JP2007309388A - Hub unit bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hub unit bearing which prevents the coming-off of an inner ring element from a hub shaft when adjusting and machining both side surfaces of a brake rotor. <P>SOLUTION: In the hub unit bearing, a small-diameter part is provided to a hub shaft through the medium of a step part. An annular recess is provided to the inner peripheral surface of an inner ring element press-fitted and fixed in the small-diameter part. An annular protrusion is provided to the small-diameter part. While the vehicle outer end side end surface of the inner ring element is abutted to the step part, the annular recess is fitted to the annular protrusion. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a hub unit bearing for a wheel, and more particularly to an improvement of a hub unit bearing that supports a wheel and a rotor.

Conventionally, the hub unit bearing Hz as shown in FIG. 6 has double-row inner circumferential tracks 11z and 12z, an outer ring 1z having a flange 1fz attached to the vehicle body on the outer circumferential surface, and a vehicle outer end side (left side in the figure). An inner ring 2z having a flange (2fz) for attaching a wheel (not shown) and a brake rotor 8z, and having double-row outer peripheral tracks 2a ₁ z, 2b ₁ z toward the axial vehicle center side (right side in the figure); A ball 3z interposed between the outer ring 1z and the inner ring 2z, a cage 4z holding the ball 3z, and sealing seals 5az and 5bz attached to both ends of the outer ring 1z.

The inner ring 2z has the flange 2fz described above, and has a small diameter via an integral outer peripheral track 2a ₁ z provided from the flange 2fz side toward the vehicle center side and a step portion 2cz formed at the center portion 2mz. A hub shaft 2ahz having a portion 2nz and an inner ring element 2bz press-fitted into the small diameter portion 2nz.

An end surface 2b ₂ z facing the vehicle outer end side of the inner ring element 2bz is abutted against the step portion 2cz.

The hub unit bearing Hz shown in FIG. 6 is used for driving wheels, and the brake rotor 8z attached to the flange 2fz of the hub shaft 2ahz has an axial runout to suppress a phenomenon called judder during use. It is necessary to keep R ₁ and R ₂ small. For this purpose, the outer ring 1z is fixed to the fixing member 9z in a state where the brake rotor 8z is temporarily fixed to the bearing with a hub nut equivalent or a small screw, and the inner ring 2z is fixed to a predetermined shaft with a drive shaft (not shown). Turning and grinding to bring the runouts R ₁ and R ₂ of the axially opposite side surfaces 81z and 82z of the brake rotor 8z, which are sliding surfaces with the brake pad (not shown), while driving at the rotational speed to the standard values. Adjustment processing such as processing is applied to both side surfaces 81z and 82z.

  The inner ring 2z may not be fixed in the axial direction by the drive shaft from the point of work efficiency in the adjustment process or because the spline is used to drive the hub axle. There are cases where a force greater than the fixing force acts on the fitting portion into which 2 nz and the inner ring element 2 bz are press-fitted, loosening occurs due to vibration during adjustment processing, and creep occurs.

  If the adjustment process is advanced in the above-described state, the inner ring element 2bz may be displaced from the fitting portion of the small diameter portion 2nz to the vehicle center side (referred to as a pull-out).

  When slipping out occurs, the contact between the rolling element and the track becomes abnormal, and there is a possibility that abnormal noise is generated and the life is shortened.

There is a proposal regarding prevention of loosening or slipping out of the inner ring 2z (see, for example, Patent Document 1).
JP 2003-65347 A

  Hereinafter, although it considers regarding patent document 1, the wording used in patent document 1 is used for the wording regarding the following description as it is.

  In Patent Document 1, an uneven surface is formed on one of the hub ring and the inner ring, and the other engaging surface is bitten into the uneven surface by expansion caulking to cause plastic deformation. This is a combination of the inner ring and the inner ring.

