JP2003004037A - Bearing device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to expand area of a pulsar portion without enlarg ing a dimension of diametrical direction of a bearing device for a vehicle. SOLUTION: A structure of this bearing device for a vehicle is as follows. A hub wheel 2 for supporting a wheel in a freely rotatable manner and a double row ball bearing 3 fitted into an outer surface of the hub wheel 2 are provided; an outer race 8 of the double row ball bearing 3 is fixed to a vehicle body side; a vehicle inner side shoulder portion 7a of an inner race 7 of the double row ball bearing 3 is enlarged in diameter in diametrical and outward direction, so that an end face 7b of the inner race is enlarged, the pulsar portion P is provided at the end face 7b; a vehicle inner side end of an outer race 8 of the double row ball bearing 3 is extended further than the position of the above pulsar portion P toward the vehicle inner side; a magnetic sensor S is inserted to be fitted into the extended portion 7a from the outer diametrical side to the inner diametrical side in an axial direction to be opposed to the pulsar portion P in the axial direction.

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 including a shaft body for rotatably supporting a wheel and a rolling bearing externally fitted to the shaft body.

[0002]

2. Description of the Related Art In such a bearing device for an axle, as a method of detecting relative rotation of inner and outer rings by using a magnetic sensor, for example, as shown in Japanese Patent Application Laid-Open No. 11-183492, a magnetic sensor is used. Sensor on the outer ring side,
There is a system in which a pulsar portion as a detected portion is fixed to the inner ring side and a magnetic sensor and a pulsar portion are arranged so as to face each other in the axial direction.

[0003]

By the way, in order for the magnetic sensor to be able to detect the relative rotation of the inner and outer rings with high accuracy without a detection error due to the magnetic change between the magnetic sensor and the pulsar part, the pulsing part detects SN. Good, that is, it is necessary to generate a magnetic information signal having a level sufficiently large as compared with the noise component. Since the level of this magnetic information signal is proportional to the area of the pulser portion, it is necessary to secure a sufficient area of the pulser portion in order to improve the SN.

Further, in the technique disclosed in the above publication, a member having a large radial area dedicated to installing the pulsar portion is arranged separately from the inner ring, resulting in a high cost and a complicated structure.

As a result of further earnest studies, the inventor of the present invention increased the area of the pulsar portion without increasing the radial dimension of the bearing device for an axle and provided a magnetic information signal excellent in SN from the pulsar portion. The invention that can occur has been completed.

Therefore, it is an object of the present invention to be able to expand the area of the pulsar portion without increasing the radial dimension of the axle bearing device.

[0007]

According to the present invention, there is provided a shaft body for rotatably supporting a wheel, a rolling bearing fitted on the shaft body, and a fixing means for fixing the rolling bearing to the shaft body. A bearing device for an axle, wherein the outer ring of the rolling bearing is fixed to the vehicle body side, and the vehicle inner side shoulder portion of the inner ring of the rolling bearing is radially outwardly expanded to increase its end surface. A detection portion is provided on the end surface radially outside of the fixing means, and a vehicle inner side end portion of the outer ring of the rolling bearing extends further toward the vehicle inner side than the installation position of the detection portion. A sensor for detecting relative rotation in the circumferential direction of the detected portion is attached to the extended portion, and the extended portion is opposed to the detected portion in the axial direction.

The above-mentioned sensor is not limited to the magnetic sensor, but includes an optical sensor and other sensors, and the detected portion is not limited to the pulsar portion, and, in short, is not limited thereto. If it corresponds to the type of sensor, it includes all of them.

According to the present invention, the rolling bearing has a structure in which the vehicle inner side shoulder portion of the inner ring is radially outwardly enlarged to increase the end surface thereof, and the detected portion is provided on the end surface. It is not necessary to increase the wall thickness of the entire inner ring, and the installation area of the detected part can be expanded. Therefore, it becomes possible to increase the area of the detected part and generate a magnetic information signal excellent in SN for the sensor. In this case, since the shoulder portion of the inner ring on the vehicle inner side is only radially expanded outward, the radial dimension of the axle bearing device is not increased.

From the above, according to the present invention, the area of the detected portion is expanded without increasing the radial dimension of the axle bearing device, and the sensor detects the relative rotation of the detected portion with high accuracy without any detection error. You will be able to detect.

