JP2007192294A - Bearing with sensor - Google Patents

Abstract

Provided is a sensor-equipped bearing that can secure a large degree of freedom in a region for arranging a detection element, can stably fix a substrate, and can detect the rotation state of the bearing with high accuracy. To do.
A rotating wheel 3 and a fixed wheel 2 which are arranged to face each other so as to be relatively rotatable, a rolling element 4 incorporated between raceway surfaces of the rotating wheel 3 and the fixed wheel 2, and a rotating wheel with respect to the fixed wheel 3. In the sensor-equipped bearing including the sensor unit 5 that detects the rotational state of the sensor 2, the sensor unit 5 extends to the rotating wheel 2, and a predetermined signal is encoded and recorded along the rotation direction of the rotating wheel 2. The encoder E, the at least one detection element S that is disposed on the fixed wheel 3 so as to face the encoder E and detects the change in the sign of the encoder E that rotates together with the rotating wheel 2, and power is supplied to the detection element S And a substrate 58 that transmits the detection signal output from the detection element S to a predetermined signal processing unit, and the substrate 58 has a continuous annular shape along the fixed ring 2.
[Selection] Figure 1

Description

  The present invention relates to a sensor-equipped bearing that detects a rotation state (for example, a rotation speed and a rotation direction) of the bearing, and more particularly to a sensor-equipped bearing characterized by the shape and arrangement of a sensor substrate.

  2. Description of the Related Art Conventionally, as a bearing 1 with a sensor, for example, as shown in FIG. 2, a rotating wheel (for example, an inner ring 2) and a fixed ring (an outer ring 3) that are opposed to each other so as to be relatively rotatable, the inner ring 2 and the outer ring 3 A configuration including a plurality of rolling elements 4 that are rotatably incorporated between raceway surfaces 21 and 31 that are formed on the opposing surfaces of the inner ring 2 and a sensor unit 5 that detects the rotation state of the inner ring 2 with respect to the outer ring 3. It is widely known (for example, see Patent Document 1).

  The sensor unit 5 is fixed to the inner ring 2 and includes a magnetic encoder E composed of a magnetic material (permanent magnet) in which different magnetic poles (N poles and S poles) are alternately arranged along the rotation direction of the inner ring 2, and the outer ring 3 and a detection element S that detects a change in the magnetic pole of the magnetic encoder E that rotates with the inner ring 2, and a detection signal that is arranged on the outer ring 3 to supply power to the detection element S and that is output from the detection element S. Is transmitted to a predetermined signal processing unit (not shown).

  The magnetic encoder E is formed in an annular shape along the inner ring 2 and is fixed to the inner ring 2 by an annular holding metal fitting 55. In this case, the holding metal 55 has the encoder E fixed to the outer peripheral side end portion thereof, and the inner peripheral side end portion thereof is fitted to the one end side of the inner ring outer peripheral surface in the fixing groove 22 continuous in the circumferential direction. Yes.

  The detection element S is supported by the sensor housing 52 so as to face the magnetic encoder E. The sensor housing 52 is provided with a notch surface 521 on the surface facing the magnetic encoder E so that the magnetic encoder E rotating with the inner ring 2 does not slide. In this case, since a slight gap is formed between the cut-out surface 521 and the magnetic encoder E, the rotating magnetic encoder E does not come into contact with the sensor housing 52 to be worn or worn, for example. Absent. As the detection element S, for example, a Hall element, Hall IC, MR element, MGR element, or the like can be used.

  In such a bearing 1, when the magnetic encoder E rotates together with the inner ring 2, the change of the magnetic pole is detected by the detection element S, and at that time, a predetermined detection signal is output from the detection element S. The detection signal output at this time is processed by a signal processing unit (not shown) to detect the rotation state of the bearing 1. For example, when the detection is performed by one detection element S, the rotation speed of the bearing can be detected. As shown in FIG. 2A, a detection signal having a phase difference of 90 ° is generated between the two detection elements S. When arranged so as to be output, it is possible to detect the rotational direction in addition to the rotational speed of the bearing.

  The substrate 51 is sandwiched and fixed between the sensor housing 52 and the sensor cover 56. The sensor cover 56 is externally fitted to the outer ring 3 so as to cover the sensor unit 5 described above. Thus, the sensor housing 52 and the substrate 51 are fixed to the outer ring 3 together with the sensor cover 56. The board 51 is connected with a cable 6 for supplying power to the detection element S and transmitting a detection signal output from the detection element S to a predetermined signal processing unit (not shown).

