JP2004308724A - Bearing with rotation sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing with a rotation sensor capable of detecting the information on an absolute position of the rotation even in multiple rotation. <P>SOLUTION: This bearing with the rotation sensor has a rolling bearing part 1 composed of a rotation-side bearing ring 2, a fixed bearing ring 3 and a rolling element 4, and further comprises a detected part fixed to a ball-cage 5, and periodically changing its magnetic characteristic in the circumferential direction, and a magnetic detecting part 8 composed of a magnetic sensor of analogue output mounted in opposition to the detected part 7. Further the magnetic characteristic to the magnetic detecting part 8, of the detected part 7 is changed with respect to one rotation of the ball-cage 5 as one cycle. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a bearing with a rotation sensor used for rotation detection in various devices, for example, rotation detection of a shaft whose rotation range is limited to a fixed region such as a steering angle sensor, position detection of a motor shaft, and the like.
[0002]
[Prior art]
FIG. 10 shows a general configuration of a bearing with a rotation sensor. In the figure, a bearing 51 with a rotation sensor includes a rolling bearing composed of an inner ring 52 as a rotating raceway, an outer race 53 as a fixed raceway, a rolling element 54 and a retainer 55. An annular magnetic encoder 56 is fixed to the inner ring 52 (for example, the inner ring 52), and a magnetic sensor 57 is fixed to the non-rotating raceway ring (for example, the outer ring 53) so as to face the magnetic encoder 56. As the magnetic sensor 57, a Hall element, a Hall IC, or the like is used. The magnetic encoder 56 is made of, for example, a rubber magnet, and has an N pole and an S pole alternately magnetized in the circumferential direction as shown in FIG. The magnetic sensor 57 is resin-molded while being inserted into the resin case 58, and the resin case 58 is fixed to the outer ring 53 by being fitted to the outer ring 53 via the metal case 59. FIG. 11 shows the arrangement of the magnetic sensors. The two magnetic sensors 57a and 57b are arranged such that the output phase difference (electrical angle) becomes 90 °.
[0003]
With this configuration, with the rotation of the inner ring 52, the magnetic sensor 57 detects a magnetic change of the magnetic encoder 56, and the detection signal is an incremental rotation pulse signal whose phase is shifted by 90 ° as shown in FIG. Become. From this signal, the number of rotations and the direction of rotation of the inner ring 52 can be known. The bearing with a rotation sensor having the above configuration is small in size, does not require assembly adjustment, has characteristics such as robustness, and is used as a motor support bearing or the like.
[0004]
[Problems to be solved by the invention]
However, in the configuration shown in FIG. 10, only the relative rotation angle of the rotation shaft can be detected, and the absolute position information is not known. Further, when the rotation axis rotates multiple times, it is difficult to know the absolute position information in the multiple rotations.
[0005]
SUMMARY OF THE INVENTION An object of the present invention is to provide a bearing with a rotation sensor capable of detecting the absolute position information of the rotation even in multiple rotations.
Another object of the present invention is to make it possible to detect an absolute position without performing an initialization operation when power is turned on.
[0006]
[Means for Solving the Problems]
A bearing with a rotation sensor according to the present invention includes a rolling bearing portion including a rotating raceway ring, a fixed raceway ring, a rolling element, and a retainer, and a bearing fixed to the retainer and having magnetic characteristics that periodically change in a circumferential direction. The apparatus includes a detection unit and a magnetic detection unit including an analog output magnetic sensor facing the detection target.
In the rolling bearing portion, the retainer rotates at a lower speed than the rotating raceway, as the rotating raceway rotates. Due to the rotation of the cage, the detection target fixed to the cage is detected by the magnetic detection unit, and the rotation of the cage is detected. The above-mentioned reduction ratio varies depending on the dimensions of the rolling bearing portion, but is generally about 2.5. Further, there is a certain relationship between the rotational position of the retainer and the rotational position of the rotating raceway. Therefore, by detecting the rotational position of the retainer, the rotational position of the rotating raceway is detected. The magnetic characteristics of the detected part fixed to the cage periodically change in the circumferential direction. However, since the analog output magnetic sensor is used as the magnetic detection part, the output is electrically processed to be detected. Position detection can be performed in the middle of one cycle of the magnetic characteristics of the detection unit. The absolute angle can be detected by setting the cycle of the change to a specific cycle for one rotation of the cage, or by using initialization or appropriate origin recognition means when the power is turned on. As described above, since the retainer is decelerating with respect to the rotating race, the absolute position can be detected within the range of the rotation speed of the rotating race according to the reduction ratio. For example, if the reduction ratio is 2.5, the absolute position can be detected in the range of 2.5 rotations.
