JP2009041704A - Rolling bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling bearing device enabling to improve the distortion detecting accuracy of an outer ring with a small number of distortion gages. <P>SOLUTION: In the rolling bearing device, a first outer peripheral face 23 of the outer ring 1 on which the first and second distortion gages 26, 27 are mounted crosses a ball 8 with its normal L1 inclined to a radial plane P1 by a contact angle θ1 of the ball 8, and a second outer peripheral face 25 of the outer ring 1 on which the third and fourth distortion gages 28, 30 are mounted crosses a ball 12 with its normal L2 inclined to a radial plane P2 by a contact angle θ2 of a ball 12. The distortion amount of each of the outer peripheral faces 23, 25, when the balls 8, 12 pass through first and second raceway surfaces 5, 6 corresponding to the first and second outer peripheral faces 23, 25 of the outer ring 1 on which the first, second, third and fourth distortion gages 26, 27, 28, 39 are mounted, are greater than in the case that the inclination angles of the normals L1, L2 are different from the contact angles θ1, θ2, respectively. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rolling bearing device to which a strain gauge for detecting strain of an outer ring is attached.

  Conventionally, as this kind of rolling bearing device, a wheel bearing rolling bearing unit is disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2004-142577). In this rolling bearing unit, two strain gauges are respectively attached to three to four places at equal intervals in the circumferential direction on the cylindrical outer peripheral surface of the outer ring in a state where their central axes are orthogonal to each other (Patent Document 1). (See FIGS. 6 and 7).

By the way, in the above-mentioned conventional rolling bearing device, a large number of strain gauges are required to detect the strain of the outer ring, and it is difficult to obtain a desired detection accuracy.
JP 2004-142577 A

  Accordingly, an object of the present invention is to provide a rolling bearing device that can improve the accuracy of strain detection of the outer ring even if the number of strain gauges is small.

In order to solve the above problems, a rolling bearing device of the present invention includes an outer ring,
A rolling element that rolls on the raceway surface of the outer ring and is given a predetermined contact angle;
The outer ring is
An outer peripheral surface having a normal line inclined by the contact angle with respect to a radial plane orthogonal to the axial direction and the normal line intersecting the rolling element,
Furthermore, a strain gauge attached to the outer peripheral surface is provided.

  According to the rolling bearing device of the present invention, the outer peripheral surface of the outer ring to which the strain gauge is attached is inclined with respect to the radial plane by the contact angle of the rolling element and intersects the rolling element. . Thereby, the amount of distortion of the outer peripheral surface when the rolling element passes through the raceway surface of the outer ring corresponding to the outer peripheral surface to which the strain gauge is attached is compared with the case where the inclination angle of the normal is different from the contact angle. Can be bigger. Therefore, the outer peripheral surface of the outer ring is likely to be distorted when a radial bending moment is applied to the bearing. Therefore, according to the strain gauge attached to the outer peripheral surface of the outer ring, the accuracy of detecting the distortion of the outer ring can be improved.

Further, in the rolling bearing device according to one embodiment, the outer ring has first and second raceway surfaces adjacent in the axial direction,
A first rolling element that rolls on the first raceway surface and is given a first contact angle;
A second rolling element that rolls on the second raceway surface and is given a second contact angle;
The outer ring is
A first outer periphery having a first normal line inclined by the first contact angle with respect to a radial plane orthogonal to the axial direction, and the first normal line intersecting the first rolling element Surface,
A second outer periphery having a second normal that is inclined by the second contact angle with respect to a radial plane orthogonal to the axial direction, and wherein the second normal intersects the second rolling element; With a surface,
Furthermore, the first and second strain gauges that are displaced from each other by 180 ° in the circumferential direction and are attached to the first outer peripheral surface;
And third and fourth strain gauges which are displaced from each other by 180 ° in the circumferential direction and are attached to the second outer peripheral surface.

  According to this embodiment, the first strain gauge attached to the first outer peripheral surface of the outer ring is spaced apart from the first strain gauge in the axial direction and is 180 ° displaced in the circumferential direction. By using the fourth strain gauge, the outer ring distortion due to the bending moment applied to the bearing in the radial direction can be detected with high accuracy. Further, the second strain gauge attached to the first outer peripheral surface of the outer ring and the third strain gauge are axially separated from the second strain gauge and are displaced by 180 ° in the circumferential direction. With this strain gauge, it is possible to detect the distortion of the outer ring due to the bending moment in the direction opposite to the bending moment applied to the bearing in the radial direction with high accuracy.

