JP2005326262A - Bearing device with rotation sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing device with a rotation sensor capable of preventing coil from breaking, and small-sizing and lightening a rotation sensor. <P>SOLUTION: The bearing device with a rotation sensor comprises an exterior member 1 and an interior member 2, a rotor 3 intervening among the two members and the rotation sensor 7. To the either of the exterior member 1 and the interior member 2, a ring-shape magnetic yoke 8 containing a coil 12 is attached and to the other member, a pulser ring 9 is attached, respectively, and the rotation sensor 7 is constituted of the magnetic yoke 8 and the pulser ring 9. Rotation detection is attained by generated voltage induced by the relative rotation between the yoke 8 and the pulser ring 9. The coil 12 of the magnetic yoke 8 is made by tightening the coil winding in one body. The coil winding is fixed by using a self-welding wire or bonding agent. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a bearing device for a wheel of an automobile provided with various devices, for example, an anti-lock brake device, and a bearing device with a rotation sensor used for factory facilities.

The anti-lock brake device (ABS) obtains steering stability by detecting a tire lock during a low friction road or a panic brake, and securing a tire grip by releasing the brake. An ABS sensor that detects tire lock is provided in a wheel bearing device, for example. As a passive ABS sensor provided in such a wheel bearing device, an annular rotation sensor, that is, an annular rotation sensor has been proposed (for example, Patent Document 1). This annular type rotation sensor includes a multi-pole magnet and a U-shaped magnetic yoke with a built-in coil. In the magnetic yoke, a plurality of teeth are alternately formed at the same pitch as the magnetic pole of the multipolar magnet at positions facing the magnetic poles of the multipolar magnet. A voltage is induced in the coil by changing the passing magnetic flux. Thereby, a rotation sensor detects rotation of a wheel.
JP-A-5-264562 JP-A-8-285879

  In order to reduce the size and weight of the rotation sensor configured as described above, it is desirable to use a copper wire as thin as possible as a coil winding built in the magnetic yoke. However, when a bearing device with a rotation sensor equipped with such a rotation sensor is used as a bearing for machine parts such as a bearing for a wheel of a railway vehicle or an automobile or a factory facility, if the coil winding of the rotation sensor is thin, There is a possibility that the coil winding is disconnected due to vibration or the like. Therefore, conventionally, a bobbin wound with a coil is housed in a magnetic yoke, and then the inside of the magnetic yoke is molded with a resin or the like to prevent disconnection of the coil winding due to vibration. However, only by molding in this manner, the mold resin does not penetrate into the coil winding, and thus the inside of the coil cannot be hardened. For this reason, there is a possibility of partial loosening inside the coil, which may cause disconnection. Therefore, it is not possible to use a very thin copper wire as the coil winding, making it difficult to reduce the size and weight of the rotation sensor. It was.

  An object of the present invention is to provide a bearing device with a rotation sensor capable of reducing the size and weight of the rotation sensor while preventing disconnection of the coil.

The bearing device with a rotation sensor according to the present invention includes an outer member having a rolling surface on the inner periphery, an inner member having a rolling surface facing the rolling surface, and a plurality of members interposed between the both rolling surfaces. A rotation sensor bearing device having a rotation sensor, wherein the rotation sensor is attached to one of the outer member and the inner member and has a ring-like magnet with a built-in coil. It consists of a yoke and a pulsar ring attached to the other member. This rotation sensor detects rotation by a generated voltage induced by relative rotation between the magnetic yoke and pulsar ring, and the coil is formed by consolidating coil windings.
According to this configuration, the coil in the magnetic yoke in the rotation sensor is integrated by solidifying the coil winding to the inside. It is possible to prevent the disconnection caused by. As a result, a thin copper wire can be used as the coil winding, and the rotation sensor can be reduced in size and weight accordingly.

In the present invention, the coil may be solidified by using a self-bonding electric wire for the coil winding. When the self-bonding electric wire is used, the coil can be hardened with a thermosetting adhesive applied around the coating of the self-bonding electric wire by heating. Therefore, an operation of applying an adhesive is not required, and the coil can be easily hardened to the inside. The coil can be solidified by self-heating when an electric current is passed through the electric wire. In this case, no heating work is required.
The coil winding may be solidified with an adhesive and integrated. If it hardens with an adhesive agent, a general covered electric wire can be used and it can be made cheap.

