JP2006170323A - Bearing with rotation sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing with a rotation sensor capable of eliminating the need of power supply and enabling wiring treatment to be simplified. <P>SOLUTION: This bearing with the rotation sensor comprises a rolling bearing part 1 having an inner ring 2, an outer ring 3, rolling elements 4, and a cage 5 and a rotation sensor part 6. The inner ring 2 forms a rotating side raceway and the outer ring 3 forms a fixed side raceway. The rotation sensor part 6 comprises a stress-electricity conversion element 8 fitted to the outer ring 3 and converting a stress to an electric signal and a stress imparting means 7 fitted to the inner ring 2 and imparting a stress to the stress-electricity conversion element 8. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a bearing with a rotation sensor that is installed in a motor, an engine or the like and can detect a rotation angle and the like.

As a conventional example of this type of bearing with a rotation sensor, a pulsar ring is fixed to an inner ring that is a rotating side wheel fitted to a rotating shaft, and a magnetic sensor made of, for example, a Hall element is attached to an outer ring that is a fixed side wheel. A bearing with a rotation sensor that can obtain a rotation pulse signal and a rotation direction is known (for example, Patent Document 1).
JP 2002-40037 A

  However, the above-described conventional configuration has a problem that it is not easy to assemble because power supply is required to operate the magnetic sensor and wiring processing is involved.

An object of the present invention is to provide a bearing with a rotation sensor that does not require power supply.
Another object of the present invention is to provide a bearing with a rotation sensor that can simplify wiring processing.

A bearing with a rotation sensor according to a first aspect of the present invention is provided with a rolling bearing portion composed of a rotating side race ring, a fixed side race ring, a rolling element, and a cage, and an electrical signal for applying stress to the fixed side race ring. And a stress applying means that is provided on the rotation-side raceway and applies stress to the stress / electrical conversion element. The stress / electrical conversion element is composed of, for example, a bimorph piezoelectric element.
According to this configuration, the stress / electric conversion element provided on the fixed-side raceway is repeatedly subjected to the stress change and generates a voltage by the stress applying means that rotates integrally with the rotation-side raceway. This voltage change can be taken out as a rotation detection signal of the rotation side race. Since the stress / electrical conversion element can output a rotation detection signal without supplying power from the outside, it is sufficient to have two wirings for signal output and grounding, and wiring for power supply becomes unnecessary. This eliminates the need for a power supply circuit and wiring processing and facilitates assembly.

  In the present invention, the stress applying means may have at least one set of concave and convex portions arranged in the circumferential direction. In the case of this configuration, the stress / electrical conversion element is subjected to stress change by sliding on the step changing from the concave portion to the convex portion of the stress applying means that rotates integrally with the rotating side raceway. Accordingly, a rotation detection signal having a sufficient output level can be obtained from the stress / electrical conversion element.

  In this invention, the said recessed part and convex part may be directly provided in the rotation side ring. In the case of this configuration, it is not necessary to provide another member as the stress applying means, so that the configuration of the rotation sensor can be simplified.

In the present invention, a permanent magnet is fixed to the stress-electrical conversion element of the stationary side race, and at least one pair of N poles and S poles are magnetized on the rotary side race as the stress applying means. An encoder may be provided.
In this configuration, when the magnetic encoder, which is a stress applying unit, rotates integrally with the rotating side race, the N magnetic pole and the S magnetic pole alternately change with respect to the stress / electrical conversion element. Suction and repulsion will be repeated in between. Stress due to this repetitive action is applied to the stress / electrical conversion element, and a rotation detection signal is output from the stress / electrical conversion element. Thus, since the stress / electrical conversion element does not have to be brought into direct contact with the magnetic encoder as the pressure applying means, the life of the stress / electrical conversion element can be extended.

  In this invention, even if the stress / electrical conversion element provided on the fixed side raceway and the stress applying means provided on the rotation side raceway are accommodated inside the end face of the rolling bearing portion. good. In the case of this configuration, the rotation sensor can be housed inside the end face of the rolling bearing portion, and the overall configuration can be made compact.

