Sensor-equipped bearing and bearing device

Abstract

To provide a bearing device with a sensor capable of reusing at least a sensor unit even when a rolling bearing is exchanged.SOLUTION: A bearing with a sensor is equipped with a bearing that includes a rotary ring, a fixed ring, and a rolling body, and a sensor unit. The rotary ring has a rotary ring raceway surface extending in a circumferential direction. The fixed ring has a fixed ring raceway surface extending in the circumferential direction and opposing the rotary ring raceway surface at an interval in a radial direction. The rolling body is disposed between the rotary ring raceway surface and the fixed ring raceway surface. The sensor unit has a generation coil that is detachably attached to the fixed ring and generates induction electromotive voltage with rotations of the rotary ring, a sensor that outputs physical amount or chemical amount as an electric signal, and a radio communication module that radio-transmits the output of the sensor to the outside.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] The present invention relates to a sensor-equipped bearing and a bearing device. [Background technology]

[0002] For example, Japanese Patent Laid-Open Publication No. 2005-256892 (Patent Document 1) describes a bearing with a sensor. The bearing with a sensor described in Patent Document 1 includes a rolling bearing, a magnetic ring, and a sensor unit.

[0003] The rolling bearing has an inner ring, an outer ring, rolling elements, and a cage. The magnetic ring has a core and a magnetic rubber layer. The inner ring is press-fitted onto the inner circumferential surface of the core. The magnetic rubber layer is disposed on the outer circumferential surface of the core. The sensor unit has an outer ring and a sensor housing. The outer ring is press-fitted onto the inner circumferential surface of the outer ring. The sensor housing is attached to the inner circumferential surface of the outer ring. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-256892 Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, in the sensor-equipped bearing disclosed in Patent Document 1, the magnetic ring and sensor unit are fixed to the inner ring and outer ring, respectively, by press-fitting, so the magnetic ring cannot be removed from the inner ring, and the sensor unit cannot be removed from the outer ring. Therefore, when the rolling bearing is replaced due to a rolling abnormality or the like, the magnetic ring and sensor unit must also be replaced. From another perspective, in the sensor-equipped bearing disclosed in Patent Document 1, the magnetic ring and sensor unit cannot be reused.

[0006] The present invention has been made in view of the above-mentioned problems. More specifically, the present invention provides a bearing device with a sensor and a bearing device that enable at least the sensor unit to be reused even when the rolling bearing is replaced. [Means for solving the problem]

[0007] The sensor-equipped bearing of the present invention comprises a bearing including a rotating ring, a fixed ring, and rolling elements, and a sensor unit. The rotating ring has a rotating ring raceway surface extending circumferentially. The fixed ring has a fixed ring raceway surface extending circumferentially and facing the rotating ring raceway surface in the radial direction with a gap therebetween. The rolling elements are disposed between the rotating ring raceway surface and the fixed ring raceway surface. The sensor unit is detachably attached to the fixed ring, and comprises a power generating coil that generates an induced voltage as the rotating ring rotates, a sensor that outputs a physical quantity or chemical quantity as an electrical signal, and a wireless communication module that wirelessly transmits the sensor output to an external device.

[0008] The above-mentioned sensor-equipped bearing may further include a magnetic ring detachably attached to the rotating ring. The magnetic ring may be magnetized with north and south poles alternately arranged along the circumferential direction. The sensor may detect the rotation state of the rotating ring and output the result as an electrical signal.

[0009] In the above-described sensor-equipped bearing, the sensor unit may generate an induced voltage in the power generating coil as the magnetic ring rotates, and detect the rotation speed of the rotating ring based on the waveform of the induced voltage generated in the power generating coil.

[0010] In the above-described sensor-equipped bearing, the sensor unit may have an annular stator detachably attached to the fixed ring and having a power generating coil mounted thereon. The stator may extend circumferentially and have an inner peripheral surface facing the magnetic ring at a distance in the radial direction. The inner peripheral surface of the stator may have a plurality of comb teeth arranged at intervals in the circumferential direction. The comb teeth may form a magnetic path for magnetic flux from the magnetic ring. The number of magnetic poles of the magnetic ring may be equal to the number of comb teeth.

