JP2003054210A - Bearing device for axle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing device for an axle capable of ensuring the calculated service life by accurately managing a pre-load applied to a double row rolling bearing in a connection process of a hub wheel to a shaft. SOLUTION: An end face on a vehicle inner side of the hub wheel 1 is allowed to abut on a step wall face 29 of a boundary between a cylindrical face 27 and an inner ring raceway surface 26 in the shaft 25 from the axial direction. On the other hand, an end fringe on a vehicle inner side of a spline 14 on a hub wheel 1 side is not allowed to abut on an end fringe on a vehicle inner side of a spline 28 on a shaft 25 side and is separated from it. Consequently, when the hub wheel 1 and the shaft 25 are mutually connected and a pre-load is applied to the double row rolling bearing 3, arbitrary compression stress can be applied to a contact part of the end face on the vehicle inner side of the hub wheel 1 and the step wall face 29 of the shaft 25 to manage a pre-load simply and accurately.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an axle bearing device for supporting drive wheels on a vehicle body.

[0002]

2. Description of the Related Art As a basic configuration of an axle bearing device of the type used for supporting the drive wheels, there is, for example, the one shown in FIG. 1 cited in the description of the embodiment.

In FIG. 1, the shaft portion 25 of the bowl-shaped outer ring 21 of the constant velocity joint 2 is spline-connected to the center hole of the hub wheel 1 so that the hub wheel 1 is sandwiched from both ends in the axial direction. Double-row rolling bearing 3 on the outer circumference
Has a structure.

In this example, the hub wheel 1 and the shaft portion 25 of the bowl-shaped outer ring 21 of the constant velocity joint 2 are also used as the two inner ring raceways of the double-row rolling bearing 3, so that the double-row rolling bearing 3 is The structure is such that the two inner rings are omitted.

Here, the structure for connecting the hub wheel 1 and the bowl-shaped outer ring 21 of the constant velocity joint 2 will be described.

That is, on the inner peripheral surface of the hub wheel 1, a female spline 14 is provided in an axially intermediate region, and on both sides of the female spline 14 in the axial direction, cylindrical surfaces 15 and 16 which are radially outwardly expanded are provided. Also on the outer peripheral surface of the shaft portion 25 of the bowl-shaped outer ring 21 provided in the constant velocity joint 2, the female spline 14 of the hub wheel 1 and the cylindrical surface 15 on the vehicle inner side are formed.
Corresponding to, the male spline 28 and the cylindrical surface 27 are provided, and by fitting the cylindrical surfaces together, the hub wheel 1 and the bowl-shaped outer ring 21 of the constant velocity joint 2 are centered, and the spline 14, By fitting 28, rotation torque is transmitted between the hub wheel 1 and the constant velocity joint 2.

The bowl-shaped outer ring 21 of the constant velocity joint 2
By bending the free end of the shaft portion 25 outward in the radial direction and caulking the stepped wall surface at the boundary between the cylindrical surface 16 on the vehicle outer side of the hub wheel 1 and the female spline 14, the double row rolling bearing 3 A preload is applied to the. At this time, the vehicle inner side end surface of the hub wheel 1 is
If the stepped wall surface 29 at the boundary between the cylindrical surface 27 of the shaft portion 25 and the inner ring raceway surface 26 is axially abutted, a compressive stress is generated at the vehicle inner end of the hub wheel 1 by the caulking. Therefore, a predetermined preload can be applied to the double-row rolling bearing 3.

[0008]

In the above-mentioned conventional example, it is pointed out that it is difficult to control the preload applied to the double-row rolling bearing 3 with high accuracy for the following reasons, and there is room for improvement here. is there.

That is, the axial lengths of the cylindrical surface 15 of the hub wheel 1 on the vehicle inner side and the cylindrical surface 27 of the shaft portion 25 side, and the vehicle inner of the female spline 14 of the hub wheel 1 and the male spline 28 of the shaft portion 25. In the process of connecting the shaft portion 25 of the constant velocity joint 2 to the hub wheel 1 due to variations in the position of the side edge due to manufacturing tolerances, the vehicle inner side edge of the female spline 14 on the hub wheel 1 side. Contact the vehicle inner side edge of the male spline 28 on the shaft portion 25 side, so that the vehicle inner side end surface of the hub wheel 1 becomes a cylindrical surface 27 of the shaft portion 25 and an inner ring raceway surface 26.
The stepped wall surface 29 at the boundary with may be separated without coming into contact.