A bearing with a rotation sensor according to a second aspect of the present invention comprises a rolling bearing portion comprising a rotating side race, a fixed side race, a rolling element, and a cage, an electrode terminal provided on the fixed side race, Means for repeating electrical contact and non-contact with the electrode terminal by rotation of the rotation side raceway ring provided on the side raceway ring.
According to this configuration, with the rotation of the rotating raceway, the electrode terminal and the contact / non-contact repeating means repeat contact / non-contact, and this contact / non-contact is electrically turned on / off, A rotation detection signal can be obtained from between the terminal and the fixed-side track ring. Since this signal can be output from one signal line drawn from the electrode terminal, the number of wirings can be reduced, and wiring processing can be simplified in assembly.

  In this invention, the electrode terminal provided in the stationary-side raceway may be in contact with the rotation-side raceway by the preload means. The preload means may be a spring, for example. In the case of this configuration, the electrode terminal is biased by the preloading means to the side in contact with the contact / non-contact repeating means, so that the contact / non-contact operation can be ensured.

  In the present invention, a lubricant may be interposed between the electrode terminal of the stationary side race and the contact / non-contact repeating means of the rotation side race facing the electrode terminal. In the case of this configuration, the sliding friction when the electrode terminal is in sliding contact with the contact / non-contact repeating means can be reduced by the intervention of the lubricant, and the life of the electrode terminal can be extended.

  In the case of each of the above-described configurations in the first and second inventions, the rolling bearing portion may be a wheel bearing. In the case of this configuration, the rotation sensor can be easily assembled to the wheel bearing, and the rotation of the wheel can be detected.

  In the second aspect of the present invention, the electrode terminal provided on the stationary-side raceway and the means provided on the rotation-side raceway to repeat electrical contact and non-contact with the electrode terminal include the rolling bearing portion. It may be housed inside the end face of. In the case of this configuration, the rotation sensor can be housed inside the end face of the rolling bearing portion, and the overall configuration can be made compact.

A first bearing with a rotation sensor according to a first aspect of the present invention is provided with a rolling bearing portion including a rotating side race, a fixed side race, a rolling element, and a cage, and a stress provided on the fixed side race. Rotation detection without supplying power because it is equipped with a stress / electrical conversion element that converts the signal into an electrical signal and a stress applying means that is provided on the rotating raceway and applies stress to the stress / electrical conversion element This eliminates the need for a power supply circuit and wiring processing, and facilitates assembly.
A bearing with a rotation sensor according to a second aspect of the present invention comprises a rolling bearing portion comprising a rotating side race, a fixed side race, a rolling element, and a cage, an electrode terminal provided on the fixed side race, Since there is provided means for repeating the electrical contact / non-contact with the electrode terminal by the rotation of the rotation-side raceway provided on the side raceway, the number of wires can be reduced, and the wiring process can be simplified.

  A first embodiment of the present invention will be described with reference to FIGS. This bearing with a rotation sensor includes a rolling bearing portion 1 having an inner ring 2 and an outer ring 3 that are rotatable with respect to each other via a rolling element 4, a stress applying means 7 provided at one end of the inner ring 2, and the stress applying means 7 And a stress / electrical conversion element 8 provided at one end of the outer ring 3. The stress applying means 7 and the stress / electrical conversion element 8 constitute a rotation sensor unit 6 that detects the rotation of the rotating side race ring 2. Here, the inner ring 2 is a rotating side race and the outer ring 3 is a fixed side race. The raceway surfaces 2 a and 3 a of the rolling element 4 are formed on the outer diameter surface of the inner ring 2 and the inner diameter surface of the outer ring 3, and the rolling element 4 is held by a cage 5. The annular space between the inner ring 2 and the outer ring 3 is sealed with a seal member 9 at the end opposite to the installation side of the stress applying means 7 and the stress / electric conversion element 8.