[0011] In the above-described sensor-equipped bearing, the stator may be configured so that magnetic flux from the magnetic ring passes from the comb-tooth portion around the generator coil.

[0012] The above-mentioned sensor-equipped bearing may further include a ring-shaped first fastener. The sensor unit may be detachably attached to the fixed ring by an elastic repulsive force acting along the radial direction from the first fastener.

[0013] In the above-described bearing with sensor, the first fastener may have a plurality of first biasing portions arranged at intervals in the circumferential direction, and the sensor unit may be detachably attached to the fixed ring by elastic repulsive force acting along the radial direction from the first biasing portions.

[0014] The sensor-equipped bearing may further include a ring-shaped second fastener. The magnetic ring may be detachably attached to the rotating ring by an elastic repulsive force acting in the radial direction from the second fastener.

[0015] In the sensor-equipped bearing described above, the second fastener may have a plurality of second biasing portions arranged at intervals in the circumferential direction, and the magnetic ring may be detachably attached to the rotating wheel by elastic repulsive forces acting along the radial direction from the second biasing portions.

[0016] The sensor-equipped bearing may further include a ring-shaped rubber member. The sensor unit may be detachably attached to the fixed ring by elastic repulsive force acting along the radial direction from the rubber member.

[0017] The sensor-equipped bearing may further include a compression coil spring. The sensor unit may be detachably attached to the fixed ring by elastic repulsive force in the radial direction from the compression coil spring.

[0018] In the above-described sensor-equipped bearing, the sensor and the wireless communication module may be driven by an induced voltage generated in the power generating coil.

[0019] In the above-described sensor-equipped bearing, the wireless communication module may continuously or intermittently modulate a carrier wave with the output from the sensor and wirelessly transmit the modulated carrier wave to the outside.

[0020] In the above-described sensor-equipped bearing, the open portion of the sensor unit may be sealed with a resin material.

[0021] In the above-described sensor-equipped bearing, the sensor may be a vibration sensor. The sensor unit may be detachably attached to the fixed ring so that the detection direction of the sensor coincides with the load direction of the bearing. The sensor unit may be provided with a mark for aligning the detection direction of the sensor with the load direction of the bearing.

[0022] The bearing device of the present invention includes a shaft, a housing, and a sensor-equipped bearing. One of the rotating ring and the fixed ring is fitted to the shaft. The other of the rotating ring and the fixed ring is fitted to the housing. [Effects of the Invention]

[0023] According to the sensor-equipped bearing and the bearing device of the present invention, even when the rolling bearing is replaced, at least the sensor unit can be reused. [Brief explanation of the drawings]

