JP2007198886A - Encoder, sealing device for roller bearing, and roller bearing apparatus with sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an encoder, a sealing device for a roller bearing, and a roller bearing apparatus with a sensor, which enable the sensor to be enhanced in resolution, in order to precisely detect an operational state of a rotor, such as a rotor number and the like of the bearing. <P>SOLUTION: The encoder which is built in the roll bearing apparatus and disposed opposite to the sensor for detecting the operating state of the roll bearing, comprises a member to be detected 14, which has a plurality of recess sections 14b and projection sections 14c (sections to be detected) being formed on different positions on the surface side to be detected 14a around the axis center of the roller bearing and having different gaps among themselves and a detection plane of the sensor, when the surface side to be detected 14a is positioned opposite to the detection plane. The member to be detected 14 is constituted of carbon nanotube rubber. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an encoder used for detecting the rotational speed of a rotating body, a sealing device for a rolling bearing having the encoder, and a rolling bearing device with a sensor.

  Some rolling bearing devices that support wheels of automobiles or the like incorporate a sensor device for detecting the rotational speed of the wheels in order to control an antilock brake system or the like. In such a conventional rolling bearing device with a sensor, for example, as described in Patent Document 1 below, a magnetized pulsar ring (encoder) installed on the inner ring (rotating raceway) side is opposed to this encoder. Sensor. In the encoder, magnetic powder such as ferrite is mixed into an elastic member made of heat-resistant nitrile rubber or the like, and the elastic member is vulcanized to a member on the rotating race ring side of a sealing device that seals an annular opening between the inner and outer rings. By being bonded, it is attached to the rotating raceway side so as to be integrally rotatable. In the encoder, a plurality of N / S poles are alternately arranged around the circumferential direction. On the other hand, the sensor is provided with a magnetic detection element, and is arranged so that its detection surface faces the detection surface of the encoder. And a sensor detects the rotation speed of a bearing and the rotational speed of the said wheel by detecting the change of the magnetic field from the encoder according to bearing rotation.

JP 2002-155962 A

  However, in the conventional encoder as described above, it is difficult to increase the number of poles of the N and S poles. For this reason, the resolution of the sensor cannot be increased, and the detection accuracy such as the bearing rotation speed is improved. There was a problem that it was difficult to improve. More specifically, in the conventional encoder, since a plurality of N / S poles are alternately arranged around the circumferential direction, when the interval dimension (pitch) between adjacent N poles and S poles is reduced, Magnetic interference between these magnetic poles increases, and the sensor may not be able to accurately detect magnetic field changes. Therefore, in this conventional encoder, the pitch of the N / S poles cannot be reduced to increase the sensor resolution, and the bearing rotational speed and the like can be increased with high accuracy particularly when applied to a small-diameter rolling bearing device. It was difficult to detect.

  In view of the conventional problems as described above, the present invention can increase the resolution of the sensor, and thus can detect the operating state of the rotating body such as the rotational speed of the bearing with high accuracy, and a rolling bearing. An object of the present invention is to provide a sealing device and a rolling bearing device with a sensor.

The encoder of the present invention is an encoder comprising a detected surface that is arranged to face a detection surface of a sensor that detects an operating state of a rotating body,
When the detected surface is arranged to face the detection surface of the sensor, the detected surface has a plurality of detected portions having different gaps with the detection surface at different positions around the axis of the rotating body. A member to be detected formed on a side of the rotating member, and a support member that supports the member to be detected and is attached to the rotating body so as to be integrally rotatable, and the member to be detected is made of carbon nanotube rubber. It is what.

  In the detected member in the encoder configured as described above, a plurality of detected portions having different gaps from the detection surface of the sensor are formed on the detected surface side at different positions around the axis of the rotating body. Unlike the above-described conventional example, the detection result of the sensor can be changed in accordance with the rotating operation of the rotating body without magnetizing the encoder side to the N · S pole. Moreover, since the member to be detected is made of carbon nanotube rubber having high mechanical strength and excellent shape stability, each of the plurality of detected portions can be accurately and the interval between these detected portions. The dimension can be reduced and formed on the detected surface side of the detected member. As a result, the resolution of the sensor can be increased, and the operating state of the rotating body can be detected with high accuracy.

