JP2006112454A - Bearing device with sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing device with a sensor, capable of reducing the size by shortening the dimension in the axial direction, improving deflection accuracy of an encoder and reducing cost. <P>SOLUTION: This bearing device 10 with the sensor is provided with a rolling bearing 11 having an outer ring 13, an inner ring 14 and a plurality of rolling elements 15 arranged between the outer ring 13 and the inner ring 14 and with a speed detecting device 12 having the encoder 19 for speed pulse generation, a speed detecting element 20 for speed pulse detection and a magnet 21 for magnetic flux generation. The speed detecting device 12 is arranged between the outer ring 13 and the inner ring 14. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sensor-equipped bearing device that includes a sensor that detects the rotational speed of a rolling bearing incorporated in, for example, a railway vehicle or an automobile.

  As this type of conventional bearing device with a sensor, for example, the one shown in FIG. 4 is known (see, for example, Patent Document 1).

  In this sensor-equipped bearing device, a plurality of rolling elements 103 are arranged between an outer ring 101 and an inner ring 102 so as to be able to roll in the circumferential direction via a cage 104, and the inner circumference of one axial end portion of the outer ring 101 is arranged. A rolling bearing 107 in which a sealing device 106 is mounted in a circumferential groove 105 a formed on the surface, and a speed detection device 108 disposed on the other axial end side of the rolling bearing 107 are provided.

The speed detector 108 includes a multipolar magnet encoder 110 disposed with a speed pulse generation surface facing outward in the axial direction, and a speed sensor 111 disposed facing the encoder 110 in the axial direction. Prepare. The encoder 110 is attached to the outer peripheral surface of the end portion of the inner ring 102 via a metal screen 109, and the speed sensor 111 is held by a holding device 113 while being housed in the sensor carrier 112. The holding device 113 is fixed to a circumferential groove 105b formed on the inner circumferential surface of the other axial end portion of the outer ring 101 by welding or the like.
Japanese Patent Laid-Open No. 7-311212

  By the way, in the sensor-equipped bearing device described in Patent Document 1, since the encoder 110 and the speed sensor 111 are disposed so as to protrude from the axial end face of the rolling bearing 107, the axial dimension becomes longer and the size reduction is achieved. It becomes a cause to hinder.

  Further, since the encoder 110 made of a multipolar magnet is fixed via a metal screen 109 attached to the outer peripheral surface of the end portion of the inner ring 102 by press-fitting or the like, the end face shake of the encoder 110 occurs, and the encoder 110 There is a problem that it is difficult to improve runout accuracy.

  Further, since a large number of parts such as the metal screen 109, the sensor carrier 112, and the holding device 113 are required, there is a problem that the cost increases accordingly.

  The present invention has been made in order to eliminate such inconveniences, and an object of the present invention is to provide a sensor-equipped bearing device that can be reduced in size by reducing the axial dimension. Furthermore, an object of the present invention is to provide a sensor-equipped bearing device that can improve the deflection accuracy of the encoder and can reduce the cost.

The above object of the present invention is achieved by the following configurations.
(1) a rolling bearing having a fixed wheel, a rotating wheel, and a plurality of rolling elements disposed between the fixed wheel and the rotating wheel, an encoder for generating a speed pulse, and a speed detecting element for detecting a speed pulse; A speed detecting device having a magnet for generating magnetic flux, and a sensor-equipped bearing device,
The speed detecting device is provided between the fixed wheel and the rotating wheel.
(2) The sensor-equipped bearing device according to (1), wherein the encoder is formed in an uneven shape in a circumferential direction.
(3) The sensor-equipped bearing device according to (2), wherein the encoder is directly provided on a part of the rotating wheel.
(4) The sensor-equipped bearing device according to any one of (1) to (3), wherein the speed detection element is fixed integrally with the magnet.
(5) The sensor-equipped bearing device according to (4), wherein the speed detection element and the magnet are molded with resin.
(6) The sensor-equipped bearing device according to any one of (1) to (5), wherein the speed detection device further includes a magnetic circuit for magnetic bypass.

  According to the sensor-equipped bearing device of the present invention, a speed pulse generating encoder, a speed pulse detecting speed detecting element, and a magnetic flux generating magnet as a speed detecting device include a fixed ring and a rotating ring. Since it is provided in between, the axial dimension is shortened, and the size can be reduced.

  Also, by forming the encoder in an uneven shape in the circumferential direction and providing it directly on a part of the rotating wheel, it is possible to improve the deflection accuracy of the encoder and reduce the number of parts and reduce the cost. In addition, an expensive magnet can be obtained by using a magnet for generating a magnetic flux as a part of the speed detecting element side, so that further cost reduction can be achieved.

