JP2009092168A - Rolling bearing device with sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling bearing device with a sensor having a structure for preventing exposure of a magnetic body outside without deteriorating rotating performance, in regard to the structure for fixing the sensor to the bearing device. <P>SOLUTION: An annular member 10 formed of a fixing portion 30 for fixing a sensor 20 and a cover portion 40 for covering a magnetic body is installed in a bearing device 1. The cover portion 40 comprises a fitting surface 15, on which an outer ring 4 is to be fitted, an abutting surface 16 to be made to abut on an outer ring end surface 4a for positioning, and a deflector portion 19 forming labyrinth structure along the shape of a shaft 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rolling bearing device with a sensor.

  In measuring rotational motion in various devices, a bearing device may be equipped with a measurement mechanism. For example, when an ABS mechanism is configured for a vehicle axle drive wheel, there is an example in which an ABS sensor that detects a rotational speed is fixed to a bearing device. In that case, the ABS sensor is fixed to the cover member fitted to the outer diameter of the bearing non-rotating wheel, and the ABS sensor detects the rotation speed due to the change in magnetic flux density caused by the rotation of the magnet rotor (magnetic material) fitted to the rotating wheel. To do.

  In a structure in which an encoder made of a permanent magnet is fixed to a rotating wheel of a bearing that rotatably supports a driving wheel of a vehicle, foreign matter wound up from the road surface during traveling will adhere to the surface unless the encoder is protected by any method. As a result, the rotational speed detection performance deteriorates. In Patent Document 1 below, a seal ring is disposed between the inner peripheral portion of the knuckle that supports and fixes the bearing device and the axle, and the encoder is blocked from the external space, thereby preventing foreign matter from adhering to the encoder. Techniques to do this are disclosed.

JP 2001-147252 A

  However, in the technique of the above-mentioned Patent Document 1, although the encoder can be shut off from the outside by the seal ring, sliding resistance is generated because the seal ring is in sliding contact with the fixed portion. Therefore, it becomes a resistance to driving of the vehicle, which is an obstacle to the low fuel consumption of the automobile. This is a major drawback as the demand for improving the performance of automobiles increases.

  Accordingly, in view of the above problems, the problem to be solved by the present invention is a sensor-equipped rolling bearing device having a structure in which a magnetic body is not exposed to the outside without deteriorating rotational performance in a structure in which a sensor is fixed to the bearing device. Is to provide.

Means for Solving the Problems and Effects of the Invention

  In order to solve the above-described problems, a rolling bearing device with a sensor according to the present invention detects a magnetic body attached so that a magnetic field alternately changes along a circumferential direction of a rotating wheel, and detects the magnetic field of the magnetic body. A sensor-equipped rolling bearing device having a sensor fixed to a non-rotating wheel so as to measure the rotational speed of the rotating wheel, comprising an annular member for fixing the sensor to the non-rotating wheel, the annular member being A cylindrical portion fitted to the non-rotating wheel, and an extending portion extending from the axially outer end portion of the cylindrical portion to the side where the rotating wheel is provided in the radial direction. The abutting surface that abuts against the end surface of the non-rotating wheel in a state in which the cylindrical portion of the annular member is fitted and attached to the non-rotating wheel is formed on the portion, and the magnetic body is pivoted on the extending portion. A covering surface covering from the direction, and the covering surface is more axial than the protruding surface It is formed at a position of the outer, and wherein a gap is formed between the magnetic body and the covering surface.

  As a result, since the annular member can be positioned by abutting the abutting surface against the end surface of the non-rotating wheel, the positioning of the annular member is stable compared to the conventional technique in which the abutting surface is not formed on the annular member. It becomes a bearing device with a sensor. Therefore, since the position and posture of the sensor are prevented from shifting due to the wobbling of the annular member, the reliability of the measured value of the sensor can be further improved. Moreover, since the outer diameter and inner diameter of the extending part in the annular member are set so that the extending part covers the magnetic body, it is possible to prevent foreign matters from being mixed from the outside and adhering to the magnetic body. Therefore, the reliability of detection of the magnetic field of the magnetic material by the sensor is increased. Therefore, a sensor-equipped bearing device with high reliability of the measurement value by the sensor can be configured in combination with the improvement of the fixing property and stability of the sensor.

  In addition, a drain hole for drainage may be formed in the extended portion without causing a part of the abutting surface to abut against the end surface of the non-rotating wheel.

  As a result of the drain hole being formed, muddy water that has entered the bearing device can be discharged to the outside, so that contamination of the sensor and magnetic material due to muddy water is reduced, so that the sensor may obtain an erroneous measurement value due to contamination. It is suppressed. Therefore, a sensor-equipped bearing device with high reliability of sensor measurement values can be configured.