[0024] [Figure 1A] FIG. 2 is a cross-sectional view of the sensor-equipped bearing 100. [Figure 1B] 1 is a cross-sectional view of the sensor-equipped bearing 100 when the sensor unit 20 and the magnetic ring 30 are removed from the rolling bearing 10. FIG. [Figure 2] FIG. 1B is an enlarged view of II in FIG. 1A. [Figure 3] FIG. 1B is a cross-sectional view taken along line III-III in FIG. 1A. [Figure 4A] FIG. 4 is a first enlarged view of IV in FIG. [Figure 4B] FIG. 4 is a second enlarged view of IV in FIG. [Figure 5] FIG. 4B is a cross-sectional view taken along line VV in FIG. 4A. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 4B. [Figure 7A] 1 is a first enlarged cross-sectional view of the sensor-equipped bearing 100 according to Modification 1 in the vicinity of the biasing portion 51. FIG. [Figure 7B] 10 is a second enlarged cross-sectional view of the sensor-equipped bearing 100 according to the first modified example in the vicinity of the biasing portion 51. FIG. [Figure 8] 10 is a cross-sectional view of a sensor-equipped bearing 100 according to a second modification. FIG. [Figure 9] FIG. 9 is an enlarged view of IX in FIG. 8. [Figure 10] FIG. 10 is a cross-sectional view of a sensor-equipped bearing 100 according to a third modification. [Figure 11] FIG. 11 is an enlarged view of XI in FIG. [Figure 12] FIG. 10 is a cross-sectional view of a sensor-equipped bearing 100 according to a fourth modification. [Figure 13] FIG. 13 is an enlarged view of XIII in FIG. [Figure 14] FIG. 2 is a cross-sectional view of a sensor-equipped bearing 100A. [Figure 15] FIG. 15 is an enlarged view of XV in FIG. [Figure 16] 10 is a cross-sectional view of a sensor-equipped bearing 100A according to a first modified example. FIG. [Figure 17]FIG. 17 is an enlarged view of XVII in FIG. [Figure 18] 10 is a cross-sectional view of a sensor-equipped bearing 100A according to a second modification. FIG. [Figure 19] FIG. 19 is an enlarged view of XIX in FIG. [Figure 20] FIG. 10 is a cross-sectional view of a sensor-equipped bearing 100A according to a third modification. [Figure 21] FIG. 21 is an enlarged view of XXI in FIG. [Figure 22] FIG. 2 is a cross-sectional view of a sensor-equipped bearing 100B. [Figure 23] FIG. 23 is an enlarged view of XXIII in FIG. [Figure 24] 10 is a cross-sectional view of a sensor-equipped bearing 100B according to a first modified example. FIG. [Figure 25] FIG. 25 is an enlarged view of XXV in FIG. [Figure 26] FIG. 10 is a cross-sectional view of a sensor-equipped bearing 100B according to a second modification. [Figure 27] FIG. 27 is an enlarged view of XXVII in FIG. [Figure 28] FIG. 2 is a cross-sectional view of a sensor-equipped bearing 100C. [Figure 29] The cross section taken along line XXIX-XXIX in FIG. 28 is shown. [Figure 30] FIG. 29 shows the lid 26 superimposed thereon. DETAILED DESCRIPTION OF THE INVENTION

[0025] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are designated by the same reference numerals, and redundant description will not be repeated.

[0026] (First embodiment) A sensor-equipped bearing according to a first embodiment (hereinafter referred to as "sensor-equipped bearing 100") will be described.

[0027] <Configuration of sensor-equipped bearing 100> The configuration of the sensor-equipped bearing 100 will be described below.

[0028] FIG. 1A is a cross-sectional view of the sensor-equipped bearing 100. FIG. 1A shows a cross-section passing through the central axis (central axis A) of the inner ring 11 and parallel to the axial direction. FIG. 1B is a cross-sectional view of the sensor-equipped bearing 100 when the sensor unit 20 and magnetic ring 30 have been removed from the rolling bearing 10. FIG. 2 is an enlarged view of II in FIG. 1A. FIG. 3 is a cross-sectional view taken along III-III in FIG. 1A. As shown in FIGS. 1A, 1B, 2, and 3, the sensor-equipped bearing 100 has the rolling bearing 10, the sensor unit 20, the magnetic ring 30, a first fastener 40, and a second fastener 50.

[0029] The direction along the central axis A is defined as the axial direction. The direction passing through the central axis A and perpendicular to the axial direction is defined as the radial direction. The direction along the circumference of a circle centered on the central axis A when viewed along the axial direction is defined as the circumferential direction.

[0030] The rolling bearing 10 is, for example, a deep groove ball bearing. However, the rolling bearing 10 is not limited to this. The rolling bearing 10 has an inner ring 11, an outer ring 12, a plurality of rolling elements 13, and a cage 14. The rolling bearing 10 may further have a seal 15. The inner ring 11 is a rotating ring, and the outer ring 12 is a fixed ring.