  The stress / electrical conversion element 8 is an element that converts stress into an electrical signal. Here, a bimorph type piezoelectric element is used, and its action part 8 a is arranged toward the inner diameter side of the rolling bearing part 1. The stress / electrical conversion element 8 is accommodated in the sensor holder 10 and is attached to the outer ring 3 side by fixing the sensor holder 10 to the outer ring 3 via the annular case 11.

  The stress applying means 7 is a means for applying stress to the stress / electrical conversion element 8 and is formed of an annulus having at least one set of the concave portion 7a and the convex portion 7b arranged in the circumferential direction. Here, the punching window formed in the annular body is the recess 7a, and the non-forming portion of the punching window is the protrusion 7b. The stress applying means 7 is attached to the inner ring 2 by press-fitting into the outer diameter surface of the inner ring 2. The outer diameter size of the stress applying means 7 and the radial position of the stress / electrical conversion element 8 are set as follows. The concave portion 7 a is set so that the action portion 8 a of the stress / electrical conversion element 8 is immersed in the concave portion 7 a at a position facing the stress / electrical conversion element 8. The convex portion 7 b is set so that the action portion 8 a is deformed and slidably contacts the convex portion 7 b at a position facing the stress / electrical conversion element 8.

  In this bearing with a rotation sensor, when the stress applying means 7 integrally rotates with the inner ring 2 in the direction indicated by the arrow A in FIG. 2A, the action portion 8a of the bimorph type piezoelectric element 8 which is a stress / electrical conversion element. As shown in FIGS. 2 (B) and 2 (C), the posture changes due to the step difference of the stress applying means 7 from the concave portion 7a to the convex portion 7b. Since the bimorph-type piezoelectric element 8 generates a voltage when the action portion 8a receives a change in stress, the bimorph-type piezoelectric element 8 outputs an electric signal corresponding to the stress generated by the step change from the concave portion 7a to the convex portion 7b. FIG. 3 shows a waveform diagram of the output signal. From the figure, it can be seen that a rotation detection signal having a sufficient output level can be obtained from the bimorph piezoelectric element 8 in accordance with the rotation of the inner ring 2. Further, since the bimorph-type piezoelectric element 8 can output a rotation detection signal without supplying power from the outside, it is sufficient to have two wires for signal output and ground, and no power supply wire is required. . For this reason, wiring processing becomes easy in assembly.

  4 and 5 show another embodiment of the present invention. In this embodiment, the bimorph piezoelectric element 8 and the stress applying means 7 </ b> A are accommodated inside the end face of the rolling bearing portion 1. In this bearing with a rotation sensor, in the first embodiment shown in FIGS. 1 to 3, the bimorph piezoelectric element 8, which is a stress / electrical conversion element housed in the sensor holder 10, is attached to the inner surface of the outer ring 3. It is attached to the outer ring 3 by press-fitting 10. Further, the stress applying means 7A is configured by forming at least one set of the concave portion 7a and the convex portion 7b arranged in the circumferential direction at a position facing the bimorph piezoelectric element 8 on the outer diameter surface of the inner ring 2. . Other configurations are the same as those of the first embodiment.

  In this embodiment, in attaching the bimorph type piezoelectric element 8 to the outer ring 3, the annular case 11 (FIG. 1) in the first embodiment is omitted, and an annular body serving as a stress applying means is omitted and the inner ring is omitted. Since the stress applying means 7A is configured by directly forming the concave portion 7a and the convex portion 7b on the outer diameter surface of No. 2, the configuration of the rotation sensor unit 6 can be simplified. In addition, with such a configuration, the rotation sensor unit 6 can be housed inside the end face of the rolling bearing unit 1, and the overall configuration can be made compact.

