JP2734451B2 - Rotation detection device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation detecting device for detecting the number of rotations of a rotating member integrated with a rotating wheel. 2. Description of the Related Art In various industrial machines, a bearing assembly including a bearing and a supporting member is sometimes used to support a rotating member. An example is an anti-skid brake system in a vehicle. This is a device for detecting the number of rotations of the wheels, releasing the brake momentarily when the vehicle is about to be locked, and blocking the locking of the wheels. For detecting the rotation speed, a sensor rotor made of a magnetic material fixed to an outer ring or an inner ring (rotating wheel) and an electromagnetic pickup type sensor are preferably used. On the other hand, in order to protect the inside of the bearing, a seal member serving also as a sensor rotor is interposed around the bearing of the apparatus (for example, US Pat. No. 4,161,611).
No. 20). [0004] In this case, the seal member and the bearing are separate bodies, and simply providing both in the axial direction increases the axial length of the bearing assembly. In addition, since the seal member cannot be handled integrally with the bearing, the number of components increases, and it becomes extremely difficult to mount the seal member on the device. There are also problems in terms of sealing performance and lubricant retention. An object of the present invention is to solve the above-mentioned problems in the prior art, and to provide a rotation detecting device capable of improving detection accuracy despite being compact as a whole. With the goal. In order to achieve the above object, the present invention provides a bearing in which one of the wheels is fixed and the other is rotatable, including an inner ring, an outer ring, and a rolling element interposed between the two wheels. In a rotation detection device including an assembly and a rotation sensor that detects rotation of a rotation ring of the bearing assembly, the bearing assembly has a seal at an axial end portion between the inner ring and the outer ring. The seal includes an annular support member attached to the rotating wheel, the annular support member having a cylindrical portion for stable support extending inward of the bearing, and the annular support member sliding toward the fixed wheel. An annular sensor rotor having an elastic lip in contact with and sealing the inside of the bearing, and having a magnetic property alternately changing in a circumferential direction, wherein the rotation sensor faces the annular sensor rotor and the bearing assembly; Said inner ring and It is supported in the axial direction outside the end face of the wheel. An embodiment of the present invention will be described below with reference to the drawings. This is an application of the present invention to an anti-skid brake system for a vehicle. [0008] As shown in FIG.
An outer ring 20 disposed concentrically with the outer ring 20, a plurality of balls 30 interposed between the two wheels, and interposed between both side edges of the outer ring 20 and a portion of the inner ring 10 opposed thereto. It comprises a seal member 34 and a sensor rotor / seal member 40. The inner ring 10 has a cylindrical portion 12 and a flange portion 14 extending in a radial direction from the cylindrical portion 12. A notch 16 is formed on an outer peripheral surface of one side of the cylindrical portion 12, and a ball rolling groove 15 is formed. It is attached to. An annular member 19 having a ball rolling groove 18 formed on the outer peripheral surface is fitted into the notch 16. The inner ring 10 is fixed to a vehicle (not shown) and a brake at a flange portion 14. A pair of ball rolling grooves 22 are formed on the inner peripheral surface of the outer race 20, and the ball 30 is interposed between the rolling grooves 15, 18 and 22. The ball 30 is held by a holder 32. The seal member 34 is a normal one. The sensor rotor / seal member 40 includes a first annular member 42 and a second annular member 46 as shown in FIG. The annular member 42 includes a cylindrical portion 64
And a flange portion 66. The first core bar 44 is made of a magnetic material and has an L-shaped cross section, and a first rubber seal 50 having one contact piece 48 fixed thereto. The annular member 46 is made of a magnetic material having a cylindrical portion 62 and a flange portion 68 and has a second core bar 52 having an L-shaped cross section, and a second seal portion fixed to the second core bar 52 and having two contact pieces 54 and 56. 5
8 The contact piece 48 is a cylindrical portion 62 of a cored bar 52.
, And the contact pieces 54, 56 contact the cylindrical portion 64 of the cored bar 44.
And the flange portion 66 respectively. The flange portion 68 of the second metal core 52 faces outward in the axial direction, and a rectangular hole 72 extending in the radial direction is spaced in the cylindrical direction in this portion. Material fills the holes 72 and also covers the inner and outer surfaces of the flange portion 68. The pick-up type sensor 70 is disposed close to the sensor rotor, that is, the flange portion 68 of the cored bar 52, as shown by a two-dot chain line in FIG. Next, the operation and effect of this embodiment will be described. When the inner ring 10 rotates together with the wheel, the second annular member 46 rotates integrally with the inner ring, and the slit 72 of the flange portion 68 of the cored bar 52 and the other portions alternately pass in front of the sensor 70. Will be. As a result, the line of magnetic force periodically changes in front of the sensor 70, and by examining this change, the rotation speed of the wheel is detected.
That is, in the present embodiment, the second annular member 46 including the core 52 having the hole 72 functions as a sensor rotor. Further, the second annular member 46 cooperates with the first annular member 44 to prevent the lubricating oil inside the bearing from leaking to the outside and prevent external dust and dust from entering the inside of the bearing. I do. As described above, the single annular member 40 has both the function as the sensor rotor and the function as the seal member.
There is an advantage that the space for arrangement is halved. Further, since the inner and outer surfaces of the flange portion 68 are protected by the seal 58, the rust of the flange portion 68 is prevented. Next, a modification of the above embodiment will be described. In the modification shown in FIG. 3, the annular member 80 includes one core metal 82 and one seal portion 84. More specifically, the core metal 82 has an L-shaped cross section composed of a cylindrical portion 86 and a flange portion 88, and an appropriate number of holes 9 are formed in the flange portion 88.
0 has been opened. Also in this modification, the annular member 80 functions as a sensor rotor and seal member,
There is less space to place this. Although the above two examples are of the inner ring rotation type, the present invention can also be applied to an outer ring rotation type as required. Needless to say, the bearing may be of a single-row type. Further, the size, number, and the like of the holes in the flange portion of the cored bar are arbitrarily selected as needed. As described above, according to the present invention, a single annular member has both a function as a sensor rotor and a function as a seal member, and is integrated with a bearing. Therefore, in a device for detecting the number of rotations of a rotating wheel in a bearing having a sealing function, a space required particularly in an axial direction can be reduced. In addition, since the seal member can be handled integrally with the bearing, it is easy to handle and assemble the device, and the bearing is a lubricant (eg, grease) sealed bearing, which is effective in terms of lubrication performance, sealing performance, and the like. is there.

