion 33 . A portion of the protrusion 33 excluding the circumferential side wall portion 33a, that is, the radial tip portion 33b of the protrusion 33 has no interference with the small recess 37, and the radial dimension of the small recess 37 is It is set larger than the convex portion 33 . Therefore, the small concave portion 37 has a gap p with respect to the radial tip portion 33 b of the convex portion 33 . Since the radial tip 33 b of the projection 33 has no interference with the small recess 37 , the shape of the radial tip 33 b of the projection 33 is not transferred to the small recess 37 .

As the stem portion 30 of the outer joint member 24 is press-fitted into the shaft hole 35 of the hub wheel 1, the circumferential side wall portion 33a of the convex portion 33 pushes the circumferential side wall portion of the small concave portion 37 by an amount corresponding to the interference n. be cut. At the same time, the circumferential side wall portion 33 a of the convex portion 33 slightly deforms (elastically deforms) the circumferential side wall portion of the small concave portion 37 . As a result, the shape of the circumferential side wall portion 33a of the projection 33 is transferred to the surface of the hub wheel 1 on which the recess is formed. As the circumferential side wall portion 33a of the convex portion 33 bites into the concave portion forming surface, the inner diameter of the hub wheel 1 is slightly expanded, and relative movement of the convex portion 33 in the axial direction is permitted. When the axial relative movement of the convex portion 33 stops, the shaft hole 35 of the hub wheel 1 tries to return to its original diameter and is reduced in diameter. As a result, the convex portion 33 and the concave portion 40 are in close contact with each other over the entire fitting contact portion X, and the outer joint member 24 and the hub wheel 1 can be firmly joined together. It is preferable that the surface hardness of the protrusions 33 is higher than that of the small recesses 37 so that the press-fitted protrusions can smoothly cut the small recesses 37 .

Since the small recess 37 is formed so as to have an interference n only with respect to the circumferential side wall portion 33a of the protrusion 33, the cutting allowance when cutting the small recess 37 with the press-fitted protrusion 33 is small. Therefore, it is possible to press-fit the outer joint member 24 into the hub wheel 1 by the axial force generated by tightening the bolt 42 . That is, after the wheel bearing 20 is attached to the knuckle (152: see FIG. 7) of the vehicle body, the outer joint member 24 is drawn toward the hub wheel 1 by tightening the bolt 42, and the outer joint member 24 is attached to the inner circumference of the hub wheel 1. can be press-fitted. Therefore, it is possible to improve the workability when assembling the wheel bearing 20 to the vehicle body, and prevent damage to the parts during the assembling. In addition, since a large press-fitting load is not applied, it is possible to prevent the unevenness of the concave-convex fitting structure M from being damaged (plucked) due to the press-fitting, realizing a high-quality, long-life concave-convex fitting structure M. can.

As shown in FIG. 3B, a recessed receiving portion 44 is formed at the axial end of the stem portion 30 on the outboard side of the first spline 34 of the stem portion 30 . A protruding portion 45 produced by cutting with the press-fitted convex portion 33 is accommodated in the accommodating portion 44 . By holding the protruding portion 45 in the accommodating portion 44 in this way, the situation where the protruding portion 45 gets caught in the concave-convex fitting structure M can be prevented. By holding the protruding portion 45 in the housing portion 44, the removal process of the protruding portion 45 becomes unnecessary, and the number of man-hours for work can be reduced, and workability can be improved and costs can be reduced.

With such a concave-convex fitting structure, a gap that causes backlash is not formed in the radial direction and the circumferential direction of the fitting portion between the stem portion 30 and the hub wheel 1, so that the entire fitting contact portion X contributes to rotational torque transmission. Stable torque transmission is possible, and harsh rattling noise can be prevented for a long period of time. Since the fitting contact portions are in close contact with each other over the entire area X, the strength of the torque transmission portion is improved, so that the weight and size of the vehicle bearing device can be reduced through the compactness of the torque transmission portion.

In the above embodiment, the case where the interference n is provided only for the circumferential side wall portion 33a (see FIG. 3B) of the projection 33 has been described, but the present invention is limited to this. Instead, the interference n is set not only in the circumferential side wall portion 33a of the projection 33 but also in the region including the radial tip portion 33b, that is, the region from the mountain-shaped midsection to the mountain-shaped top of the projection 33. may In this case, the circumferential dimension and radial dimension of the small recess 37 are smaller than those of the projection 33 .

Characteristic configurations of the present invention will be described below.
As shown in FIG. 1, in the wheel bearing device of the present invention, a receiving member 50 is arranged in the shaft hole 35 of the hub wheel 1 to fit the inner peripheral surface of the outboard side end portion of the shaft hole 35 . there is The end surface of the receiving member 50 on the outboard side engages with the bolt seat surface 42a of the bolt 42 in the axial direction. Further, the receiving member 50 has a center hole 52 in the axial center, and the cylindrical portion of the bolt 42 without the male thread portion 43 passes through the center hole 52 in a clearance fit state. In the present embodiment, as shown in FIG. 4, the outer peripheral surface 51 of the receiving member 50 is formed in a tapered surface (conical surface) having a smaller diameter toward the inboard side. The taper angle α of the outer peripheral surface 51 with respect to the axis is preferably about 5° to 15°.