[0007]
In the present invention, the magnetic characteristic of the detected part with respect to the magnetic detection part may be changed as one cycle for one rotation of the cage.
If the magnetic characteristics change by one cycle for one rotation of the cage, the absolute position of the rotation position of the cage is detected, and the absolute position can be detected without performing initialization when the power is turned on. In this case, it is possible to detect an absolute position in a range of several rotations of the rotating raceway.
[0008]
Another bearing with a rotation sensor according to the present invention includes a rolling bearing portion including a rotating side bearing ring, a fixed bearing ring, a rolling element, and a retainer, and a magnetic characteristic fixed to the retainer and periodically changing in a circumferential direction. A first magnetic detecting portion comprising an analog output magnetic sensor facing the detected portion on the retainer side, and a magnetic characteristic fixed in the circumferential direction and fixed to the rotating raceway. It comprises a periodically detected part on the side of the bearing ring which is changed, and a second magnetic detecting part comprising an analog output magnetic sensor facing the detected part on the side of the bearing ring.
In the case where the detected portion fixed to the rotating raceway and the second detected portion opposed thereto are provided in addition to the first magnetic detection portion corresponding to the detected portion of the cage as described above, By electrically processing the signals obtained from the two magnetic detectors, it is possible to detect the absolute position of the rotating raceway in a range of several forward and reverse rotations.
[0009]
In this bearing with a rotation sensor, the magnetic characteristics of the detected part on the retainer side are changed as one cycle for one rotation of the cage, and the magnetic characteristics of the detected part on the raceway side are changed to one of the rotation side raceway. The rotation may be changed as one cycle.
In the case of this configuration, the absolute position can be detected in the range of forward / reverse rotation of the rotating raceway ring without performing initialization when the power is turned on.
[0010]
In the bearing with a rotation sensor having any one of the above-described configurations of the present invention, a pair of a detected portion and a magnetic detection portion facing the same may be disposed on both sides of the rolling bearing portion in the axial direction. In this case, in a case where the rolling elements of the rolling bearing section are of a double row and have two cages for holding the rolling elements of each row, the detected parts on both sides are fixed to these two cages, respectively. You may.
Since the detection signal can be multiplexed by providing the pair of the detected part and the magnetic detection part on both sides in this manner, it is possible to support when one of the magnetic detection parts fails, and to provide a support for the rotation sensor bearing. This leads to improved reliability.
[0011]
In the present invention, it is preferable that the rolling bearing is used with a preload applied. If there is a gap or slip between the raceway surface of the bearing ring and the rolling element, the rotation of the retainer will be delayed. However, by applying a preload, the above-mentioned slippage is prevented, and the rotation-side raceway is detected by detecting the rotation of the retainer. Accurate rotation detection can be performed.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
A first embodiment of the present invention will be described with reference to FIGS. The bearing with a rotation sensor shown in FIG. 1A includes a rolling bearing 1 having a rotating raceway ring 2 and a fixed raceway ring 3 rotatable with each other via a rolling element 4, and a detection target fixed to a retainer 5. A portion 7, a magnetic detection portion 8 attached to one end of the fixed side bearing ring 3 with respect to the detected portion 7, and a magnetic detection circuit board 11. The rolling bearing portion 1 is a deep groove ball bearing. For example, an inner ring thereof is a rotating race 2 and an outer ring thereof is a fixed race 3. The raceway surfaces 2a, 3a of the rolling elements 4 are formed on the outer diameter surface of the rotating side raceway 2 and the inner diameter surface of the fixed side raceway 3, and the rolling elements 4 are held by a retainer 5. The annular space between the rotating raceway ring 2 and the fixed raceway ring 3 is sealed with a seal member 6 at the end opposite to the installation side of the detected part 7 and the magnetic detection part 8.
