JPH09105418A - Manufacture of bearing device for axle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately provide a bearing axial gap by a method wherein when an inner ring is pressed in an axle, press-in is stopped once in short of a time when the inner ring makes contact with an axle shoulder part, and a movement amount when the outer ring is axially moved is measured, and thereafter, the inner ring in a stroke amount exceeding a movement amount is pressed in. SOLUTION: The tip of a press-in jig 10 having a recessed part 10a having a given depth is brought into contact with the large part end face 3b of an inner ring 3. When the inner ring 3 is forcibly advanced toward the shoulder part 2b of an axle 2, at a point of time when the bottom of the recessed part 10a makes contact with the end of the axle 2, the inner ring 3 does not advance any more and press-in of the inner ring 3 is stopped once. An axial size A between the large part end face 3b and the reference surface 2e of the axle 2 is then measured and further, the outer ring 1 is axially moved and an axial movement amount Δa' is measured. Thereafter, the inner ring 3 is pressed in by the press-in jig 11 until the inner ring 3 is brought into contact with the shoulder part 2b, and an axial size B between the large part end face 3b and a reference surface 2e is measured. From Δa=Δa'-(A-B), a negative bearing axial gap Δa is determined. Thus, a stable bearing gap is maintained.

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 used for a wheel of an automobile or the like, and more particularly to a method for manufacturing an axle bearing device having a structure in which a rolling surface is directly formed on the axle.

[0002]

2. Description of the Related Art A bearing device for an axle shown in FIG.
Of the double row rolling surfaces 21a, 21b provided on the inner circumference of 1,
The rolling surface 23a facing the rolling surface 21b is directly formed on the outer circumference of the inner ring 23, and the rolling surface 22a facing the rolling surface 21a is directly formed on the outer circumference of the axle 22. A flange 21c for fixing to a vehicle body (not shown) is integrally provided on the outer periphery of the outer ring 21, and a flange 22g for mounting the hub bolt 27 is integrally provided on the outer periphery of the shaft end of the axle 22. . Further, a rolling surface 22a and a press-fitting portion 22c for press-fitting the inner ring 23 are provided on the shoulder portion 2 around the outer periphery of the center of the axle 22.
2b are connected in series. The inner ring 23 is press-fitted into the press-fitting portion 22c of the axle 22 and fixed with a nut 26 screwed to the shaft end of the axle 22.

By the way, in this type of bearing device,
From the aspects of bearing rolling life, rigidity, and fretting, it is advantageous to use the bearing axial gap with a negative pressure, that is, with a predetermined preload, but it is difficult to measure the negative gap from the aspect of gap management. Therefore, the amount of reduction in the gap caused by press-fitting the inner ring 23 into the press-fitting portion 22c and the nut 2
The initial clearance is set in consideration of the decrease in the clearance due to tightening in 6. That is, the tightening torque of the nut 26 corresponding to a desired preload amount is set in advance, and the inner ring 23 is pushed toward the shoulder 22b side of the axle 22 until the tightening torque of the nut 26 reaches this set value.
Therefore, in such a preload (gap) management means, it is essential that there is a space W between the small-diameter end surface of the inner ring 23 and the shoulder portion 22b of the axle 22 when the press-fitting is completed.

[0004]

In the conventional bearing device,
Even if the optimum preload amount (optimal clearance) is set in terms of bearing life and rigidity, there is no means to measure it, and there are variations in the tightening torque of the nut, so there is a problem in terms of reliability. It was Furthermore, since there is a gap W between the inner ring 23 and the shoulder portion 22b, the inner ring 23 may slightly move toward the shoulder portion 22b during operation, and an excessive preload may be applied to the bearing.

Therefore, an object of the present invention is to improve the reliability of this type of bearing device by providing a manufacturing method in which the bearing negative clearance of the above-mentioned bearing device for an axle is guaranteed.