According to the present invention, preferably, a cover is attached to the extending portion of the outer ring to conceal the detected portion and the sensor from the outside. This can eliminate the risk of muddy water entering from the outside.

In the present invention, the detected portion is formed by a plurality of circumferentially irregular portions formed on the end surface of the vehicle inner side end portion of the inner ring, or the vehicle inner side end portion of the inner ring is formed. It may be formed by a magnetized pulsar adhered to the end face and the sensor may be composed of a magnetic sensor.

In the present invention, more preferably, the sensor is penetrated from the outer diameter side of the vehicle body, and is also penetratingly attached to the extended portion of the outer ring of the rolling bearing. In such a case, it becomes easy to replace the sensor from the vehicle body side for maintenance or the like.

In the present invention, more preferably, the sensor is arranged between an axial position indicated by the vehicle inner side end of the fixing means and an axial position indicated by the detected portion. In such a case, the axial length of the axle bearing device can be made compact, which is preferable.

[0015]

DETAILED DESCRIPTION OF THE INVENTION The details of the present invention will be described below with reference to the embodiments shown in the drawings. In the present embodiment, the bearing device for an axle is applied to a vehicle hub unit, but the present invention is not limited to such a hub unit for a vehicle, and may be applied to another axle bearing device. Can also be applied.

FIG. 1 is a side sectional view of a vehicle hub unit as an axle bearing device according to an embodiment of the present invention, and FIG.
3 is a perspective view of a main part of a part of the hub wheel and a knuckle to which the hub wheel is attached, and FIG. 3 is an enlarged view of the main part of FIG. 1. Here, in FIG. 1, the right side is the vehicle outer side and the left side is the vehicle inner side.

In these figures, reference numeral 1 shows the entire vehicle hub unit for the driven wheels.

The vehicle hub unit 1 includes, as a shaft body, a hub wheel 2 for rotatably supporting wheels, and a double row rolling bearing 3 fitted onto the hub wheel 2.

The hub wheel 2 has a small diameter outer peripheral area 2a on the vehicle inner side and a large diameter outer peripheral area 2 on the vehicle outer side.
b is formed. A radially outward flange 4 for mounting a wheel is formed on the vehicle outer side end of the large diameter outer peripheral region 2b.

The flange 4 is provided with a bolt hole 6 into which a bolt (not shown) for mounting the disc brake rotor and the wheel is inserted.

The double-row rolling bearing 3 has one inner ring 7 fitted and fixed to the small-diameter outer peripheral region 2a of the hub wheel 2 and having a single raceway, and a single outer ring 8 having two rows of raceway grooves. A plurality of balls 9a and 9b arranged in two rows and two crown-shaped cages 10a and 10b are provided, and the large diameter outer peripheral region 2b of the hub wheel 2 is the other inner ring.

Further, a knuckle 11 which is a part of the vehicle body is externally fitted to an end portion of the outer ring 8 of the double row rolling bearing 3 on the vehicle inner side.

A flange 13 radially outward is provided on the outer peripheral surface of the outer ring 8 of the double-row rolling bearing 3, and a proper number of bolt insertion holes 13a are formed in the circumferential direction. A bolt mounting hole 11a is provided on the end surface of the knuckle 11. This makes the knuckle 1
1 is attached to the flange 13 of the outer ring 8 by inserting and tightening the bolt 14 into the bolt insertion hole 13a and the bolt attachment hole 11a.

This embodiment is characterized by having the following configuration.

That is, in the double-row rolling bearing 3, the vehicle inner side shoulder portion 7a of the inner ring 7 is radially outwardly expanded and the end surface 7b thereof is enlarged in the radial direction. Then, the end surface 7b of the inner ring 7 is provided with a circumferentially uneven portion to form a pulsar portion P as a detected portion. The pulsar portion P is an uneven portion made of steel because the inner ring 7 is made of steel.

In the double-row rolling bearing 3, the end of the outer ring 8 on the vehicle inner side extends further toward the vehicle inner side than the pulsar portion P formed on the end surface 7b of the inner ring 7, and the extended portion 8a. A magnetic sensor S for detecting the rotation of the pulsar portion P in the circumferential direction, which is an example of a sensor, is inserted through the through hole 8b of the cover fitting portion fixedly fitted thereto and from the outer diameter side to the inner diameter side. It is opposed to the portion P from the axial direction.