[0013]
The detected part 7 is of an axial type, and is an annular component in which the magnetic characteristics of the magnetic detecting part 8 are continuously changed. Specifically, it has a ring-shaped back metal 7b and a magnet generating member 7a provided on one side thereof and having one magnetic pole N and S that change in the circumferential direction and is magnetized. The detected portion 7 has a back metal 7b fixed to the holder 5, and can be rotated integrally with the holder 5. When the cage 5 is made of resin, a nail may be provided on the side surface of the cage 5 and the detected portion 7 may be fixed with the nail, or the resin molding may be performed. At this time, the detected part 7 may be incorporated. Further, if the retainer 5 is made of resin, the magnetic force of the detected portion 7 is not affected. The magnetism generating member 7a is, for example, a rubber magnet and is vulcanized and bonded to the back metal 7b. The magnetism generating member 7a may be formed of a plastic magnet or a sintered magnet.
[0014]
The magnetic detector 8 includes two magnetic sensors 8a and 8b that generate an output signal corresponding to the magnetic flux density. These two magnetic sensors 8a and 8b are arranged at a predetermined interval (here, electrically 90 ° phase difference) in the circumferential direction as shown in FIG. 1 (B). Both of these magnetic sensors 8a and 8b are composed of analog output sensors. For example, a Hall element, a Hall IC with analog output, or the like can be used. These magnetic detecting sections 8a and 8b are mounted on a magnetic detecting circuit board 11 as shown in FIG. 1A, and inserted into a resin case 9 together with the magnetic detecting circuit board 11, and then poured into a resin molding material 12 and solidified. Can be By fixing the resin case 9 to the fixed raceway ring 3 via the metal case 10, the magnetic detection units 8a and 8b and the magnetic detection circuit board 11 are mounted on the fixed raceway ring 3. The magnetic detection circuit board 11 is a board on which a circuit for supplying power to the magnetic detection unit 8 and processing an output signal of the magnetic detection unit 8 and outputting the processed signal to the outside is mounted.
[0015]
Here, when the rotating raceway 2 rotates, the detected part 7 is decelerated and rotated in the same direction as the rotating raceway 2. The reason is that the bearing portion 1 acts as a so-called planetary reduction gear, so that the rotating race 2 is a sun gear, the rolling element 4 is a planetary gear, the fixed race 3 is an internal gear, and the retainer 5 is a carrier. It is easy to understand when it is considered. The reduction ratio varies depending on the bearing dimensions, but is generally about 2.5. For example, assuming that the reduction ratio is 2.5, the retainer 5 makes one rotation while the rotating race 2 rotates 2.5 times. At this time, if there is a gap or slip between the rolling element 4 and the raceway surfaces 2a, 3a of the races 2, 3, the rotation of the retainer 5 is delayed. Is preferably used. Alternatively, the use of a four-point contact bearing as the bearing 1 can also prevent the cage 5 from delaying.
[0016]
FIG. 2 shows waveforms of detection signals of the magnetic sensors 8a and 8b accompanying the rotation of the rotating raceway ring 2. While the rotating race 2 rotates about 2.5 times, that is, 900 degrees in mechanical angle, a sine wave signal having a phase difference of 90 degrees is output. When an analog output Hall IC is used as the magnetic detection unit 8, a sine wave output proportional to the magnetization strength of the magnetism generating member 7a can be obtained with reference to a half value Vc / 2 of the power supply voltage Vc. If these output signals are electrically processed and the sine wave signal is interpolated and divided by n, then about 2.5 rotations of the rotating race 2 are divided by n. For example, if the division number n is 256, it is possible to divide the area around 2.5 rotations of the rotating race 2 into 256 and display the absolute position.
[0017]
FIG. 3 is an example for interpolating and dividing one cycle of a sine wave having a phase difference of 90 °. An output ratio b / a obtained by dividing the output signal of the magnetic sensor 8b by the output signal of the magnetic sensor 8a, taking the midpoint (Vc / 2) of the output of the magnetic sensors 8a and 8b as 0 (dotted line in the figure) And a position within an electrical angle of 360 ° from a correction table indicating the relationship between the output ratio b / a and the position based on the quadrant position within one cycle of the sine wave obtained from the quadrant discrimination of the magnetic sensors 8a and 8b. Based on this value, the range of 360 ° in electrical angle is interpolated and divided.