  In the rolling bearing device of one embodiment, the strain gauge is attached to the outer peripheral surface of the outer ring so as to detect the strain in the circumferential direction of the outer ring.

  According to the rolling bearing device of this embodiment, the strain gauge attached to the outer peripheral surface of the outer ring can measure the bending moment applied to the bearing with high accuracy by detecting the strain in the circumferential direction of the outer ring. It has been found that due to the bending moment, the circumferential distortion of the outer ring is larger than the axial distortion of the outer ring.

  According to the rolling bearing device of the present invention, the outer peripheral surface of the outer ring to which the strain gauge is attached is inclined with respect to the radial plane by the contact angle of the rolling element and intersects the rolling element. . Thereby, the outer peripheral surface of the outer ring is likely to be distorted when a radial bending moment is applied to the bearing. Therefore, according to the strain gauge attached to the outer peripheral surface of the outer ring, the distortion of the outer ring can be detected with high accuracy.

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

  FIG. 1 shows a hub unit as an embodiment of the rolling bearing device of the present invention. The hub unit includes an outer ring 1, a shaft member 2, and an inner ring 3. The shaft member 2 is fitted and fixed to the inner ring 3 and is fixed by caulking 2A at the end of the shaft member 2 in the axial direction.

  The outer ring 1 has an angular first raceway surface 5 and an angular second raceway surface 6 spaced axially from the first raceway surface 5. Between the first raceway surface 5 and the raceway surface 7 of the inner ring 3, a plurality of balls 8 as first rolling elements are arranged at a predetermined interval in the circumferential direction. The plurality of balls 8 are held by a cage 9. A plurality of balls 12 as second rolling elements are arranged in the circumferential direction at a predetermined interval between the second raceway surface 6 of the outer ring 1 and the raceway surface 11 of the shaft member 2. The plurality of balls 12 are held by a cage 10.

  Further, an engagement fitting 15 </ b> A of the magnetic sensor 15 is fitted and fixed to the inner peripheral surface of the one end portion 13 in the axial direction of the outer ring 1. Reference numeral 15B denotes a connector portion of the magnetic sensor 15. On the other hand, a pulsar ring 16 having a plurality of openings 16A is fixed to the outer peripheral surface of the inner ring 3 at a predetermined interval in the circumferential direction. When the inner ring 3 rotates with respect to the outer ring 1, the magnetic path is interrupted at a period corresponding to the rotation of the pulsar ring 16, and a pulse signal is output from the connector portion 15B.

  Further, a seal portion 20 is fixed to the other end portion 17 of the outer ring 1 in the axial direction, and a seal lip of the seal portion 20 is in sliding contact with the step portion 18 of the shaft member 2. The shaft member 2 has a flange portion 21 adjacent to the step portion 18, and serrations 22 </ b> A of bolts 22 are press-fitted into a plurality of through holes formed in the flange portion 21. For example, a brake disk (not shown) is fastened to the flange portion 21 by a bolt 22.

  As shown in FIGS. 1 and 2, the first outer peripheral surface 23 corresponding to the first raceway surface 5 of the outer ring 1 has a normal line L1 intersecting with the ball 8 as the first rolling element, and this The normal line L1 is a ball with respect to the radial plane P1 orthogonal to the central axis J so as to improve the adhesion between the first outer peripheral surface 23 of the outer ring 1 and the first and second strain gauges 26, 27. 8 is inclined by an inclination angle θ1 (45 ° as an example) equal to the contact angle of 8. Further, the second outer peripheral surface 25 corresponding to the second raceway surface 6 of the outer ring 1 has a normal line L2 that intersects the ball 12 as the second rolling element, and this normal line L2 is the outer ring 1. Inclination equal to the contact angle of the ball 12 with respect to the radial plane P2 orthogonal to the central axis J so as to improve the adhesion between the second outer peripheral surface 25 and the third and fourth strain gauges 28, 30 It is inclined by an angle θ2 (45 ° as an example). The inclined outer peripheral surfaces 23 and 25 can reduce the weight of the hub unit. Also, one end of the first to fourth strain gauges 26, 27, 28, 30 is caught on a flat surface (cylindrical surface) between the two outer peripheral surfaces 23 and 25 formed by the two inclination angles θ1 and θ2. Therefore, the displacement of the strain gauges 26 to 30 in the inter-ball direction (axial direction) can be prevented.

