WO2008007462A1

WO2008007462A1 - Bearing device for wheel

Info

Publication number: WO2008007462A1
Application number: PCT/JP2007/000744
Authority: WO
Inventors: Kiyotake Shibata
Original assignee: Ntn Corporation
Priority date: 2006-07-11
Filing date: 2007-07-10
Publication date: 2008-01-17
Also published as: JP2008018759A

Abstract

A bearing device for a wheel, in which hoop stress acting in outer diameter sections of inner rings is reduced to achieve sufficient bearing strength without radially or laterally increasing the wall thickness of the inner ring. The bearing device has double-row rolling bodies (5) placed between raceway surfaces (3, 4) of an outer member (1) and an inner member (2). The inner member (2) has a hub ring (9) with a solid shaft section (9b) and a flange (9a), and also has two inner rings (10A, 10B) press fitted on the outer periphery of the shaft section (9b) of the hub ring (9) and having outboard side and inboard side raceway surfaces (4), respectively. A hole (9d) in an inboard side end face of the shaft section (9b) of the hub ring (9), and an end face of the inner ring (10B) on the inboard side is axially fastened by a staking section (9e) formed by staking a circular tubular section on the outer periphery of the hole (9d) to the outer diameter side of the circular tubular section. The position of the bottom surface of the hole (9d) of the hub ring (9) is closer to the inboard side than a position (P1) at which a line (L1) intersects with the surface of fitting between the outer peripheral surface of the hub ring (9) and the inner ring (10B), where the line (L1) is a line extended from the axial center of the raceway surface (4), which belongs to the inner ring (10B) on the inboard side, in the direction normal to the inboard side to the raceway surface (4) of the inner ring (10B). Also, the position of the bottom surface of the hole (9d) is closer to the outboard side than the end face on the inboard side of the inner ring (10B).

Description

Specification

Wheel bearing device

Technical field

TECHNICAL FIELD [0001] The present invention relates to a wheel bearing device in an automobile or the like, and more particularly to a wheel bearing device in which one or two inner rings are press-fitted into a hub wheel.

Background art

In a wheel bearing device in which an inner ring is press-fitted into a hub ring, hoop stress, that is, stress that is pulled in the circumferential direction is applied to the raceway surface and outer diameter surface of the inner ring. In particular, in a type in which a caulking portion is provided at the end of the hub ring on the impand and the inner ring is tightened in the axial direction with respect to the hub ring (for example, Patent Document 1), the outer diameter surface of the hub ring is increased due to caulking. Because of the diameter, the hoop stress that acts on the outer diameter of the inner ring further increases. If the hoop force acting on the outer diameter of the inner ring becomes extremely high, the durability of the inner ring will decrease.

Therefore, in the above caulking type wheel bearing device, the hoop stress is reduced by increasing the thickness in the radial direction and width direction of the inner ring.

Patent Document 1: Japanese Patent Application Laid-Open No. 1 1-1 2 9 700

[0003] However, in the caulking type wheel bearing device, when the inner ring is thickened in the radial direction or axial direction, the shaft diameter of the hub ring is increased in order to secure the hub ring strength. Design is required. Therefore, it becomes an impediment to reducing costs by reducing materials.

Disclosure of the invention

An object of the present invention is to provide a wheel bearing device that can reduce hoop stress acting on the outer diameter portion of the inner ring without increasing the thickness in the radial direction and width direction of the inner ring, and can secure sufficient bearing strength. Is to provide.

The wheel bearing device according to the present invention has an outer member that has a double-row raceway surface on the inner periphery and is attached to the vehicle body, and a double-row raceway surface that faces the raceway surface on the outer periphery. An inner member having a wheel mounting flange on the outer periphery of the pod side end, and a double row rolling element interposed between the outer member and the raceway surface of the inner member, the inner member Force A hub ring having a solid shaft portion and the flange, and one inner ring having an impingement-side raceway surface that is press-fitted into the outer periphery of the shaft portion of the hub ring, or a track on the impode side and the autopod side A caulking portion that is formed by two inner rings each having a surface, and a hole is provided in the end surface of the shaft side of the hub ring, and the cylindrical portion of the outer periphery of the hole is caulked to the outer diameter side. In the wheel bearing device in which the width surface of the inner ring on the impeller side is tightened in the axial direction, the bottom surface position of the hole portion of the hub wheel is from the axial center of the raceway surface of the inner ring on the inboard side. The straight line extending in a direction perpendicular to the raceway surface of the inner ring is on the impingement side from the position where the outer peripheral surface of the hub ring and the mating surface of the inner ring intersect, and on the board side than the end surface of the inner ring on the inner ring It is located in.