  In the present invention, the coil winding may be integrated with the coil bobbin with an adhesive. When the coil winding is bonded to the coil bobbin, the coil does not move in the coil bobbin, and disconnection or contact failure of the connection portion with the connector pin or the like can be prevented.

In this invention, the pulsar ring is a multipolar magnet in which magnetic poles are arranged in a circumferential direction, and the magnetic yoke is equidistant in the circumferential direction at the same pitch as the magnetic pole pitch on the surface facing the multipolar magnet. It may have a lined tooth.
Combining a multipolar magnet with a magnetic yoke having teeth arranged in the circumferential direction can increase the resolution of rotation detection.

In the present invention, the pulsar ring is a magnetic ring provided with windows at equal intervals in the circumferential direction, and the magnetic yoke has a plurality of teeth arranged in the circumferential direction on a surface facing the window. May be.
Also in the case of combining a magnetic ring provided with windows arranged in the circumferential direction and a magnetic yoke having teeth arranged in the circumferential direction, the resolution of rotation detection can be increased.

  The bearing device with a rotation sensor of the present invention is attached to one of the outer member and the inner member of the bearing as a rotation sensor, and is attached to the other member, a ring-shaped magnetic yoke having a built-in coil. Since there is a pulsar ring, and the one that detects rotation by the generated voltage induced by the relative rotation of the magnetic yoke and the pulsar ring is provided, and the coil is integrated by consolidating the coil winding. Even if a thin copper wire is used, disconnection due to vibration can be prevented, and the rotation sensor can be made smaller and lighter.

  A first embodiment of the present invention will be described with reference to FIGS. The bearing device with a rotation sensor according to this embodiment is a deep groove ball bearing, and has an outer member 1 having a rolling surface 1a on the inner periphery and a rolling surface 2a facing the rolling surface 1a on the outer periphery. An inner member 2, a plurality of rolling elements 3 interposed between the rolling surfaces 1 a and 2 a, and a rotation sensor 7 are provided. The outer member 1 is a fixed-side race and is formed of an integral outer ring. The inner member 2 is a raceway on the rotation side, and is composed of an integral inner ring that is press-fitted to the rotation shaft 6. The rolling element 3 is a ball and is held by a cage 4. One end between the inner and outer rings 2 and 1 is sealed with a seal member 5.

  The rotation sensor 7 is an annular type, that is, an annular one, and includes a ring-shaped magnetic yoke 8 that is attached to the outer member 1 and incorporates a coil 12, and a pulsar ring 9 that is attached to the inner member 2. . The rotation sensor 7 detects rotation based on a power generation voltage induced by relative rotation between the magnetic yoke 8 and the pulsar ring 9.

The pulsar ring 9 includes a multipolar magnet 11 having a cored bar 10. The cored bar 10 is a stepped cylindrical member having a Z-shaped cross section composed of a large-diameter portion 10a and a small-diameter portion 10b, and the multipolar magnet 11 made of, for example, a rubber magnet is vulcanized around the small-diameter portion 10b. Glued. The cored bar 10 is preferably a magnetic material. The pulsar ring 9 has a large diameter portion 10a of the core metal 10 that is press-fitted into the outer diameter surface of the inner ring 2 so that the end portion of the inner ring 2 is opposite to the side where the seal member 5 is installed. It is attached in a state of protruding outward in the axial direction. As described above, by providing the multipolar magnet 11 on the small-diameter portion 10b of the cored bar 10, the rotation sensor 7 can be easily attached to the bearing end portion having no space. The multipolar magnet 11 is a ring-shaped rubber magnet as shown in FIG. 2, and magnetic poles N and S are alternately magnetized at equal intervals in the circumferential direction.
The multipolar magnet 11 may be a plastic magnet or a sintered magnet in addition to a rubber magnet. Furthermore, as the multipolar magnet 11, ferrite, Nd-based, and SmFe-based rare earth magnets may be used.

