JP2007192293A - Bearing with sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing with a sensor having a simple configuration and excellent sealing property. <P>SOLUTION: This bearing A with the sensor is provided with a pair of rotary ring 2 and stationary ring 4 arranged opposingly so as to rotate relatively, a plurality of rolling bodies 6 incorporated between raceway surfaces 2b and 4b formed on opposing faces 2a, 4a of the rotary ring and the stationary ring so as to roll freely, respectively, a cage 8 for holding the plurality of rolling bodies so as to rotate freely, sealing plates 10a, 10b provided between the rotary ring and the stationary ring, and the sensor for measuring a rotation condition of the bearing. The sensor is provided with a multipolarly magnetized permanent magnet 40 and a detection element 42 for detecting change of magnetic field. The permanent magnet is attached to the cage, and the detection element is attached to the sealing plate so as to oppose to the permanent magnet. At least the sealing plate 10a to which the detection element is attached forms an annular shape, and its outside diameter part is fixed to the stationary ring. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sensor-equipped bearing having a sensor function for measuring the rotation state (for example, rotation speed, rotation direction, etc.) of the bearing.

  Conventionally, it has a sensor function for measuring the rotation state (for example, rotation speed, rotation direction, etc.) of a bearing, such as a rolling bearing used in an electric power steering device or a wheel support device of an automobile. Various types of bearings with sensors are known (see Patent Document 1).

As an example of the configuration of such a bearing with a sensor, for example, the configuration as shown in FIG. 2 is given. The sensor-equipped bearing B includes a pair of race rings (an inner ring 2 and an outer ring 4) arranged to face each other so as to be relatively rotatable, and raceway surfaces 2b and 4a formed on opposing surfaces 2a and 4a of the inner and outer rings 2 and 4, respectively. There are provided a plurality of rolling elements 6 that are rotatably incorporated between 4b, and a cage 8 that rotatably holds the plurality of rolling elements 6 one by one. In this case, the inner ring 2 is a rotating wheel that rotates together with a rotating shaft (not shown) of the bearing B, and the outer ring 4 is a stationary wheel that is always maintained in a non-rotating state.
On one end side (the left end side in FIG. 2) of such a bearing B, an annular sealing plate 10 is interposed between the inner ring 2 and the outer ring 4, thereby allowing foreign matters (for example, foreign matters from the outside of the bearing (for example, Water and dust) and lubricant (for example, lubricating oil and grease) from the inside of the bearing are prevented from leaking. In this case, a contact-type seal is applied as the sealing plate 10, and the seal is positioned with its outer diameter portion fixed to the outer ring 4 and its inner diameter portion in contact with the inner ring 2.

  In the configuration shown in FIG. 2, a sensor for measuring the rotation state (for example, the rotation speed and the rotation direction) of the bearing B is provided on the other end side (the right end side in FIG. 2) of the bearing B. ing. The sensor includes an annular magnet (encoder) 20 that is magnetized with multiple poles as the detection target, and two detections that detect changes in the magnetic field (for example, the strength and direction of the magnetic field, changes in the magnetic poles, etc.) as the detection body. An element 24 (for example, a Hall IC or a Hall element) is provided. In this case, each detection element 24 is supported in a state of being accommodated in the housing 30, and the housing 30 is attached to the outer ring 4 that is a stationary wheel together with the fixed cover 28. On the other hand, the encoder 20 is fixed (for example, bonding or welding) to the outer diameter portion of the holder 22 so as to face the detection element 24, and is attached to the inner ring 2 that is a rotating wheel via the holder 22. Yes. The fixed cover 28 has an annular shape, and its outer diameter portion is fixed to the outer ring 4 (outer peripheral surface 4c). In this state, the tip of the inner diameter portion and the outer diameter portion of the rotating shaft (not shown) of the bearing B are provided. A predetermined gap is formed between the two. The holder 22 has an annular shape, and an inner diameter portion thereof is fixed to the inner ring 2 (opposing surface 2a). In this state, a predetermined gap is provided between the tip of the outer diameter portion and the opposing surface 4a of the outer ring 4. Is configured to occur. As a result, the encoder 20 rotates together with the inner ring 2 while facing the detection element 24.