When such a situation occurs, the preload applied to the double-row rolling bearing 3 cannot be managed properly, and the calculated life cannot be secured.

In view of the above-mentioned circumstances, the present invention is directed to a bearing device for an axle, in which the hub wheel and the shaft are coupled in the following process.
The purpose is to accurately manage the preload applied to the double-row rolling bearings and ensure the calculated life.

[0012]

According to a first aspect of the present invention, there is provided a bearing device for an axle, comprising: a hub wheel to which a wheel is attached; and a shaft fitted to a center hole of the hub wheel. , A double row rolling bearing that rotatably supports the hub wheel with respect to the vehicle body, and each of which is coupled in a state where the shaft is axially positioned with respect to the hub wheel, and a preload is applied to the double row rolling bearing. A hub surface on the vehicle inner side at the outer circumference of the shaft, while a cylindrical surface is provided on the vehicle inner side and a spline or serration is provided on the vehicle outer side in the center hole of the hub wheel. A spline that has a cylindrical surface that fits on the wheel side cylindrical surface and that fits on the vehicle outer side with respect to the hub wheel side spline or serration. Or, serrations are provided, and the vehicle inner side end surface of the hub wheel is axially with respect to the step wall surface at the boundary between the cylindrical surface of the shaft and the large diameter portion provided on the vehicle inner side of the cylindrical surface. While abutting, the vehicle inner side edge of the hub wheel side spline or serration is separated from the vehicle inner side edge of the shaft side spline or serration.

According to a second aspect of the present invention, there is provided a bearing device for an axle according to claim 2.
As described above, in the first, a constant velocity joint is provided on the vehicle inner side of the shaft, and the shaft is integrally connected to the small diameter side of the bowl-shaped outer ring provided in the constant velocity joint.

According to a third aspect of the present invention, there is provided a bearing device for an axle according to claim 3.
As described above, in the first or second, the shaft also serves as the vehicle inner side inner ring of the double row rolling bearing, and the hub wheel also serves as the vehicle outer side inner ring of the double row rolling bearing. .

According to a fourth aspect of the present invention, there is provided a bearing device for an axle in claim 4.
As shown in, in any of the above first to third,
The inner diameter of the hub wheel side cylindrical surface is set to be larger than the root diameter of the hub wheel side spline or serration, and the outer diameter dimension of the shaft side cylindrical surface is set to the shaft side spline. Or, it is set to be larger than the tip circle diameter of the serration.

According to a fifth aspect of the present invention, there is provided an axle bearing device as set forth in claim 5.
As shown in, in any of the above first to fourth,
The inner diameter of the hub wheel side cylindrical surface is set to be larger than the addendum circle diameter of the shaft side spline, and the axial length of the hub wheel side cylindrical surface is the shaft side spline or serration. Is set longer than.

According to a sixth aspect of the present invention, there is provided an axle bearing device as set forth in claim 6.
As shown in, in any of the above first to fifth,
The spline or serration on the shaft side is set to a large diameter that presses each tooth tip of the spline or serration on the hub wheel side, and a twist angle is added to either one of the splines or serrations. By press-contacting the tooth surfaces of the above, the interference portions in the radial direction and the circumferential direction are attached to the fitting portion by the spline or the serration.

In short, in the present invention, the end surface of the hub wheel on the vehicle inner side is axially contacted with the step wall surface at the boundary between the cylindrical surface of the shaft and the large diameter portion provided on the vehicle inner side of the cylindrical surface. While being in contact with each other, the vehicle wheel inner side edge of the hub wheel side spline or serration is separated from the vehicle wheel inner side edge of the shaft side spline or serration without abutting. Thus, when the hub wheel and the shaft are coupled by the coupling means and at the same time a preload is applied to the double-row rolling bearing, the contact portion between the end surface of the hub wheel on the vehicle inner side and the stepped wall surface of the shaft can be arbitrarily set. It becomes possible to apply the compressive stress of the above, and the preload control can be performed easily and accurately.