  The extending portion extends from the radial end portion of the covering surface outward in the axial direction, and follows the shape of the shaft from the radial direction while having a gap with the shaft. A deflector portion covering the shaft may be formed.

  As a result, the deflector portion covers the shaft from the radial direction with a space between the shaft and the deflector portion, so that a labyrinth structure is formed by the deflector portion, thereby preventing foreign matters from being mixed into the bearing from the vicinity of the shaft. Accordingly, it is possible to suppress the foreign matter from adhering to the magnetic body and reducing the reliability of the measurement value obtained by the sensor. Furthermore, since there is no contact between the deflector portion and the shaft, contact resistance does not occur unlike the use of a seal and the like, so that foreign matter can be prevented from being mixed into the bearing without reducing rotational performance. Therefore, a sensor-equipped bearing device with high reliability of the measurement value by the sensor can be configured.

  Further, the shaft has a shaft-side conical portion whose outer diameter increases as the distance from the bearing increases, and also in the deflector portion, the deflector-side conical portion whose inner diameter increases as the outer diameter of the shaft increases. The degree of increase of the inner diameter with respect to the distance from the bearing in the deflector-side conical portion may be greater than the degree of increase of the outer diameter with respect to the distance from the bearing in the shaft-side conical portion.

  As a result, the inner diameter of the deflector portion increases as the outer diameter of the shaft increases, and the degree of increase in the inner diameter of the deflector portion exceeds the degree of increase in the outer diameter of the shaft, so that the labyrinth structure can be easily formed along the shape of the shaft. . By setting the degree of increase in the diameters of the shaft and the deflector portion, the deflector portion comes into contact with the shaft and does not become a resistance to rotation, and foreign matter can be prevented from entering from the outside. Therefore, a sensor-equipped bearing device with high reliability of the measurement value by the sensor can be configured.

  The sensor includes a through hole, the annular member includes a hole, and the sensor is configured to be annular by fastening with a bolt or a rivet between the through hole of the sensor and the hole of the annular member. It may be fixed to the member.

  As a result, the sensor is fixed to the annular member by bolt fastening or rivet crimping, so that the sensor is firmly fixed to the annular member, and it is possible to suppress the possibility of errors in measurement values due to deviations in the position and orientation of the sensor. Further, since bolt fastening or rivet crimping is used, there is no need to separately form a part for fixing the sensor. In a conventional bearing device with a sensor, an opening is formed in the annular member in order to integrally form the annular member and the sensor fixing portion, and the magnetic body is exposed to the outside. However, since the sensor fixing portion need not be formed on the annular member in the above configuration, it is easy to form the covering surface and the deflector portion in a shape that does not expose the magnetic body to the outside. Therefore, a sensor-equipped bearing device with high reliability of the measurement value by the sensor can be configured without attaching foreign matter to the magnetic body.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an axial sectional view of a rolling bearing device with a sensor 1 (bearing device) according to the present invention. The bearing device 1 rotatably supports a vehicle axle driving wheel, an inner ring 3 that fits on an axle shaft 2 (shaft) and rotates integrally with the shaft, an outer ring 4 fixed to the vehicle body, and an inner ring 3. And rolling elements 5 (rollers) sandwiched between the raceway surface formed on the outer ring 4 and the raceway surface formed on the outer ring 4. 1 is the wheel side, and the right side is the vehicle center side.

  A seal 6 is disposed on the outer side in the axial direction (wheel side) of the bearing device 1 to prevent foreign matter from entering the bearing from the outside. A magnet rotor 7 (magnetic body) made of a permanent magnet is fitted on the inner ring 3 on the outer side of the seal 6. The magnet rotor 7 has a structure in which N poles and S poles are alternately arranged along the circumferential direction. The magnetic flux density is changed by the rotation of the shaft 2 and the inner ring 3, and the ABS sensor 20 (sensor) described later changes this change. The rotation speed is measured by detecting.

  A ring-shaped annular member 10 for fixing the sensor 20 to the bearing device 1 is fitted on the outer ring 4. The annular member 10 includes a fixing portion 30 and a cover portion 40 which will be described later. A sensor 20 is fixed to the annular member 10. A method for fixing the sensor 20 to the annular member 10 will be described below.

  FIG. 2 is a perspective view of the bearing device 1. 3 is a view showing only the fixing portion 30, FIG. 4 is a view showing only the sensor 20, and FIG. 5 is a view showing only the cover portion 40. In the fixing portion 30 shown in FIG. 3, a seat receiving surface 32 for mounting the sensor 20 is formed, and a hole 33 is formed in the seat receiving surface 32. A nut 36 is welded to the radially inner side of the hole 33.