Further, a fan-shaped printed circuit board 26 is fixed to the housing 30 (for example, press-fitting or bonding), and the two detection elements 24 are attached to the printed circuit board 26 at an electrical angle (one cycle of a signal sine wave is 360). The phases are shifted by 90 ° (with a phase difference), and the respective connections are fixed. As the encoder 20 (annular magnet with multiple poles), for example, a bonded magnet in which N poles and S poles are alternately magnetized in the circumferential direction, N poles, S poles, no poles, or S poles are used. A bond magnet in which N poles and no poles are alternately magnetized is used.
In such a bearing B, when the inner ring 2 rotates, the encoder 20 also rotates together with this, so that the positions of the magnetic poles (for example, the N pole and the S pole) with respect to the detection element 24 change alternately and continuously. Changes in the magnetic field at this time (for example, the strength and direction of the magnetic field, changes in the magnetic pole, etc.) are detected by the two detection elements 24, and the output signals (data) are transmitted to a controller (not shown) for calculation processing. Thus, for example, the rotational speed and rotational direction of the rotating wheel (inner ring 2) of the bearing B can be obtained.

  By the way, a lubricant (for example, lubricating oil or grease) is sealed in the bearing B, and for example, the raceway surfaces 2b and 4b of the inner and outer rings 2 and 4 and the rolling surface of the rolling element 6 are lubricated. In this case, in the configuration shown in FIG. 2, a sealing plate (contact type seal) 10 is interposed between the inner and outer rings 2 and 4 on one end side (the left end side in FIG. 2) of the bearing B. One end side (left end side in FIG. 2) of the bearing B is sealed. On the other hand, since the detection element 24 and the encoder 20 are provided on the other end side (the right end side in FIG. 2) of the bearing B, a space for interposing the sealing plate 10 between the inner and outer rings 2 and 4 should be secured. I can't.

  Further, in order to detect the change in the magnetic field due to the rotation of the encoder 20 (for example, the change in magnetic field strength, direction, and change in magnetic pole) by the detection element 24, a predetermined gap is secured between the encoder 20 and the detection element 24. There is a need to. For example, in the configuration illustrated in FIG. 2, a predetermined gap (labyrinth L) is provided between the detection element 24 and the housing 30, and the encoder 20 and the holder 22. The labyrinth L is open to the outside of the bearing through an opening G between the left end inner diameter portion 30 h of the housing 30 and the right end inner diameter portion 2 m of the inner ring 2.

Thus, in a state where the other end side of the bearing B (the right end side in FIG. 2) is not sealed, for example, a lubricant (for example, lubricating oil or grease) enclosed in the bearing is opened through the labyrinth L. It may leak from G to the outside of the bearing. In addition, foreign matter (for example, water or dust) outside the bearing may enter the bearing through the labyrinth L from the opening G.
JP-A-2005-249545

  The present invention has been made to solve such a problem, and an object thereof is to provide a sensor-equipped bearing having a simple structure and excellent sealing performance.

In order to achieve such an object, a bearing with a sensor according to the present invention is formed on a pair of rotating wheels and stationary wheels that are opposed to each other so as to be relatively rotatable, and on opposite surfaces of the rotating wheels and stationary wheels, respectively. A plurality of rolling elements rotatably incorporated between the raceway surfaces formed, a cage for rotatably holding the plurality of rolling elements, a sealing plate interposed between the rotating wheel and the stationary wheel, and a bearing A sensor for measuring the rotation state of the sensor, the sensor comprising a multi-pole magnetized permanent magnet and a detection element for detecting a change in the magnetic field, the permanent magnet being attached to the cage, wherein the detection element is the permanent magnet The sealing plate is attached to the sealing plate so as to be opposed to the magnet, and at least the detection element is attached to form an annular shape, and the outer diameter portion thereof is fixed to the stationary ring.
In such a configuration, the sensor is provided with a substrate for supplying power to the detection element from a predetermined power supply device and transmitting a detection signal output from the detection element to a predetermined signal processing unit. This substrate is fixed to a sealing plate. In this case, the sealing plate is formed with an accommodating portion that substantially matches the outline of the substrate, and is fixed in a state where the substrate is accommodated in the accommodating portion. The detection element is soldered on the substrate.