  The magnetic yoke 8 is a radial type, and is formed of a magnetic ring member having a coil 12 incorporated therein at a position facing the multipolar magnet 11 of the pulsar ring 9 in the radial direction. The magnetic yoke 8 is attached to the outer ring 1 via the support member 13. The support member 13 is a stepped cylindrical member having a Z-shaped cross section composed of a small diameter portion 13a and a large diameter portion 13b, and the magnetic yoke 8 is attached to the inner periphery of the large diameter portion 13b. By fitting the small-diameter portion 13a of the support member 13 to the inner diameter surface of the outer ring 1, the outer ring 1 has an end opposite to the installation side of the seal member 5 and is axially outward from the end. The magnetic yoke 8 is attached in the overhanging state. A connector pin 14 extends from the inside to the outside of the magnetic yoke 8, and the coil 12 is connected to the inner end of the connector pin 14.

  The magnetic yoke 8 is composed of two magnetic rings 15 and 16 each having a groove-like cross-sectional shape opening in the axial direction, as shown in a side view in which a half portion is broken in FIG. Both magnetic rings 15 and 16 are faced so that their openings are opposed to each other and are fitted to each other at the outer diameter portions of both members 15 and 16 to form a ring body having a substantially square cross section. Comb-like teeth 15a and 16a extending opposite to each other in the axial direction are formed on the inner peripheral side portions of the magnetic body rings 15 and 16 facing the multipolar magnet 11. The two sets of teeth 15 a and 16 a are alternately arranged in the circumferential direction at the same interval as the magnetic poles of the multipolar magnet 11. These magnetic rings 15 and 16 may be assembled together with an adhesive, or may be assembled with resin or the like. By configuring the magnetic yoke 8 in this way, the area of the magnetic yoke 8 facing the multipolar magnet 11 can be increased, and the magnetic flux guided to the magnetic yoke 8 can be increased accordingly. As a result, the power generation voltage of the coil 12 in the magnetic yoke 8 can be increased, and the output of the rotation sensor 7 can be increased.

  For the coil 12 built in the magnetic yoke 8, a self-bonding electric wire is used as a coil winding. Specifically, a self-bonded copper wire is used. In the self-bonding copper wire, a thermosetting adhesive is applied around the coating, and the coil 12 is hardened by heating the adhesive. In this case, the self-bonded copper wire may be heated by a heating furnace or by self-heating when a current is passed through the copper wire. The coil 12 thus hardened is bonded to the coil bobbin 18 with an adhesive 17. The coil bobbin 18 is integrated with the magnetic yoke 8 by housing the coil bobbin 18 in the magnetic yoke 8 and then molding the magnetic yoke 8 with a molding agent such as a resin 19.

  In the rotation sensor 7, a voltage having a frequency proportional to the number of rotations of the inner member 2 is induced in the coil 12 built in the magnetic yoke 8 by the relative rotation between the pulsar ring 9 and the magnetic yoke 8, and the induced voltage is rotated. Signal. Since the pulsar ring 9 uses a multipolar magnet 11 and the magnetic yoke 8 has comb teeth 15a and 16a arranged in the circumferential direction, rotation detection with high resolution and high accuracy can be performed. This rotation signal is output from the connector pin 14 to the outside. Note that the rotation signal induced in the coil 12 may be output to the outside by a conducting wire, not the connector pin 14.

  According to the bearing device with a rotation sensor having this configuration, the coil 12 in the magnetic yoke 8 of the rotation sensor 7 is integrated with the coil winding made of a self-bonding copper wire integrated into the inside, so that it is the same as the conventional example. Therefore, it is possible to prevent disconnection caused by vibration. As a result, a thin copper wire can be used as the coil winding, and the rotation sensor 7 can be reduced in size and weight accordingly. In addition, since the coil 12 is bonded to the coil bobbin 18, the coil 12 does not move in the coil bobbin 18, and disconnection and contact failure of the connection portion with the connector pin 14 can be prevented. Further, since the coil bobbin 18 is integrated with the magnetic yoke 8 by molding the inside of the magnetic yoke 8 with the resin 19 or the like, the coil bobbin 18 does not move in the magnetic yoke 8, and the coil bobbin 18 is damaged or cracked. It can also be prevented.