Furthermore, by fixing the speed detection element integrally with the magnet and molding both with resin, the mold part can be attached to the fixed ring by means of press-fitting or bonding, so that the assemblability is improved and further improved. The cost can be reduced.
Moreover, since the volume of the magnetic flux generating magnet can be reduced by providing a magnetic circuit for magnetic bypass, further cost reduction can be achieved.

  Hereinafter, each embodiment concerning the bearing device with a sensor of the present invention is described in detail with reference to drawings.

(First embodiment)
First, with reference to FIG.1 and FIG.2, the bearing apparatus with a sensor which is 1st Embodiment of this invention is demonstrated.
As shown in FIG. 1, the sensor-equipped bearing device 10 of the present embodiment includes a rolling bearing 11 and a speed detection device 12. The rolling bearing 11 includes a plurality of rolling wheels disposed so as to be able to roll between an outer ring 13 that is a fixed ring, an inner ring 14 that is a rotating ring, and an outer ring raceway surface 13 a of the outer ring 13 and an inner ring raceway surface 14 a of the inner ring 14. Attached to a moving body 15, a cage 16 having a plurality of pockets for holding the plurality of rolling elements 15 at predetermined intervals in the circumferential direction, and a circumferential groove 17 formed on an inner circumferential surface of one end portion in the axial direction of the outer ring 13 And the sealing device 18 to be operated. The speed detection device 12 is provided between the inner peripheral surface of the outer ring 13 and the outer peripheral surface of the inner ring 14 at the other axial end opposite to the sealing device 18 with respect to the rolling element 15.

The outer ring 13 and the inner ring 14 have substantially the same axial dimension, and each raceway surface 13a, 14a is formed near one axial end where the sealing device 18 is disposed with respect to each axial center. . That is, the outer ring 13 and the inner ring 14, the raceway surfaces 13a, the axial dimension _{L 1} from the center of the 14a to the end surface of one axial end of the sealing device 18 is arranged, axially from the center of each raceway surfaces 13a, 14a is set shorter than the axial dimension L ₂ to the end face of the direction other end, between the inner and outer circumferential surfaces of the inner ring 14 of the outer ring 13 in the other axial end portion is provided with a speed detection device 12 Space is secured.

  The speed detection device 12 includes an encoder 19 for generating a speed pulse, a speed detecting element 20 for detecting a speed pulse, a magnet 21 for generating a magnetic flux, a resin 22 for molding the speed detecting element 20 and the magnet 21, and speed detection. And a lead 23 for transmitting a detection signal from the element 20 to the outside.

  The encoder 19 is formed on the outer peripheral surface of the other end portion in the axial direction of the inner ring 14 by directly processing the concave and convex shape at equal intervals along the circumferential direction by, for example, cutting, and the processed concave and convex portion is subjected to a polishing process. It has been subjected.

  The speed detection element 20 is integrally fixed to the magnet 21 by adhesion or the like. The speed detection element 20 and the magnet 21 are entirely molded with a resin 22 by injection molding or potting to form a ring-shaped sensor unit 24. The sensor unit 24 moves the speed detection element 20 in the radial direction with respect to the encoder 19. Is attached to the inner peripheral surface of the other end portion in the axial direction of the outer ring 13 by press-fitting or bonding.

  In the sensor unit 24 attached in this way, the axial inner side surface 22a formed by the resin 22 is positioned axially inward from the encoder 19, and the inner peripheral surface of the sensor unit 24 near the axial inner side surface 22a. And a labyrinth seal 25 is formed between the inner ring 14 and the outer peripheral surface in the vicinity of the encoder 19 facing the encoder 19.

  As the resin 22, for example, PPS, 66 nylon, 46 nylon or the like, which is an engineering plastic, can be used. In this case, glass fiber or the like may be added to improve the strength. Moreover, as the magnet 21, for example, a metal magnet such as neodymium or ferrite magnet, a plastic magnet, or the like can be used.

  After the lead 23 is bent in the resin 22 of the sensor unit 24, a part of the lead 23 protrudes axially outward from the resin 22 to form a connector pin 23a, and a female connector can be fixed to the peripheral portion of the pin 23a. The resin 22 is formed into the shape of the connector 26 (see FIG. 2). This eliminates the need to provide a separate connector, thereby reducing the cost.

  The magnetic flux in the speed detection device 12 flows in the order of the magnet 21 → the inner ring 14 → the rolling element 15 → the outer ring 13 → the magnet 21. When the inner ring 14 rotates, the magnetic flux transmitted through the speed detection element 20 changes as the encoder 19 rotates. The rotational speed can be detected based on the amount of change in the magnetic flux. Further, even if the arrangement of the magnets shown in FIG. 1 is reversed (N pole is on the upper side), the same effect can be obtained only by reversing the flow of magnetic flux.