  6 and 7 show still another embodiment of the present invention. In this rotation sensor-equipped bearing, in the first embodiment shown in FIGS. 1 to 3, the permanent magnet 12 is fixed to the tip of the bimorph piezoelectric element 8, which is a stress / electric conversion element, facing the inner diameter side of the action portion 8 a. At the same time, the inner ring 2 is provided with stress applying means 7B made of a magnetic encoder instead of the stress applying means 7 made of an annular body. The magnetic encoder 7B, which is a stress applying means in this case, has a rubber magnet 14 in which at least one set of N magnetic poles and S magnetic poles alternately arranged in the circumferential direction is magnetized on the outer periphery of an annular cored bar 13 made of a magnetic material. Fixed and configured. The magnetic encoder 7 </ b> B is attached to the inner ring 2 by press-fitting and fixing an annular cored bar 13 to the outer diameter surface of the inner ring 2. Instead of this, a sintered magnet or a plastic magnet may be used as the rubber magnet 14 in the magnetic encoder 7B. Other configurations are the same as those of the first embodiment.

  In this embodiment, when the magnetic encoder 7B, which is a stress applying unit, rotates along with the rotation of the inner ring 2, the N magnetic pole and the S magnetic pole alternately change with respect to the bimorph piezoelectric element 8 which is a stress / electrical conversion element. Attraction and repulsion are repeated between the magnetic encoder 7 </ b> B and the permanent magnet 12, and stress accompanying this repetitive action is applied to the bimorph piezoelectric element 8. As a result, the bimorph piezoelectric element 8 generates a voltage that changes in synchronization with the repetitive action, and this is output as a rotation detection signal.

  As described above, in this bearing with a rotation sensor, a stress change is applied to the bimorph piezoelectric element 8 by a magnetic force, so that the bimorph piezoelectric element 8 does not need to be brought into direct contact with the pressure applying means 7B. 8 can be extended in service life.

FIG. 8 shows still another embodiment of the present invention. 4 and 5, in the bearing with the rotation sensor, an electrode terminal 15 is provided on the outer ring 3 in place of the bimorph piezoelectric element 8 which is a stress / electric conversion element, and the electrode is formed by the rotation of the inner ring 2. Means 17 for repeating electrical contact and non-contact with the terminal 15 is provided in the inner ring 2. The electrode terminal 15 and the contact / non-contact repeating means 17 constitute a rotation sensor unit 6A.
The electrode terminal 15 is accommodated in a radial through hole 18 formed in the sensor holder 10 made of an annular body so as to be able to advance and retreat, and is brought into an inner diameter side by a spring 19 which is a preload means separately accommodated in the same through hole 18. It is energized. The electrode holder 15 and the spring 19 are attached to the outer ring 3 by press-fitting and fixing the sensor holder 10 to the inner diameter surface of the outer ring 3. In this case, the electrode terminal 15 is electrically insulated from the outer ring 3.
The contact / non-contact repeating means 17 is provided on the outer diameter surface of the inner ring 2 and is composed of a conductive ring body in which at least one or more concave portions 17a and convex portions 17b arranged in the circumferential direction are formed. As the contact / non-contact repeating means 17, as in the stress applying means 7 </ b> A in the embodiment shown in FIGS. 4 and 5, the concave portions 17 a and the convex portions 17 b aligned in the circumferential direction are directly formed on the outer diameter surface of the inner ring 2. You may form and comprise. Other configurations are the same as those of the embodiment of FIGS.

  In this embodiment, as the inner ring 2 rotates, the electrode terminal 15 and the conductive ring body 17 which is contact / non-contact repeating means repeat contact / non-contact. Since the conductive ring 17 is electrically connected to the outer ring 3 via the inner ring 2 and the rolling element 4, the contact / non-contact between the electrode terminal 15 and the conductive ring 17 is electrically turned on / off, and the fixed side A pulse signal (rotation detection signal) corresponding to the rotation of the inner ring 2 can be obtained from between the electrode terminal 15 and the outer ring 3 on the outer ring 3 side which is a raceway ring. In addition, since the electrode terminal 15 is urged by the spring 19 which is the preload means to the side that contacts the conductive ring 17 which is the contact / non-contact repeating means, the contact / non-contact operation is ensured. Can do. This effect is the same even when the contact / non-contact repeating means 17 is formed by directly forming the concave portion 17a and the convex portion 17b on the outer diameter surface of the inner ring 2 regardless of the conductive ring.