In the second structure, the shaft is integrally formed with the bowl-shaped outer ring of the constant velocity joint.

In the third structure, the inner ring of the double-row rolling bearing is omitted, which is advantageous for cost reduction.

The above-mentioned fourth structure is advantageous in facilitating the phase alignment of the splines during assembly.

In the fifth structure, when the shaft is inserted into the hub wheel, the spline on the shaft side passes through the cylindrical surface on the hub wheel side with less resistance, and the cylindrical surfaces are fitted together. Since the mating is set to be performed before the mating with the spline or the serration, the spline or the serration can be easily phased, and the hub wheel and the shaft are It is possible to perform the coupling work easily and quickly, for example, by guiding the posture so that it does not tilt.

Further, in the sixth structure, since the fitting portion of the spline or the serration is provided with the interference, after the shaft is coupled to the hub wheel, both the radial direction and the circumferential direction of the both are concerned. Rattle is suppressed to a small level.

[0024]

DETAILED DESCRIPTION OF THE INVENTION The details of the present invention will be described below with reference to the embodiments shown in the drawings.

1 to 6 show an embodiment of the present invention. 1 is a longitudinal sectional view of an axle bearing device, FIG.
1 is an enlarged view of a main part of FIG. 1. FIG. 3 is a longitudinal sectional view showing a state in which a hub wheel and a constant velocity joint are separated from each other.
FIG. 4 is a vertical cross-sectional view showing a step of inserting the constant velocity joint into the hub wheel, FIG. 5 is a cross-sectional view taken along the line (5)-(5) of FIG. 1, and FIG. It is a plane development view of a spline fitting part with a joint.

The axle bearing device shown in the figure is a hub wheel 1.
, A constant velocity joint 2 and a double row rolling bearing 3.

The hub wheel 1 has a hollow structure, and a radially outward flange 11 is formed on the outer peripheral surface of the hub wheel 1 on the vehicle outer side. The area on the vehicle inner side of the flange 11 on the outer peripheral surface of the hub wheel 1 is
In the following double-row rolling bearing 2, the inner ring raceway surface 12 of the group of balls 32 on the vehicle outer side is formed. The disc rotor 4 and wheels (not shown) of the disc brake device are applied to the flange 11 and attached by a plurality of bolts 5.

As the constant velocity joint 2, a well-known Rzeppa type CVJ (Constant Velocity Joint) is used, and is provided with a bowl-shaped outer ring 21, an inner ring 22, a plurality of balls 23, a cage 24 and the like. On the small diameter side of the bowl-shaped outer ring 21, a shaft portion 25 is integrally formed in a protruding state,
The boundary portion between the bowl-shaped outer ring 21 and the shaft portion 25 has an inner ring raceway surface 2 of the group of balls 32 on the vehicle inner side in the double row rolling bearing 3 described below.
It is assumed to be 6. It should be noted that the axle shaft 6 is spline-fitted to the inner ring 22 and fixed by a retaining ring (reference numeral omitted) or the like. Although not shown, the other end of the axle shaft 6 is attached to a differential device of the vehicle through another constant velocity joint.

The double-row rolling bearing 3 includes a single outer ring 31 having two rows of raceway grooves, a plurality of balls 32 as rolling elements arranged in two rows, and two crown-shaped cages 33. The inner raceway surface 12 of the hub wheel 1 and the inner raceway surface 26 of the bowl-shaped outer race 25 of the constant velocity joint 2 serve as inner races. A radially outward flange 34 is provided at an axially intermediate portion of the outer peripheral surface of the outer ring 31, and the flange 34 is attached to the knuckle 7, which is a part of the vehicle body, by a bolt 8.

Next, an assembling form of each of the above components will be described.

First, while inserting the shaft portion 25 of the constant velocity joint 2 into the center hole of the hub wheel 1, the double-row rolling bearing 3 is mounted on the outer periphery of the hub wheel 1 and the constant velocity joint 2. At this time, the main body portion of the bowl-shaped outer ring 21 provided in the constant velocity joint 2 is arranged axially adjacent to the hub wheel 1.