[0031] The inner ring 11 has a first end face 11a, a second end face 11b, an inner peripheral surface 11c (inner ring inner peripheral surface), and an outer peripheral surface 11d (inner ring outer peripheral surface). The first end face 11a and the second end face 11b are end faces of the inner ring 11 in the axial direction. The second end face 11b is the surface opposite the first end face 11a in the axial direction.

[0032] The inner peripheral surface 11c extends along the circumferential direction. The inner peripheral surface 11c faces the central axis A. One end and the other end of the inner peripheral surface 11c in the axial direction are connected to the first end face 11a and the second end face 11b, respectively. The outer peripheral surface 11d extends along the circumferential direction. The outer peripheral surface 11d faces the opposite side from the central axis A. In other words, the outer peripheral surface 11d is the opposite surface to the inner peripheral surface 11c in the radial direction. One end and the other end of the outer peripheral surface 11d in the axial direction are connected to the first end face 11a and the second end face 11b, respectively.

[0033] The outer peripheral surface 11d has an inner ring raceway surface 11da. The inner ring raceway surface 11da is the portion of the outer peripheral surface 11d that comes into contact with the rolling elements 13. The outer peripheral surface 11d is recessed toward the inner peripheral surface 11c at the inner ring raceway surface 11da. The inner ring raceway surface 11da is located at the center of the outer peripheral surface 11d in the axial direction. In a cross section perpendicular to the circumferential direction, the inner ring raceway surface 11da has a partial arc shape.

[0034] The outer ring 12 has a first end face 12a, a second end face 12b, an inner peripheral surface 12c (outer ring inner peripheral surface), and an outer peripheral surface 12d (outer ring outer peripheral surface). The first end face 12a and the second end face 12b are end faces of the outer ring 12 in the axial direction. The second end face 12b is the surface opposite the first end face 12a in the axial direction.

[0035] The inner peripheral surface 12c extends along the circumferential direction. The inner peripheral surface 12c faces the central axis A. One end and the other end in the axial direction of the inner peripheral surface 12c are connected to the first end face 12a and the second end face 12b, respectively. The outer ring 12 is disposed so that the inner peripheral surface 12c faces the outer peripheral surface 11d at a distance in the radial direction. The outer peripheral surface 12d extends along the circumferential direction. The outer peripheral surface 12d faces the opposite side from the central axis A. In other words, the outer peripheral surface 12d is the opposite surface to the inner peripheral surface 12c in the radial direction. One end and the other end in the axial direction of the outer peripheral surface 12d are connected to the first end face 12a and the second end face 12b, respectively.

[0036] The inner peripheral surface 12c has an outer ring raceway surface 12ca. The outer ring raceway surface 12ca is the portion of the inner peripheral surface 12c that comes into contact with the rolling elements 13. The inner peripheral surface 12c is recessed toward the outer peripheral surface 12d in the outer ring raceway surface 12ca. The outer ring raceway surface 12ca is located at the center of the inner peripheral surface 12c in the axial direction. In a cross section perpendicular to the circumferential direction, the outer ring raceway surface 12ca has a partial arc shape.

[0037] The rolling elements 13 are spherical. The rolling elements 13 are arranged between the outer peripheral surface 11d and the inner peripheral surface 12c. More specifically, the rolling elements 13 are lined up in the circumferential direction between the inner ring raceway surface 11da and the outer ring raceway surface 12ca.

[0038] The cage 14 holds the rolling elements 13 so that the distance between two adjacent rolling elements 13 in the circumferential direction is within a certain range. The cage 14 has, for example, an annular portion 14a and a plurality of column portions 14b. The column portions 14b hold the rolling elements 13. One axial side of the column portions 14b (the right side in FIG. 1A) is open. The annular portion 14a connects the plurality of column portions 14b so that they are lined up in the circumferential direction. From another perspective, the cage 14 is, for example, a crown-shaped cage. The cage 14 is preferably a resin molded product made of a thermoplastic resin such as glass fiber-reinforced polyamide.