  Note that the plurality of detected portions include a sensor corresponding to a rotating operation of the rotating body when the detected surface of the detected member is arranged to face the detecting surface of the sensor and the encoder is used as a sensor target. As long as the gap between the sensor and the detection surface of the sensor is different from each other and formed on the detection surface side at different positions around the axis of the rotating body, for example, The detection surface may be formed in a concavo-convex shape including a groove portion and a convex portion, and these groove portion and convex portion may be used as the detected portion. Further, the detected surface side can be configured in a gear shape, and the tooth portion or the like can be used as the detected portion. The detected member may be any member that rotates integrally with the rotating body with a support member interposed therebetween, such as a ring-shaped member arranged concentrically with the axis of the rotating body, or around the axis of the rotating body. It may be a circular arc partly provided.

A rolling bearing device with a sensor according to the present invention includes a rolling bearing including a fixed bearing ring and a rotating bearing ring, and rolling elements provided between the bearing rings so as to be freely rotatable. A rolling bearing device incorporating a sensor for detecting an operating state,
The support member on which the member to be detected is mounted is attached to the rotating raceway so as to be integrally rotatable.
In the rolling bearing device with a sensor configured as described above, the detected member capable of increasing the resolution of the sensor is attached to the rotating raceway so as to be integrally rotatable, so that the sensor faces the detected member. Thus, the operation state of the rotating raceway can be detected with high accuracy.

The rolling bearing sealing device according to the present invention includes a fixed-side annular member fixed to a fixed raceway ring, a rotary-side annular member fixed to the rotary raceway ring facing the fixed-side annular member, and the fixed side A rolling bearing sealing device comprising: an annular seal member mounted on an annular member and in sliding contact with the rotary-side annular member;
The detected member is attached to the rotation-side annular member.
The rolling bearing sealing device configured as described above is integrated with the sealing device by mounting a detected member capable of increasing the resolution of the sensor on the rotating annular member. Therefore, by disposing the sensor so as to face the detected member, it is possible to detect the operation state of the rotating raceway with high accuracy while omitting the installation of the support member that supports the detected member on the rotating raceway side. Can do.

In the rolling bearing sealing device, it is preferable that the detected member is provided with a lip portion that is in sliding contact with the fixed race or the fixed-side annular member.
In this case, since the lip portion is in sliding contact with the fixed raceway ring or the fixed-side annular member, the lip portion can seal the annular opening between the rotating raceway ring and the fixed raceway ring. Can be improved.

A rolling bearing device with a sensor according to another aspect of the present invention includes a rolling bearing including a fixed raceway and a rotary raceway, and rolling elements provided between these raceways so as to be freely rollable. A rolling bearing device in which a sensor for detecting an operating state of a rotating race is incorporated,
An annular opening between the races is sealed using the sealing device.
In the rolling bearing device with a sensor configured as described above, a detection member capable of increasing the resolution of the sensor is integrally provided in the sealing device, so that the sensor is opposed to the detection member. By disposing, the operation state of the rotating raceway can be detected with high accuracy. Furthermore, by providing the member to be detected integrally with the sealing device, the number of parts of the rolling bearing device can be reduced, and the assembly work of the bearing device can be simplified. In addition, since it is not necessary to secure a separate installation space for the member to be detected, a compact rolling bearing device can be easily configured. Moreover, when the sealing device provided with the lip portion is used, it is possible to configure a rolling bearing device having more excellent sealing performance.

  According to the present invention, since the member to be detected capable of increasing the resolution in the sensor is used, the encoder and the rolling bearing capable of detecting the operation state of the rotating body such as the rotational speed of the bearing with high accuracy. The sealing device and the rolling bearing device with sensor can be provided.

  Hereinafter, preferred embodiments of an encoder, a rolling bearing sealing device, and a sensor-equipped rolling bearing device of the present invention will be described with reference to the drawings. In the following description, the case where the present invention is applied to a hub unit for a driven wheel of a vehicle will be described as an example.