  However, the rotary caulking machine is necessary for the expansion caulking, and its introduction is expensive and causes an increase in the cost of the hub unit bearing.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a hub unit bearing that prevents the inner ring element from coming off from the hub shaft when both side surfaces of the brake rotor are adjusted.

In order to achieve the above object, the present invention provides:
An outer ring having two inner circumferential tracks in the axial direction;
An inner ring having an outer circumferential track opposed to the two inner circumferential tracks;
A rolling element interposed between the outer ring and the inner ring;
It consists of a sealing seal member provided at the vehicle outer end side end portion and the vehicle center side end portion of the outer ring,
The inner ring is provided at the outer end side end portion of the vehicle and is connected to and fixed to the brake rotor and the wheel. And a hub shaft formed integrally with the small-diameter portion provided through the step portion, and press-fitted into the small-diameter portion, and a vehicle outer end side end surface is abutted against the step portion and fixed in the axial direction. Consisting of an inner ring element having the other of the outer circumferential raceway,
In hub unit bearings,
Provided is a hub unit bearing characterized in that an annular concave portion is provided on an inner peripheral surface of the inner ring element, an annular convex portion is provided on the small diameter portion, and the annular concave portion and the annular convex portion are fitted. .

The present invention also provides:
An outer ring having two inner circumferential tracks in the axial direction;
An inner ring having an outer circumferential track opposed to the two inner circumferential tracks;
A rolling element interposed between the outer ring and the inner ring;
It consists of a sealing seal member provided at the vehicle outer end side end portion and the vehicle center side end portion of the outer ring,
The inner ring is provided at an end portion on the outer end side of the vehicle for attaching and fixing the brake rotor and the wheel, a cylindrical portion integrally formed and extending from the mounting flange toward the vehicle center side, and the cylindrical portion A hub shaft comprising a first inner ring element having one outer peripheral track fixed to the mounting flange side of the shaft, and a shaft that is press-fitted into the cylindrical portion and has an end face on the vehicle outer end abutting against the first inner ring element A second inner ring element having the other of the outer circumferential tracks fixed in the direction;
Hub unit bearing consisting of
Provided is a hub unit bearing characterized in that an annular concave portion is provided on an inner peripheral surface of the second inner ring element, an annular convex portion is provided on the cylindrical portion, and the annular concave portion and the annular convex portion are fitted. To do.

  According to the present invention, it is possible to provide a hub unit bearing that prevents the inner ring element from coming out of the hub shaft during adjustment processing of both side surfaces of the brake rotor.

  Embodiments according to the present invention will be described below with reference to the drawings.

(Embodiment 1)
Embodiment 1 of the present invention will be described with reference to FIGS. 1, 2, 3 (a), 3 (b), 4 (a), and 4 (b).

  FIG. 1 is a cross-sectional view showing the upper half of the XX center line.

  FIG. 1 shows a hub unit bearing for a wheel, particularly used for a drive wheel.

  In the following description, for the sake of simplicity of expression, the vehicle outer end side is referred to as the outer end side, and the vehicle center side is referred to as the center side.

In Figure 1, the hub unit bearing H ₁ includes an inner circumferential raceway 12 of the inner circumferential raceway 11 and the center side of the outer end to the inner periphery, an outer ring 1 has a mounting flange 1f of the vehicle body on the outer periphery , wheels (not shown) on the outer end side and the brake rotor 8 directly periphery raceway 2a ₁ to the flange 2f side outer peripheral surface of the flange 2f and the axial central portion 2m attaching the (broken line portion) is formed, the axial central portion is continuously to 2m, and the hub shaft 2ah which the small diameter portion 2n is formed on the center side, press-fitted into the hub shaft 2ah, an inner ring 2 consisting of an inner ring element 2b which outer circumferential raceway 2b ₁ is formed on the outer periphery And balls 3 and 3 interposed between the outer ring 1 and the inner ring 2, cages 4 and 4 holding the balls 3 and 3, and outer ends attached to both ends of the outer ring 1 It is composed of a side sealing seal member 5a and a center side sealing seal member 5b. There.