  Further, in this embodiment, as shown in FIG. 1, a first strain gauge 26 attached to the first outer peripheral surface 23 and a position 180 ° in the circumferential direction with respect to the first strain gauge 26. It has the 2nd strain gauge 27 which has slip | deviated and was attached to the 1st outer peripheral surface 23. FIG. Further, in this embodiment, a third strain gauge 28 attached to the second outer peripheral surface 25 and a fourth strain position that is 180 ° displaced in the circumferential direction with respect to the third strain gauge 28. A strain gauge 30 is provided. Further, the first strain gauge 26 and the third strain gauge 28 are in phase in the circumferential direction. The first to fourth strain gauges 26 to 30 are preferably attached to the first and second outer peripheral surfaces 23 and 25 so as to detect the circumferential strain of the outer ring 1, respectively. Moreover, the 1st-4th strain gauges 26-30 are attached to the 1st, 2nd outer peripheral surfaces 23 and 25 by the adhesion | attachment by an adhesive agent as an example.

  According to the hub unit configured as described above, the first outer peripheral surface 23 of the outer ring 1 to which the first and second strain gauges 26 and 27 are attached has a normal line L1 in the radial plane by the contact angle θ1 of the ball 8. It is inclined with respect to P1 and intersects with the ball 8. The second outer peripheral surface 25 of the outer ring 1 to which the third and fourth strain gauges 28 and 30 are attached is inclined with respect to the radial plane P2 by the normal line L2 by the contact angle θ2 of the ball 12. Crosses the ball 12 above.

  Accordingly, the first, second, and second outer peripheral surfaces 23, 25 of the outer ring 1 to which the first, second, third, and fourth strain gauges 26, 27, 28, 30 are attached. The amount of distortion of the outer peripheral surfaces 23 and 25 when the balls 8 and 12 pass through the raceway surfaces 5 and 6 is larger than when the inclination angles of the normal lines L1 and L2 are different from the contact angles θ1 and θ2. it can. Therefore, the outer peripheral surfaces 23 and 25 of the outer ring 1 are likely to be distorted when a radial bending moment indicated by an arrow M1 is applied to the hub unit. Therefore, according to the strain gauges 26, 27, 28, 30 attached to the outer peripheral surfaces 23, 25 of the outer ring 1, it is possible to improve the accuracy of detecting the strain of the outer ring 1.

  Here, FIG. 4 shows the time change of the strain amount represented by the signals obtained from the strain gauges 26, 27, 28 and 30. The amplitude Δε of the waveform W1 representing the time change of the distortion amount shown in FIG. 4 represents the distortion amplitude amount. Each peak of the waveform W1 is generated when the ball passes through the strain gauge. The load applied to the outer ring 1 can be estimated from the strain amplitude. As an example, FIG. 5 shows the relationship between the strain amplitude (μm) and the turning load (G). As shown in FIG. 5, the turning load can be obtained from the strain amplitude. In addition, when calculating | requiring a turning load from the absolute value of the distortion amount which the signal obtained from the said strain gauges 26,27,28,30 calculates | requires, it receives influence of a temperature change etc., and accuracy falls.

  Further, according to this embodiment, the first strain gauge 26 attached to the first outer peripheral surface 23 of the outer ring 1 and the first strain gauge 26 are spaced apart from each other in the axial direction and the periphery. The strain of the outer ring 1 due to the bending moment applied to the hub unit in the radial direction indicated by the arrow M1 can be detected with high accuracy by the fourth strain gauge 30 displaced by 180 ° in the direction. Further, the second strain gauge 27 attached to the first outer peripheral surface 23 of the outer ring 1 and the second strain gauge 27 are separated from each other in the axial direction and are displaced by 180 ° in the circumferential direction. With the third strain gauge 28, the distortion of the outer ring 1 due to the bending moment in the direction opposite to the radial direction indicated by the arrow M1 in the hub unit can be detected with high accuracy.

  Moreover, in the said embodiment, the said 1st-4th strain gauges 26-30 were attached to the 1st, 2nd outer peripheral surfaces 23 and 25 so that the distortion of the circumferential direction of the outer ring | wheel 1 might each be detected. In this case, the bending moment applied to the hub unit can be measured with high accuracy by detecting the strain in the circumferential direction of the outer ring 1 by the strain gauges 26 to 30. The reason is that it has been found that the circumferential strain of the outer ring 1 is larger than the axial strain of the outer ring 1 due to the bending moment. According to this embodiment, the moment load applied to the tire can be detected relatively inexpensively, and by inputting a signal representing the amount of strain obtained from the strain gauges 26, 27, 28, 30 to the skid control device or the like of the vehicle. High accuracy control can be achieved.