An inner peripheral surface 36 of the outboard side end portion of the shaft hole 35 of the hub wheel 1 is formed into a tapered surface (conical surface) that fits the outer peripheral surface 51 of the receiving member 50 . Therefore, by pressing the receiving member 50 toward the inboard side with the axial force of the screw tightening structure N, the outer peripheral surface 51 of the receiving member 50 and the inner peripheral surface 51 of the shaft hole 35 of the hub wheel 1 on the outboard side are aligned. make face contact.

By arranging the receiving member 50 in such a manner as to fit with the inner peripheral surface 36 of the outboard side end portion of the shaft hole 35 of the hub wheel 1 , the outboard end portion of the shaft hole 35 of the hub wheel 1 can be moved. Therefore, it is possible to prevent an annular gap from being formed between the inner peripheral surface of the shaft hole 35 of the hub wheel 1 and the outer peripheral surface of the stem portion 30 . Therefore, the rigidity of the hub wheel 1 can be increased, and the bearing rigidity of the wheel bearing device can be improved.

Further, in this embodiment, the axial force of the screw tightening structure N is received by the taper fitting of the receiving member 50 and the hub wheel 1 . When the receiving member is formed in a straight cylindrical shape in the axial direction, in order to receive the axial force of the screw tightening structure N, the receiving member 50 is formed in a cylindrical shape with a flange having a flange protruding in the outer diameter direction. It is necessary to axially engage the end face of the hub wheel 1 on the outboard side of the hub wheel 1. However, in the case of a cylindrical receiving member with a collar, machining such as turning requires a large amount of machining allowance. , the processing cost of the receiving member 50 rises. As in the present embodiment, if the receiving member 50 and the hub wheel 1 are taper-fitted to receive the axial force of the screw tightening structure N, the machining allowance when manufacturing the receiving member 50 by machining is reduced. It is possible to reduce the manufacturing cost of the receiving member 50 .

The present invention is by no means limited to the above-described embodiments, and can be embodied in various forms without departing from the gist of the present invention.

For example, in the present embodiment, the stem portion 30 of the outer joint member 24 is formed with the first spline 34 having the convex portion 33, and the inner peripheral surface of the hub wheel 1 is formed with the second spline 38 having the small concave portion 37. Contrary to this, a first spline having a convex portion is formed on the inner peripheral surface of the shaft hole 35 of the hub wheel 1, and the outer peripheral surface of the stem portion 30 has an interference with respect to the convex portion. A second spline may be formed with a small recess. In this case, in the area on the outboard side of the first spline of the shaft hole 35 of the hub wheel 1, the inner diameter dimension of the shaft hole 35 of the hub wheel 1 is equal to the maximum diameter of the first spline 38 (the bottom of the root of the spline). inner diameter).

Any structure can be adopted as the screw tightening structure N as long as it can apply an axial force to the hub wheel 1 in the direction toward the shoulder portion 31 of the outer joint member 24 . For example, as shown in FIG. 6, a small diameter portion 46 having a smaller outer diameter is provided on the outboard side of the portion of the stem portion 30 that constitutes the concave-convex fitting structure M. 47 may be provided, and a nut member 48 may be screwed onto the male threaded portion 47 so that the bearing surface 48a of the nut member 48 is engaged with the receiving member 50 in the axial direction. Even with such a configuration, the same effects as those of the embodiment shown in FIGS. 1 and 4 can be obtained.

1 Inner member (hub wheel)
2 Inner member (inner ring)
3, 4 rolling elements 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 33 convex portion 34 first spline 37 small concave portion 38 second spline 40 concave portion 41 female screw portion 42 bolt 43 Male threaded portion 47 Male threaded portion 48 Nut member n Interference M Uneven fitting structure N Screw tightening structure X Fitting contact portion

Claims (4)

an outer member having a double-row outer raceway surface formed on its inner circumference; an inner member having a double-row inner raceway surface facing the outer raceway surface on its outer circumference, and having a hub ring and an inner ring; A wheel bearing comprising double-row rolling elements interposed between an outer raceway surface of a lateral member and an inner raceway surface of an inner member, wherein a shaft hole is formed in the inner circumference of the hub wheel, and the The stem portion of the outer joint member of the constant velocity universal joint is fitted into the shaft hole, and the stem portion of the outer joint member is separably coupled to the hub wheel by a screw tightening structure,
One of the hub ring and the stem portion of the outer joint member is formed with a projection extending in the axial direction, and the other is formed with a recess formed by cutting by press-fitting the projection, and the screw is tightened. In a wheel bearing device in which the axial force of the structure is set to a magnitude that enables cutting by press-fitting the convex portion,
A receiving member is arranged in the shaft hole of the hub wheel to fit the inner peripheral surface of the shaft hole, and the inner peripheral surface of the shaft hole and the outer peripheral surface of the receiving member support the axial force of the screw tightening structure. A wheel bearing device, characterized in that the wheel bearing device is formed in a shape of tapered surfaces that receive and come into surface contact with each other. 2. The wheel bearing device according to claim 1, wherein cutting by press-fitting of said protrusion is performed on a small recess formed on said other side and having an interference with respect to said protrusion. 3. The wheel bearing device according to claim 1 or 2, wherein the receiving member is arranged at an outboard side end portion of the shaft hole of the hub wheel. The inner peripheral surface of the shaft hole of the hub wheel is formed on the outboard side of the recess and has a diameter larger than the maximum diameter of the projection formed in the shaft hole of the hub wheel or the maximum diameter of the recess. The wheel bearing device according to any one of claims 1 to 3.

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