  Moreover, the hole part 31 for fixing the fixing | fixed part 30 to a cover part is formed. Further, a sensor hole 34 for mounting the sensor 20 is formed, and a rail 35 is formed in the sensor hole 34 at a position facing the side surface of the sensor 20.

  The sensor 20 shown in FIG. 4 is roughly divided into a main body 21 and a signal line 22. The main body 21 is provided with a detection unit that detects the magnetic flux density. A signal carrying the measured value is sent to the ECU mounted on the vehicle through the signal line 22.

  The surface of the main body 21 includes a tip 24, an upper surface 23, and side surfaces 25. The main body 21 has another side surface, which is a surface on the back side of the side surface 25 in a portion not shown in FIG. Further, the main body portion 21 is formed with a protruding portion 29, and a through hole 27 is formed in this portion. As shown in FIG. 2, the sensor 20 has a fixed portion 30 in a posture in which the tip 24 faces inward in the radial direction and the protrusion 29 faces inward in the axial direction (direction toward the inside of the bearing). Fixed to.

  As shown in FIG. 4, a rail groove 26 is formed on the side surface 25 from the middle of the side surface 25 to the tip 24. It is assumed that the rail groove is formed in the same shape on both side surfaces.

  As shown in FIG. 1, the cover portion 40 shown in FIG. 5 has a fitting surface 15 for fitting on the outer ring 4, and extends radially inward from the end of the fitting surface 15. It has an abutment surface 16 that is provided and abuts against the outer ring end surface 4a. The fitting surface 15 is press-fitted into the outer peripheral surface of the outer ring 4, and the abutting surface 16 is abutted against the outer ring end surface 4 a, whereby the cover portion 40 is positioned.

  Further, a cover surface 17 that covers the magnet rotor 7 is formed on the inner peripheral side of the abutting surface 16. The covering surface 17 covers the magnet rotor 7 along the circumferential direction with a gap therebetween. The inner diameter φb of the cover surface is set to be equal to or smaller than the inner diameter φa of the magnet rotor 7. As a result, the cover surface 17 prevents the magnet rotor 7 from being exposed to the outside.

  Thereby, it is possible to prevent foreign matters from being mixed in and attached to the magnet rotor 7 from the outside. In addition, since the gap c is formed between the magnet rotor 7 and the cover surface 17, even if foreign matter is mixed in, the accumulation between the magnet rotor 7 and the cover surface 17 is suppressed. Such a shape of the cover surface improves the reliability of the magnet rotor 7 in long-term use.

  Further, a deflector portion 19 is formed from the radially inner end portion of the cover surface 17 outward in the axial direction (in a direction away from the bearing). The deflector portion 19 has a shape along the shape of the shaft 2, and the inner diameter of the deflector portion 19 increases as the diameter increases as the shaft 2 approaches the wheel. By forming the deflector portion 19 as described above, foreign matter can be prevented from entering the bearing from the axial direction. In particular, the angle θb between the inner peripheral surface of the deflector shown in FIG. 1 and the axial center line may be equal to or larger than the angle θa between the axial center line of the outer shaft diameter. If comprised in this way, it can avoid that the deflector part 19 contacts with an axis | shaft and becomes resistance of rotation of an axis | shaft.

  Further, as shown in FIG. 5, a hole 41 is formed in the cover 40. As will be described later, the hole 41 is used for fixing the fixing portion 30 to the cover portion 40. In addition, a sensor hole 45 is formed in the cover 40, and the sensor 20 is fixed at the position of the sensor hole 45, and the measurement part of the sensor 20 directly faces the magnet rotor 7, thereby generating a magnetic field. Measurement is possible.

  The sensor 20 is integrated with the fixed portion 30 so that the rail groove portion 26 and the rail portion 35 are fitted. Furthermore, as shown in FIG. 2, the sensor 20 is fixed to the fixed portion 30 by fastening the hole 33 and the through hole 27, to which the nut 36 is welded on the back side, with a bolt 55. Then, the fixing portion 30 is fixed to the cover portion 40 by fastening the through hole 31 formed in the fixing portion 30 and the hole portion 41 formed in the cover portion 40 with a bolt 51.

  In the above embodiment, the through holes 33 and 31 may or may not be formed with taps. The nut 36 may not be welded. Moreover, although the bolt fastening was used with respect to the through-holes 33 and 31 above, you may use a rivet caulking as another method, for example. In the case of rivet caulking, the number of parts can be reduced as compared with the use of bolts and nuts.