  Accordingly, in the sensor-equipped bearing device 10 of the present embodiment, the speed pulse generating encoder 19 as the speed detection device 12 and the speed detection for speed pulse detection are provided between the outer ring 13 and the inner ring 14 of the rolling bearing 11. Since the element 20 and the magnet 21 for generating magnetic flux are provided, the axial dimension can be shortened and the size can be reduced.

  Further, the encoder 19 is formed by directly processing the uneven shape on the outer peripheral surface of the end portion of the inner ring 14 along the circumferential direction by, for example, cutting, and polishing the processed uneven portion. The accuracy of the coaxiality between the raceway surface 14a and the outer peripheral surface of the encoder 19 is increased, and the deflection of the outer peripheral surface of the encoder 19 can be made substantially zero, whereby the deflection accuracy of the encoder 19 can be improved.

  Furthermore, since the encoder 19 is formed by directly processing the concavo-convex shape on the outer peripheral surface of the end portion of the inner ring 14, the number of parts can be reduced and the cost can be reduced. Since it is sufficient to use a magnet 21 for generating magnetic flux in a part of the side, further cost reduction can be achieved.

  Further, since the speed detection element 20 is fixed integrally with the magnet 21 and is molded with the resin 22 to form a ring-shaped sensor unit 24, the sensor unit 24 is attached to the inner peripheral surface of the end of the outer ring 13. It can be assembled by means such as press-fitting or adhesion, thereby improving the assemblability and further reducing the cost.

(Second Embodiment)
Next, a sensor-equipped bearing device according to a second embodiment of the present invention will be described with reference to FIG. In addition, about the part equivalent to 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted or simplified.

As shown in FIG. 3, the sensor-equipped bearing device 30 according to the present embodiment includes a rolling bearing 31 and a speed detection device 32. The rolling bearing 31 includes a plurality of rolling wheels disposed so as to be able to roll between an outer ring 33 that is a fixed ring, an inner ring 34 that is a rotating ring, and an outer ring raceway surface 33 a of the outer ring 33 and an inner ring raceway surface 34 a of the inner ring 34. The moving body 15, the cage 16, and the sealing device 18 are provided. As in the first embodiment, the outer ring 33 and the inner ring 34 have one axial end where the sealing device 18 is disposed from the center of the raceway surfaces 33 a and 34 a. the axial dimension L ₁ to the end face of the section is set shorter than the axial dimension L ₂ to the end face of the other axial end portion of the raceway surface 33a, the speed detecting device 32 from the center of 34a is provided.

  Moreover, the step part 33b is provided in the axial direction other end part of the outer ring | wheel 33, and the inner peripheral surface by the side of an end surface is diameter-expanded. On the other hand, a step 34b is also provided at the other axial end of the inner ring 34, and the outer peripheral surface on the end surface side is reduced in diameter. A speed detection device 32 is provided between the large-diameter outer peripheral surface 33c of the outer ring 33 whose diameter has been increased and the small-diameter inner peripheral surface 34c of the inner ring 34 whose diameter has been reduced. The step 34b of the inner ring 34 is formed axially inward from the step 33b of the outer ring 33, and the step surface 34d of the inner ring 34 is located axially inward from the step surface 33d of the outer ring 33. Yes.

  The speed detection device 32 molds the speed pulse generation encoder 19, the speed detection element 20 for speed pulse detection, the magnet 21 for magnetic flux generation, the speed detection element 20 and the magnet 21, and constitutes the connector 26. Resin 22, a lead 23 that transmits a detection signal from the speed detection element 20 to the outside, and a magnetic body 35 that forms a magnetic circuit for magnetic bypass.

  The encoder 19 is formed by directly processing a concavo-convex shape at equal intervals along the circumferential direction, for example, by cutting or the like, on the large-diameter outer peripheral surface 34c of the other end portion in the axial direction of the inner ring 34. Is polished.

  The speed detection element 20 and the magnet 21 are integrally fixed to each other by bonding or the like, and then resin-molded by injection molding or potting in a state where the magnetic body 35 is used as a metal core to constitute a cylindrical sensor unit 36. .

  The magnetic body 35 is formed in a ring shape having an L-shaped cross section by a cylindrical portion 35a and an annular plate portion 35b extending radially inward from the end portion of the cylindrical portion 35a, and the cylindrical portion 35a defines the outer peripheral surface of the resin 22. The cylindrical portion 35a of the magnetic body 35 is magnetically connected to the magnet 21. The cylindrical portion 35a of the magnetic body 35 is integrally formed with the resin 22 so as to cover the inner surface in the axial direction of the resin 22 with the annular plate portion 35b. As the magnetic body 35, for example, iron, martensitic stainless steel, ferritic stainless steel, or the like can be used.

  The sensor unit 36 press-fits the cylindrical portion 35a of the magnetic body 35 into the large-diameter inner peripheral surface 33c at the other end in the axial direction of the outer ring 33 with the speed detection element 20 facing the encoder 19 in the radial direction. It is attached by bonding or the like.