[Embodiment 1]
FIG. 1 is a sectional view of a rolling bearing device with a sensor according to an embodiment of the present invention. In the figure, the right side is the vehicle inner side, and the left side is the vehicle outer side (wheel side). The sensor-equipped rolling bearing device 1 of this embodiment includes a rolling bearing device 2 and a sensor device 3. This rolling bearing device 2 is of a double-row angular ball bearing type, and includes an outer ring member 4, an inner shaft (hub wheel) 5 and an inner ring constituting member 6 as inner ring members, and a rolling element 7 composed of a plurality of balls. 8 and. Further, in the rolling bearing device 2, retainers 9 and 10 that hold the rolling elements 7 and 8 at predetermined intervals along the circumferential direction, respectively, and a seal member 11 disposed in a gap between the outer ring member 4 and the inner shaft 5. And are provided.

  The outer ring member 4 is a fixed race ring fixed to the vehicle body side, and double row outer ring races 4a and 4b are formed on the inner peripheral side thereof. On the other hand, the rotating raceway is composed of an inner shaft 5 and an inner ring constituent member 6, and an inner ring raceway 5a is formed at a position of the inner shaft 5 facing the outer ring raceway 4a. It rolls between the tracks 4a. Further, an inner ring raceway 6a is formed at a position of the inner ring constituent member 6 facing the outer ring raceway 4b, and the rolling element 8 rolls between the outer ring raceway 4b.

Further, the outer ring member 4 is formed with a cylindrical portion extending in the axial direction on the inner side of the vehicle, and a bottomed cover for closing the inside of the bearing is formed on the inner peripheral surface 4c of the cylindrical portion. 12 is press-fitted. In the rolling bearing device 2, the cover 12 seals the annular opening between the inner and outer rings from the vehicle inner side, and together with the seal member 11 that seals the annular opening from the vehicle outer side, The entry of foreign objects is prevented.
Further, the outer ring member 4 is formed with a flange portion 4d formed on the outer side in the radial direction, and the suspension of the vehicle is provided by a bolt (not shown) inserted into a bolt hole 4d1 formed in the flange portion 4d. The knuckle part (not shown) included in the is fixed.

The inner shaft 5 is provided with an inlay portion 5b and a flange portion 5c for mounting a wheel on the outer side of the vehicle, and a plurality of hub bolts 16 for fixing a wheel or the like are press-fitted into the flange portion 5c. It is fixed. Further, a step portion 5d is formed on the inner side of the inner shaft 5 on the vehicle inner side, and the inner ring constituting member 6 is fitted on the step portion 5d. Further, the inner ring constituting member 6 is fixed to the inner shaft 5 by a caulking portion 5e in which a tip end portion of the step portion 5d is bent and deformed radially outward.
An encoder E included in the sensor device 3 is attached to the inner side of the inner ring constituent member 6 so as to be integrally rotatable with the inner ring constituent member 6.

The sensor device 3 is arranged so as to be opposed to the encoder E, which is constituted by a support member 13 having an L-shaped cross section and a ring-shaped detected member 14 fixed to the support member 13. And a sensor 15 fixed to the cover 12. The sensor 15 detects the rotational speed of the rolling bearing device 2 to detect the rotational speed of the wheel.
The support member 13 has a cylindrical portion that is fitted and fixed to the outer peripheral surface of the inner ring constituent member 6, and together with the detected member 14 that is mounted on a ring-shaped portion formed at right angles to the cylindrical portion, It rotates integrally with the component 6.

  The detected member 14 is made of carbon nanotube rubber (hereinafter also referred to as “CNT rubber”) in which an appropriate amount of carbon nanotubes is blended with rubber such as nitrile. This CNT rubber is imparted with conductivity by blending carbon nanotubes, and has mechanical strength equal to or higher than that of existing rubber such as ferrite rubber and nitrile rubber. In addition, the CNT rubber has wear resistance equal to or higher than that of the above-mentioned rubber, and has excellent shape stability compared to these rubbers.

  In addition, referring to FIG. 2, the detected member 14 includes a ring-shaped detected surface 14a disposed opposite to the detected surface 15a (FIG. 1) of the sensor 15, and the detected surface 14a. A plurality of groove portions 14b and convex portions 14c formed alternately at equal intervals around the circumferential direction are provided. These groove portions 14b and convex portions 14c constitute a plurality of detected portions having different (air) gaps from the detection surface 15a when the detected surface 14a is arranged to face the detection surface 15a. When the detected member 14 rotates integrally with the inner ring constituent member 6, the groove portions 14b and the convex portions 14c alternately provided in the rotation direction (bearing rotational direction) of the inner ring constituent member 6 are sequentially formed on the detection surface 15a. Oppositely, the detection result (sensor output) of the sensor 15 is changed (details will be described later).