  Thus, in this bearing with a rotation sensor, electrical on / off between the electrode terminal 15 and the outer ring 3 is output as a pulse signal which is a rotation detection signal from one signal line drawn from the electrode terminal 15. As a result, wiring processing is facilitated during assembly. Further, since the electrode terminal 15 and the contact / non-contact repeating means (conductive ring) 17 constituting the rotation sensor portion 6A are housed inside the end face of the rolling bearing portion 1, the overall configuration is made compact. it can.

  In the embodiment shown in FIG. 8, a non-conductive resin (not shown) is embedded in the concave portion 17a of the contact / non-contact repeating means 17 so that the resin surface is the same cylindrical surface as the convex portion 17b. The contact repeating means 17 may be an outer diameter surface without unevenness. In this case, by providing the non-conductive resin, the conductive protrusion 17a and the conductive / non-conductive are repeated. Since there is no step on the outer diameter surface of the contact / non-contact repeater 17, wear when the electrode terminal 15 is in sliding contact with the contact / non-contact repeater 17 can be reduced, and the life of the electrode terminal 15 can be extended.

  In the embodiment shown in FIG. 8, a lubricant may be interposed between the electrode terminal 15 on the outer ring 3 side and the contact / non-contact repeating means 17 on the inner ring 2 side. Also in this case, the sliding friction when the electrode terminal 15 is in sliding contact with the contact / non-contact repeating means 17 can be reduced by the intervention of the lubricant, and the life of the electrode terminal 15 can be extended.

  FIG. 9 shows an example in which the rotation sensor bearing of the embodiment shown in FIGS. 1 to 3 is applied to a wheel bearing. This wheel bearing is a third generation type, which rotates the inner ring, and is a bearing for driving wheel support. In this bearing with a rotation sensor, the rolling bearing portion 1A includes an outer member 21 having double-row raceway surfaces 21a on the inner periphery, an inner member 22 having raceway surfaces 22a facing the raceway surfaces 21a, and these It consists of the double row rolling elements 23 interposed between the double row raceway surfaces 21a and 22a, and supports the wheel rotatably with respect to the vehicle body. The outer member 21 is a fixed-side bearing ring, and is an integral member having a vehicle body mounting flange 21b on the outer periphery. The inner member 22 is a rotating raceway, a hub wheel 24 having a wheel mounting flange 24a at the outer end of the outer board, and a hub fitted in a press-fit state at the outer end of the hub ring 24 in the inboard side. The hub inner ring 25 is clamped and fixed in the axial direction with respect to the hub ring 24 by a flange-like caulking portion 24 b formed on the inboard side end of the hub ring 24. Each of the hub ring 24 and the hub inner ring 25 is formed with a row of raceway surfaces 22a out of the double row raceway surfaces 22a. A wheel (not shown) is attached to the wheel attachment flange 24 a of the hub wheel 24 with a bolt 29. The rolling bearing portion 1A is a double-row angular ball bearing, and contact angles of the raceway surfaces 21a and 22a are formed so as to be back-to-back. The rolling elements 23 are held by a holder 26 for each row. Both ends of the annular space formed between the inner and outer members 22 and 21 are sealed with a pair of seal members 27 and 28.

  The stress applying means 7 in the embodiment of FIG. 1 is attached to the outer periphery of the inboard side end of the hub inner ring 25 which is a component of the inner member 22, and the stress and The electrical conversion element 8 is attached via the sensor holder 10 and the annular case 11. The rotation sensor unit 6 is composed of the stress applying means 7 and the stress / electrical conversion element 8 as in the embodiment of FIG.

  Thus, by applying the bearing with a rotation sensor of the present invention to a wheel bearing, the rotation sensor unit 6 can be easily assembled to the wheel bearing, and the rotation of the wheel can be detected.