  In the sensor unit 36 attached in this way, the inner surface in the axial direction of the annular plate portion 35b of the magnetic body 35 is positioned axially inward from the encoder 19, and the cylindrical portion 35a of the magnetic body 35 is replaced with the step portion 33b. When the abutting step 33d is brought into contact with the stepped surface 33d, the inner diameter portion of the annular plate portion 35b of the magnetic body 35 faces the stepped surface 34d of the stepped portion 34b with a predetermined gap. A labyrinth seal 37 is formed between the inner diameter portion of the resin 22 and the annular plate portion 35 b and the step portion 34 b of the inner ring 34.

  A magnetic path 38 (shown by a broken line) of the magnetic flux in the speed detection device 32 flows in the order of the magnet 21 → the inner ring 34 → the magnetic body 35 → the magnet 21, and when the inner ring 34 rotates, the encoder 19 rotates and the speed detection element 20. The magnetic flux passing through the magnetic flux changes, and the rotational speed can be detected based on the amount of change in the magnetic flux. Similar to the first embodiment, the same effect can be obtained even if the direction of the magnet is reversed.

  Therefore, in this embodiment, since the magnetic body 35 that forms the magnetic circuit for magnetic bypass is provided in the sensor unit 36, the magnetic flux can be used effectively, and the magnetic flux transmitted through the speed detection element 20 can be reduced. Thus, the volume of the magnet 21 can be reduced, and further cost reduction can be achieved.

  Further, since the magnetic flux passes through the magnetic circuit for magnetic bypass, it is possible to prevent the magnetic flux passing through the rolling element 15 from being reduced and collect iron powder or the like on the raceway surfaces of the outer ring 33 and the inner ring 34.

Furthermore, since the cylindrical portion 35a of the magnetic body 35 can be fixed to the stepped portion 33b on the inner circumferential surface of the end portion of the outer ring 33 by press fitting or the like, loosening due to creep of the resin 22 can be prevented.
Since other configurations and operations are the same as those in the first embodiment, description thereof is omitted.

In addition, this invention is not limited to this embodiment, In the range which does not deviate from the summary of this invention, it can change suitably.
For example, in this embodiment, the case where only the speed detection element is molded on the resin is shown, but the present invention is not limited to this, and the temperature detection element and the vibration detection element are integrally molded on the resin to detect the temperature and vibration. May be.

Moreover, although this embodiment shows the case where an inner ring | wheel is used as a rotating wheel, this invention is applicable also when an outer ring | wheel is used as a rotating wheel.
Furthermore, in this embodiment, although the case where the uneven part of the encoder is formed by cutting is shown, it is not always necessary to do this, and by forming the uneven part of the encoder by pressing or forging, the cost can be reduced. Can be achieved.
Further, the present invention is not limited to a ball bearing, and may be a tapered roller bearing or a cylindrical roller bearing.

  In addition, the material, shape, dimensions, form, number, arrangement location, etc. of each member of the rolling bearing and the speed detection device are arbitrary and are not limited as long as the present invention can be achieved.

It is principal part sectional drawing for demonstrating the bearing apparatus with a sensor which is 1st Embodiment of this invention. It is the figure which looked at the speed detection apparatus from the arrow II direction of FIG. It is principal part sectional drawing for demonstrating the bearing apparatus with a sensor which is 2nd Embodiment of this invention. It is principal part sectional drawing for demonstrating the conventional bearing apparatus with a sensor.

Explanation of symbols

10, 30 Bearing device with sensor 11, 31 Rolling bearing 12, 32 Speed detector 13, 33 Outer ring (fixed ring)
14,34 Inner ring (rotating wheel)
DESCRIPTION OF SYMBOLS 15 Rolling body 19 Encoder 20 Speed detection element 21 Magnet 22 Resin 35 Magnetic body (Magnetic circuit for magnetic bypass)

Claims (6)

A rolling bearing having a fixed wheel, a rotating wheel, and a plurality of rolling elements disposed between the fixed wheel and the rotating wheel; a speed pulse generating encoder; a speed pulse detecting speed detecting element; and a magnetic flux generating A sensor-equipped bearing device comprising: a speed detection device having a magnet;
The speed detecting device is provided between the fixed wheel and the rotating wheel.   The sensor-equipped bearing device according to claim 1, wherein the encoder is formed in an uneven shape in a circumferential direction.   The sensor-equipped bearing device according to claim 2, wherein the encoder is directly provided on a part of the rotating wheel.   The sensor-equipped bearing device according to claim 1, wherein the speed detection element is fixed integrally with the magnet.   The sensor-equipped bearing device according to claim 4, wherein the speed detection element and the magnet are molded with resin.   The sensor-equipped bearing device according to claim 1, wherein the speed detection device further includes a magnetic circuit for magnetic bypass.

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