JP5857470B2 - Rolling bearing device with sensor - Google Patents

Description

  The present invention relates to a rolling bearing device including a sensor that measures a rotation state of a race.

2. Description of the Related Art Conventionally, a rolling bearing provided with a magnetic sensor that measures a rotation state (for example, rotation speed, rotation direction, rotation angle) of a rotating wheel is known. In such a rolling bearing with a sensor, the magnetic sensor detects a magnetic field other than the magnetic field to be detected (hereinafter sometimes referred to as “noise magnetic field”), and an error occurs in the measurement result of the rotating state of the rotating wheel. There was a fear. For this reason, a rolling bearing with a sensor has been proposed in which a noise magnetic field is cut off from the magnetic sensor to reduce adverse effects on the magnetic sensor.
For example, Patent Document 1 discloses a sensor-equipped rolling bearing including a magnetic ring that forms a magnetic path. Since the leakage magnetic field generated from the motor or the like flows through the magnetic ring having the smallest magnetic resistance, the adverse effect of the leakage magnetic field on the magnetic sensor is suppressed.

JP 2002-174258 A

However, since the rolling bearing with sensor disclosed in Patent Document 1 blocks an external magnetic field, if a noise magnetic field is generated inside the rolling bearing with sensor, a sufficient effect may not be obtained. It was.
For example, in a rolling bearing with a sensor in which a magnetic sensor is configured by making an annular magnet attached to a rotating wheel and a magnetic detection element attached to a stationary wheel (non-rotating wheel) face each other with a sensor gap therebetween, When the magnetic detection element is located at or near the boundary portion between the S pole and the N pole, the magnetic detection element may detect a noise magnetic field.

That is, at the boundary portion between the S pole and the N pole of the annular magnet, as shown in FIG. 6, a detection direction magnetic field along the circumferential direction of the annular magnet and a radial extending in an arc shape radially outward of the annular magnet Directional magnetic field is generated. Therefore, the closer the position of the magnetic detection element is to the boundary portion, the easier it is to detect the radial magnetic field, which is a noise magnetic field, and there is a risk that an error will occur in the measurement result of the rotation state of the rotating wheel. For example, when the magnetic detection element outputs a pulse signal, an error may occur in the pitch, duty ratio, and the like, and when an analog signal is output, an error may occur in the pitch, amplitude, offset, and the like.
Therefore, the present invention solves the problems of the prior art as described above, and even when a noise magnetic field is generated inside, it is difficult to be adversely affected by the noise magnetic field, and the rotational state of the rotating wheel can be measured with high accuracy. An object of the present invention is to provide a rolling bearing device with a sensor that can be used.

In order to solve the above problems, an aspect of the present invention has the following configuration. That is, the sensor-equipped rolling bearing device according to one aspect of the present invention includes a rotatable rotating wheel, a fixed wheel that rotatably supports the rotating wheel, a raceway surface that the rotating wheel has, and a track that the fixed wheel has. It comprises a plurality of rolling elements that are arranged so as to be able to roll between the surface and a sensor that measures the rotational state of the rotating wheel, and satisfies the following five conditions.

Condition A: The sensor is a detection part attached to the rotating wheel so as to be rotatable integrally with the rotating wheel, and a detection attached to the fixed wheel so as to face the detection part with a sensor gap. And a rotation state of the detected portion accompanying rotation of the rotating wheel is measured by the detection portion.
Condition B: The detected portion is an annular magnet, and a magnetic field in the detection direction along the circumferential direction of the annular magnet is generated in the annular magnet.
Condition C: The detection unit is a magnetic detector including a Hall element that is a magnetic detection element and an amplifier that amplifies an output signal from the Hall element.
Condition D: A magnetic shield that blocks a magnetic field generated from the annular magnet other than a magnetic field in a direction along the circumferential direction of the annular magnet from at least one of both sides in the circumferential direction of the detection unit. Provided.
Condition E: The two detection units were arranged on the fixed wheel with a circumferential interval and a phase difference of an electrical angle of 180 °.

In such a sensor-equipped rolling bearing device, a plurality of the detection units can be arranged on the fixed ring with a circumferential interval therebetween. Then, the two detection units may be arranged adjacent to each other in the circumferential direction, and the magnetic shield may be provided between the two detection units, or the two detection units may have an electrical angle of 90 ° or 180 °. The phase difference may be provided and arranged on the fixed ring.
The magnetic shield is preferably made of a soft magnetic material. As the soft magnetic material, permalloy, electromagnetic soft iron, or silicon steel is preferable.