[0018]
FIG. 4 is an example of a processing circuit for generating a rotation pulse signal by interpolation division from the signals of the two magnetic sensors 8a and 8b, and is mounted in the magnetic detection circuit board 11. The processing circuit 13 includes a divider 14 for calculating the output ratio of the magnetic sensors 8a and 8b, a quadrant discriminating unit 15, and a correction operation unit 16. The correction operation unit 16 includes a correction table 16a. Assuming that the output of the magnetic sensor 8a is a and the output of the magnetic detector 8b is b, the divider 14 obtains the output ratio b / a. The output ratio may be obtained by analog signal processing, or digital processing may be performed by incorporating an A / D conversion circuit (not shown) in the input stage of the divider 14. The quadrant discriminating section 15 discriminates a quadrant within a range of an electrical angle of 360 ° obtained from one pole pair of the detected section 7 and inputs the quadrant to the correction calculating section 16. The correction calculation unit 16 associates the output ratio b / a with the storage item in which the output ratio and the electrical angle are preliminarily stored in the correction table 16a based on the output ratio b / a and the quadrant discrimination result. The range of ° is divided into n. If a one-chip microcomputer incorporating an A / D converter and a memory is used as the processing circuit, the circuit is simplified and advantageous.
[0019]
As shown in FIGS. 4A and 4B, if the signal divided into n is taken out as a code output in multiple bits (bits), the rotation from the 0 to n- as shown in FIGS. A code output that repeats 1 is obtained.
Here, as a signal division method, the output ratio of the magnetic sensors 8a and 8b was obtained, but another interpolation division method based on the sine wave output of the magnetic sensors 8a and 8b may be used.
[0020]
As described above, according to the bearing with the rotation sensor of this embodiment, the detection target portion 7 magnetized with one pole pair (N, S pairs) is fixed to the retainer 5, and the fixed side raceway ring 3 composed of the outer ring is magnetically fixed. Since the detection unit 8 is fixed, the detection unit 7 makes one rotation about 2.5 rotations of the rotating raceway ring 2 as the inner ring. At this time, an analog output type magnetic sensor is used as the magnetic detection unit 8 and the two magnetic sensors 8a and 8b are arranged so as to have an output phase difference of 90 ° in electrical angle. An analog sine wave (sin θ, cos θ) of one cycle is obtained by five rotations, and by electrically processing this analog sine wave, it is possible to detect the absolute position of the rotating race 2 during 2.5 rotations. That is, since the retainer 5 rotates at a lower speed than the rotation-side bearing ring 2 as the rotation-side bearing ring 2 of the bearing portion 1 rotates, the reduction mechanism is applied. In addition, the absolute position can be detected during several rotations (2.5 rotations in this example) of the rotating raceway 2.
[0021]
6 and 7 show a second embodiment. In the structure of FIG. 1, an absolute position output is possible in a range of 2.5 rotations of the rotating side raceway (inner ring) 2, whereas in the second embodiment, the rotation side raceway (inner ring) 2 The absolute position can be detected in the forward and reverse 2.5 rotations, that is, within the range of ± 2.5 rotations.
FIG. 6A is a cross-sectional view illustrating the configuration of the second embodiment. This embodiment is the same as the first embodiment, except for items to be particularly described. The difference from the first embodiment is that a detected portion 18 is newly fixed to the rotating raceway 2 and a second magnetic detecting portion 19 is added at a position facing the detected portion 18. The detected portion 18 and the magnetic detection portion 19 form a second position detection portion 22. The detected portion 18 has an annular back metal 18b, and a magnetic generating member 18a provided on the outer periphery thereof and having one magnetic pole N and S that change in the circumferential direction and magnetized by one pair. The detected portion 18 is press-fitted and fixed to the rotating side raceway 2 via a back metal 18b. The magnetism generating member 18a is, for example, a rubber magnet and is vulcanized and bonded to the back metal 18b. The magnetism generating member 18a may be formed of a plastic magnet or a sintered magnet, and in this case, the back metal 18b is not necessarily provided.
FIG. 6B shows a configuration of the detection target 7 and the first magnetic detection unit 8 fixed to the holder 5, and the description is omitted because it is the same as that of FIG. 1B described above. A first position detecting unit 21 is configured by the detected unit 7 and the first magnetic detecting unit 8.
[0022]
FIG. 6C shows the structure of the second position detection unit 22 added as the second embodiment. The magnetic detection unit 19 includes two magnetic sensors 19a and 19b that generate an output signal according to a magnetic flux density. These two magnetic sensors 19a and 19b are arranged at positions facing each other at a predetermined interval (here, an electrical phase difference of 90 °) in the circumferential direction of the detected portion 18. Both of the magnetic sensors 19a and 19b are analog sensors, and may use, for example, a Hall element or an analog output Hall IC. These magnetic sensors 19a and 19b are mounted on a magnetic detection circuit board 11 'as shown in FIG.