  Next, each component will be described in detail with reference to FIGS. 2, 3 (a), 3 (b), 4 (a), and 4 (b).

  2 shows an enlarged view of part A of FIG. 1 (outer rings, cages and sealing seal members are omitted), and FIGS. 4 (a) and 4 (b) show enlarged views of the inner peripheral surface of the inner ring element.

  Next, each component and part will be described.

  As described above, the outer ring 1 has the inner peripheral track 11 on the outer end side and the inner peripheral track 12 on the center side on the inner periphery, and the mounting flange 1f to the knuckle 9 (broken line portion) which is a part of the vehicle body on the outer periphery. have. A bolt hole 1g for mounting to the knuckle 9 is provided in the mounting flange 1f.

  Moreover, it has the inner peripheral surface 1d which attaches the center side sealing seal member 5b to the center side edge part 14 of the outer ring | wheel 1. FIG. Further, the outer end side end portion 13 of the outer ring 1 has an inner peripheral surface 1c for attaching the outer end side sealing seal member 5a.

As described above, the inner ring 2 includes a flange 2f for attaching a wheel (not shown) and a brake rotor 8 (broken line) on the outer end side, an outer peripheral track 2a ₁ successively from the flange 2f toward the center, a central portion 2m axially following the outer peripheral raceway 2a _1, a stepped portion 2c is provided continuously in the axial center portion 2m, the center side via a step portion 2c and the small diameter portion 2n is formed integrally hub shaft 2ah which are, and are press-fitted into the small diameter portion 2n of the hub shaft 2ah, consists an inner ring element 2b having an outer peripheral raceway 2b ₁ to the outer periphery.

The outer circumferential track 2a ₁ is one outer circumferential track, and the outer circumferential track 2b ₁ corresponds to the other outer circumferential track.

The outer circumferential track 2a ₁ faces the inner circumferential track 11 of the outer ring 1, and the outer circumferential track 2b ₁ faces the inner circumferential track 12.

  A bolt 7 for attaching a wheel (not shown) is attached to the flange 2f of the hub shaft 2ah.

  The small diameter portion 2n is a fitting portion that press-fits the inner ring element 2b and fixes it in the axial direction.

The small diameter portion 2n, annular convex portion 2p is provided from the stepped portion 2c in the axial direction by a predetermined distance L _1. The cross-sectional shape of the annular convex portion 2p has a substantially arc shape.

As described below, the shape it is necessary to strictly control the height of the annular convex portion 2p, annular convex portion 2p is desirably and simultaneous grinding of the outer circumferential raceway 2a ₁ of the hub shaft 2ah, suitable for co-grinding As an arc.

The outer end side end surface 2b ₂ of the inner ring element 2b is a contact surface with the stepped portion 2c.

The inner circumferential surface 2b ₃ of the inner ring element 2b has a circumferential groove which is an annular recess between the groove bottom 2b ₄ (the smallest diameter portion of the outer circumferential track 2b ₁ ) and the outer end side end surface 2b ₂ in the axial direction. 2b ₅ is formed. In particular, as will be described later, the small diameter portion so that circumferential stress generated when the annular convex portion 2p and the fitting of 2n does not affect the groove bottom portion 2b _4, the groove bottom 2b ₄ from a remote outer end side end face 2b ₂ It is desirable that the width of the annular projection 2p is set to be approximately the same as that of the annular projection 2p.

The distance dimension _{L 2} from the outer end side end face 2b ₂ to circumferential grooves 2b ₅ is set equal to the axial dimension _{L 1} of the stepped portion 2c of the hub shaft 2ah to an annular protrusion 2p of the small diameter portion 2n.

