JP2008196598A - Bearing device with rotation sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the entry of foreign matters from an opening portion between a sensor unit and a magnetic encoder into the sensor unit. <P>SOLUTION: Outside the opening portion 10 communicated with the inside of the sensor unit 8 in which a magnetic sensor 7 is incorporated, a contact type rubber seal 11 having two seal lips 11a for shutting off the opening portion 10 from the outside is mounted on the inner diameter face of an inner ring 8c of the sensor unit 8, thereby preventing the entry of foreign matters from the opening portion 10 into the sensor unit 8. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a bearing device with a rotation sensor.

  In the bearing device that supports the rotating member of various rotating devices with a rolling bearing, in order to detect the rotation speed (number of rotations) of the rotating member, the rotating bearing ring attached to the rotating member of the bearing ring of the rolling bearing, A magnetic sensor that mounts annular magnetic encoders magnetized on magnetic poles that are alternately different in the circumferential direction, and detects changes in magnetic flux associated with the rotation of a fixed race that is attached to a fixed member, facing the magnetic encoder. There is a bearing device with a rotation sensor, which is equipped with a sensor unit that incorporates.

  In such a bearing device with a rotation sensor, usually, an opening leading to the inside of the sensor unit in which the magnetic sensor is incorporated is formed between the sensor unit and the magnetic encoder (see, for example, Patent Document 1).

JP 2002-349556 A

  As described in Patent Document 1, in a bearing device with a rotation sensor in which an opening leading to the inside of a sensor unit in which a magnetic sensor is incorporated is formed between a sensor unit and a magnetic encoder, dust, iron powder, etc. The foreign matter enters the inside of the sensor unit from the opening between the sensor unit and the magnetic encoder, and there is a problem that the detection output of the magnetic sensor incorporated in the sensor unit is disturbed. For this reason, the detection accuracy of the rotation sensor may decrease, or in some cases, the detection output of the magnetic sensor may become unstable, causing the rotation sensor to malfunction.

  Accordingly, an object of the present invention is to prevent foreign matter from entering the inside of the sensor unit from the opening between the sensor unit and the magnetic encoder.

  In order to solve the above-mentioned problems, the present invention mounts an annular magnetic encoder magnetized with magnetic poles alternately arranged in the circumferential direction on a rotating raceway ring that is attached to a rotating member of a rolling bearing raceway ring. A sensor unit incorporating a magnetic sensor for detecting a change in magnetic flux accompanying the rotation is attached to a fixed race that is attached to a fixed member so as to face the magnetic encoder, and the sensor unit and the magnetic encoder In a bearing device with a rotation sensor in which an opening that communicates with the inside of the sensor unit in which the magnetic sensor is incorporated is formed, the opening is shielded from the outside outside the opening that communicates with the inside of the sensor unit. A configuration in which a contact type rubber seal having a seal lip is mounted is adopted.

  In other words, by attaching a contact-type rubber seal having a seal lip that blocks the opening from the outside, outside the opening that leads to the inside of the sensor unit, foreign matter does not enter the inside of the sensor unit from the opening. did.

  The rubber seal can be attached to the outer surface of the sensor unit as a ring-shaped one.

  The rubber seal may be attached to the outer surface of the sensor unit by vulcanization adhesion.

  The rubber seal may be attached to the rotating member side as a ring shape.

  The rotating member may be a rotating shaft, and the rubber seal may be mounted in a circumferential groove formed on the rotating shaft.

  A circumferential groove for mounting the rubber seal can be formed on the outer diameter surface of the rotating shaft.

  By making the inner diameter dimension of the rubber seal smaller than the outer diameter dimension of the circumferential groove, the rubber seal can be easily attached to the circumferential groove by elastic contraction force.

  The circumferential groove for mounting the rubber seal can be formed on the side surface of the flange provided on the outer diameter surface of the rotating shaft.

  An annular recess that escapes to both sides is provided at the bottom of the circumferential groove, an annular projection that protrudes to both sides is provided at the base of the rubber seal, and the annular projection is fitted into the annular recess of the circumferential groove, thereby providing a rubber seal. The base portion of this can be elastically deformed and can be easily mounted in the circumferential groove.

  By providing a gap at the base of the rubber seal, the base of the rubber seal can be easily elastically deformed.