[0006]

SUMMARY OF THE INVENTION According to the present invention, there is provided an outer ring having a flange on its outer circumference and a double row of rolling surfaces on its inner circumference, and a rolling surface facing one of the rolling surfaces of the outer ring. An inner ring provided on the outer periphery, a rolling surface that faces the other of the rolling surfaces of the outer ring, and an axle in which a press-fitting portion for press-fitting the inner ring is continuously provided on the outer periphery via a shoulder, an outer ring, an inner ring, and an axle. In manufacturing the bearing device for an axle having a double row of balls interposed between and, when press-fitting the inner ring into the press-fitting portion of the axle, the press-fitting is temporarily stopped before the inner ring comes into contact with the shoulder portion of the axle, The axial movement of the outer ring is measured when the outer ring is moved in the axial direction, and then the inner ring is press-fitted by a stroke amount exceeding the measured axial movement of the outer ring to complete the press-fitting. .

When press-fitting the inner ring into the press-fitting portion of the axle, once the press-fitting is stopped before the inner ring comes into contact with the shoulder portion of the axle,
The bearing axial gap is in a positive state, and the axial gap actually exists. Therefore, in this state, the outer ring can move in the axial direction by the bearing axial gap (Δa ′). From the axial movement amount (Δa ′) of the outer ring at this time,
By subtracting the axial movement amount of the inner ring from the state where the press-fitting is once stopped to the state where the press-fitting is completed, the bearing axial gap (Δa) after the press-fitting completion, that is, the assembly completion is obtained.

Regarding the axial movement amount of the inner ring from the state where the press-fitting is once stopped to the state where the press-fitting is completed, the axial direction between the reference plane of the axle and the reference plane of the inner ring is as follows. Dimension (A) and axial dimension (B) between the reference surface of the axle and the reference surface of the inner ring after completion of press fitting of the inner ring
It is possible to employ either one of measuring and measuring the difference between them and directly measuring the press-fitting stroke amount (C) of the inner ring from the state where the press-fitting is once stopped until the press-fitting is completed. In the former case, the negative bearing axial gap (Δa) after the assembly is completed is represented by Δa = Δa ′ − (AB),
In the latter case, it is represented by Δa = Δa′−C.

In the manufacturing (assembly) process of the bearing, the press-fitting of the inner ring is temporarily stopped when the bearing axial gap is positive, and in this state the outer ring is moved in the axial direction to measure the axial movement amount of the outer ring, and the measurement is performed. By subtracting the measured value of the press-fitting amount until the press-fitting of the inner ring is completed, the negative clearance of the bearing can be reliably measured. Therefore, unlike the conventional case, the bearing negative clearance can be accurately and easily measured without strictly controlling the tightening torque of the nut. Further, it is not necessary to provide a space between the inner ring and the shoulder portion of the axle at the time of completion of the press-fitting, and the gap can be measured even with a structure in which both are brought into contact.

[0010]

Embodiments of the present invention will be described below.

The bearing device for an axle shown in FIG. 1 guarantees a bearing negative clearance by using a bearing clearance measuring method described later. This bearing device includes an outer ring 1 having double rows of rolling surfaces 1a and 1b provided on the inner circumference thereof, an inner ring 3 having a rolling surface 3a facing the rolling surface 1b of the outer ring 1 provided at the outer circumference thereof, and an outer ring 1 of the outer ring 1. A rolling surface 2a facing the rolling surface 1a, and an axle 2 in which a press-fitting portion 2c for press-fitting the inner ring 3 is continuously provided on the outer periphery via a shoulder portion 2b,
Double rows of balls 4a, 4b interposed between the outer ring 1, the axle 2 and the inner ring 3, retainers 5a, 5b for holding the balls 4a, 4b, and a nut 6 screwed onto the outer circumference of the axle end of the axle 2. Composed of. A flange 1c for fixing the outer ring 1 to a vehicle body (not shown) is integrally provided around the outer ring 1. A flange 2g for mounting a hub bolt 7 is integrally provided around one shaft end outer periphery of the axle 2, and a screw portion 2d for screwing a nut 6 is provided around the other shaft end outer periphery. I have. Further, the end surface 2e of the press-fitting portion 2c of the axle 2 is machined with high accuracy and serves as a reference surface (hereinafter referred to as a reference surface 2e) for measuring the bearing negative clearance after the assembly is completed, as described later. The reference surface 2e may be simultaneously ground with the rolling surface 2a and the shoulder portion 2b by using a processing grindstone 15 as shown in FIG. 12, for example. In this way, the dimensions P1 and L1
The accuracy of (the axial dimension from the shoulder portion 2b to the reference surface 2e) can be ensured. The inner ring 3 is press-fitted into the press-fit portion 2c of the axle 2 and is fixed with a nut 6 screwed to the screw portion 2d of the axle 2. The bearing device for an axle of this embodiment is different from the conventional device shown in FIG. 13 in that the inner ring 3 is in contact with the shoulder portion 2b of the axle 2 and there is no space between them, and the bearing after assembly is completed. The three points are that the reference surface 2e for measuring the negative clearance is formed and that the bearing negative clearance after the assembly is completed is guaranteed using the reference surface 2e.