From the peripheral groove 2b ₅ toward the inner peripheral surface 2b ₃ from the predetermined position of the side _{2b 51} and the side _{2b 51} having a start-up angle [delta] ₁ from the inner circumferential surface 2b ₃ near the outer end side end face 2b ₂ sides _{2b 52} Metropolitan Is formed.

The rising angle δ ₁ of the side 2b ₅₁ should be made as large as possible in order to increase the anti-disengagement force after the circumferential groove 2b ₅ is fitted to the annular convex portion 2p. For example, it can be set to 90 degrees.

Further, the side 2b ₅₂ may be a straight line or a radially outward arc, as long as it can accommodate the annular convex portion 2p. When the rising angle δ ₁ is set to 90 degrees, the circumferential groove 2b ₅ may have a rectangular shape.

The angle δ ₂ of the chamfered portion 2b ₆ between the outer end side end surface 2b ₂ and the inner peripheral surface 2b ₃ may be set to 30 degrees or less so that the inner ring element 2b can easily pass through the annular convex portion 2p during press-fitting. desirable.

When setting the height t ₁ of the annular projection 2p, when the inner ring element 2b passes through the annular projection 2p, circumferential tensile stress occurring in the inner ring element 2b is greater immediately after passing through, instantly Since the characteristic decreases, it is necessary to set the height dimension t ₁ so as not to exceed the strength intended for the impact fracture strength.

The calculation of the circumferential tensile stress can be fitted with a thick-walled combined cylinder formula. The outer ring side outer peripheral surface 2b ₇ of the inner ring element 2b has an outer diameter dimension, and the inner peripheral surface 2b ₃ has an inner diameter dimension.

  In the case of a general hub unit bearing for a passenger car, the circumferential stress is 1000 MPa, and the height of the convex portion at this time is about 0.1 · 0.15 mm. is there.

  When so-called shrink fitting is performed by heating the inner ring element 2b, the pulling force of the inner ring element 2b can be increased to 0.13 to 0.18 mm.

Since the side 2b ₅₁ of the circumferential groove 2b ₅ can set the rising angle δ ₁ large, the inner ring element 2b once press-fitted has a shape that is difficult to come off. Furthermore, it is desirable that the small-diameter portion 2n is provided with a hardened and hardened layer 2u (see FIG. 2) so that the annular convex portion 2p does not wear or collapse due to plastic deformation when the inner ring element 2b is press-fitted.

Therefore, by setting the specifications of each part as described above, when the inner ring element 2b is fitted to the small-diameter portion 2n, the annular convex portion 2p and the circumferential groove 2b ₅ that is the annular concave portion are accurately matched. Therefore, even when the fitting between the small-diameter portion 2n and the inner ring element 2b is loosened during adjustment processing of the brake rotor 8, it is possible to prevent the inner ring element from shifting (disengaging) to the center side.

The balls 3 and 3 are interposed in double rows between the inner circumferential tracks 11 and 12 of the outer ring 1 and the outer circumferential tracks 2a ₁ and 2b ₁ of the inner ring 2, and support the outer ring 1 and the inner ring 2 so as to be relatively rotatable. It is a rolling element.

  The cages 4 and 4 hold the balls 3 and 3.

  The outer end side sealing seal member 5 a is attached to the inner peripheral surface 1 c of the outer ring 1, and is in sliding contact with the hub shaft 2 ah to seal between the outer ring 1 and the inner ring 2.

  The center-side sealing seal member 5b is attached to the inner peripheral surface 1d of the outer ring 1 and seals between the outer ring 1 and the inner ring 2 in sliding contact with the inner ring element.

It will now be described modification hub unit bearing of H ₂ in the present embodiment with reference to FIG.

  Differences between this modification and the first embodiment will be described below.

  In addition, description is abbreviate | omitted about the same code | symbol demonstrated in Embodiment 1, and the same site | part.