By the way, the conventional substrate 51 has, for example, a rectangular shape or a fan shape as indicated by a dotted line in FIG. For this reason, for example, in the case of a bearing having a small diameter such as the reference number 6204 (inner diameter 20 mm, outer diameter 47 mm), the conventional rectangular or fan-shaped substrate 51 limits the degree of freedom of arrangement of the detection elements S. Will be.
Specifically, when the conventional substrate 51 is formed small so as to be adapted to a bearing having a small diameter, the region where the detection element S can be arranged is also limited to a small size. For this reason, it may be difficult to arrange the plurality of detection elements S so as to obtain a detection signal having a phase difference of 90 °.

  In this case, even if the plurality of detection elements S can be arranged so as to obtain a detection signal having a phase difference of 90 ° in the small limited region of the substrate 51, they are arranged close to each other. The power flowing through the detection element S and the detection signals output from the detection element S are likely to interfere with each other. For this reason, an inaccurate detection signal cannot be obtained, resulting in a disadvantage that the detection accuracy is lowered.

Further, since the conventional substrate 51 has a rectangular shape or a sector shape, a portion where the substrate 51 is sandwiched and a portion where the substrate 51 is not sandwiched are generated between the sensor cover 56 and the sensor housing 52. For this reason, in the state where the sensor cover 56 is externally fitted to the outer ring 3, the sensor cover 56 is fitted with the outer ring 3 at a portion where the substrate 51 is not sandwiched deeper than a portion where the substrate 51 is sandwiched. In some cases, imbalances occurred. In this case, due to the imbalance of the fitting, the fixing force for sandwiching the substrate 51 is not stable, and there is a disadvantage that accurate fixing of the substrate is not realized.
JP-A-2005-249545

  The object of the present invention is to ensure a large degree of freedom in the area for arranging the detection element regardless of the type of the bearing, to be able to fix the substrate stably and to increase the rotational state of the bearing. It is to provide a bearing with a sensor capable of detecting with accuracy.

  In order to achieve the above object, a first aspect of the present invention provides a rotating wheel and a fixed wheel, which are arranged to face each other so as to be relatively rotatable, and tracks formed on opposing surfaces of the rotating wheel and the fixed wheel, respectively. In a sensor-equipped bearing including a plurality of rolling elements that are rotatably incorporated between surfaces and a sensor unit that detects a rotation state of a rotating wheel with respect to a fixed wheel, the sensor unit extends to the rotating wheel, An encoder in which a predetermined signal is encoded and recorded along the rotation direction of the rotating wheel, and at least one detection that detects a change in the sign of the encoder that is disposed on the fixed wheel so as to face the encoder and rotates together with the rotating wheel. And a substrate that supplies power to the detection element and transmits a detection signal output from the detection element to a predetermined signal processing unit, and the substrate forms a continuous annular shape along the fixed ring. Doing It resides in that the sensor-equipped bearing according to claim.

  Further, according to a second aspect of the present invention, in the first aspect, the sensor unit includes a sensor cover attached to the fixed ring so as to cover the sensor unit, and a detection element that is opposed to the magnetic encoder. And a sensor housing that is attached to the stationary ring together with the sensor cover, and the substrate is sandwiched between the sensor cover and the sensor housing and fixed. It is.

  Furthermore, according to a third aspect of the present invention, in the first or second aspect of the present invention, the sensor section is provided with a detection element so that a detection signal having a phase difference of 90 ° is output. This is a sensor-equipped bearing characterized by

  According to the present invention, it is possible to secure a large degree of freedom in the region for arranging the detection element regardless of the type of the bearing, and to fix the substrate stably and to increase the rotational state of the bearing. A bearing with a sensor capable of detecting accuracy can be provided.

Hereinafter, a bearing with a sensor according to an embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 shows a configuration of a sensor-equipped bearing 1 as a configuration example of the present embodiment.
In addition, since structures other than the board | substrate 58 of this embodiment are the same as that of the bearing 1 with a sensor shown in FIG. 2, it abbreviate | omits description and demonstrates here the structure and effect of the board | substrate 58 peculiar to this embodiment. .

  As shown in FIG. 1, in the sensor-equipped bearing 1 according to the present embodiment, the substrate 58 has a continuous annular shape along the outer ring 3. In this case, the substrate 58 is sandwiched and fixed between the sensor cover 56 and the sensor housing 52.

  Since the annular substrate 58 is sandwiched and fixed between the sensor housing 52 and the sensor cover 56, the substrate is placed between the sensor cover 56 and the sensor housing 52 with a uniform force over the entire circumference. 58 is sandwiched. In this case, the sensor cover 56 is fitted to the outer ring 3 with a uniform depth over the entire circumference. Therefore, since the fixing force for sandwiching the substrate 52 is stabilized by the uniform fitting of the sensor cover 56, the substrate 58 is fixed accurately and stably.