  By providing a plurality of seal lips for the rubber seal, it is possible to more reliably prevent foreign matter from entering from the opening.

  In the bearing device with a rotation sensor according to the present invention, a contact type rubber seal having a seal lip that shuts off the opening from the outside is provided outside the opening leading to the inside of the sensor unit. It is possible to prevent the detection accuracy of the magnetic sensor from deteriorating and the malfunction of the rotation sensor by preventing foreign matter from entering the sensor.

  By providing a plurality of seal lips for the rubber seal, it is possible to more reliably prevent foreign matter from entering from the opening.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 and 2 show a first embodiment. As shown in FIG. 1, this bearing device with a rotation sensor supports a main shaft 21 of a motor as a rotating member with a ball bearing as a rolling bearing, and an inner ring 1 of the ball bearing is externally fitted to the main shaft 21. The rotating raceway and the outer race 2 are fixed raceways fitted inside the lid 22a of the motor housing 22. A plurality of balls 3 are held by the cage 4 between them, and the outboard side is sealed by the seal member 5. Has been. A stator 23 is attached to the inner diameter surface of the housing 22, and a rotor 24 is attached to the outer diameter surface of the main shaft 21.

  As shown in FIG. 2, on the inboard side of the inner ring 1, an annular magnetic encoder 6 magnetized with different magnetic poles alternately in the circumferential direction is mounted, and on the inboard side of the outer ring 2, a magnetic encoder is mounted. 6, a sensor unit 8 incorporating a magnetic sensor 7 for detecting a change in magnetic flux accompanying rotation thereof is mounted. The magnetic encoder 6 is fitted and fixed to the outer diameter surface of the inner ring 1 with a metal core 6a, and the sensor unit 8 is fitted and fixed to the inner diameter surface of the outer ring 2 with an outer ring 8a.

  The sensor unit 8 is covered on three sides by an outer ring 8a, an integrated side plate 8b and an inner ring 8c, and a magnetic sensor 7 and a circuit board 7a for processing the detected output are molded resin 9 It is fixed with. An opening 10 is formed between the magnetic encoder 6 and the sensor unit 8 so as to communicate with the inside of the sensor unit 8. Two seal lips 11 a that are in contact with the outer diameter surface of the main shaft 21 outside the opening 10. A ring-shaped rubber seal 11 having an inner diameter is attached to the inner surface of the inner ring 8c by vulcanization and the opening 10 is blocked from the outside.

  3 to 5 show a modification of the first embodiment. In the modification of FIG. 3, the rubber seal 11 is attached to the outer surface of the side plate 8b of the sensor unit 8 by vulcanization, and in the modification of FIG. 4, the disk is bent inward at the tip of the inner ring 8c. 5 is provided with a rubber seal 11 attached to the disk portion 8d by vulcanization adhesion. In the modified example of FIG. 5, a flange 21a is provided on the outer diameter surface of the main shaft 21, and the outer surface of the side plate 8b is vulcanized. The two seal lips 11a of the rubber seal 11 attached by adhesion are brought into contact with the side surface of the flange 21a.

  FIG. 6 shows a second embodiment. This rolling sensor-equipped rolling bearing has the same basic configuration as that of the first embodiment, and a ring-shaped rubber seal 11 is mounted in a circumferential groove 21b formed on the outer diameter surface of the main shaft 21, The difference is that the two seal lips 11a are brought into contact with the inner diameter surface of the inner ring 8c of the sensor unit 8 to block the opening 10 from the outside. The inner diameter of the rubber seal 11 is smaller than the outer diameter of the circumferential groove 21b, and the rubber seal 11 is attached to the circumferential groove 21b by elastic contraction force. Other parts are the same as those of the first embodiment.

  7 and 8 show a modification of the second embodiment. In this modification, as shown in FIG. 7, a flange 21a is provided on the main shaft 21, and a rubber seal 11 is attached to a circumferential groove 21c formed on a side surface of the flange 21a. The difference is that the sensor unit 8 is in contact with the outer surface of the side plate 8b.

  As shown in an enlarged view in FIG. 8, an annular recess 21d that escapes to both sides is provided at the bottom of the circumferential groove 21c, and an annular projection 11b that projects to both sides is provided at the base of the rubber seal 11. 11 is mounted by fitting the annular convex portions 11b on both sides of the base portion into the annular concave portions 21d at the bottom of the circumferential groove 21c. Further, a gap 11c is provided at the base of the rubber seal 11, and is easily elastically deformed when the annular protrusion 11b is fitted into the annular recess 21d of the circumferential groove 21c.