After this, the shaft portion 25 of the constant velocity joint 2 is previously prepared.
Of the double row rolling bearing 3 by bending the cylindrical portion provided on the free end side (see the chain double-dashed line in FIG. 1) outward in the radial direction and crimping it to the predetermined portion on the vehicle outer side of the hub wheel 1. A required preload is applied to. The caulking portion is denoted by reference numeral 13.

By the way, in this embodiment, since the connecting portion between the hub wheel 1 and the constant velocity joint 2 is devised, it will be described in detail below.

Specifically, a female spline 14 is provided in an axially intermediate region of the center hole of the hub wheel 1, and cylindrical surfaces 15 and 16 are provided on both axial sides of the female spline 14.

In the shaft portion 25 of the bowl-shaped outer ring 21 of the constant velocity joint 2, a cylindrical surface 27 having a diameter smaller than that of the inner ring raceway surface 26 is provided on the root side, and a male spline 28 is provided on the free end side. It is provided.

The shaft portion 25 on the constant velocity joint 2 side with respect to the cylindrical surface 15 on the vehicle inner side of the hub wheel 1 is described.
The cylindrical surface 27 of the hub wheel 1 is fitted, and the female spline 14 of the hub wheel 1 is fitted to the male spline 28 of the shaft portion 25.

Here, in a state where the shaft portion 25 is inserted into the center hole of the hub wheel 1 and is positioned and coupled in the axial direction, as shown in FIG. The stepped wall surface 29 at the boundary between the cylindrical surface 27 and the inner ring raceway surface 26 in the portion 25 is axially abutted, while the vehicle inner side edge of the female spline 14 on the hub wheel 1 side is connected to the shaft portion 25 side. The male spline 28 is set to be separated from the inner edge of the vehicle inner side.

To do so, the axial length of the cylindrical surface 15 on the vehicle inner side of the hub wheel 1 is A1, the axial length of the female spline 14 is B1, and the axial direction of the cylindrical surface 27 of the shaft portion 25 is the axial direction. When the length is A2 and the axial length of the male spline 28 is B2, the relations of A1> A2 and B1 <B2 may be satisfied.

As a result, when the free end of the shaft portion 25 is caulked outward in the radial direction with the shaft portion 25 inserted into the hub wheel 1, the hub wheel 1 is pressed by the pressure applied during the crimping. Vehicle inner side end surface and step wall surface 2 of shaft portion 25
It is possible to apply an arbitrary compressive stress to the abutting portion with 9, and the preload applied to the double row rolling bearing 3 can be easily and accurately managed. in this way,
Since an appropriate preload can be applied to the double-row rolling bearing 3, its rolling characteristics and life can be set as designed.

By the way, in this embodiment, the hub wheel 1 and the shaft portion 25 are further connected to the two fitting portions of the cylindrical surfaces 15 and 27 and the fitting portions of the splines 14 and 28. In order to make it possible to easily and quickly insert the shaft portion 25 of the constant velocity joint 2 with respect to the above, in order to suppress rattling in the radial direction and the circumferential direction of the both, the following (a) to (d) are performed. Stipulates.

(A) At the initial stage of insertion, the male spline 28 of the shaft portion 25 is attached to the cylindrical surface 15 of the hub wheel 1.
In order to pass through with less resistance, the inner diameter C1 of the cylindrical surface 15 on the vehicle inner side of the hub wheel 1 and the addendum circle diameter D2 of the male spline 28 are set to a relationship of C1> D2.

(B) Cylindrical surface 1 in the middle of insertion
5 and 27 are fitted to each other before the splines 14 and 28, the axial length A1 of the cylindrical surface 15 on the vehicle inner side of the hub wheel 1 and the axial length of the male spline 28 are set. B2 and A2 are set to have a relationship of A1> B2. However, as described above, A1> A2, B1 <B2
Relationship shall be maintained.

(C) In order to reduce the insertion resistance in the latter half stage of the insertion in which the splines 14 and 28 start fitting after the cylindrical surfaces 15 and 27 are fitted to each other, the cylindrical surface 15 on the vehicle inner side of the hub wheel 1 is reduced. Inner diameter C1 of
By setting the outer diameter C2 of the cylindrical surface 27 of the shaft portion 25 to C1 ≧ C2, the cylindrical surfaces 15 and 27 are fitted to each other.