  In this embodiment, the coil 12 is hardened by using a self-bonded copper wire as the copper wire of the coil 12, but instead, the coil 12 is hardened by immersing an adhesive into the coil winding. May be. If an anaerobic adhesive such as Loctite is used as the adhesive in this case, the adhesive is solidified after the coil 12 is molded, so that the coil 12 can be easily manufactured.

  4 to 6 show another embodiment of the present invention. This embodiment shows an example applied to a wheel bearing device. This wheel bearing device is a third generation inner ring rotating type and is for supporting a driven wheel. In this specification, the side closer to the outer side in the vehicle width direction of the vehicle when attached to the vehicle is referred to as the outboard side, and the side closer to the center of the vehicle is referred to as the inboard side. In FIG. 4, the left side is the outboard side and the right side is the inboard side. This bearing device with a rotation sensor includes an outer member 1 having double-row rolling surfaces 1a on the inner periphery, an inner member 2 having rolling surfaces 2a respectively facing the rolling surfaces 1a, and rolling surfaces. A plurality of rolling elements 3 interposed between 1a and 2a and a rotation sensor 7A are provided. The outer member 1 has a vehicle body attachment flange 1b at one end, and is attached to a knuckle (not shown) of the vehicle body via the vehicle body attachment flange 1b.

  The inner member 2 has a wheel mounting flange 2b, and a wheel (not shown) is mounted to the wheel mounting flange 2b with bolts 20. This bearing device is a double-row angular contact ball bearing, and contact angles of the respective rolling surfaces 1a and 2a are formed so as to be back-to-back. The rolling elements 3 are held by a holder 4 for each row. Outside the rolling body 3 on the outboard side, the annular space between the outer member 1 and the inner member 2 is sealed by a seal member 5.

The inner member 2 is formed by integrally combining a hub wheel 2A integrally having a wheel mounting flange 2b and an inner ring 2B provided on the outer periphery of the inboard side end by plastic coupling such as caulking. Each of the hub wheel 2A and the inner ring 2B is formed with a rolling surface 2a in each row of the double-row rolling surfaces 2a. Since the hub wheel 2A is for a driven wheel, it has a shape that does not have an inner diameter hole.
A cap 21 that covers the entire end portion on the inboard side of the bearing device is attached to the outer member 1, and a rotation sensor 7 </ b> A is disposed inside the cap 21. The cap 21 prevents water from entering the bearing device from the outside. The cap 21 has a cylindrical shape, and one end thereof is a closed end surface portion 21c except for the connector fitting portion 21b.

  The rotation sensor 7A in this case is also an annular type, and includes a ring-shaped magnetic yoke 8A that is attached to the outer member 1 and incorporates the coil 12, and a pulsar ring 9A that is attached to the inner member 2. The rotation is detected by the generated voltage induced by the relative rotation between the magnetic yoke 8A and the pulsar ring 9A.

The pulsar ring 9 </ b> A is formed by providing a multi-pole magnet 23 on a cored bar 22. The cored bar 22 is an annular body having an L-shaped cross section, and a multipolar magnet 23 made of, for example, a rubber magnet is vulcanized and bonded to the side surface of the standing plate portion 22b. The cored bar 22 is preferably a magnetic material. The pulsar ring 9A is attached to the inner member 2 by press-fitting the cylindrical portion 22a of the cored bar 22 to the outer diameter surface of the inboard side end of the hub inner ring 2B, and rotates together with the inner member 2. As in the case of the first embodiment, the multipolar magnet 23 is a ring-shaped rubber magnet as shown in FIG. 5, and the magnetic poles N and S are alternately magnetized at equal intervals in the circumferential direction. ing.
Also in this example, the multipolar magnet 23 may be a plastic magnet or a sintered magnet. Furthermore, as the multipolar magnet 23, a ferrite, or an Nd-based or SmFe-based rare earth magnet may be used.

  The magnetic yoke 8A is of an axial type, and is made of a magnetic ring member in which the coil 12 is built in a position facing the multipolar magnet 23 of the pulsar ring 9A in the axial direction. The magnetic yoke 8A is attached to the outer member 1 via the cap 21 by being fitted to the inner diameter surface of the cylindrical portion 21a of the cap 21, and does not rotate when the wheel rotates.