  ADVANTAGE OF THE INVENTION According to this invention, the sensor-equipped bearing excellent in sealing performance can be provided by attaching a sensor (detection element) to a sealing board.

Hereinafter, a sensor-equipped bearing according to an embodiment of the present invention will be described with reference to the accompanying drawings.
1 (a) to 1 (c) show a sensor-equipped bearing A according to the present embodiment, and the bearing A is a pair of rotating wheels (inner ring 2) arranged so as to be capable of relative rotation. And a stationary wheel (outer ring 4), a plurality of rolling elements 6 which are rotatably incorporated between raceway surfaces 2b and 4b formed on the opposing surfaces 2a and 4a of the inner ring 2 and the outer ring 4, respectively, and a plurality of rolling elements 6, a retainer 8 that rotatably holds 6, sealing plates 10 a and 10 b interposed between the inner ring 2 and the outer ring 4, and a sensor that measures the rotational state of the bearing A.

In the configuration shown in FIGS. 1A to 1C, the inner ring 2 that is a rotating wheel rotates together with the rotating shaft (not shown) of the bearing A, while the outer ring 4 that is a stationary wheel is a housing (not shown). It is fixed and always kept in a non-rotating state. Further, the raceway surfaces 2b, 4b of the inner and outer rings 2, 4 are formed so as to be offset toward one end side (the left end side in FIGS. 1A and 1B) of the opposing surfaces 2a, 4a. For this reason, the space inside the bearing A is not uniform on both sides of the rolling element 8, and one side (the right side in FIGS. 1A and 1B) is the other side (FIGS. 1A and 1B). It is larger than the left side).
Further, the cage 8 is alternately provided with pockets 8p for holding the rolling elements 6 and column portions 8h for connecting adjacent pockets 8p along the circumferential direction. In this case, the cage 8 has an opening 8k for inserting each rolling element 6 into the pocket 8p on one side (left side of FIGS. 1A and 1B), and the other side (FIG. 1A). , (b) right side) has a closed crown shape (so-called crown-shaped cage). The cage 8 has its closed side (the right side in FIGS. 1 (a) and 1 (b)) positioned on the side with the larger space inside the bearing (the right side in FIGS. 1 (a) and (b)), and the inner and outer rings. Built between 2 and 4. In addition, a pair of claw portions 8t protruding so as to partially cover the opening 8k are provided on the column portion 8h of the cage 8, and the rolling elements 6 inserted into the pockets 8a are separated by the claw portions 8t. It is held in the pocket 8a in a sandwiched state.

Further, in the configuration shown in FIGS. 1A to 1C, as an example, the sealing plates 10a and 10b are configured as contact type seals, and the sealing plates 10a and 10b are the inner and outer rings 2 of the bearing A. , 4 are respectively interposed at both ends (the left end and the right end in FIGS. 1A and 1B). In this case, the seals 10a and 10b are formed by coating a core material (for example, a flat metal core made of various metals) with an elastic material (for example, a seal material such as rubber or synthetic resin). The seals 10a and 10b have an annular shape, and the outer diameter portion thereof is fixed to a mounting groove 4m formed continuously in the circumferential direction along the opposing surface 4a of the outer ring 4, while the tip of the inner diameter portion ( The lip p) is positioned so as to contact a seal groove 2m formed continuously in the circumferential direction along the facing surface 2a of the inner ring 2.
As a result, the inside of the bearing A is maintained in a sealed state. For example, a lubricant (for example, lubricating oil or grease) sealed inside the bearing leaks to the outside of the bearing, or foreign matter (for example, water or It is possible to prevent dust from entering the bearing.
Note that the sizes, shapes, and numbers of the seals 10a and 10b are not particularly limited here because they are arbitrarily set depending on the size of the bearing A, for example. Further, for example, by providing a plurality of lips p at the tips of the inner diameter portions of the seals 10a and 10b and bringing the lips p into contact with the bottom and side portions of the seal groove 2m, the sealing performance of the bearing A is further enhanced. be able to.