(D) At the fitting portions of the splines 14 and 28, in order to eliminate rattling in the radial direction and the circumferential direction, the root circle diameter D1 of the female spline 14 and the tip circle diameter D2 of the male spline 28 are set. , D1 ≦ D2, that is, the so-called large diameter matching is set, and the male spline 28 is provided with a predetermined twist angle θ as shown in FIG. Make contact with the tooth surface at an angle and make a interference between the teeth.

If the dimensional relationship of each part is defined as shown in (a) to (d), when the shaft portion 25 on the constant velocity joint 2 side is inserted into the center hole of the hub wheel 1, the hub wheel 1 The male spline 28 of the shaft portion 25 can be passed through the cylindrical surface 15 on the vehicle inner side of
First, as shown in FIG. 4, the cylindrical surface 1 on the hub wheel 1 side
The cylindrical surface 27 on the shaft portion 25 side can be fitted to the shaft 5.

Thereafter, the female spline 1 of the hub wheel 1
4, the male spline 28 of the shaft portion 25 is fitted to the female spline 14 of the hub wheel 1 by aligning the phase of the male spline 28 of the shaft portion 25 with respect to 4. It will be.

Thus, the cylindrical surface 1 on the hub wheel 1 side
The male spline 28 of the shaft portion 25 is loosely fitted to the shaft 5, and the cylindrical surfaces 15 and 27 are fitted to each other before the splines 14 and 28 are fitted to each other. Since the phases of 14 and 28 can be easily adjusted, and the postures of the hub wheel 1 and the constant velocity joint 2 can be guided so as not to tilt in the process of advancing the fitting of the splines 14 and 28. , Insertion work can be done easily and quickly.

Moreover, although the fitting interference between the cylindrical surfaces 15 and 27 is set to be large, the spline 14,
Since the fitting interference amount of 28 is set to be small, after the hub wheel 1 and the constant velocity joint 2 are coupled, the radial and circumferential rattling of the both can be eliminated.

Thus, the shaft portion 25 of the bowl-shaped outer ring 21 provided in the constant velocity joint 2 with respect to the center hole of the hub wheel 1.
It is possible to easily and quickly perform the work of inserting the hub, and the hub wheel 1 and the constant velocity joint 2 can be coupled with each other in the radial direction and the circumferential direction without rattling, and the torque transmission loss can be suppressed. .

The present invention is not limited to the above embodiment, and various modifications and applications are possible.

(1) In the above embodiment, the free end of the shaft portion 25 of the constant velocity joint 2 is crimped, but instead of this, as shown in FIG. The outer peripheral surface may have a male screw shape, and the nut 9 may be screwed therein. That is, the connecting means in the claims is the step wall surface 29 and the caulking portion 26 of the shaft portion 25 shown in the above embodiment.
In addition to the structure sandwiched between and, the stepped wall surface 29 of the shaft portion 25 and the nut 9
A structure sandwiched between and is also included.

(2) In the above embodiment, the constant velocity joint 2 is provided, but the constant velocity joint 2 is omitted and the axle shaft 6 is directly coupled to the center hole of the hub wheel 1. Those made into are also included in the present invention.

(3) In the above embodiment, the hub wheel 1
The splines 14 and 28 are provided on the shaft part 25 and
You can use serrations.

[0054]

In the bearing device for an axle according to the present invention, the end surface of the hub wheel on the vehicle inner side includes the cylindrical surface of the shaft and the large diameter portion provided on the vehicle inner side of the cylindrical surface. The hub wheel side spline or serration vehicle inner side edge is separated from the shaft spline or serration vehicle inner side edge while not being in contact with the shaft wheel side wall surface in the axial direction. Due to the structure, when the hub wheel and the shaft are coupled and the preload is applied to the double-row rolling bearing at the same time, the contact portion between the end surface of the hub wheel on the vehicle inner side and the stepped wall surface of the shaft is arbitrary. It becomes possible to apply the compressive stress of the above, and the preload control can be performed easily and accurately.

In particular, in the invention of claim 3, the inner ring of the double row rolling bearing is omitted, which is advantageous in reducing the cost.

