JP2000088869A - Bearing device for axle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make compact the axial length of a bearing device for an axle equipped with a sensor for detecting the number of revolutions of the axle. SOLUTION: A nut 7 for inner-ring fastening is screwed on a screw shaft part 6 of an axle 2, and a cylinder part 8 formed on the nut 7 is caulked in the inside diametral direction to thereby lock the nut so as not to be revolved. A pulse ring 12 is press fitted on a projecting shaft part 11 formed on the end face of the screw shaft 6, and a sensor 17 for detecting the number of revolutions facing to the pulse ring 12 in the axial direction is supported by a cover 16 installed on the end part of an outer ring 1. The pulse ring 12 is folded to the outside diameter side of the cylinder part 8 of the nut 7 to thereby form a cylindrical part 15a, and a number-of-revolution detecting part is installed on the opening side end part of the cylindrical part 15a to thereby make the axial length compact.

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 provided with a detection mechanism for detecting the rotation speed of an axle.

[0002]

2. Description of the Related Art Anti-lock brake system (ABS) control of an automobile controls a braking force in accordance with the number of rotations of a wheel at the time of a brake operation, thereby preventing the wheel from locking and preventing the vehicle from skidding. This A
In order to adopt the BS control, it is necessary to detect the rotation speed of the wheel.

An axle bearing device in which a sensor for detecting the number of revolutions of the wheel is incorporated in an axle bearing device has been conventionally known, and FIG. 2 shows an example thereof. This axle bearing device rotatably supports an axle 23 that supports a non-drive wheel by a bearing that incorporates a rolling element 22 between an outer ring 20 and an inner ring 21 that are fixed to a vehicle body. A nut 25 for tightening the inner ring 21 is screw-engaged with a screw shaft portion 24 provided at the end, and a cylindrical portion 26 provided on an end surface of the nut 25.
The nut 25 is prevented from rotating by caulking in the inner diameter direction.

A pulse ring 28 is mounted on a protruding shaft portion 27 provided on the end surface of the screw shaft portion 24 by press-fitting, and the pulse ring 28 is covered with a cover 29 mounted on an end portion of the outer ring 20. A sensor 30 that is opposed to the ring 28 in the axial direction is supported. The sensor 30 detects the number of rotations of the pulse ring 28 and calculates the rotation speed of the non-driven wheels.

Here, the pulse ring 28 is made of a press-formed product of a metal plate, and a magnetic ring 28b having N poles and S poles alternately magnetized in the circumferential direction is bonded to a ring holder 28a.
The magnetic ring 28 is attached by welding, vulcanization or the like.
An active type sensor 30 using a Hall IC, an MR element, or the like is opposed to b, and the Hall IC is operated by an alternating magnetic field obtained when the pulse ring 28 rotates, thereby detecting the number of rotations.

[0006]

In the bearing device for an axle, a pulse ring 28 is provided axially outside a cylindrical portion 26 of a nut 25 for tightening the inner ring 21, and a sensor 30 is provided outside the pulse ring 28. Because of this configuration, the axial length of the axle bearing device is long, and there is still a point to be improved in achieving a compact axial length.

An object of the present invention is to reduce the axial length of an axle bearing device in which an axle rotational speed sensor is incorporated.

[0008]

In order to solve the above-mentioned problems, according to the present invention, a screw shaft is provided at an end of an axle supporting a non-drive wheel, and a nut screw-engaged with the screw shaft is provided. By tightening the inner ring of the bearing that rotatably supports the axle, a pulse ring made of an annular plate is press-fitted into a protruding shaft portion provided on the end surface of the screw shaft portion, and the rotation provided on the outer peripheral portion of the pulse ring is rotated. In an axle bearing device in which a sensor axially opposed to a detected portion is supported by a cover attached to an outer ring of a bearing, the pulse ring is bent toward a nut to form a rotation detected portion axially opposed to the sensor. The configuration provided on the nut outer peripheral side is adopted.