  In the above-described embodiment, the case where the outer ring 1 has the double-row raceway surfaces 5 and 6 has been described, but the present invention can also be applied to the case where the outer ring has a single-row raceway surface. Moreover, in the said embodiment, although the 1st outer peripheral surface 23 and the 2nd outer peripheral surface 25 of the outer ring | wheel 1 were spaced apart only the predetermined dimension to the axial direction, it replaces with the outer ring | wheel 1 and the outer ring | wheel 31 shown in FIG. You may prepare. The outer ring 31 has angular first and second raceway surfaces 38 and 39 that are spaced apart in the axial direction, and a first outer peripheral surface 33 and a second outer peripheral surface 35 that are adjacent in the axial direction. The first and second strain gauges 26 and 27 are attached to the first outer peripheral surface 33. Further, the third and fourth strain gauges 28 and 30 are attached to the second outer peripheral surface 35. A normal line L31 of the first outer peripheral surface 33 is inclined by a contact angle θ31 of the ball 8 with respect to a radial plane P31 orthogonal to the central axis J. The normal line L32 of the second outer peripheral surface 35 is inclined by the contact angle θ32 of the ball 12 with respect to the radial plane P32 orthogonal to the central axis J. According to the outer ring 31 shown in FIG. 3, the first and second outer peripheral surfaces 33 and 35 can be constituted by, for example, a circumferential groove having a V-shaped cross section formed on the flat outer peripheral surface 31 </ b> A of the outer ring 31. .

It is sectional drawing of the hub unit which is embodiment of the rolling bearing apparatus of this invention. It is sectional drawing of the outer ring | wheel of the said embodiment. It is sectional drawing of the outer ring | wheel which the modification of the said embodiment has. It is a wave form diagram showing the time change of the amount of distortion which the signal obtained from strain gauges 26, 27, 28, and 30 expresses in the above-mentioned embodiment. It is a figure which shows the relationship between distortion amplitude amount (micrometer) and turning load (G).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 31 Outer ring 2 Shaft member 3 Inner ring 5, 38 1st raceway surface 6, 39 2nd raceway surface 7 Raceway surface 8, 12 ball 13 One end part 15 Magnetic sensor 15A Engagement metal fitting 15B Connector part 16 Pulsar ring 16A Opening 17 Other end portion 18 Step portion 20 Seal portion 21 Flange portion 22 Bolt 23, 33 First outer peripheral surface 25, 35 Second outer peripheral surface 26 First strain gauge 27 Second strain gauge 28 Third strain gauge 30 First No. 4 strain gauge L1, L2 Normal P1, P2 Radial plane J Central axis θ1, θ2 Inclination angle

Claims (3)

Outer ring,
A rolling element that rolls on the raceway surface of the outer ring and is given a predetermined contact angle;
The outer ring is
Having a normal line that is inclined by the contact angle with respect to a radial plane orthogonal to the axial direction and having an outer peripheral surface that intersects the rolling elements,
Furthermore, the rolling bearing apparatus provided with the strain gauge attached to the said outer peripheral surface. The rolling bearing device according to claim 1,
The outer ring has first and second raceway surfaces adjacent in the axial direction,
A first rolling element that rolls on the first raceway surface and is given a first contact angle;
A second rolling element that rolls on the second raceway surface and is given a second contact angle;
The outer ring is
A first outer periphery having a first normal line inclined by the first contact angle with respect to a radial plane orthogonal to the axial direction, and the first normal line intersecting the first rolling element Surface,
A second outer periphery having a second normal that is inclined by the second contact angle with respect to a radial plane orthogonal to the axial direction, and wherein the second normal intersects the second rolling element; With a surface,
Furthermore, the first and second strain gauges that are displaced from each other by 180 ° in the circumferential direction and are attached to the first outer peripheral surface;
A third strain gauge and a fourth strain gauge that are displaced from each other by 180 ° in the circumferential direction and are attached to the second outer peripheral surface;
The rolling bearing device, wherein the first strain gauge and the third strain gauge have the same phase in the circumferential direction. In the rolling bearing device according to claim 1 or 2,
The strain gauge is
A rolling bearing device mounted on an outer peripheral surface of the outer ring so as to detect a circumferential distortion of the outer ring.

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