[0006] In such a caulking type wheel bearing device, the hoop stress is highest due to the press-fitting of the inner ring on the impingement side and the caulking of the hub ring on the inboard side on the outer diameter surface of the inner ring. Near the end face. According to the present invention, the bottom surface position of the hole on the end surface of the hub ring is located on the outer pod side of the end surface on the impode side of the inner ring. That is, the hole is positioned directly below the end face of the inner ring. As described above, the hole is provided immediately below the inner ring end surface corresponding to the position where the hoop stress is highest, so that the expansion amount of the end portion of the inner ring outer diameter surface caused by press-fitting and caulking can be suppressed. And hoop stress can be reduced. In addition, the action line, which is a straight line extending in a direction perpendicular to the raceway surface of the inner ring from the center in the axial direction of the raceway surface, which is the action point of the inner ring on the inboard side, is The position of the bottom surface of the hole is closer to the impingement side than the position where it intersects the fitting surface. That is, the hole is not formed immediately below the intersection of the inner ring action line and the outer peripheral surface of the hub ring. Therefore, even if the hole is provided, the bearing has sufficient strength.

Therefore, the hoop stress acting on the outer diameter portion of the inner ring can be reduced without increasing the thickness in the radial direction and width direction of the inner ring, and sufficient bearing strength can be ensured.

[0007] In the present invention, the wheel bearing device is a tapered roller bearing type, and the double-row raceway surface of the inner member is a tapered surface whose end portions on the side away from each other are on the large diameter side. There may be.

[0008] Further, in the tapered roller bearing type wheel bearing device, the bottom surface position of the hole portion of the hub wheel is from the large-diameter side end portion of the raceway surface of the inner ring on the inboard side. The straight line extending in a direction perpendicular to the surface may be located on the impeller side from the position where the outer peripheral surface of the hub ring meets the fitting surface of the inner ring.

In the case of a tapered roller bearing type wheel bearing device, as in this configuration, the bottom surface position of the hole of the hub ring is from the large-diameter end of the raceway surface of the inner ring on the inboard side. The straight line extending in the direction perpendicular to the raceway surface of the inner ring is on the impingement side of the position where the outer ring surface of the ring wheel meets the inner ring fitting surface. Even if it is located closer to the auto pod side, the hoop stress acting on the outer diameter part of the inner ring can be reduced without increasing the thickness in the radial direction and width direction of the inner ring, and sufficient bearing strength can be secured. it can. In addition, in this configuration, a straight line extending from the axial center of the inner ring raceway surface to the right angle to the inner raceway surface / Since it is biased further toward the impingement side than the position where the outer ring surface of the ring wheel and the fitting surface of the inner ring intersect, sufficient bearing strength can be secured.

[0010] In the present invention, the bottom surface position of the hole portion of the hub wheel may be 3 mm or more on the outer pod side than the end surface of the inner ring on the inboard side.

As described above, the hoop stress acting on the outer diameter portion of the inner ring is highest at the end portion of the inner ring on the impode side. If the position on the auto pod side of 3 mm or more is the bottom surface position of the hole of the hub ring, the effect of reducing the hoop stress acting on the outer diameter part of the inner ring can be further enhanced.

Brief Description of Drawings

[001 1] The present invention will be understood more clearly from the following description of preferred embodiments with reference to the accompanying drawings, in which: However, the examples and drawings are for illustration and explanation only and should be used to define the scope of the present invention. Not kimono. The scope of the invention is defined by the appended claims. In the accompanying drawings, the same part number in multiple drawings indicates the same part.

FIG. 1 is a cross-sectional view of a wheel bearing device according to a first embodiment of the present invention.

2 is an enlarged cross-sectional view of part A in FIG.

FIG. 3 is a cross-sectional view showing another configuration example of part A.

FIG. 4 is a cross-sectional view showing still another configuration example of part A.

FIG. 5 is a cross-sectional view showing still another configuration example of part A.

BEST MODE FOR CARRYING OUT THE INVENTION

[0012] A first embodiment of the present invention will be described with reference to Figs. This embodiment is an inner ring rotating type and is applied to a wheel bearing device for supporting a driven wheel. In this specification, the side closer to the outer side in the vehicle width direction of the vehicle when attached to the vehicle is referred to as the autopod side, and the side closer to the center of the vehicle is referred to as the import side.