In the bearing machining process, the bearing clearance is such that the pitch P0 and groove diameter of the double row rolling surfaces 1a and 1b of the outer ring 1 and the axial dimension P1 from the shoulder 2 of the rolling surface 2a of the axle 2 and the groove. Diameter,
Also, the desired negative clearance can be set by managing and selectively combining the axial dimension P2 from the small-diameter end surface of the rolling surface 3a of the inner ring 3 and the groove diameter. Therefore, unlike the conventional apparatus, it is not necessary to manage the bearing gap by the tightening torque of the nut in the assembling process, the setting of the bearing gap is reliable, and the bearing gap does not fluctuate after assembly. Then, the bearing negative clearance thus set to the desired value is measured by the measuring method described below, and by assuring this, the reliability of the bearing life and the like is significantly improved.

The bearing axial clearance (Δa) is measured in the process of press-fitting the inner ring 3 in the order shown in FIGS.

First, as shown in FIG. 2, the inner race 3 is press-fitted into the press-fitting portion 2c of the axle 2 using a press-fitting jig 10 having a recess (or claw) 10a having a predetermined depth H. When the inner ring 3 is pushed toward the shoulder portion 2b of the axle 2 while the tip of the press-fitting jig 10 is brought into contact with the large-diameter end surface 3b of the inner ring 3, the press-fitting jig 1
When the bottom of the recessed portion 10a of 0 comes into contact with the shaft end of the axle 2, the inner ring 3 does not move any further. Thereby, the press-fitting of the inner ring 3 is temporarily stopped. At this time, the small-diameter end surface of the inner ring 3 is not in contact with the shoulder 2b, there is a predetermined space S between the two, and the bearing axial gap is positive. In such a state, the depth H of the press-fitting jig 10 and the shoulder portion 2 of the axle 2 are
The axial dimension L1 from b to the reference surface 2e of the press-fitting portion 2c,
This can be achieved by controlling the axial dimension L2 from the reference surface 2e to the axial end and the width dimension of the inner ring 3.

Next, in this state, the large-diameter end surface 3 of the inner ring 3 is
The axial dimension A from b (the reference surface of the inner ring 3) to the reference surface 2e of the axle 2 is measured (FIG. 3), and the outer ring 1 is moved in the axial direction to measure the axial movement amount Δa ′ of the outer ring. (Fig. 4).

After that, as shown in FIG.
Using, the inner ring 3 is press-fitted until it contacts the shoulder portion 2b of the axle 2. After the press-fitting is completed, the large-diameter end surface 3b of the inner ring 3 is
The axial dimension B between the shaft and the reference surface 2e of the axle 2 is measured (FIG. 6). From the above, the negative bearing axial gap Δa can be obtained from Δa = Δa ′ − (AB). Alternatively, as shown in FIG. 5, the inner ring 3 by the press-fitting jig 11 is
It is also possible to measure the press-fitting stroke C of and to obtain the negative bearing axial clearance Δa from Δa = Δa′−C.