  Further, the groove portion 14b and the convex portion 14c are formed by molding, and the distance between the centers in the circumferential direction of the detected surface 14a, that is, the pitch dimension between the adjacent groove portion 14b and the convex portion 14c is, for example, It is set to 0.1 mm. Further, the depth dimension of the groove portion 14b from the detected surface 14a, that is, the gap difference from the detection surface 15a, the separation dimension between the surface of the groove portion 14b and the surface of the convex portion 14c in the thickness direction of the detected member 14. Is set to 0.3 mm, for example. Furthermore, the molds for forming the groove portions 14b and the convex portions 14c have shapes that are processed with high accuracy by etching, and CNT rubber has excellent mechanical strength and shape stability. In combination with this, the groove 14b and the protrusion 14c are formed with high accuracy in a state where the error of the pitch dimension is minimized.

  The sensor 15 is constituted by, for example, an eddy current displacement sensor, and generates a magnetic field with the encoder E and detects a change in magnetic flux (density) of the magnetic field according to the bearing rotation. Specifically, the sensor 15 detects a magnetic field generator that generates a (bias) magnetic field toward the detected surface 14a side of the detected member 14, and a magnetic flux that has returned from the detected surface 14a side to the detection surface 15a. And a magnetic detection unit having a magnetic detection element such as a Hall element (not shown). In the sensor 15, when a magnetic field is generated from the magnetic field generating portion, an eddy current is generated in each surface layer portion of the groove portion 14 and the convex portion 14c so as to cancel the magnetic flux due to the conductivity imparted by the carbon nanotubes. In the case where the detection surface 15a is opposed to the groove portion 14b and the case where the detection surface 15a is opposed to the convex portion 14c, the gap of air having a small magnetic permeability is different. Is a larger value when facing the convex portion 14c than when facing the groove portion 14b. As described above, in the sensor 15, the magnetic flux detection value changes in accordance with the groove 14b or the convex portion 14c facing the detection surface 15a, and the sensor 15 outputs a detection (voltage) signal indicating the magnetic flux detection value. It outputs to control parts (not shown), such as ECU of vehicles. And the rotation speed of the rolling bearing apparatus 2 and the rotational speed of a wheel are detected in a control part, and it is reflected in control of the antilock brake system etc. of a vehicle.

  In the first embodiment configured as described above, the member 14 to be detected of the encoder E is composed of CNT rubber having high mechanical strength and excellent shape stability. In addition, on the detection surface 14a of the detection member 14, a plurality of groove portions 14b and convex portions 14c as detection portions have high precision alternately at equal intervals around the circumferential direction in a state in which an error in pitch dimension is minimized. Is formed. Thus, unlike the above-described conventional example in which the magnetized pulsar ring is used for the encoder, the detection result of the sensor 15 is determined according to the rotational operation of the rolling bearing device 2 (rotating body) without providing the N / S pole on the encoder E side. Can be changed. Further, since it is not necessary to magnetize the encoder E, the groove 14b and the protrusion 14c can be accurately formed, and the pitch dimension of the groove 14b and the protrusion 14c can be reduced, and the resolution of the sensor 15 can be reduced. Can be increased. As a result, the rotational speed of the rolling bearing device 2 and the rotational speed of the wheel can be detected with high accuracy.

  In the verification test conducted by the inventors of the present application, the sensor resolution when the same displacement sensor is used is four times higher than that of the conventional example using the magnetized pulsar ring. It has been confirmed that bearing information such as the number of rotations can be detected more accurately. In addition, the manufacturing cost of the encoder E can be suppressed to 70% or less as compared with the magnetized pulsar ring. In addition, even in the case of a small-diameter rolling bearing device having an outer ring outer diameter of about 60 mm, which is difficult to apply the magnetizing pulsar ring due to mutual interference of magnetic poles, the encoder E is attached to the rotating raceway to accurately obtain bearing information. It has been confirmed that it can be detected.