  A connector 24 for taking out a rotation signal from the magnetic yoke 8A is fitted to the connector fitting portion 21b in the cap 21, and the magnetic yoke 8A is connected to an external ECU (electric control unit) via the connector 24. ). An elastic ring 25 is interposed near the outlet of the connector 24 in the connector fitting portion 21b, thereby waterproofing the connector fitting portion 21b.

  The magnetic yoke 8A includes two magnetic rings 26 and 27 having an L-shaped cross section and a groove-shaped cross-sectional shape that opens in the axial direction, as shown in a side view in which a half is broken in FIG. By fitting the magnetic body rings 28 that are formed into a ring shape, the ring body has a substantially square cross section. Comb-like teeth 26a and 27a extending in the radial direction are formed on the side surfaces of the two magnetic rings 26 and 27 facing the multipolar magnet 23. The two sets of teeth 26 a and 27 a are alternately arranged in the circumferential direction at the same interval as the magnetic poles of the multipolar magnet 23. These magnetic rings 26 to 28 may be assembled integrally with an adhesive, or may be assembled by being fixed to a resin or the like.

  Further, the connector pin 14 of the connector 24 extends from the inside to the outside of the magnetic yoke 8A, and the coil 12 in the magnetic yoke 8A is connected to the inner end of the connector pin 14. The connector pin 14 is bent outside the magnetic yoke 8A. The configuration inside the magnetic yoke 8A is the same as that in the first embodiment. Note that the magnetic yoke 8A may be integrally formed with the cap 21 together with the connector 24 by resin without being fitted to the inner diameter surface of the cap cylindrical portion 21a. Further, the magnetic yoke 8 </ b> A and the connector 24 may be integrally formed, and this integrally formed product may be bonded to the cap 21.

  In the bearing device with a rotation sensor having this configuration, when the inner member 2 to which the pulsar ring 9A is attached rotates integrally with the wheel, the relative rotation between the pulsar ring 9A and the magnetic yoke 8A causes the wheel 12 to rotate at the coil 12 of the magnetic yoke 8A. A voltage with a frequency proportional to is induced, and this is output from the magnetic yoke 8A as a rotation signal. The output is taken out through the connector 24.

  FIG. 7 shows still another embodiment of the present invention. The bearing device with a rotation sensor of this embodiment is obtained by replacing the axial type rotation sensor 7A with a radial type rotation sensor 7B in the embodiment shown in FIG. The rotation sensor 7B in this case is also an annular type rotation sensor, and includes a magnetic yoke 8B attached to the outer member 1 via the cap 21 and a pulsar ring 9B attached to the inner member 2. The pulsar ring 9B is a ring member having a Z-shaped cross section composed of a large diameter portion 9Ba and a small diameter portion 9Bb, and a plurality of windows 30 arranged at equal intervals in the circumferential direction are formed in the small diameter portion 9Bb. The pulsar ring 9B is attached in a state where it protrudes outward in the axial direction from the end of the hub inner ring 2B by press-fitting the large-diameter part 9Ba to the outer diameter surface of the hub inner ring 2B.

  The magnetic yoke 8B is a magnetic ring member in which the coil 12 is built in a position facing the small diameter portion 9Bb of the pulsar ring 9B in the radial direction. This magnetic yoke 8B is obtained by combining a magnetic ring 35 having a groove-like cross-sectional shape opening in the axial direction and a magnetic ring 36 having an L-shaped cross-section so as to face each other. The cross section is a substantially square ring. Comb-like teeth 35a and 36a extending in the axial direction are formed on the inner peripheral side portions of the magnetic rings 35 and 36 facing the small-diameter portion 9Bb of the pulsar ring 9B. The teeth 35a and 36a are alternately arranged in the circumferential direction at the same interval as the window 30 of the pulsar ring 9B.