  6 and 7 show a first modification of the above embodiment, which will be described below. In the rolling bearing device with sensor 1b (bearing device) according to the first modification, a drain hole 18 for drainage is formed in the lower portion of the cover 40 in the figure. The lower part illustrated in FIGS. 6 and 7 may correspond to the lower part in a state where the bearing device 1b is actually installed. Through this drain hole 18, muddy water or the like that has entered the bearing device 1 b can be discharged to the outside.

  FIG. 7 shows an axial sectional view of the sensor-equipped bearing device 1b. As shown in FIG. 7, the inner diameter φe of the drain hole 18 is greater than or equal to the outer diameter φd of the magnet rotor 7. This suppresses the magnet rotor 7 from being exposed to the outside due to the presence of the drain hole 18. Accordingly, since foreign matters are prevented from entering and adhering to the magnet rotor 7 through the drain hole 18 from the outside, the reliability of the magnet rotor 7 in long-term use is improved.

  Next, FIGS. 8 and 9 show a sensor-equipped bearing device 1c according to a second modification. In Modification 2, the fixing unit 30 is not used, and the sensor is directly fixed to the cover unit 40. A sensor 20a according to the second modification is shown in FIG. The sensor 20a includes a main body portion 21a and a signal line 22a. The main body portion 21a of the sensor 20a has protrusions 23a formed on both side surfaces 25a, and through holes 24a are formed in the protrusions 23a. Although only one side surface 25a is shown in FIG. 8, the other side surface 25a is a surface on the back side of the side surface 25a in FIG.

  As shown in FIG. 9, the through hole 24 a and the aforementioned hole 41 are fastened by the bolt 51 in a state where the measurement part of the sensor 20 a is disposed at the position of the sensor hole 45, The sensor 20a is fixed to the cover part 40. In this way, the fixing unit 30 is omitted and the sensor 20a is directly attached to the cover unit 40, so that the cost can be reduced. The fixing of the sensor 20a and the cover part 40 is not limited to bolt fastening, and a rivet may be used.

The axial direction sectional view of the rolling bearing device with a sensor concerning the present invention. The perspective view of a rolling bearing device with a sensor. The perspective view of a fixing | fixed part. The perspective view of a sensor. The perspective view of a cover part. The perspective view of the rolling bearing apparatus with a sensor of the modification 1. FIG. The axial direction sectional drawing of the rolling bearing apparatus with a sensor of the modification 1. FIG. The perspective view of the sensor of the modification 2. FIG. The perspective view of the rolling bearing apparatus with a sensor of the modification 2. FIG.

Explanation of symbols

1, 1b, 1c Rolling bearing device with sensor 2 axis (axle shaft)
3 Inner ring 4 Outer ring 5 Rolling element (roller)
6 Seal 7 Magnet rotor (magnetic material)
DESCRIPTION OF SYMBOLS 10 Annular member 15 Fitting surface 16 Abutting surface 17 Cover surface 18 Drain hole 19 Deflector part 20 ABS sensor (sensor)
21 Body portion 26 Rail groove portion 27 Through hole 30 Fixing portion 33 Hole portion 35 Rail portion 36 Nut 40 Cover portion 51, 55 Bolt

Claims (3)

Fixed to a non-rotating wheel so as to measure the rotation speed of the rotating wheel by detecting the magnetic field of the magnetic body and the magnetic body mounted so that the magnetic field alternately changes along the circumferential direction of the rotating wheel A rolling bearing device with a sensor having a sensor,
An annular member for fixing the sensor to the non-rotating wheel is provided. The annular member rotates in a radial direction from a cylindrical portion fitted to the non-rotating wheel and an axially outer end of the cylindrical portion. An extending portion extending to the side with the ring,
In the extended portion, a contact surface that abuts against an end surface of the non-rotating wheel is formed in a state in which the cylindrical portion of the annular member is fitted and attached to the non-rotating wheel,
The extending portion has a covering surface that covers the magnetic body from the axial direction,
The rolling bearing device with a sensor is characterized in that the covering surface is formed at a position axially outward from the protruding surface, and a gap is formed between the covering surface and the magnetic body.   The rolling bearing device with a sensor according to claim 1, wherein a drain hole for drainage is formed in the extended portion without causing a part of the abutting surface to abut against an end surface of the non-rotating wheel.   The extending portion extends from the radial end portion of the covering surface outward in the axial direction, and follows the shape of the shaft from the radial direction while having a gap with the shaft. The rolling bearing device with a sensor according to claim 1, wherein a deflector portion covering the shaft is formed.

Images