[0039] The space between the outer peripheral surface 11d and the inner peripheral surface 12c is the bearing space. The seal 15 closes the bearing space from the other axial side (the left side in FIG. 1A ). A groove 12cb is formed in the inner peripheral surface 12c. The groove 12cb extends annularly in the circumferential direction. The groove 12cb is located axially between the second end face 12b and the outer ring raceway surface 12ca. The seal 15 is annular. The outer peripheral edge of the seal 15 is inserted into the groove 12cb. The inner peripheral edge of the seal 15 is in contact with the outer peripheral surface 11d. The seal 15 is formed, for example, by vulcanization bonding oil-resistant rubber (NBR, HNBR, FKM, ACM, etc.) to a core bar. The seal 15 may have a core bar surface that has been subjected to an anti-rust treatment. A lubricant is sealed in the bearing space.

[0040] The sensor-equipped bearing 100 constitutes a bearing device by fitting the inner ring 11 to a shaft at its inner peripheral surface 11c and fitting the outer ring 12 to a housing at its outer peripheral surface 12d.

[0041] The sensor unit 20 includes a stator 21 , a power generating coil 22 , a circuit board 23 , a sensor 24 , and a wireless communication module 25 .

[0042] The stator 21 is annular and extends in the circumferential direction. The stator 21 has a first member 21a and a second member 21b. The first member 21a is annular and extends in the circumferential direction. The first member 21a is divided into a first annular portion 21aa, a second annular portion 21ab, and a third annular portion 21ac in the radial direction. The first annular portion 21aa is located at the innermost position in the radial direction, and the third annular portion 21ac is located at the outermost position in the radial direction. The second annular portion 21ab is located between the first annular portion 21aa and the third annular portion 21ac.

[0043] A power generating coil 22 is disposed in the first annular portion 21aa. The power generating coil 22 is housed in a coil bobbin 22a. The power generating coil 22 is formed, for example, by winding an enameled wire. The coil bobbin 22a is formed, for example, from a resin material. The number of turns and wire diameter of the power generating coil 22 are determined appropriately taking into consideration the power generated, the amount of self-heat generation, the cross-sectional area it occupies, etc.

[0044] The second member 21b is disposed on the first annular portion 21aa, thereby defining a space in which the power generation coil 22 is disposed. The first member 21a and the second member 21b are preferably made of a magnetic material.

[0045] The second annular portion 21ab is divided in the circumferential direction into a first region 21aba and a second region 21abb. A circuit board 23 is disposed on the first region 21aba. The circuit board 23 extends in the circumferential direction. The base material of the circuit board 23 is formed, for example, from an epoxy resin containing glass fiber. From the viewpoint of improving the detection accuracy of the vibration sensor, the base material of the circuit board 23 preferably has a compressive strength of 340 MPa to 500 MPa and a bending strength of 390 MPa to 550 MPa. A plurality of electronic components 23a are disposed on the circuit board 23.

[0046] The multiple electronic components 23a constitute a power supply unit and a conversion unit. The power supply unit converts the induced electromotive force (AC) generated in the power generating coil 22 into DC. The conversion unit detects the rotation speed of the inner ring 11 by converting the AC waveform of the induced electromotive force generated in the power generating coil 22 into a pulse waveform. A power storage unit is also arranged on the circuit board 23. The power storage unit stores the power generated in the power generating coil 22 and converted to DC by the power supply unit. The power supply unit is composed of, for example, a circuit that rectifies and smooths AC and a boost circuit. The conversion unit is composed of, for example, a comparator circuit. The power storage unit is composed of, for example, an electric double layer capacitor or a secondary battery.

[0047] The sensor 24 is disposed on the circuit board 23. The number and type of the sensors 24 may be plural. The sensors 24 include, for example, a temperature sensor and a vibration sensor. The temperature sensor may be a MEMS, a platinum resistor, a thermistor, a thermocouple, a thermoelectric element, or the like. The vibration sensor may be a MEMS, capacitance type, eddy current type, piezoelectric element type, or strain gauge type. The vibration sensor may be one that detects vibration along one axis, or may be one that detects vibration along two or three axes. The sensor 24 detects the rotational state (e.g., temperature, vibration) of the inner ring 11 and outputs a signal corresponding to the rotational state. The sensor 24 may be any sensor that outputs a physical or chemical quantity as an electrical signal.