Et al is, the magnetic detection element may be designed to output a pulse signal indicating the rotating state, may output an analog signal indicating the rotating state.
Further, the detection unit and the detected unit may be axially opposed with a sensor gap therebetween or may be radially opposed.
Further, the annular magnet may be two-pole magnetized with two poles of S-pole and N-pole in the circumferential direction, or multi-pole magnetized with four or more poles alternately in the circumferential direction. Magnetization is also possible.

  The rolling bearing device with a sensor according to the present invention includes a magnetic shield that blocks a magnetic field generated from an annular magnet other than a magnetic field in a direction along the circumferential direction of the annular magnet from at least one of the circumferential sides of the detection unit. Therefore, even when a noise magnetic field is generated inside, it is difficult to be adversely affected by the noise magnetic field, and the rotation state of the rotating wheel can be measured with high accuracy.

It is a perspective view which shows the structure of one Embodiment of the rolling bearing apparatus with a sensor which concerns on this invention. It is a disassembled perspective view of the rolling bearing apparatus with a sensor of FIG. It is a figure explaining arrangement | positioning of a magnetic detection element and a magnetic shield. It is a figure explaining arrangement | positioning of the magnetic detection element and magnetic shield which show the modification of this embodiment. It is a figure explaining arrangement | positioning of the magnetic detection element and magnetic shield which show another modification of this embodiment. It is a figure explaining the noise magnetic field which arises from an annular magnet.

  Embodiments of a rolling bearing device with a sensor according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing a structure of a rolling bearing device with a sensor according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view of the rolling bearing device with a sensor of FIG. FIG. 3 is a view for explaining the arrangement of magnetic detection elements and magnetic shields provided in the sensor-equipped rolling bearing device of FIG.

  The deep groove ball bearing 10 of the present embodiment includes an inner ring 1 having a raceway surface on an outer peripheral surface, an outer ring 2 having an inner race surface facing a raceway surface of the inner ring 1, a raceway surface of the inner ring 1, and an outer ring 2. There are provided a plurality of rolling elements (balls) 3 that are arranged so as to roll freely between the raceway surfaces, and a cage (not shown) that holds the rolling elements 3 between the inner ring 1 and the outer ring 2. . Note that the cage may not be provided. Further, a lubricant (for example, lubricating oil or grease) may be enclosed in a bearing internal space formed between the outer peripheral surface of the inner ring 1 and the inner peripheral surface of the outer ring 2.

  In this deep groove ball bearing 10, the inner peripheral surface of the inner ring 1 is fitted to, for example, a rotating shaft (not shown) to be a rotatable rotating ring, and the outer peripheral surface of the outer ring 2 is fixed to, for example, a bearing housing (not shown). And it can be set as the fixed ring (namely, non-rotating wheel) which supports the inner ring | wheel 1 which is a rotating wheel rotatably. That is, if the deep groove ball bearing 10 is interposed between a rotating shaft (not shown) and the bearing housing, the rotating shaft can be rotatably supported with respect to the bearing housing. However, on the contrary, the inner ring 1 may be a fixed ring and the outer ring 2 may be a rotating ring.

  A sealing device (not shown) that covers the opening of the gap between the inner ring 1 and the outer ring 2 (either a contact type or a non-contact type, such as a steel shield or rubber seal) is provided in the axial direction of the deep groove ball bearing 10. A sensor that is provided only at one end (in the bearing center axis direction) and measures the rotation state (for example, rotational speed, rotational direction, rotational angle) of the inner ring 1 that is a rotating wheel at the other end. 20 is attached.

  Next, the configuration of the sensor 20 will be described. The sensor 20 is attached to the detected part 22 that is attached to the inner ring 1 so as to be rotatable integrally with the inner ring 1 that is a rotating wheel, and is attached to the outer ring 2 that is a fixed ring so as to face the detected part 22 with a sensor gap. The detection unit 24 is provided. And the detection part 24 can measure the rotation state of the detected part 22 that rotates in the same rotation state as the inner ring 1 as the inner ring 1 rotates.

