JP2006224901A - Hub unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hub unit with suppressed axis eccentricity of a forged surface of a faucet joint inner diameter part 4 and reduced dynamic imbalance. <P>SOLUTION: The hub unit 1 comprises a shaft body 11, a flange 12 provided on a vehicle outer side of the shaft body 11, an inner ring 21 to be a rotating ring provided on the peripheral surface of the shaft body 11, an outer ring 22 to be a fixed ring arranged on the periphery of the inner ring, and double row rolling elements 23 interposed to freely roll between the inner ring 21 and the outer ring 22. The hub unit 1 is characterized by the forged surface of the faucet joint inner diameter part 4 of the shaft body 11 machined taking as a reference the peripheral surface of the shaft body 11 on the vehicle inner side more than the flange 12. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a hub unit to which wheels are mounted.

  2. Description of the Related Art A hub unit as an axle bearing of an automobile generally has a structure in which a rolling bearing is mounted in a retaining state on an outer periphery of a shaft body and a shaft having a radially outward flange at one end portion of the shaft body. The rolling bearing holds an inner ring mounted on the outer periphery of the shaft body, an outer ring fixed to the vehicle body via a steering knuckle, a double row rolling element disposed between the inner ring and the outer ring, and the rolling element. It consists of a cage. The shaft is formed by forging for cost reduction, and the inner surface of the annular portion formed in the direction opposite to the shaft main body from the root portion of the flange, that is, the inner diameter portion of the spigot of the shaft is also a forged surface.

  On the other hand, the flange side surface and the shaft outer peripheral surface are turned to prevent the deflection of the flange, but the inner diameter surface (inner inner diameter surface) and side surface of the annular part are turned during the turning process. Things have been done. That is, it has been proposed to turn the inner diameter surface and the side surface of the annular portion, clamp the inner diameter surface based on the side surface of the annular portion, and finish the side surface of the flange and the outer peripheral surface of the shaft in a clamped state (Patent Document 1). reference).

JP 10-217011 A

However, the turning of the inner diameter surface of the inlay described in Patent Document 1 is performed by turning the inner diameter portion of the inlay in the turning process of the outer peripheral surface of the flange and the shaft body for the purpose of suppressing flange runout. It is not intended to reduce the amount of shaft eccentricity of the forged surface. Therefore, the turning of the inner surface of the inlay described in Patent Document 1 cannot reduce the amount of shaft eccentricity of the forged surface of the inner surface of the inner portion.
In view of such circumstances, an object of the present invention is to provide a hub unit that suppresses the amount of axial eccentricity of the forged surface of the inner diameter portion of the spigot and reduces the dynamic imbalance.

The hub unit of the present invention includes a shaft main body, a flange provided on the vehicle outer side of the shaft main body, an inner ring serving as a rotating wheel provided on the outer peripheral surface of the shaft main body, and a fixed disposed on the outer periphery of the inner ring. A hub unit comprising an outer ring serving as a ring, and a double row rolling element interposed between the inner ring and the outer ring so as to be freely rollable, wherein a forged surface of an inner diameter portion of the shaft body includes the flange Further, it is characterized in that it is turned with reference to the outer peripheral surface of the shaft main body on the vehicle inner side.
By turning the forged surface outermost part of the inner diameter part of the shaft or the entire surface by turning, the shaft eccentricity of the inner diameter part of the inner part is suppressed, the dynamic unbalance of the hub wheel is improved, and the entire hub unit is further improved. Dynamic imbalance is improved.