[0023]
FIG. 7A shows an output example of the magnetic sensors 8a and 8b and the magnetic sensors 19a and 19b. In FIG. 7A, a sine wave signal (magnetic sensors 8a, 8b) of one cycle with 2.5 rotations of the rotating raceway ring 2 is an output from the first position detection unit 21 and is the same as that in FIG. It is. By electrically processing this signal, a code output as shown in FIG. 7B is obtained. From the magnetic sensors 19a and 19b of the second position detector 22, one cycle of a sine wave is obtained for each rotation (mechanical angle of 360 °) of the rotating race 2, and this signal is electrically processed. By doing so, a code output as shown in FIG. 7C is obtained. The code output changes from 0 to n-1 each time the rotating raceway 2 makes one rotation. However, when the code output of the forward rotation and the code output of the reverse rotation are compared, the phase is shifted by 180 °. By comparing the code output of FIG. 7C with the code output of FIG. 7B, it is possible to determine the number of rotations of the rotating raceway 2. From the result, as shown in FIG. 7 (D), the absolute position can be detected at ± 2.5 rotations of the rotating raceway 2.
[0024]
As described above, the first position detection unit 21 in which the detected portion (one-pole magnetized magnetic encoder) 7 is provided on the retainer 5 and another detected portion (1) is provided on the rotating side raceway (inner ring) 2. By providing the second position detector 22 to which the pole pair magnetized magnetic encoder 18 is fixed, the absolute position can be detected within a range of ± 2.5 rotations of the rotating raceway (inner ring) 2.
[0025]
8 and 9 show a third embodiment. FIG. 8 shows a configuration in which a double-row type is used as the rolling bearing 1 ', and each means for detecting rotation described in FIG. 1 is mounted on both axial sides of the rolling bearing 1'. I have. That is, the detected part 7, the magnetic detection part 8, and the magnetic detection circuit board 11 are provided on both sides of the bearing 1 '.
By providing the set of the detected part 7 and the magnetic detection part 8 on both sides in this way, the sensor signals can be multiplexed, so that it is possible to support when one of the sensors fails, and to provide a bearing with a rotation sensor. This leads to improved reliability.
[0026]
FIG. 9 shows a configuration in which the first and second position detectors 21 and 22 described in FIG. 6 are mounted on both sides of a double-row rolling bearing 1 '. When the sensor functions are arranged on both sides of the bearing portion 1 'as shown in FIGS. 8 and 9, the output specifications on both sides may be the same, or they may be mounted with different output specifications. If the sensor function can be fixed to both side surfaces of the bearing 1 ', installation space can be saved.
[0027]
In each of the examples of FIGS. 8 and 9, the detected part 7 is fixed to one side of each cage 5 using a double-row type rolling bearing 1 ′, but a single-row type rolling bearing is used. Even if the unit 1 is used, the same mechanism as in each example of FIGS. In this case, the detected portions (not shown) may be fixed to both the left and right sides of one cage 5, and the type of the bearing is not limited to the double row type.
[0028]
In each of the above embodiments, the signals of the two magnetic sensors 8a and 8b constituting the magnetic detection unit 8 are divided, so that even if there is an amplitude difference between the two output signals, the accuracy is not so affected. The accuracy is improved when the sine wave amplitude obtained from the magnetic sensors 8a and 8b is kept constant. Therefore, an isotropic ferrite magnet is more preferable as a magnetism generating member of the detected part 7 than an anisotropic ferrite magnet. In addition, the value of the correction table 16a (FIG. 4) used for calculating the angle can be increased in accuracy by inputting a unique value corrected based on the actually measured data.
Further, the detected parts 7 and 18 described above may be of a radial type or an axial type. Although the processing circuit has been described as being mounted on the magnetic detection circuit boards 11 and 11 ', all or a part of the processing circuit may be inserted in the middle of an output cable (not shown) or connected to an external circuit. A processing circuit function may be provided.
Although the sensor component has been described as a means for fixing to the side surface of the bearing in a protruding manner, an annular ring formed by extending the width of the rotating race 2 or the fixed race 3 of the bearings 1, 1 ′. The configuration may be such that the magnetic detection units 8 and 19 and the detected unit 18 are accommodated in the space.