In the first embodiment, the outer ring 2a ₁ on the outer end side is directly formed on the hub shaft 2ah of the inner ring 2, and the outer ring 2b ₁ on the center side is press-fitted and fixed to the small diameter portion 2n of the hub shaft 2ah. The inner ring element 2b is abutted against the stepped portion 2c, whereas in the present modification, the cylindrical portion 2n is integrally formed and extended from the flange 2f toward the center. The first inner ring element 2a having the outer circumferential track 2a ₁ formed separately from the portion 2n, and the second inner ring element 2b adjacent to the first inner ring element 2a are press-fitted, and the outer side of the second inner ring element 2b The end side end surface 2b ₂ is abutted against and fixed to the center side end surface 2a ₂ of the first inner ring element 2a.

  In the embodiment and the modification described above, a ball is used as a rolling element, but the present invention is also carried out using a tapered roller. In that case, it goes without saying that the inner circumferential track, the outer circumferential track, the cage and the like are matched to the tapered rollers.

It is sectional drawing which shows Embodiment 1 of this invention. FIG. 2 is an explanatory diagram of a main part of Embodiment 1. FIG. 2 is an explanatory diagram of a main part of Embodiment 1. FIG. 2 is an explanatory diagram of a main part of Embodiment 1. FIG. 6 is a cross-sectional view showing a modification of the first embodiment. It is sectional drawing which shows a prior art.

Explanation of symbols

H _{1, H 2:} hub unit bearing 1: outer ring 11, 12: inner circumferential raceway 1f: flange 2: inner ring 2a, 2b: inner ring element _2a 1, 2b _1: outer circumferential raceway 2b _2: the outer end side end face 2b _3: the Peripheral surface 2b ₄ : groove bottom 2b ₅ : circumferential groove (annular recess)
2b _{51, 2b 52:} edges 2b _6: chamfer 2c: stepped portion 2n: small diameter portion, the cylindrical portion 2p: annular protrusion [delta] _1: start-up angle [delta] _2: chamfer angle 3: rolling element 4: cage 5a, 5b: Sealing seal member

Claims (2)

An outer ring having two inner circumferential tracks in the axial direction;
An inner ring having an outer circumferential track opposed to the two inner circumferential tracks;
A rolling element interposed between the outer ring and the inner ring;
It consists of a sealing seal member provided at the vehicle outer end side end portion and the vehicle center side end portion of the outer ring,
The inner ring is provided at the outer end side end portion of the vehicle and is connected to and fixed to the brake rotor and the wheel. And a hub shaft formed integrally with the small-diameter portion provided through the step portion, and press-fitted into the small-diameter portion, and a vehicle outer end side end surface is abutted against the step portion and fixed in the axial direction. Consisting of an inner ring element having the other of the outer circumferential raceway,
In hub unit bearings,
A hub unit bearing characterized in that an annular concave portion is provided on an inner peripheral surface of the inner ring element, an annular convex portion is provided on the small diameter portion, and the annular concave portion and the annular convex portion are fitted. An outer ring having two inner circumferential tracks in the axial direction;
An inner ring having an outer circumferential track opposed to the two inner circumferential tracks;
A rolling element interposed between the outer ring and the inner ring;
It consists of a sealing seal member provided at the vehicle outer end side end portion and the vehicle center side end portion of the outer ring,
The inner ring is provided at an end portion on the outer end side of the vehicle for attaching and fixing the brake rotor and the wheel, a cylindrical portion integrally formed and extending from the mounting flange toward the vehicle center side, and the cylindrical portion A hub shaft comprising a first inner ring element having one outer peripheral track fixed to the mounting flange side of the shaft, and a shaft that is press-fitted into the cylindrical portion and has an end face on the vehicle outer end abutting against the first inner ring element A second inner ring element having the other of the outer circumferential tracks fixed in the direction;
Hub unit bearing consisting of
A hub unit bearing characterized in that an annular concave portion is provided on an inner peripheral surface of the second inner ring element, an annular convex portion is provided on the cylindrical portion, and the annular concave portion and the annular convex portion are fitted.

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