Further, in the invention of claim 5, when the shaft is inserted into the hub wheel, the cylindrical surfaces are fitted with each other with less resistance before the splines or the serrations are fitted. Phase adjustment can be easily performed, and the hub wheel and shaft can be guided so that they do not tilt during the process of mating splines or serrations, making coupling work easy and quick. It can be carried out.

Further, in the invention of claim 6, since the fitting portion of the spline or the serration is provided with the interference, after the hub wheel and the shaft are coupled, the rattling in the radial direction and the circumferential direction of the both is performed. It will be possible to contribute to the reduction of torque transmission loss, such as being able to suppress it small.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of an axle bearing device according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is a vertical cross-sectional view showing a state in which the hub wheel of FIG. 1 and a constant velocity joint are separated from each other.

FIG. 4 is a vertical cross-sectional view showing the insertion of the constant velocity joint into the hub wheel.

5 is an arrow view of a cross section taken along line (5)-(5) of FIG.

FIG. 6 is a plan development view of a spline fitting portion between a hub wheel and a constant velocity joint.

FIG. 7 is a vertical sectional side view of an axle bearing device according to another embodiment of the present invention.

[Explanation of symbols]

1 hub wheel 2 constant velocity joint 3 Double row rolling bearing 7 knuckles 11 Hub wheel flange 14 hub wheel female spline 15 Hub wheel cylindrical surface on the vehicle inner side 21 Bowl-shaped outer ring of constant velocity joint 25 Shaft part of bowl-shaped outer ring 26 Inner ring raceway of shaft 27 Cylindrical surface of shaft 28 Male shaft spline 29 Stepped wall surface of shaft

Claims (6)

[Claims] 1. A hub wheel to which a wheel is attached, a shaft fitted in a center hole of the hub wheel, a double row rolling bearing for rotatably supporting the hub wheel with respect to a vehicle body, and the shaft. And a coupling means for coupling each in a state of being positioned in the axial direction with respect to the hub wheel and applying a preload to the double row rolling bearing, wherein a cylindrical surface on the vehicle inner side in the center hole of the hub wheel, Further, while a spline or serration is provided on the vehicle outer side, a cylindrical surface fitted to the hub wheel side cylindrical surface on the vehicle inner side on the outer periphery of the shaft, and the hub on the vehicle outer side. A spline or serration fitted to the spline or serration on the wheel side is provided, and the vehicle inner of the hub wheel is provided. The end surface is in axial contact with a step wall surface at the boundary between the cylindrical surface of the shaft and a large diameter portion provided on the vehicle inner side of the cylindrical surface, while the spline on the hub wheel side or The vehicle inner bearing of the serration is separated from the shaft-side spline or the vehicle inner-side edge of the serration. 2. The axle shaft bearing device according to claim 1, wherein a constant velocity joint is provided on a vehicle inner side of the shaft, and the shaft is integrally formed on a small diameter side of a bowl-shaped outer ring provided in the constant velocity joint. A bearing device for an axle, which is connected to each other. 3. The axle bearing device according to claim 1 or 2, wherein the shaft is a vehicle inner side inner ring of a double row rolling bearing, and the hub wheel is a vehicle outer side inner ring of a double row rolling bearing. A bearing device for an axle, which is also used as a bearing. 4. The axle bearing device according to any one of claims 1 to 3, wherein the inner diameter of the hub wheel side cylindrical surface is set to be larger than the root circle diameter of the spline or serration on the hub wheel side. An outer diameter dimension of the shaft side cylindrical surface is set larger than a tip circle diameter of the spline or serration on the shaft side. 5. The axle bearing device according to any one of claims 1 to 4, wherein the inner diameter of the hub wheel side cylindrical surface is set to be larger than the tip circle diameter of the spline on the shaft side. A bearing device for an axle, wherein an axial length of the cylindrical surface on the hub wheel side is set longer than a spline or serration on the shaft side. 6. A bearing device for an axle according to any one of claims 1 to 5, wherein a large-diameter alignment is performed in which each tooth tip of the spline or serration on the shaft side and each tooth root of the spline or serration on the hub wheel side are brought into pressure contact with each other. In addition, by setting a helix angle to either one of the splines or serrations and pressing the tooth surfaces of the splines or serrations together, the fitting portions by the splines or serrations are provided with radial and circumferential interference. A bearing device for an axle, which is characterized in that