[Embodiment 2]
FIG. 3 is a cross-sectional view showing the main part of a rolling bearing device with a sensor according to another embodiment. In the figure, the main difference between the second embodiment and the first embodiment is that the detected member is integrally provided in a rolling bearing sealing device.
In FIG. 3, in the second embodiment, a sealing device 17 is provided between the outer ring member 4 and the inner ring constituting member 6, and the annular opening between these inner and outer rings is sealed. The sealing device 17 includes a cored bar 18 as a fixed-side annular member attached to the fixed raceway side and a slinger 19 as a rotating-side annular member attached to the fixed raceway side. A pack seal in which members are assembled together is formed.
The core metal 18 is formed in a substantially L-shaped cross section having a cylindrical portion 18a and an annular portion 18b extending radially inward from one end of the cylindrical portion 18a. The shape portion 18 a and the annular portion 18 b are fitted to a step portion formed on the inner peripheral surface side of the outer ring member 4. An annular seal member 20 is vulcanized and bonded to the cored bar 18. The seal member 20 is provided with radial lip portions 20 a and 20 b that are in sliding contact with the outer peripheral surface of the slinger 19, and an axial lip portion 20 c that is in sliding contact with the inner surface in the axial direction of the slinger 19.

The slinger 19 is formed in a substantially L-shaped cross section having a cylindrical portion 19a and an annular portion 19b extending radially outward from one end of the cylindrical portion 19a. Is fitted and fixed to the outer peripheral surface of the inner ring constituent member 6 so that the slinger 19 rotates integrally with the inner ring constituent member 6.
The slinger 19 also serves as a support member for the encoder E, and the detected member 21 of the encoder E is fixed to the outer side of the annular portion 19b in the axial direction. This detected member 21 is made of CNT rubber as in the first embodiment, and on the detected surface 21a disposed opposite to the detecting surface 15a (FIG. 1) of the sensor 15, A plurality of groove portions 21b and convex portions 21c formed alternately at equal intervals around the circumferential direction are provided. Further, the detected member 21 is formed with a lip portion 21 d that is in sliding contact with the inner peripheral surface of the cylindrical portion 18 a of the cored bar 18. In addition to this description, for example, the axial dimension of the cylindrical portion 18a may be shortened, and the lip portion 21d may be in direct sliding contact with the inner peripheral surface side of the outer ring member 4 (fixed raceway ring).

With the above configuration, in the second embodiment, as in the first embodiment, the resolution of the sensor 15 can be made high, and the rotational speed of the rolling bearing device 2 and the rotational speed of the wheel can be set with high accuracy. Can be detected. In the second embodiment, since the support member of the encoder E is also used as the slinger 19 and the detected member 21 of the encoder E is integrated into the sealing device 17, the components of the rolling bearing device 1 with the sensor are included. The number of points can be reduced, and the assembly work of the bearing device 1 can be simplified. In addition, since it is not necessary to secure a separate installation space for the detected member 21, the rolling bearing device 1 can be easily made compact. In addition, when the member 21 to be detected is integrated with the sealing device 17 as described above, the installation of the cover 12 shown in FIG. 1 can be omitted, and the number of parts of the rolling bearing device 1 can be further reduced. .
Moreover, in this Embodiment 2, since the said lip | rip part 21d slidably contacted with the inner peripheral surface of a metal core is provided in the to-be-detected member 21 using the outstanding abrasion resistance of CNT rubber, the sealing performance of the sealing device 17 Thus, it is possible to configure the rolling bearing device 1 having a better sealing property that can prevent muddy water and foreign matter from entering the bearing as much as possible.

  In the above description, using the detected member of the encoder provided with the detected portions consisting of a plurality of grooves and convex portions provided alternately at equal intervals around the circumferential direction on the ring-shaped detected surface, Although the configuration for detecting the rotational speed of the bearing and the rotational speed of the wheel has been described, the encoder of the present invention is not limited to this. That is, according to the present invention, the detected member having a plurality of detected portions capable of changing the sensor output according to the rotation operation of the rotating body due to the difference in the gap with the detection surface of the sensor is constituted by the carbon nanotube rubber. The shape, the number of installed parts, the configuration, etc. of the detected parts may be appropriately changed according to the detection type of the sensor, the detection target, the attachment location on the rotating body, or the like.