In addition, the sensor includes a multi-pole magnetized permanent magnet 40 and a detection element (for example, a Hall IC or a Hall element) 42 that detects a change in the magnetic field (for example, the intensity or direction of the magnetic field, a change in the magnetic pole). The permanent magnet 40 is attached to the cage 8, and the detection element 42 is attached to the sealing plate (seal 10 a) so as to face the permanent magnet 40.
In the configuration shown in FIGS. 1A to 1C, a multi-pole magnetized annular magnet is applied as the permanent magnet 40. As the permanent magnet 40, for example, an N pole and an S in the circumferential direction are used. A bond magnet in which poles are alternately magnetized, a bond magnet in which N poles, S poles and no poles, or S poles, N poles and no poles are alternately magnetized, and the like can be applied. In this case, as an example, the permanent magnet 40 is fixed to a mounting groove 8m formed continuously along the end surface of the cage 8 on the closed side (the right side in FIGS. 1A and 1B). As described above, since the space inside the bearing A is relatively large on the closed side of the cage 8 (the right side in FIGS. 1A and 1B), it is permanently on the closed side of the cage 8. By fixing the magnet 40, the permanent magnet 40 can be attached to the cage 8 (incorporated inside the bearing A) without particularly increasing the size of the bearing A (for example, the bearing width).

The method for fixing the permanent magnet 40 to the cage 8 is not particularly limited. For example, any method such as welding or press fitting can be used. In this case, the permanent magnet 40 is bonded with an adhesive as an example. Thus, it is fixed to the cage 8. Further, the mounting groove 8m of the cage 8 may be formed by, for example, press working integrally with the cage 8 or cutting after molding the cage. In the configuration shown in FIGS. 1A and 1B, as an example, with the permanent magnet 40 fixed, the end face of the cage 8 on the closed side (right side of FIGS. 1A and 1B) The mounting groove 8m is formed so that the facing surface of the permanent magnet 40 with respect to the detection element 42 is substantially flush and the inner diameter surface of the cage 8 and the facing surface of the permanent magnet 40 with respect to the inner ring 2 are substantially flush. The depth and width of the groove 8m are not particularly limited here because, for example, the depth and width of the groove 8m are arbitrarily set depending on the size of the cage 8 and the permanent magnet 40, for example.
Further, in the case where a larger space can be secured inside the bearing A, for example, the mounting groove 8m is not formed in the retainer 8 and, for example, the closed side of the retainer 8 (FIGS. 1A and 1B). The permanent magnet 40 may be fixed (for example, bonded) to the right end face). Further, the permanent magnet 40 is not limited to a multi-pole magnetized annular magnet. For example, a N-pole or S-pole single-pole magnet may be applied as the permanent magnet 40. In this case, for example, a plurality of N-pole and S-pole single-pole magnets are fixed continuously or intermittently (for example, to the end surface of the cage 8 on the closed side (the right side in FIGS. 1A and 1B)). , Bonding).

In addition, the sensor is supplied with power from a predetermined power supply device (not shown) to the detection element 42 and transmits a detection signal output from the detection element 42 to a predetermined signal processing unit (not shown). (Printed circuit board 44) is provided, and this circuit board is fixed to a sealing plate (seal 10a). In the configuration shown in FIGS. 1A to 1C, the printed circuit board 44 has, for example, a fan-shaped flat plate shape, and the detection element 42 is fixed to the printed circuit board 44. In this case, the printed circuit board 44 is fixed to the seal 10 a so that the detection element 42 faces the permanent magnet 40 with a predetermined space therebetween.
The method for fixing the detection element 42 to the printed circuit board 44 is not particularly limited. For example, any method such as adhesion or press-fitting can be used. In this case, the detection element 42 is printed by soldering as an example. It is fixed to the substrate 44.