[Brief description of the drawings] FIG. 1 is a front sectional view showing an embodiment of the present invention. FIG. 2 is a partially enlarged view of FIG. FIG. 3 is a partial sectional view showing a modification of FIG. 2; [Description of Signs of Main Parts] 10 Inner ring 20 Outer ring 30 rolling elements 40 annular member 46, 52, 82 core metal 50, 58, 84 seal 62, 64, 86 cylindrical part 66, 68, 88 Flange part 70 sensors 72, 90 holes

Claims (1)

(57) [Claims] A bearing assembly including an inner ring, an outer ring, and a rolling element interposed between these two wheels, one of which is fixed and the other of which is rotatable; and detecting rotation of a rotating wheel of the bearing assembly. A rotation sensor comprising a rotation sensor, wherein the bearing assembly has a seal at an axial end between the inner ring and the outer ring, the seal including an annular support member attached to the rotation ring; The support member has a cylindrical portion for stable support extending toward the inside of the bearing on the rotating wheel side, and the annular support member is in sliding contact with the fixed wheel side to seal the inside of the bearing. And a circular sensor rotor whose magnetic characteristics alternately change in the circumferential direction, wherein the rotation sensor is opposed to the circular sensor rotor and is more axially than the end faces of the inner ring and the outer ring of the bearing assembly. Externally supported Rotation detecting device, characterized in that.