As the sensor 20, a magnetic sensor that detects a change in magnetic state (such as a magnetic field strength or direction (specifically, a change in magnetic flux density)) is used. An annular magnet magnetized with two or more poles (hereinafter referred to as “encoder 22”) is applied as the detected portion 22 of the magnetic sensor, and a change in magnetic state (for example, magnetic flux) is used as the detecting portion 24. A magnetic detection element (hereinafter, referred to as “magnetic detection element 24”) for detecting density fluctuation is applied.
Here, the magnetic detection element 24 and the encoder 22 will be further described. In the present embodiment, the sensor 20 includes two magnetic detection elements 24. As shown in FIG. 3, the two magnetic detection elements 24 are arranged adjacent to each other with a gap in the circumferential direction of the encoder 22.

  As the magnetic detection element, for example, a Hall element, a magnetoresistive effect element (MR element), a giant magnetoresistive effect element (GMR element), or the like can be used. Among these, since the Hall element is inexpensive, the sensor-equipped rolling bearing device can be manufactured at low cost. Moreover, since the magnetoresistive effect element is highly sensitive, a highly sensitive rolling bearing device with a sensor can be obtained.

  However, a magnetic detector may be used instead of the magnetic detection element 24. The magnetic detector includes a magnetic detection element and an amplifier that amplifies an output signal from the magnetic detection element. Since the change amount of the output signal from the magnetic detection element with respect to the magnetic flux is small, the magnetic detector amplifies the output signal from the magnetic detection element with an amplifier and outputs the amplified signal. As the amplifier, for example, an operational amplifier is used.

  On the other hand, the number of magnetic poles magnetized in the encoder 22 may be arbitrarily set according to the rotational speed of the inner ring 1 and the detection accuracy of the magnetic detection element 24. For example, the circumferential surface of the encoder 22 in the circumferential direction is S. Two-pole magnetization in which the other half of the circumferential surface is magnetized to the N pole may be used. By using dipole magnetization, the absolute rotation angle of the rotating wheel can be measured by the sensor 20.

  However, the larger the number of magnetized magnetic poles, the easier it is to detect a change in the magnetic state in the magnetic detection element 24, and the measurement accuracy of the rotational state (for example, rotational speed, rotational direction, rotational angle) of the deep groove ball bearing 10 is increased. Therefore, it is preferable to use multipolar magnetization in which four or more S poles and N poles are alternately magnetized in the circumferential direction. For example, the encoder 22 is an annular magnet having a total of 100 magnetic poles in which 50 circumferentially alternating N poles and S poles are magnetized in the circumferential direction at a constant pitch on the circumferential surface (magnetic pole face). be able to. In the case of multipolar magnetization, a multi-period pulse signal or an analog signal can be obtained. In the case of multipolar magnetization, the absolute rotation angle position cannot be calculated, but the relative rotation angle position can be calculated accurately.

  Further, the sensor 20 is provided with a substrate 30 (hereinafter referred to as “circuit substrate 30”) on which a predetermined circuit is wired, and a predetermined power supply device (not shown) is connected to the magnetic detection element 24 by the circuit substrate 30. ), And a signal (electric signal indicating the rotation state of the encoder 22) output from the magnetic detection element 24 is transmitted to a predetermined signal processing unit (not shown). .

  In this case, the magnetic detection element 24 and the signal processing unit may be directly connected to the circuit board 30 or may be connected via a signal cable (not shown). In the present embodiment, the magnetic detection element 24 is directly connected to the annular circuit board 30. Although the magnetic detection element 24 is not shown in FIG. 2, the magnetic detection element 24 is disposed on the end face (the face facing downward in FIG. 2) of the circuit board 30 on the side facing the encoder 22. Is connected.

  In addition, the sensor 20 includes a magnetic shield 28. As described above, the detection direction magnetic field along the circumferential direction of the annular magnet and the radial magnetic field extending in an arc shape radially outward of the annular magnet are formed at the boundary between the S pole and the N pole of the annular magnet. It has occurred. The magnetic shield 28 is used to block the magnetic detection element 24 from a magnetic field generated by the encoder 22 that is an annular magnet other than a magnetic field in a direction along the circumferential direction of the encoder 22, that is, a radial magnetic field that is a noise magnetic field. Is.

  The magnetic shield 28 has a substantially plate shape and protrudes from the circuit board 30 in the axial direction. As shown in FIG. 3, the magnetic shield 28 is provided so as to face the both sides in the circumferential direction of the magnetic detection element 24 with a gap (that is, the magnetic detection element 24 has both sides in the circumferential direction on the magnetic shield 28. The side surface in the circumferential direction of the magnetic detection element 24 is surrounded by the plate surface of the magnetic shield 28. In the present embodiment, as shown in FIG. 3, the two magnetic detection elements 24 are adjacent to each other with a gap in the circumferential direction. It is sufficient to arrange the magnetic shield 28, and one magnetic shield 28 surrounds one circumferential side surface of the two magnetic detection elements 24.