With this configuration, the axial length of the axle bearing device can be reduced by an amount corresponding to the axial length of the cylindrical portion formed in the pulse ring.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. As shown, an axle 2 is provided inside an outer ring 1 attached to a vehicle body. Axle 2
Are double-row rolling elements 3a, 3b incorporated between the outer ring 1 and
The rolling element 3b is rotatably supported on the inner ring 4 which is press-fitted into the small diameter shaft portion 2a of the axle 2.

The axle 2 has a flange 5 for supporting non-driving wheels.
Is provided at one end, and a screw shaft 6 is provided at the other end. The inner ring 4 is tightened by tightening a nut 7 screwed to the screw shaft 6, and a preload is applied to the double row rolling elements 3a, 3b. Has been granted.

The nut 7 has a cylindrical portion 8 at an end, and the cylindrical portion 8 is caulked in the inner diameter direction. The crimping protrusion 9 formed by the crimping engages with an engagement groove 10 formed on the outer periphery of the screw shaft portion 6, and the nut 7
Is locked.

A projecting shaft 11 is provided on an end face of the screw shaft 6. A pulse ring 12 is attached to the protruding shaft portion 11. The pulse ring 12 includes an annular ring holder 13 formed by pressing a metal plate and the ring holder 1.
And a magnetic ring 14 as a rotation detecting portion fixed to an outer peripheral portion of one surface of the ring holder 3 by bonding or the like, and a cylindrical body 13a is formed in an inner diameter portion of the ring holder 13;
a is press-fitted into the protruding shaft portion 11.

The ring holder 13 has a cylindrical portion 8 of a nut 7.
Is bent to the outer diameter side to form a cylindrical portion 15a,
A flange 15b that supports the magnetic ring 14 is provided from the open end of the cylindrical portion 15a toward the outer diameter direction.

Here, the magnetic ring 14 has a configuration in which N poles and S poles are alternately magnetized in the circumferential direction, and is made of a rolled magnet or a rubber magnet.

The pulse ring 12 is covered by a cover 16 attached to the end of the outer race 1, and the cover 16 supports an active type sensor 17 using a Hall IC, an MR element or the like.

The sensor 17 is opposed to the magnetic ring 14 in the axial direction. The sensor 17 detects the rotation speed of the pulse ring 12 by operating a Hall IC or the like based on a change in the magnetic field obtained when the pulse ring 12 rotates. The rotation speed is calculated.

As described above, the ring holder 13 forming the pulse ring 12 is bent toward the outer diameter side of the cylindrical portion 8 of the nut 7 to form the cylindrical portion 15a, so that the conventional axle bearing device shown in FIG. As compared with the above, the axial length of the bearing device can be reduced in size by an amount corresponding to the axial length of the cylindrical portion 15a.

In the embodiment, the magnetic ring 14 is mounted on the ring holder 13 which is press-fitted into the protruding shaft portion 11 as the pulse ring 12.
Is not limited to this. For example, a metal plate may be press-formed to form an annular pulse tooth row on the outer periphery. An appropriate sensor 17 according to the pulse ring 12
Is used.

[0020]

As described above, in the present invention, the pulse ring made of a metal plate is bent toward the nut, and the rotation-detected portion of the pulse ring that faces the sensor in the axial direction is provided on the outer periphery of the nut. This makes it possible to reduce the axial length of the axle bearing device.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view showing a conventional axle bearing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outer ring 2 Axle 3a, 3b Rolling element 4 Inner ring 7 Nut 8 Cylindrical part 11 Protrusion part 12 Pulse ring 15a Cylindrical part 16 Cover 17 Sensor

Claims (1)

[Claims] An axle supporting a non-drive wheel is rotatably supported by a bearing having a rolling element provided between an outer ring and an inner ring, and a screw shaft provided at an end of the axle is used to tighten an inner ring. A nut is screw-engaged, a pulse ring made of an annular plate is press-fitted into a protruding shaft provided on an end surface of the screw shaft, and a cover for covering the pulse ring is attached to an end of the outer ring. In an axle bearing device supporting a rotational speed detection sensor axially opposed to a rotation detection portion provided on an outer peripheral portion of a ring, the pulse ring is bent toward a nut side to rotate the pulse ring axially opposite the sensor. A bearing device for an axle, wherein a detected part is provided on an outer peripheral side of a nut.