The wheel bearing device includes an outer member 1 having a double-row raceway surface 3 on the inner periphery, an inner member 2 having a double-row raceway surface 4 facing the raceway surfaces 3 on the outer periphery, and A double row rolling element 5 interposed between the raceway surfaces 3 and 4 of the outer member 1 and the inner member 2 is provided, and the wheel is rotatably supported with respect to the vehicle body. This wheel bearing device is a tapered roller bearing type in which the rolling elements 5 are tapered rollers, and the double-row raceway surface 4 of the inner member 2 is a tapered surface whose end portions on the side away from each other are on the large diameter side. ing. The rolling elements 5 are held by the cage 6 for each row. The bearing spaces between the outer member 1 and the inner member 2 are sealed by seals 7 and 8, respectively.

[0013] The outer member 1 is an integral part as a whole as a fixed side member, and is attached to a suspension device (not shown) of a vehicle body via another member that is externally fitted to the outer member 1. It is

The inner member 2 is a member on the rotation side, and has a hub ring 9 having a wheel mounting flange 9 a on the outer periphery of the end of the board, and an outer periphery of the solid shaft portion 9 b of the hub ring 9. Are arranged in two axial rows in the axial direction. The inner ring 1 OA and 1 0 B are included. On the outer periphery of these two rows of inner rings 10 A and 10 B, the raceway surfaces 4 of each row are formed. The inner rings 1 OA and 1 OB, the outer member 1, and the rolling elements 5 constitute a bearing independent of the hub ring 9.

[0014] A pilot portion 9c for guiding a wheel and a brake rotor (both not shown) protrudes from the side surface of the hub ring 9 at the base end of the flange 9a. A hole 9 d is provided on the end surface of the shaft 9 b of the hub wheel 9, and a caulking portion 9 e is formed by caulking the cylindrical portion of the outer periphery of the hole 9 d to the outer diameter side. The width surface of the inner ring 10 0 B on the imported side is tightened in the axial direction. A step surface 9 f facing in the axial direction is provided in the vicinity of the flange 9 a of the hub wheel 9, and the step surface 9 f and the caulking portion 9 e are fitted to the shaft portion 9 b of the hub wheel 9. The two rows of inner rings 1 OA and 10 B are fastened and fixed in the axial direction.

FIG. 2 is an enlarged view of part A in FIG. As shown in the figure, the bottom surface position of the hole 9 d of the hub wheel 9 is from the axial center of the raceway surface 4 of the inner ring 10 B on the impingement side to the raceway surface 4 of the inner ring 10 B. The line of action L1, which is a straight line extending at a right angle, is at the impeller side from the position P1 where the outer circumferential surface of the hub wheel 9 and the fitting surface of the inner ring 10 B meet. It is located within the range W 1 on the autopod side of the end face on the side.

[0016] In such a caulking type wheel bearing device, the hoop stress is the highest when the inner ring 10 B on the impingement side is press-fitted and the caulking portion 9 e of the hub ring 9 is caulked. This is the vicinity of the end surface on the impose side of the outer diameter surface of the inner ring 10 B. In this embodiment, the bottom surface position of the hole 9d on the end surface of the hub wheel 9 is positioned closer to the outer pod side than the end surface on the inward side of the inner ring 1OB. That is, the hole 9 d is located immediately below the end face of the inner ring 10 B. As described above, the hole 9d is provided immediately below the inner ring end surface corresponding to the position where the hoop stress is highest, so that the outer ring surface end portion of the inner ring 1OB generated by press-fitting and caulking is provided. The amount of expansion can be suppressed, and the hoop stress can be reduced. In addition, the bottom surface position of the hole 9d of the hub wheel 9 is a gauge that is the point of application of the inner ring 10 B on the impede side. A line of action that is a straight line L 1 extending perpendicularly to the raceway surface 4 of the inner ring 10 B from the axial center of the road surface 4 intersects the outer peripheral surface of the hub ring 9 and the fitting surface of the inner ring 10 B. Positioned at the impeller side from position P1. That is, the hole 9 d is not opened immediately below the intersection P 1 between the straight line L 1 serving as the working line of the inner ring 10 B and the outer peripheral surface of the hub ring. Therefore, even if the hole 9d is provided, the bearing has sufficient strength.

Therefore, the hoop stress acting on the outer diameter portion of the inner ring 10 B can be reduced without increasing the thickness in the radial direction and the width direction of the inner ring 10 B, and sufficient bearing strength can be ensured.