  In addition, although each said embodiment demonstrated the case where the inner ring | wheel 2 was a rotation side track ring, this invention is applicable also when the outer ring | wheel 3 is a rotation side track ring. In that case, the inner ring 2 is provided with a stress / electric conversion element, and the outer ring 3 is provided with a stress applying means.

It is sectional drawing of the bearing with a rotation sensor concerning 1st Embodiment of this invention. It is operation | movement explanatory drawing of the rotation sensor. It is an output waveform diagram of the same rotation sensor. It is sectional drawing of the bearing with a rotation sensor concerning other embodiment of this invention. It is a cross-sectional view of the rotation sensor. It is sectional drawing of the bearing with a rotation sensor concerning other embodiment of this invention. It is a cross-sectional view of the rotation sensor. It is a cross-sectional view of the rotation sensor in the bearing with a rotation sensor concerning further another embodiment of this invention. It is sectional drawing of the bearing for wheels provided with the rotation sensor of FIG.

Explanation of symbols

1, 1A ... Rolling bearing 2 ... Inner ring (rotating side race)
3. Outer ring (fixed-side raceway)
DESCRIPTION OF SYMBOLS 4 ... Rolling body 5 ... Cage 6, 6A ... Rotation sensor part 7, 7A, 7B ... Stress-applying means 7a ... Concave part 7b ... Convex part 8 ... Stress-electric conversion element 12 ... Permanent magnet 15 ... Electrode terminal 17 ... Contact * Non-contact repeating means 19 ... preloading means 21 ... outer member (fixed-side raceway)
22 ... Inward member (rotating side race)
23 ... rolling element 26 ... cage

Claims (12)

  A rolling bearing portion comprising a rotation side raceway, a fixed side raceway, a rolling element, and a cage, a stress / electric conversion element provided on the fixed side raceway to convert stress into an electrical signal, and the rotation side raceway A bearing with a rotation sensor, comprising: a stress applying means which is provided on a ring and applies stress to the stress / electrical conversion element.   2. The bearing with a rotation sensor according to claim 1, wherein the stress applying means has at least one set of a concave portion and a convex portion arranged in the circumferential direction.   2. The bearing with a rotation sensor according to claim 1, wherein the stress / electrical conversion element is a bimorph type piezoelectric element.   The bearing with a rotation sensor according to claim 2, wherein the recess and the protrusion are provided directly on the rotation-side race.   2. The permanent magnet is fixed to the stress / electrical conversion element of the fixed-side raceway according to claim 1, and at least one pair of N-pole and S-pole is magnetized to the rotation-side raceway as the stress applying means. A bearing with a rotation sensor provided with a magnetic encoder.   The bearing with a rotation sensor according to claim 1, wherein the stress / electrical conversion element provided on the stationary side raceway and the stress applying means provided on the rotation side raceway are accommodated inside the end face of the rolling bearing portion. .   Rolling bearings composed of rotation-side raceways, fixed-side raceways, rolling elements, and cages, electrode terminals provided on the stationary-side raceways, and rotation-side raceways provided on the rotation-side raceway A bearing with a rotation sensor comprising means for repeating electrical contact and non-contact with the electrode terminal.   The bearing with a rotation sensor according to claim 7, wherein the electrode terminal provided on the stationary side raceway is in contact with the rotation side raceway by the preloading means.   8. The bearing with a rotation sensor according to claim 7, wherein a lubricant is interposed between the electrode terminal of the fixed-side raceway and the means for repeating contact / non-contact of the rotation-side raceway facing the electrode terminal.   The bearing with a rotation sensor according to any one of claims 1 to 9, wherein the rolling bearing portion is a wheel bearing.   The bearing with a rotation sensor according to claim 8, wherein the preload means is a spring.   In Claim 7, The electrode terminal provided in the stationary-side raceway and the means provided in the rotation-side raceway to repeat electrical contact and non-contact with the electrode terminal are located on the inner side of the end face of the rolling bearing portion. Bearing with rotation sensor housed in

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