  In the deep groove ball bearing 10 of the present embodiment, the encoder 22 is fixed to the inner ring 1 and rotates together with the inner ring 1. In the configuration shown in FIG. 2, as an example, the encoder 22 is fixed to a magnet holder 32 made of a magnetic material by conventional fixing means such as adhesion or welding, and the magnet holder 32 is attached to the inner ring 1. Thus, the encoder 22 is fixed to the inner ring 1.

  The magnet holder 32 has an annular shape, and an inner diameter portion thereof is fixed to the inner ring 1 so as not to come into contact with the outer ring 2, the rolling elements 3, the cage, and the sensor cover 26 described later. Thereby, the encoder 22 can rotate together with the inner ring 1 in the same rotational state as the inner ring 1 without contacting any of the outer ring 2, the rolling element 3, and the cage while facing the magnetic detection element 24. it can.

  On the other hand, the magnetic detection element 24 is held by a substantially annular sensor cover 26 in a state of being connected to the circuit board 30 so as to face the encoder 22 with an axial sensor gap therebetween, and the sensor cover 26 is attached to the outer ring. It is fixed with respect to the outer ring 2 by being attached to the end portion in the axial direction. The outer diameter portion of the sensor cover 26 is fixed to the outer ring 2, and when the deep groove ball bearing 10 is attached to the rotating shaft, a predetermined gap is formed between the tip of the inner diameter portion of the sensor cover 26 and the outer peripheral surface of the rotating shaft. A gap is formed.

  In the example shown in FIGS. 1 and 2, the magnetic detection element 24 is arranged such that the axial end face of the magnetic detection element 24 and the axial end face (magnetic pole face) of the encoder 22 are axially opposed with a sensor gap in the axial direction. Is positioned relative to the encoder 22. By making it axially opposed, the radial dimension of the rolling bearing device with sensor can be reduced. However, the relative positional relationship between the magnetic detection element 24 and the encoder 22 is limited to the relative position shown in FIG. 1 as long as the element disposition surface of the magnetic detection element 24 and the magnetic pole surface of the encoder 22 face each other. It is not a thing.

  For example, the radially inner surface of the magnetic detection element 24 and the outer peripheral surface of the encoder 22 may be radially opposed to each other with a radial sensor gap therebetween, or the radially outer surface of the magnetic detection element 24 and the encoder. The inner peripheral surface of 22 may be opposed radially by leaving a radial sensor gap. In these cases, the radially inner surface or the radially outer surface of the magnetic detection element 24, which is a mutually opposing surface, is configured as the element disposition surface, and the outer peripheral surface or inner peripheral surface of the encoder 22 is also used. What is necessary is just to comprise as a magnetic pole surface. By adopting radial facing, the axial dimension of the sensor-equipped rolling bearing device can be reduced.

By positioning the encoder 22 and the magnetic detection element 24 with respect to the inner ring 1 and the outer ring 2 as described above, the encoder 22 faces the magnetic detection element 24, specifically, the axial end face (magnetic pole) of the encoder 22 It is possible to make a structure that rotates together with the inner ring 1 in a state where the surface) is opposed to the axial end surface (element arrangement surface) of the magnetic detection element 24.
That is, in the deep groove ball bearing 10, when the inner ring 1 rotates, the magnet holder 30 and the encoder 22 also rotate with it, and the positions of the magnetic poles (N pole and S pole) with respect to the magnetic detection element 24 change alternately and continuously. At this time, the magnetic flux passing through the magnetic detection element 24 (more specifically, the magnetic flux density and the direction of the magnetic flux) changes continuously, and the change of the encoder 22 is detected by detecting the change by the magnetic detection element 24. Information such as position and angle can be obtained.

  Then, the change in the magnetic flux detected by the magnetic detection element 24 is converted into an electric signal by the circuit board 30 and the electric signal (data) is transmitted to a signal processing unit (not shown). It is possible to measure the rotational state of the deep groove ball bearing 10 (specifically, the inner ring 1 to which the encoder 22 is fixed) by calculating the amount of variation such as the position and angle of the encoder 22 per unit time. It becomes.