  In each of the above-described embodiments, the rolling bearing is a ball bearing whose inner ring is a rotating raceway. However, the bearing device with a rotation sensor according to the present invention uses other types of rolling bearings such as roller bearings. Can also be applied. Also, the present invention can be applied to a rolling bearing in which the outer ring is a rotating raceway. In this case, the magnetic encoder of the rotation sensor may be mounted on the outer ring side, and the sensor unit incorporating the magnetic sensor may be mounted on the inner ring side.

Longitudinal sectional view showing a bearing device with a rotation sensor of the first embodiment attached to a motor 1 is an enlarged longitudinal sectional view showing the bearing device with a rotation sensor in FIG. FIG. 2 is a longitudinal sectional view showing a modification of FIG. FIG. 2 is a longitudinal sectional view showing a modification of FIG. FIG. 2 is a longitudinal sectional view showing a modification of FIG. The longitudinal cross-sectional view which expands and shows the bearing apparatus with a rotation sensor of 2nd Embodiment. FIG. 6 is a partially cutaway longitudinal sectional view showing a modification of FIG. FIG. 7 is an enlarged cutaway sectional view showing the rubber seal mounting portion of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inner ring 2 Outer ring 3 Ball 4 Cage 5 Seal member 6 Magnetic encoder 6a Core metal 7 Magnetic sensor 7a Circuit board 8 Sensor unit 8a Outer ring 8b Side plate 8c Inner ring 8d Disc part 9 Mold resin 10 Opening part 11 Rubber seal 11a Seal lip 11b annular convex part 11c gap 21 main shaft 21a flange 21b, 21c circumferential groove 21d annular concave part 22 housing 22a lid 23 stator 24 rotor

Claims (11)

  An annular magnetic encoder magnetized with different magnetic poles alternately in the circumferential direction is mounted on a rotating bearing ring attached to the rotating member of the rolling bearing ring, and the fixed bearing ring attached to the fixing member A sensor unit that incorporates a magnetic sensor that detects a change in magnetic flux associated with the rotation of the sensor unit is mounted opposite to the magnetic encoder, and the sensor unit that incorporates the magnetic sensor is interposed between the sensor unit and the magnetic encoder. In a bearing device with a rotation sensor in which an opening that leads to the inside is formed, a contact-type rubber seal having a seal lip that shuts off the opening from the outside is attached to the outside of the opening that leads to the inside of the sensor unit. A bearing device with a rotation sensor.   The bearing device with a rotation sensor according to claim 1, wherein the rubber seal is ring-shaped and attached to an outer surface of the sensor unit.   The bearing device with a rotation sensor according to claim 2, wherein the rubber seal is attached to an outer surface of the sensor unit by vulcanization adhesion.   The bearing device with a rotation sensor according to claim 1, wherein the rubber seal is ring-shaped and mounted on the rotating member side.   The bearing device with a rotation sensor according to claim 4, wherein the rotation member is a rotation shaft, and the rubber seal is mounted in a circumferential groove formed on the rotation shaft.   The bearing device with a rotation sensor according to claim 5, wherein a circumferential groove for mounting the rubber seal is formed on an outer diameter surface of the rotation shaft.   The bearing device with a rotation sensor according to claim 6, wherein the inner diameter dimension of the rubber seal is made smaller than the outer diameter dimension of the circumferential groove, and the rubber seal is attached to the circumferential groove by an elastic contraction force.   The bearing device with a rotation sensor according to claim 5, wherein a circumferential groove for mounting the rubber seal is formed on a side surface of a flange provided on an outer diameter surface of the rotation shaft.   An annular recess that escapes to both sides is provided at the bottom of the circumferential groove, an annular projection that protrudes to both sides is provided at the base of the rubber seal, and the annular projection is fitted into the annular recess of the circumferential groove. The bearing device with a rotation sensor according to claim 6 or 8, wherein a rubber seal is attached to the circumferential groove.   The bearing device with a rotation sensor according to claim 9, wherein a gap is provided in a base portion of the rubber seal.   The bearing device with a rotation sensor according to claim 1, wherein a plurality of seal lips of the rubber seal are provided.

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