Since the pulsar portion P is composed of unevenness in the circumferential direction, the magnetic sensor S is rotated every time the pulsar portion P rotates integrally with the inner ring 7 and passes in the axial direction forward of the magnetic sensor S in the circumferential direction. The axial distance between the pulsar portion P and the pulsar portion P changes, and accordingly, the magnetic sensor S can detect the rotation of the pulsar portion P, that is, the rotation of the inner ring 7 and the hub wheel 2.

The pulsar portion P and the magnetic sensor S are provided in the extended portion 8a of the outer ring 8 of the double row rolling bearing 3.
It has a structure in which it is hidden by a bottomed cylindrical cover 12 fitted on the inner peripheral surface to prevent intrusion of muddy water or the like.

Further, the magnetic sensor S is mounted through the through hole 11c provided in the bottom surface of the magnetic sensor installation recess 11b provided in the knuckle 11, and the extension of the outer ring 8 of the double-row rolling bearing 3 is performed. Part 8a and bottomed cover 1
The pulsar portion P is axially opposed to the pulsar portion P by being penetratingly mounted in the through hole 8b provided in the No. 2.

Further, the sensor S has an axial position indicated by the vehicle inner side end of the nut 20, which is a fixing means for fixing the rolling bearing 3 including the inner ring 7 to the hub wheel 2.
It is possible to reduce the axial length of the bearing device for an axle by being located between the detected position and the axial position indicated by the pulsar portion P.

In this case, the pulsar section P which is the detected section
Is located radially outside of the nut 20, which is a fixing means.

According to the above construction, in the double row rolling bearing 3, the vehicle inner side shoulder portion 7a of the inner ring 7 of the double row rolling bearing 3 is radially outwardly expanded and the end surface 7b thereof is enlarged. The pulsar part P to be installed can be installed in a large area. As a result, in the magnetic sensor S axially opposed to the pulsar portion P having a large area, the inner ring 7, that is, the hub wheel 2 and the outer ring 8 are arranged.
Relative rotation with and can be detected with high accuracy without detection error.

In this case, in the present embodiment, in order to expand the area of the pulsar portion P, it is not necessary to increase the overall thickness of the inner ring 7, and the installation area of the pulsar portion P can be expanded. The radial size of the vehicle hub unit 1 does not increase.

The present invention is not limited to the above-described embodiment, and various applications and modifications can be considered. (1) The pulsar portion P in the above-described embodiment is formed by a magnetized pulsar in which magnetic poles N and S are alternately provided in the circumferential direction instead of the unevenness of the end surface 7b of the vehicle inner side end of the inner ring 7. May be. It should be noted that the projections and depressions on the end face 7b and the front view of the magnetized pulsar are omitted. (2) Instead of the pulsar portion P in the above-described embodiment, a light reflection portion including unevenness or a light reflection film having a different light reflectance in the circumferential direction in the circumferential direction is used, and the light change that occurs in place of the magnetic sensor S is generated. It may be a sensor for detecting. Since such an optical system is affected by the surrounding SN as in the case of magnetism, it is required to secure a large installation area as a light reflecting portion. (3) In the above-described embodiment, the bottomed cylindrical cover 12 is attached to the inner peripheral surface of the vehicle inner side end of the outer ring 8, but as shown in FIG. You may make it fit externally in the notch recessed part 8c of an outer peripheral surface.
In this case, the outer diameters of the outer peripheral surface of the cover 12 and the outer peripheral surface of the outer ring 8 are the same or substantially the same, and the knuckle 11 can be attached. (4) In the above-described embodiment, the outer end surface of the inner ring 7 has the nut 20.
As shown in FIG. 5, the vehicle inner side end portion 2c of the hub wheel 2 is formed into a tubular shape, and the tubular end portion 2c is deformed radially outward so that the outer end surface of the inner ring 7 is You may fasten by caulking. The pulsar portion P, which is the detected portion, is located radially outside the tubular end portion 2c, which is the fixing means. Further, the sensor S is positioned between the axial position indicated by the vehicle inner side end of the tubular end 2c which is the fixing means and the axial position indicated by the pulsar part P which is the detected part, and is used for the axle. The axial length of the bearing device can be made compact.