  Since the deep groove ball bearing 10 of this embodiment includes the magnetic shield 28, the magnetic field generated from the encoder 22 is a magnetic field other than the magnetic field in the direction along the circumferential direction of the encoder 22, that is, a radial magnetic field that is a noise magnetic field. The directional magnetic field is cut off from the magnetic detection element 24. As a result, the detection direction magnetic field along the circumferential direction of the encoder 22 is detected by the magnetic detection element 24, and the radial direction magnetic field is hardly detected by the magnetic detection element 24. Therefore, even if a noise magnetic field is generated inside the sensor 20, it is difficult to be adversely affected by the noise magnetic field, the detection sensitivity of the magnetic detection element 24 is increased, and the error of the output signal is reduced. Therefore, it is possible to measure the rotation state of the rotating wheel with high accuracy.

The shape, size, thickness, and the like of the magnetic shield 28 are not particularly limited as long as the radial magnetic field that is a noise magnetic field can be blocked from the magnetic detection element 24, but the shape is preferably a plate shape. The size is preferably the same as the circumferential side surface of the magnetic detection element 24 or larger than the circumferential side surface.
Further, if the magnetic shield 28 is provided on one side in the circumferential direction of the magnetic detection element 24, it is possible to block the noise magnetic field from the magnetic detection element 24. However, the magnetic shield 28 is provided on both sides in the circumferential direction of the magnetic detection element 24. In other words, the effect of blocking the radial magnetic field, which is a noise magnetic field, from the magnetic detection element 24 is higher when the magnetic detection element 24 is sandwiched between the magnetic shields 28 from both sides in the circumferential direction.

  Further, the material of the magnetic shield 28 is not particularly limited as long as the noise magnetic field can be blocked from the magnetic detection element 24. However, since the hysteresis is small and the effect of blocking the noise magnetic field is high, permalloy, Soft magnetic materials such as electromagnetic soft iron and silicon steel are preferred. In the soft magnetic material, permalloy is more preferable because hysteresis is particularly small.

  In addition, this embodiment shows an example of this invention and this invention is not limited to this embodiment. For example, in the present embodiment, the case where the number of the magnetic detection elements 24 is two is described as an example. However, the number of the magnetic detection elements 24 provided in the sensor 20 is used for measuring the rotational state of the deep groove ball bearing 10. However, it may be set arbitrarily according to the accuracy required for it. That is, the sensor 20 may be configured to measure the rotation state of the deep groove ball bearing 10 with one magnetic detection element 24, or measure the rotation state of the deep groove ball bearing 10 with two or more magnetic detection elements 24. It may be configured to.

  When the number of the magnetic detection elements 24 provided in the sensor 20 is two or more, it is desirable to consider the circumferential position. For example, when the two magnetic detection elements 24 are provided in the sensor 20, as described above, the two magnetic detection elements 24 may be arranged adjacent to each other in the circumferential direction (that is, with a small circumferential interval). However, it may be arranged with a large circumferential interval. For example, the two magnetic detection elements 24 shift the electrical angle (the phase when one period of the signal sine wave is 360 °), for example, by 90 ° or 180 ° at the timing of detecting the change in the magnetic state ( It may be connected to the circuit board 30 so as to be positioned (with a phase difference of 90 ° or 180 °).

  As shown in FIG. 4, when a phase difference of 90 electrical degrees is provided, when the magnetic detection element 24 outputs an analog signal, the output signals from the two magnetic detection elements 24 have a phase difference of 90 degrees. As a result, the rotation angle of the rotating wheel can be calculated. Further, as shown in FIG. 5, when a phase difference with an electrical angle of 180 ° is provided, a differential output can be obtained, so that an output signal resistant to noise can be obtained.

  For example, when three magnetic detection elements 24 are provided in the sensor 20, the three magnetic detection elements 24 are positioned by shifting their electrical angles by, for example, 120 ° (with a phase difference of 120 °). As shown, the circuit board 30 may be connected. Further, for example, when four magnetic detection elements 24 are provided in the sensor 20, the four magnetic detection elements 24 are positioned by shifting their electrical angles by 90 ° (with a 90 ° phase difference), for example. As shown, the circuit board 30 may be connected.

Thus, by comparing the detection results of the magnetic change in each magnetic detection element 24 in consideration of the phase difference, the rotational state of the deep groove ball bearing 10 (specifically, the inner ring 1 and the encoder 22) can be more accurately determined. Can be measured.
Further, the magnetic detection element 24 may be a type that outputs a pulse signal, or may be a type that outputs an analog signal. In the case of a type that outputs a pulse signal, it can be applied as an encoder. In the case of a type that outputs an analog signal, the rotation angle of the rotating wheel can be measured.