  According to the present invention, it is possible to obtain a hub unit that suppresses the shaft eccentricity of the forged surface of the inner diameter portion of the spigot and reduces the dynamic imbalance.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal side view showing the hub unit 1. The basic configuration of the hub unit 1 is as shown in FIG. The hub unit 1 has a double-row outward angular ball bearing 3 fitted on the outer peripheral surface of a shaft body 11 from the vehicle inner side. The double-row outward angular ball bearing 3 includes an inner ring 21 having a single race that is fitted around the small-diameter outer peripheral surface 11a of the shaft body 11 of the hub wheel 2, and two rows of race grooves fixed to the vehicle body via a steering knuckle. A large outer peripheral surface 11 b of the shaft body 11 of the hub wheel 2, a plurality of balls 23 arranged in two rows, and two crown-shaped cages 24, 25. Is configured as one inner ring. The hub wheel 2 to which the wheel is attached has a shape in which a radially outward flange 12 is provided near one end of the shaft body 11, and the flange 12 is in a state where the disc rotor 6 is applied to the outer end surface of the hub wheel 2. These are fixed by bolts 14 that are non-separated and press-fitted into through holes 13 provided at several circumferential positions.

  FIG. 2 is a diagram illustrating only the hub wheel 2 for explaining the turning. The shaft body 11 provided with the radially outward flange 12 has a small-diameter outer peripheral surface 11a and a large-diameter outer peripheral surface 11b, and an annular portion formed in the direction opposite to the shaft main body 11 from the root portion of the flange 12. The inner surface of 5, that is, the inner diameter portion 4 of the shaft is a forged surface.

Therefore, in this embodiment, in order to reduce the amount of shaft eccentricity with respect to the axis X, the inner spigot inner diameter portion 4 of the shaft is turned.
The portion to be turned is the forged surface outermost diameter portion 4a of the shaft inner diameter portion 4 or the entire surface of the shaft inner diameter portion 4 and the outer peripheral surface of the shaft main body 11 on the vehicle inner side from the flange 12, that is, the shaft main body. The amount of shaft eccentricity is reduced by turning on the basis of the 11 small-diameter outer peripheral surface 11a or the large-diameter outer peripheral surface 11b.

  The reason for using the outer peripheral surface of the shaft body on the inner side of the shaft body 11 as a reference during turning is as follows. During forging, the parting line Y is divided into a mold for molding the vehicle inner side part and a parting line Y for molding the vehicle outer side part, so it straddles the parting line In many cases, a deviation occurs. On the contrary, the deviation is less likely to occur in the same mold. Therefore, the small-diameter outer peripheral surface 11a or the large-diameter outer peripheral surface 11b, which is the same mold, is unlikely to be misaligned with the axis X. It may be good.

For turning the forged surface, it is desirable to keep the shaft eccentricity in a range of 0.5 to 1 mm or less.
The forging surface outermost diameter part 4a of the inner diameter part 4 of the shaft or the entire surface is cut by turning, so that the eccentric amount of the inner diameter part of the inner part is suppressed, the dynamic unbalance of the hub wheel is improved, and the hub unit A hub unit with reduced overall dynamic imbalance can be obtained.

  The invention is not limited to the above-described embodiment, and various applications and modifications are possible. Further, as shown in the above-described embodiment, the present invention is not limited to the axle including the hub unit on the driven wheel side, and may be applied to an axle bearing device including the hub unit on the drive wheel side. The present invention is not limited to a double-row outward angular ball bearing as a bearing, as shown in the above-described embodiment, and may be a rolling bearing formed with various oblique contact such as a tapered roller.

It is a vertical side view which shows the hub unit for driven wheels which shows embodiment of this invention. It is a vertical side view of a hub wheel showing an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hub unit 2 Hub wheel 3 Double row outward angular ball bearing 4 Inner inner diameter part 5 Annular part 6 Disc rotor 11 Shaft body 12 Flange 21 Inner ring 22 Outer ring 23 Rolling body X Axis line Y Parting line

Claims (1)

A shaft main body, a flange provided on the vehicle outer side of the shaft main body, an inner ring serving as a rotating wheel provided on an outer peripheral surface of the shaft main body, and an outer ring serving as a fixed ring disposed on the outer periphery of the inner ring, In a hub unit comprising a double row rolling element interposed between the inner ring and the outer ring so as to freely roll,
A hub unit, wherein a forging surface of an inner diameter inner portion of the shaft main body is turned with reference to an outer peripheral surface of the shaft main body on a vehicle inner side than the flange.

Images