[0035]

As is apparent from the above description, according to the present invention, the vehicle inner side shoulder portion of the inner ring of the rolling bearing is radially outwardly enlarged to increase the end surface thereof, and the detected portion is formed on the end surface. And a vehicle inner side end portion of the outer ring of the rolling bearing is extended further to the vehicle inner side than the installation position of the detected portion, and the extended portion detects a relative rotation in the circumferential direction of the detected portion. Is penetrated from the outer diameter side to the inner diameter side and is opposed to the detected portion in the axial direction, it is not necessary to increase the thickness of the entire inner ring, that is, the radial dimension of the bearing device for an axle is increased. The installation area of the pulsar section can be expanded without any need. Therefore, the pulsar portion can have a large area to generate a magnetic information signal excellent in SN for the magnetic sensor, and the radial dimension of the bearing device for an axle does not increase.

From the above, according to the present invention, magnetic information having a sufficient SN from the pulsar portion, that is, a level sufficiently large as compared with the noise component, is obtained without increasing the radial dimension of the bearing device for an axle. A signal is generated and the magnetic sensor can detect the relative rotation of the inner and outer wheels with high accuracy without detection error by the output of the pulsar unit. Further, since the sensor is penetratingly mounted in the through hole provided in the extended portion provided on the outer ring and the bottomed cover fitted to the extended portion,
The sensor does not come out in the axial direction from the inner ring fixing means, so that the axial dimension of the bearing device for an axle can be kept substantially the same.

[Brief description of drawings]

FIG. 1 is a side sectional view of a vehicle hub unit according to an embodiment of the present invention.

FIG. 2 is a perspective view of a part of the vehicle hub unit of FIG. 1 and a knuckle to which the hub unit is attached.

3 is a cross-sectional view of the main part of FIG.

FIG. 4 is a sectional view of a main part of a vehicle hub unit according to another embodiment of the present invention.

FIG. 5 is a sectional view of a main part of a vehicle hub unit according to still another embodiment of the present invention.

[Explanation of symbols]

1 Vehicle hub unit 2 hub wheels 3 Double row rolling bearing 7 inner ring 7a Vehicle inner shoulder 7b End face 8 outer ring 11 knuckles 12 covers P pulsar section S magnetic sensor

Claims (6)

[Claims] 1. A shaft body for rotatably supporting a wheel,
An axle bearing device, comprising: a rolling bearing externally fitted to the shaft body; and a fixing means for fixing the rolling bearing to the shaft body, wherein an outer ring of the rolling bearing is fixed to a vehicle body side. The inner side shoulder portion of the inner ring of the vehicle is expanded outward in the radial direction to increase the end surface of the inner ring, and a detected portion is provided on the end surface radially outside the fixing means. The inner side end portion is extended further toward the vehicle inner side than the installation position of the detected portion,
A bearing device for an axle, wherein a sensor for detecting relative rotation in the circumferential direction of the detected part is attached to the extending part and is opposed to the detected part in the axial direction. 2. The axle bearing device according to claim 1, wherein a cover for concealing the detected portion and the sensor from the outside is attached to the extending portion of the outer ring. Bearing device. 3. The bearing device for an axle according to claim 1, wherein the detected portion is formed by a plurality of circumferential uneven portions formed on an end surface of a vehicle inner side end portion of the inner ring. On the other hand, the bearing device for an axle, wherein the sensor is a magnetic sensor. 4. The axle bearing device according to claim 1 or 2, wherein the detected portion is formed by a magnetized pulsar adhered to an end surface of a vehicle inner side end portion of the inner ring,
A bearing device for an axle, wherein the sensor is a magnetic sensor. 5. The axle bearing device according to claim 1, wherein the sensor penetrates from the outer diameter side of the vehicle body and penetrates into the extended portion of the outer ring of the rolling bearing. A bearing device for an axle, which is mounted. 6. The bearing device for an axle according to claim 1, wherein the sensor has an axial position indicated by the vehicle inner side end of the fixing means and an axial position indicated by the detected portion. A bearing device for an axle, wherein the bearing device is arranged between the bearing and the bearing.