In the measuring method described above, the large-diameter end surface 3b of the inner ring 3 and the end surface 2e of the press-fitting portion 2c of the axle 2 are used as reference planes for measurement, but as shown in FIGS. It is also possible to perform measurement with the large-diameter end surface 3b of 3 and the shaft end surface 2f of the axle 2 as reference surfaces.

The present invention is also applicable to an axle bearing device of the type in which a space is provided between the inner ring and the shoulder portion of the axle as shown in FIG. 13 (in this case, the press-fitting stroke C).
It is desirable to use a method of managing ). Further, the invention can be applied to an axle bearing of a type in which a pair of inner rings having rolling contact surfaces opposed to the double row rolling contact surfaces of the outer wheel are fitted to the axle.

[0019]

The present invention has the following effects.

(1) In the process of manufacturing (assembling) the bearing,
Press-fit the inner ring once with the bearing axial gap being positive, measure the axial movement of the outer ring in this state, and press-fit the inner ring by an amount exceeding the measured value to complete the press-fitting. In addition, the bearing negative clearance can be accurately and easily measured without strictly controlling the tightening torque of the nut.

(2) Since the bearing negative clearance is surely ensured, the range of the initial clearance of the bearing can be increased, and thus the defective rate can be reduced.

(3) Since the bearing negative clearance can be measured even with the structure in which the inner ring is brought into contact with the shoulder portion of the axle, displacement due to fine movement of the inner ring is avoided and a stable bearing negative clearance is maintained. be able to.

(4) The bearing device in which the inner ring is press-fitted until it comes into contact with the shoulder portion of the axle and the bearing gap is guaranteed to be negative, has a remarkably high reliability in terms of bearing life, rigidity and fretting. high.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an axle bearing device according to an embodiment.

FIG. 2 is a cross-sectional view showing a bearing clearance measuring step according to the embodiment.

FIG. 3 is a cross-sectional view showing a bearing clearance measuring step according to the example.

FIG. 4 is a cross-sectional view showing a bearing clearance measuring step according to the example.

FIG. 5 is a cross-sectional view showing a bearing clearance measuring step according to the example.

FIG. 6 is a cross-sectional view showing a bearing clearance measuring step according to the example.

FIG. 7 is a cross-sectional view showing a bearing clearance measuring step according to another embodiment.

FIG. 8 is a cross-sectional view showing a bearing clearance measuring step according to another embodiment.

FIG. 9 is a cross-sectional view showing a bearing clearance measuring step according to another embodiment.

FIG. 10 is a cross-sectional view showing a bearing clearance measuring step according to another embodiment.

FIG. 11 is a cross-sectional view showing a bearing clearance measuring step according to another embodiment.

FIG. 12 is a diagram showing an axle manufacturing process.

FIG. 13 is a cross-sectional view showing a conventional axle bearing device.

[Explanation of symbols]

 1 Outer ring 1a Rolling surface 1b Rolling surface 1c Flange 2 Axle 2a Rolling surface 2b Shoulder 2c Press fit section 3 Inner ring 3a Rolling surface 4a Ball 4b Ball Δa 'Outer ring axial displacement A Axial dimension B Axial dimension C press stroke

Claims (1)

[Claims] 1. An outer ring having a flange on the outer circumference and a double row rolling surface provided on the inner circumference, and an inner ring having a rolling surface opposite to one of the rolling surfaces of the outer ring provided on the outer circumference. A rolling surface that faces the other of the rolling surfaces of the outer ring, an axle in which a press-fitting portion for press-fitting the inner ring is continuously provided on the outer periphery via a shoulder portion, and a double row that is interposed between the outer ring and the inner ring and the axle. A method for measuring a bearing clearance of an axle bearing device having a ball, wherein when press-fitting the inner ring into the press-fitting portion of the axle, the press-fitting is temporarily stopped before the inner ring comes into contact with the shoulder portion of the axle, A bearing for an axle characterized by measuring the axial movement of the outer ring when moved in the axial direction, and then press-fitting the inner ring by a stroke amount exceeding the measured axial movement of the outer ring to complete the press-fitting. Device manufacturing method.