[0017] In Fig. 2, the limit position on the impinge side of the bottom surface of the hole 9d of the hub wheel 9 is simply set to the autopod side from the end surface of the inner ring 10 B, but the inner ring 10 B The hoop stress acting on the outer diameter is highest at the end of the inner ring 10 B on the impede side. For this reason, as shown in Fig. 3, the position on the auto pod side of the inner ring 10 B, which is 3 mm or more away from the end face on the import side, should be the impediment side limit position on the bottom surface of the hole 9 d of the hub ring 9. desirable. As a result, the effect of reducing the flop stress acting on the outer diameter portion of the inner ring 10B can be further enhanced.

[0018] Also, in Fig. 2, the outboard side limit position of the bottom surface of the hole 9d of the hub wheel 9 is determined from the center in the axial direction of the raceway surface 4, which is the point of action of the inner ring 10B on the import side. The straight line L 1 extending at a right angle to the raceway surface 4 of the inner ring 10 B of the inner ring 10 B is on the import side from the position P 1 where the outer peripheral surface of the hub ring 9 and the fitting surface of the inner ring 10 B meet. Further, as shown in FIG. 4, a straight line L 2 extending in a direction perpendicular to the raceway surface 4 of the inner ring 10 B from the large-diameter side end portion of the raceway surface 4 of the inner ring 10 B on the impulse side is a hub. The position on the impinge side with respect to the position where the outer peripheral surface of the wheel 9 and the inner ring 10 B intersect with each other may be set as the outboard side limit position on the bottom surface of the hole 9 d of the hub wheel 9. In this case, since the bottom surface position of the hole 9d of the hub wheel 9 is more biased toward the import side than in the case of FIG. 2, sufficient bearing strength can be secured.

In the example of FIG. 5, in the configuration example of FIG. 4, the position on the outer side of the inner ring 10 B is 3 mm or more from the end surface on the impode side, and the bottom surface of the hole 9 d of the hub ring 9 No The board side limit position. As a result, sufficient bearing strength can be ensured, and the effect of reducing the hoop stress acting on the outer diameter portion of the inner ring 10 B can be further enhanced.

In the above-described embodiment, the second-generation type wheel bearing device in which two inner rings 1 OA and 1 OB are aligned and fitted to the hub ring 9 has been described. However, in the present invention, the inner member is a hub. It can also be applied to third-generation type wheel bearing devices consisting of a ring and an inner ring in the side row of the impeller. In the case of the example shown in FIGS. 1 to 3, the present invention can be applied not only to the tapered roller bearing type but also to an anguilla ball bearing type wheel bearing device. In that case, in the configuration of FIG. 2, “the center in the axial direction of the raceway 4 of the inner ring 10 B” is the contact point with the rolling element 5 (pole), and “the raceway 4 of the inner ring 10 B” The straight line L 1 extending at right angles to the normal line of the inner ring raceway surface.

Claims

The scope of the claims

[1] An outer member having a double-row raceway surface on the inner periphery and attached to the vehicle body; a double-row raceway surface facing the raceway surface on the outer periphery; and a wheel mounting flange on the outer periphery of the end of the autopod. And a hub ring having a solid shaft portion and the flange, the inner member having a plurality of rolling elements interposed between the outer member and the raceway surface of the inner member. And one inner ring having an impeded raceway surface that is press-fitted into the outer periphery of the shaft portion of the hub ring, or two inner rings each having an impede side and an outer side raceway surface. A wheel in which a hole is provided in the end surface on the impand side of the shaft portion of the wheel, and a cylindrical portion on the outer periphery of the hole is swaged to the outer diameter side, and the width surface of the inner ring on the impode side is tightened in the axial direction. Bearing device for

The bottom surface position of the hole of the hub ring is a straight line extending from the center in the axial direction of the raceway surface of the inner ring on the impinge side in a direction perpendicular to the raceway surface of the inner ring. The bearing device for the wheel is located on the impeding side from the position where it meets the fitting surface of the inner ring and the inner ring, and located closer to the outer pod side than the end surface of the inner ring of the parenthesis.

[2] The wheel bearing device according to claim 1, wherein it is a tapered roller bearing type, and the double-row rail surfaces of the inner member are conical surfaces whose end portions on the side away from each other are on the large diameter side.

[3] In Claim 2, the bottom surface position of the hole portion of the hub wheel extends from the end portion on the large diameter side of the raceway surface of the inner ring on the inboard side in a direction perpendicular to the raceway surface of the inner ring. A wheel bearing device in which the straight line is on the import side of the position where the straight line intersects the fitting surface between the outer peripheral surface of the hub wheel and the inner ring.

[4] The wheel bearing device according to claim 1, wherein the bottom surface position of the hole portion of the hub wheel is located at least 3 mm from the end surface of the inner ring on the impodd side on the outer pad side.