  In this rotation sensor 7B, instead of providing the multipolar magnet 11 on the pulsar ring 9, 9A side in each of the above embodiments, a magnet 32 magnetized in one direction is used in each of the magnetic rings 35, 36. It is installed in the magnetic yoke 8B so as to be sandwiched. The magnet 32 may be disk-shaped or a plurality of magnets 32 may be arranged in the circumferential direction. By configuring the magnetic yoke 8B in this way, the area of the magnetic yoke 8B facing the pulsar ring 9B can be increased, and the magnetic flux guided to the magnetic yoke 8B can be increased accordingly. As a result, the power generation voltage of the coil 12 in the magnetic yoke 8B can be increased, and the output of the rotation sensor 7B can be increased. The installation structure of the coil 12 in the magnetic yoke 8B and the connection structure between the coil 12 and the connector pin 14 are substantially the same as those in the first embodiment.

  The magnetic yoke 8B is integrally molded with resin together with the connector 24, and the magnetic yoke 8B is formed on the inner peripheral side of the cap cylindrical portion 21a by fitting the connector portion of the integrally molded product to the connector fitting portion 21b of the cap 21. is set up. Other configurations are the same as those of the embodiment shown in FIG.

  Also in the bearing device with a rotation sensor having this configuration, when the inner member 2 to which the pulsar ring 9B is attached rotates together with the wheel, the wheel rotates on the coil 12 of the magnetic yoke 8B by relative rotation between the pulsar ring 9B and the magnetic yoke 8B. A voltage having a frequency proportional to the number is induced, and is output from the magnetic yoke 8B as a rotation signal. The output is taken out through the connector 24.

It is sectional drawing of the bearing apparatus with a rotation sensor concerning 1st Embodiment of this invention. It is a front view of the multipolar magnet in the rotation sensor. (A) is a half cutaway side view of the magnetic yoke in the rotation sensor, and (B) is a front view of the magnetic yoke. It is sectional drawing of the bearing apparatus with a rotation sensor concerning other embodiment of this invention. It is a front view of the multipolar magnet in the rotation sensor. (A) is a front view of the rotation sensor, and (B) is a half cutaway side view of the magnetic yoke. It is sectional drawing of the bearing apparatus with a rotation sensor concerning further another embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Outer member 1a ... Rolling surface 2 ... Inner member 2a ... Rolling surface 3 ... Rolling body 7, 7A, 7B ... Rotation sensor 8, 8A, 8B ... Magnetic yoke 9, 9A, 9B ... Pulsar ring 11 ... Many Polar magnet 12 ... coils 15a, 16a ... comb teeth 18 ... coil bobbin 23 ... multipolar magnets 26a, 27a ... comb teeth 35a, 36a ... comb teeth

Claims (6)

  An outer member having a rolling surface on the inner periphery, an inner member having a rolling surface facing the rolling surface, a plurality of rolling elements interposed between the both rolling surfaces, and a rotation sensor The rotation sensor is a bearing device with a rotation sensor, wherein the rotation sensor is attached to one of the outer member and the inner member, and is attached to the other member. The rotation is characterized in that the rotation is detected by the generated voltage induced by the relative rotation between the magnetic yoke and the pulsar ring, and the coil is formed by consolidating the coil windings. Bearing device with sensor.   The bearing device with a rotation sensor according to claim 1, wherein a coil is hardened by using a self-bonding electric wire for the coil winding.   2. The bearing device with a rotation sensor according to claim 1, wherein the coil winding is solidified and integrated with an adhesive.   4. The bearing device with a rotation sensor according to claim 1, wherein the coil winding is integrated with a coil bobbin with an adhesive.   The pulsar ring according to any one of claims 1 to 4, wherein the pulsar ring is a multipolar magnet in which magnetic poles are arranged in a circumferential direction, and the magnetic yoke is disposed on a surface of the magnetic pole facing the multipolar magnetized magnet. A bearing device with a rotation sensor having teeth arranged at equal intervals in the circumferential direction at the same pitch as the pitch.   5. The pulsar ring according to claim 1, wherein the pulsar ring is a magnetic body ring provided with windows at equal intervals in a circumferential direction, and the magnetic yoke is disposed on a surface facing the window in a circumferential direction. A bearing device with a rotation sensor, which has a plurality of teeth arranged in parallel.

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