  Furthermore, in the present embodiment, the material of the sensor cover 26 is not particularly described, but a material that does not affect the change in the magnetic state that occurs when the encoder 22 rotates (for example, a non-resin material such as a resin). A metal material, a non-magnetic metal material, or a magnetic material coated with a non-magnetic material is preferable. If the sensor cover 26 is made of a magnetic metal material, the sensor cover 26 has a function as a magnetic shield. As a result, the magnetic field outside the sensor 20 can be blocked and the sensor 20 can be prevented from being affected by the external magnetic field. That is, it is possible to suppress a change in the magnetic state due to a factor other than the rotation of the encoder 22, and to detect only a change in the magnetic state due to the rotation of the encoder 22 by the magnetic detection element 24. As a result, it becomes easy to accurately and reliably detect a change in the magnetic state in the magnetic detection element 24, and the measurement accuracy of the rotation state of the inner ring 2 can be increased.

  Furthermore, in the present embodiment, a deep groove ball bearing has been described as an example of a rolling bearing, but the present invention can be applied to various types of rolling bearings. For example, radial rolling bearings such as angular contact ball bearings, self-aligning ball bearings, self-aligning roller bearings, cylindrical roller bearings, tapered roller bearings, needle roller bearings, and thrust types such as thrust ball bearings and thrust roller bearings This is a rolling bearing.

DESCRIPTION OF SYMBOLS 1 Inner ring 2 Outer ring 3 Rolling element 10 Deep groove ball bearing 20 Sensor 22 Encoder 24 Magnetic detection element 26 Sensor cover 28 Magnetic shield 32 Magnet holder

Claims (10)

A plurality of rolling elements that are rotatably arranged between a rotatable wheel, a fixed wheel that rotatably supports the rotating wheel, and a raceway surface that the rotary wheel has and a raceway surface that the fixed wheel has. And a sensor for measuring the rotational state of the rotating wheel, and a rolling bearing device with a sensor that satisfies the following five conditions.
Condition A: The sensor is a detection part attached to the rotating wheel so as to be rotatable integrally with the rotating wheel, and a detection attached to the fixed wheel so as to face the detection part with a sensor gap. And a rotation state of the detected portion accompanying rotation of the rotating wheel is measured by the detection portion.
Condition B: The detected portion is an annular magnet, and a magnetic field in the detection direction along the circumferential direction of the annular magnet is generated in the annular magnet.
Condition C: The detection unit is a magnetic detector including a Hall element that is a magnetic detection element and an amplifier that amplifies an output signal from the Hall element.
Condition D: A magnetic shield that blocks a magnetic field generated from the annular magnet other than a magnetic field in a direction along the circumferential direction of the annular magnet from at least one of both sides in the circumferential direction of the detection unit. Provided.
Condition E: The two detection units were arranged on the fixed wheel with a circumferential interval and a phase difference of an electrical angle of 180 °. The rolling bearing device with a sensor according to claim 1 , wherein the two detection units are arranged adjacent to each other in the circumferential direction, and the magnetic shield is provided between the two detection units. The rolling bearing device with a sensor according to claim 1 or 2 , wherein the magnetic shield is made of a soft magnetic material. The rolling bearing device with a sensor according to claim 3 , wherein the soft magnetic material is permalloy, electromagnetic soft iron, or silicon steel. The said magnetic detection element is a rolling bearing apparatus with a sensor as described in any one of Claims 1-4 which outputs the pulse signal which shows the said rotation state. The sensor-equipped rolling bearing device according to claim 1 , wherein the magnetic detection element outputs an analog signal indicating the rotation state. The rolling bearing device with a sensor according to any one of claims 1 to 6 , wherein the detection portion and the detection target portion are axially opposed to each other with a sensor gap. The rolling bearing device with a sensor according to any one of claims 1 to 6 , wherein the detection portion and the detection target portion are radially opposed to each other with a sensor gap therebetween. The rolling bearing device with a sensor according to any one of claims 1 to 8 , wherein the annular magnet is two-pole magnetized with two poles of an S pole and an N pole in a circumferential direction. The rolling bearing device with a sensor according to any one of claims 1 to 8 , wherein the annular magnet is multipolar magnetized in which four or more S poles and N poles are alternately magnetized in a circumferential direction.

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