  Specifically, for example, by making the depth of one groove portion different from the depth of the other groove portion among a plurality of groove portions, a feature point is provided in the member to be detected, and the sensor rotates by detecting this feature point. It may be configured to detect the rotation direction, origin, or rotation angle of the body. In addition, a slit hole is provided as a detected portion of the detected member so as to correspond to the optical sensor or the laser sensor, and these sensors use the difference in reflectance between the detected surface and the support member to rotate the rotating body. It may be configured to detect the operation state. In addition, the present invention can be applied to other sensors using the conductivity of carbon nanotubes, for example, a capacitance type displacement sensor.

  In the above description, the case where the present invention is applied to a hub unit for a driven wheel of a vehicle including a double row angular ball bearing type bearing has been described, but the rolling bearing device of the present invention is not limited to this, Bearing types such as the type and number of rolling elements are not limited to the above. Specifically, the present invention can be applied to a rolling bearing device that constitutes a vehicle drive wheel hub unit. Also, it is incorporated in a machine or device such as a rotating device other than a hub unit, and is applied to a rolling bearing device that uses an inner ring and an outer ring as a fixed raceway and a rotary raceway, respectively, contrary to the above embodiments. You can also.

It is sectional drawing of the rolling bearing apparatus with a sensor by which the encoder which concerns on one Embodiment of this invention was assembled | attached. It is a top view which shows the to-be-detected member of the said encoder when it sees from the sensor side. It is sectional drawing which shows the principal part of the rolling bearing apparatus with a sensor which concerns on another embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rolling bearing apparatus with a sensor 2 Rolling bearing apparatus 3 Sensor apparatus 4 Outer ring member (fixed bearing ring)
5 Inner shaft (rotating raceway)
6 Inner ring components (rotating raceway)
7, 8 Rolling element 13 Support member 14 Detected member 14a Detected surface 14b Groove (Detected surface, detected portion)
14c Convex part (detected surface, detected part)
DESCRIPTION OF SYMBOLS 15 Sensor 15a Detection surface 17 Sealing device 18 Core metal (fixed side annular member)
19 Slinger (Rotating side annular member, support member)
20 Seal member 21 Detected member 21a Detected surface 21b Groove (Detected surface, detected portion)
21c Convex part (detected surface, detected part)
21d Lip part E Encoder

Claims (5)

An encoder comprising a detected surface disposed opposite to a detection surface of a sensor for detecting an operating state of a rotating body,
When the detected surface is arranged to face the detection surface of the sensor, the detected surface has a plurality of detected portions having different gaps with the detection surface at different positions around the axis of the rotating body. A detected member formed on the side;
And a support member that is attached to the rotating body so as to be integrally rotatable, and supports the detected member.
An encoder characterized in that the member to be detected is made of carbon nanotube rubber. A fixed-side annular member fixed to the fixed raceway ring, a rotary-side annular member fixed to the rotary raceway ring facing the fixed-side annular member, and the fixed-side annular member attached to the rotary-side annular member A rolling bearing sealing device including an annular seal member that is in sliding contact with the sealing device,
A sealing device for a rolling bearing, wherein the member to be detected according to claim 1 is mounted on the rotating-side annular member.   The rolling bearing sealing device according to claim 2, wherein a lip portion slidably contacting the fixed race or the fixed-side annular member is provided on the detected member. A rolling bearing device having a rolling bearing provided with a fixed bearing ring and a rotating bearing ring, and a rolling element provided between the bearing rings so as to be freely rotatable, and incorporating a sensor for detecting an operating state of the rotating bearing ring. Because
A rolling bearing device with a sensor, wherein a support member on which the member to be detected according to claim 1 is mounted is attached to the rotating raceway so as to be integrally rotatable. A rolling bearing device having a rolling bearing provided with a fixed bearing ring and a rotating bearing ring, and a rolling element provided between the bearing rings so as to be freely rotatable, and incorporating a sensor for detecting an operating state of the rotating bearing ring. Because
A rolling bearing device with a sensor, wherein an annular opening between the bearing rings is sealed using the sealing device according to claim 2.

Images