Further, the method for fixing the printed circuit board 44 to the seal 10a is not particularly limited. For example, an accommodating portion that substantially matches the outline of the printed circuit board 44 is formed at a predetermined position of the seal 10a, and the printed circuit board 44 is accommodated in this accommodating portion. What is necessary is just to fix in the state. For example, in the configuration shown in FIGS. 1A to 1C, the surface of the seal 10a (core material and elastic material) is formed in a predetermined sector of the seal 10a in a sector shape slightly larger than the printed circuit board 44. A notch 50 (see FIG. 1 (c)) penetrating from the back surface (the left surface of FIGS. 1 (a) and 1 (b)) to the back surface (the right side surface of FIGS. 1 (a) and (b)) is formed. ing. The printed circuit board 44 is fixed to the seal 10 a by press-fitting the printed circuit board 44 into the notch 50. In addition to such press-fitting and fixing, the printed board 44 is fixed to the seal 10a by adhering the printed circuit board 44 with an adhesive without or forming a similar accommodating portion (notch 50) in the seal 10a. Also good. As a result, the detection element 42 can be fixed to the seal 10 a via the printed circuit board 44.
In addition, the shape of the printed circuit board 44 is not specifically limited, For example, rectangular shape etc. may be sufficient besides a fan shape. In this case, the accommodation portion (notch 50) formed on the seal 10a for attaching the printed circuit board 44 may be formed in a shape that matches the shape (contour) of the printed circuit board 44. Further, the method for forming the accommodating portion (notch 50) is not particularly limited, and may be formed by, for example, cutting or punching.

  In the configuration shown in FIGS. 1A to 1C, two detection elements 42 are attached to the seal 10a, and the two detection elements 42 have an electrical angle (one cycle of a signal sine wave is 360). The phase when the angle is set to 90 ° is fixed (arranged) on the printed circuit board 44 so as to be shifted by 90 ° (with a phase difference), and attached to a predetermined position of the seal 10a (see FIG. 1C). . The two detection elements 42 are connected by a cable 46 via a predetermined signal processing unit (not shown) outside the bearing and a power supply device (not shown) and a connector 48 (a cable side connector 48a and a printed circuit board side connector 48b). The power supply device is connected to receive power (voltage and current) from the power supply device, and transmits (outputs) the detected electrical signal to the signal processing unit. In this case, for example, the printed circuit board side connector 48b is soldered to a predetermined position of the printed circuit board 44 (for example, a position opposite to the fixed surface of the two detection elements 42 and a position between the two detection elements 42). It is fixed by attaching.

  In such a configuration, when the inner ring 2 rotates, the cage 8 incorporated between the inner and outer rings 2 and 4 also rotates with the inner ring 2. As the cage 8 rotates, the permanent magnets 40 attached to the cage 8 also rotate with respect to the two detection elements 42. As a result, the magnetic poles of the permanent magnet 40 with respect to each detection element 42 (for example, N The positions of the poles and S poles are alternately and continuously changed (an alternating magnetic field is generated). Changes in the magnetic field at this time (for example, changes in magnetic field strength and direction, magnetic pole changes, etc.) are detected by the two detection elements 42, and the detection results are output as electrical signals, and the signals (data) are processed by signals. Transmit (output) to a unit (not shown). Then, the transmitted electric signal (data) is subjected to arithmetic processing by the signal processing unit, so that, for example, the rotation speed and the rotation direction of the rotating wheel (inner ring 2) of the bearing A can be obtained. In the configurations shown in FIGS. 1A to 1C, the two detection elements 42 are shifted in electrical angle by a predetermined size (90 °) (provided with a phase difference) as described above. The phase difference between magnetic field changes (electrical signals) detected by the two detection elements 42 can be read, and the rotation state of the bearing A (for example, the rotation speed and the rotation direction) can be read. It can measure with high accuracy.