  Here, as a specific method for fixing the substrate 58, for example, first, the substrate 58 is arranged at a predetermined position on the side surface of the sensor cover 56 of the sensor housing 52, and the substrate 58 is fitted to the sensor cover 56 together with the sensor housing 52. Include. Then, the sensor housing 52 and the substrate 58 are fixed to the outer ring 3 together with the sensor cover 56.

Further, the substrate 58 may be fixed by the following fixing method.
On the surface of the sensor housing 52 on the sensor cover 56 side, a cutout toward the outer peripheral side is provided at a depth slightly shallower than the thickness of the substrate 58. The sensor housing 52 is fixed to the outer ring 3 together with the sensor cover 56 in a state where a part of the thickness of the substrate 58 is accommodated in the notch of the sensor housing 52. In this case, the portion of the substrate 58 that protrudes from the cutout of the sensor housing 52 is strongly pressed, so that the substrate 58 is securely fixed by applying a stronger fixing force over the entire circumference. It becomes.

  Furthermore, since the substrate 58 according to the present embodiment is formed in an annular shape, even if the substrate 58 is formed small so as to be adapted to a bearing having a small diameter, the region where the detection element S can be arranged is an annular shape. Can be secured widely in the area. Therefore, as shown in FIG. 1 (a), a plurality of detection elements S are detected with a phase difference of 90 °, for example, arranged on the substantially opposite side in the circumferential direction within a wide annular region. It is possible to arrange so as to obtain a signal. Therefore, as in the prior art, an accurate detection signal can be obtained without the power flowing through the detection elements S arranged close to each other or the detection signals output from the detection elements S interfering with each other. The accuracy is not reduced.

  In the present embodiment, the description has been made assuming that the rotating wheel is the inner ring 2 and the fixed wheel is configured as the outer ring 3. However, the rotating wheel is the outer ring 3 and the fixed wheel is configured as the inner ring 2. This embodiment can also be implemented. In this case, the magnetic encoder E is fixed to the outer ring 3 that is a rotating wheel and rotates together with the outer ring 3. And the sensor cover 56 becomes a structure fitted in the inner ring | wheel 2 which is a fixed ring | wheel.

Further, in the sensor unit 5 of the present embodiment, the magnetic pole is changed as the encoded information of the magnetic encoder E as a method for detecting the rotation state of the bearing 1, but the present invention is not limited to this, and the change of the magnetic pole is not limited thereto. Is detected by the magnetic pole detection element S, but other detection methods may be used as long as the rotation state of the bearing 1 can be detected.
For example, as encoding information, barcode-like lines may be arranged and printed on the encoder E in the circumferential direction, and the passage of the barcode lines of the encoder E may be detected by the detection element S using laser light. In this case, as the detection element S, for example, a light emitting / receiving element composed of a photodiode and a photosensor may be applied.
Alternatively, the encoder E may be configured such that comb-like slits are arranged in the circumferential direction, and the passage of the encoder E slits may be detected by an optical element such as a photocoupler.

It is explanatory drawing which shows the structure of the bearing with a sensor by one Embodiment of this invention, Comprising: (a) is the side view seen from the sensor cover side of the bearing with a sensor. (B) is a cutaway view along the AA line of the same figure (a). It is explanatory drawing which shows the structure of the conventional bearing with a sensor, Comprising: (a) is the side view seen from the sensor cover side of the bearing with a sensor. (B) is a cutaway view along the AA line of the same figure (a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bearing with sensor 2 Inner ring 3 Outer ring 4 Rolling body 5 Sensor part 6 Cable E Magnetic encoder S Magnetic pole detection element 58 Board | substrate

Claims (3)

A rotating wheel and a fixed wheel disposed so as to be relatively rotatable, and
A sensor comprising a plurality of rolling elements that are rotatably incorporated between raceway surfaces formed on opposite surfaces of the rotating wheel and the fixed wheel, and a sensor unit that detects a rotation state of the rotating wheel with respect to the fixed wheel. With bearing,
The sensor part
An encoder which is extended to the rotating wheel and recorded with information encoded along the rotating direction of the rotating wheel;
At least one detection element that is arranged on a fixed wheel facing the encoder and detects information from an encoder that rotates together with the rotating wheel;
And a substrate for supplying power to the detection element and transmitting a detection signal output from the detection element to a predetermined signal processing unit,
A sensor-equipped bearing, wherein the substrate has a continuous annular shape along a fixed ring. The sensor part is provided with a sensor cover attached to the fixed ring so as to cover the sensor part, and a sensor housing that supports the detection element facing the encoder and is attached to the fixed ring together with the sensor cover. ,
The sensor-equipped bearing according to claim 1, wherein the substrate is sandwiched and fixed between the sensor cover and the sensor housing. The sensor-equipped bearing according to claim 1, wherein the sensor unit is provided with a detection element so that a detection signal having a phase difference of 90 ° is output.

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