[0029]
【The invention's effect】
A bearing with a rotation sensor according to the present invention includes a detected part which is fixed to a retainer and whose magnetic characteristics periodically change in a circumferential direction, and a magnetic detection part comprising an analog output magnetic sensor facing the detected part. Therefore, the absolute position information of the rotation can be detected even in the case of multiple rotations. In particular, when the magnetic characteristics of the detected part with respect to the magnetic detection part are changed in one cycle for one rotation of the cage, the absolute position can be detected without performing the initialization operation when the power is turned on.
In addition to the detected portion and the magnetic detection portion, the detected portion on the raceway side, which is fixed to the rotating raceway and whose magnetic characteristics periodically change in the circumferential direction, faces the detected portion on the raceway side. In the case where the second magnetic detection unit including an analog output magnetic sensor is provided, the absolute position can be detected within a range of several rotations in both the forward and reverse directions of the rotating raceway.
When the set of the detected portion and the magnetic detection portion is provided on both left and right sides of the bearing portion, the reliability is improved.
[Brief description of the drawings]
FIGS. 1A and 1B are a partially cutaway side view of a bearing with a rotation sensor according to a first embodiment of the present invention, and a front view of a detected part and a magnetic detection part thereof.
FIG. 2 is an explanatory diagram of an output of a magnetic sensor.
FIG. 3 is an explanatory diagram of a process of performing interpolation division from an output of a magnetic sensor.
FIG. 4 is a block diagram of a processing circuit.
FIG. 5 is an explanatory diagram of a processing example of an output of a magnetic detection unit.
6 (A) to 6 (C) are each a partially cutaway side view of a bearing with a rotation sensor according to another embodiment of the present invention, a front view of a detected portion thereof, a magnetic detection portion, and a second position detection. It is sectional drawing of a part.
FIG. 7 is a waveform diagram of an output of the magnetic sensor and signals in respective processing states according to the embodiment.
FIG. 8 is a cutaway side view of still another embodiment of the present invention.
FIG. 9 is a cutaway side view of still another embodiment of the present invention.
FIG. 10 is a sectional view of a conventional example.
FIG. 11 is a front view showing a relationship between a detected part and a magnetic detection part of the conventional example.
FIG. 12 is a waveform diagram of a sensor output of the conventional example.
[Explanation of symbols]
1, 1 '... rolling bearing part 2 ... rotating raceway ring (inner ring)
3 ... Fixed side raceway (outer ring)
4 Rolling element 5 Cage 7 Detected part 7a Magnetic generation member 7b Back metal 8 Magnetic detection parts 8a and 8b Magnetic sensor 11 Magnetic detection circuit board 18 Detected part 18a Magnetic generation member 18b ... back metal 19 ... magnetic detector

Claims (7)

A rolling bearing portion including a rotating raceway ring, a fixed raceway ring, a rolling element, and a cage, a detected portion fixed to the cage and having a magnetic property periodically changing in a circumferential direction, and opposed to the detected portion. And a magnetic sensor comprising a magnetic sensor having an analog output. 2. The bearing with a rotation sensor according to claim 1, wherein a magnetic characteristic of the detected part with respect to the magnetic detection unit is changed in one cycle for one rotation of the cage. A rolling bearing portion including a rotating raceway ring, a fixed raceway, a rolling element, and a cage; a detected portion on the cage side fixed to the cage and having magnetic characteristics periodically changing in a circumferential direction; A first magnetic detection unit comprising an analog output magnetic sensor opposed to the detection unit on the retainer side; and a detection target on the raceway side fixed to the rotating raceway and whose magnetic characteristics periodically change in a circumferential direction. A bearing with a rotation sensor, comprising: a second magnetic detection unit comprising an analog output magnetic sensor facing the detected portion on the raceway side. 4. The bearing with a rotation sensor according to claim 3, wherein the magnetic characteristic of the detected part on the cage side is changed as one cycle for one rotation of the cage, and the magnetic characteristic of the detected part on the raceway side is rotated. A bearing with a rotation sensor that is changed as one cycle for one rotation of the side bearing ring. The bearing with a rotation sensor according to any one of claims 1 to 4, wherein a pair of a detected part and a magnetic detection part facing the part are arranged on both sides of the rolling bearing in the axial direction. . 6. The bearing with a rotation sensor according to claim 5, wherein the rolling elements of the rolling bearing portion are of a double row, and have two retainers for respectively holding the rolling elements of each row. Bearing with a rotation sensor to which the parts to be detected are fixed. 7. The bearing with a rotation sensor according to claim 1, wherein the rolling bearing portion is used by applying a preload.

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