  Thus, according to the present invention, it is possible to accurately measure the rotation state (for example, the rotation speed and the rotation direction) of the bearing A only by attaching the detection element 42 to the seal 10a without increasing the number of parts. The sealability of the bearing A can be improved. As a result, while having a sensor function for measuring the rotational state, for example, leakage of lubricant (e.g., lubricating oil or grease) enclosed inside the bearing to the outside of the bearing, or foreign matter (e.g., water or Dust) can be prevented from entering the inside of the bearing, and the bearing A can be used continuously with a constant performance over a long period of time.

In the above-described embodiment, two detection elements 42 are provided. However, the number is not particularly limited, and only one detection element 42 or three or more detection elements 42 may be provided. When a plurality of (for example, two) detection elements 42 are provided, in order to measure the rotation state of the bearing A (for example, the rotation speed and the rotation direction) with higher accuracy, each detection element 42 is provided with a predetermined electric Although it is preferable to fix (arrange) each by shifting by an angle (providing a phase difference), the phase difference is not limited to 90 ° as described above, and can be set to an arbitrary phase difference.
Further, in the present embodiment described above, contact type seals are applied as the sealing plates 10a and 10b. However, for example, non-contact type seals or shields (for example, metal shields) may be used. May be applied in combination. However, in order to improve the sealing performance of the bearing A, it is preferable to apply a contact-type seal as the sealing plate.
In addition, in this embodiment mentioned above, although the ball was applied as the rolling element 6, it may be a roller. In the present embodiment described above, a crown-type cage is applied as the cage 8. However, for example, a machined cage or a waveform cage may be used.
Further, in the present embodiment described above, the bearing A for inner ring rotation has been described. However, the bearing configuration may be outer ring rotation (the inner ring is a stationary ring and the outer ring is a rotating ring). In this case, at least a sealing plate (for example, a contact-type seal) to which the detection element is attached has its outer diameter portion fixed to a mounting groove formed in an inner ring that is a stationary wheel, and its inner diameter portion is a rotating wheel. What is necessary is just to position so that the seal groove formed in the outer ring may be contacted.

It is a figure which shows the structural example of the bearing with a sensor which concerns on one Embodiment of this invention, Comprising: (a) is sectional drawing along XX of the figure (c), (b) is the figure ( Sectional drawing along the YY line of c), (c) is a top view for demonstrating the connection of a connector. Sectional drawing which shows the structural example of the conventional bearing with a sensor.

Explanation of symbols

2 Inner rings 2a, 4a Opposing surfaces 2b, 4b Raceway surface 4 Outer ring 6 Rolling element 8 Cage 10a, 10b Sealing plate 40 Permanent magnet 42 Sensor element A Bearing with sensor

Claims (4)

A pair of rotating wheels and stationary wheels arranged to face each other so as to be relatively rotatable, and a plurality of rolling elements incorporated in a freely rolling manner between raceway surfaces respectively formed on opposing surfaces of the rotating wheels and stationary wheels; A sensor-equipped bearing comprising a cage for rotatably holding a plurality of rolling elements, a sealing plate interposed between a rotating wheel and a stationary wheel, and a sensor for measuring the rotational state of the bearing,
The sensor includes a multi-pole magnetized permanent magnet and a detection element that detects a change in the magnetic field. The permanent magnet is attached to a cage, and the detection element is attached to a sealing plate so as to face the permanent magnet. A sensor-equipped bearing, wherein the sealing plate to which at least the detection element is attached has an annular shape and an outer diameter portion thereof is fixed to a stationary ring.   The sensor is provided with a substrate for supplying electric power to the detection element from a predetermined power supply device and transmitting a detection signal output from the detection element to a predetermined signal processing unit. The sensor-equipped bearing according to claim 1, wherein the bearing is attached to the sensor.   3. The sensor-equipped bearing according to claim 2, wherein the sealing plate is formed with a housing portion that substantially matches the outline of the substrate, and is fixed in a state where the substrate is housed in the housing portion. The sensor-equipped bearing according to claim 3, wherein the detection element is soldered on the substrate.

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