[0048] The plurality of electronic components 23a further comprises a memory unit and a processing unit. The memory unit stores the output from the sensor 24. The processing unit performs processing to compare the output from the sensor 24 with a predetermined threshold value and to determine the rotation state of the inner ring 11 from the output of the sensor 24 based on predetermined criteria. The memory unit and processing unit are composed of, for example, a microcontroller.

[0049] The wireless communication module 25 is disposed on the circuit board 23. The wireless communication module 25 wirelessly transmits the output of the sensor 24, which has undergone predetermined processing in the processing unit, to the outside. More specifically, the wireless communication module 25 modulates a carrier wave with the output of the sensor 24, which has undergone predetermined processing in the processing unit, and transmits the modulated carrier wave from an antenna. This antenna may be built into the wireless communication module 25 or may be externally attached to the wireless communication module 25. The wireless communication module 25 complies with communication standards such as Zigbee (registered trademark), Bluetooth (registered trademark), WiFi (registered trademark), and IrDA (registered trademark), for example.

[0050] The plurality of electronic components 23a may include electronic components for attenuating or blocking harmful external electrical noise, such as a common mode filter, a single mode filter, a ceramic filter, an EMI filter, a resistor, a capacitor, a coil, a varistor, an inductor, and a ferrite bead.

[0051] A lid 26 may be placed above the circuit board 23 to prevent the circuit board 23 from being exposed to the outside. A molding resin 27 may be filled on the second region 21abb. A moisture-proof coating may be provided on the surface of the circuit board 23 to protect the electronic components 23a from migration.

[0052] The third annular portion 21ac is a portion used for attachment to the outer ring 12. The first end face 12a is formed with a step portion 12aa, a step portion 12ab, and a groove 12ac. The step portion 12aa, the step portion 12ab, and the groove 12ac extend annularly along the circumferential direction. The step portion 12aa is located at the end of the first end face 12a on the inner circumferential surface 12c side. The step portion 12ab is located radially outward of the step portion 12aa. The step portion 12ab is located in a position that protrudes to one side in the axial direction (the right side in FIG. 1A) beyond the step portion 12aa. The groove 12ac is formed at the end of the step portion 12ab opposite to the step portion 12aa. The end of the second annular portion 21ab on the third annular portion 21ac side is located on the step portion 12aa. The third annular portion 21ac conforms to the shape of the groove 12ac and the portion of the first end face 12a between the groove 12ac and the step portion 12aa.

[0053] A plurality of comb-tooth portions 28 may be formed on the inner circumferential surface of the stator 21. The plurality of comb-tooth portions 28 are arranged at intervals in the circumferential direction. Each comb-tooth portion 28 protrudes radially inward beyond the inner circumferential surface of the stator 21 between two adjacent comb-tooth portions 28.

[0054] The magnetic ring 30 has a core 31 and a magnetic rubber 32. The core 31 has a first portion 31a and a second portion 31b. The first portion 31a is cylindrical and extends along the axial direction. The second portion 31b extends radially inward from one axial end (the right end in FIG. 1A) of the first portion 31a.

[0055] The core metal 31 is formed, for example, by press-forming a thin plate, including deep drawing. This thin plate is formed, for example, from mild steel or stainless steel. Specific examples of mild steel include SPCC, SPCCT, SPCD, SPCE, and SPCEN. Specific examples of stainless steel include SUS430, SUS201, SUS304, SUS316, SUS321, SUS403, and SUS410. The core metal 31 is preferably formed from a magnetic material.

[0056] The magnetic rubber 32 is disposed on at least the outer peripheral surface of the first portion 31a. The magnetic rubber 32 is formed by kneading and vulcanizing a rubber material and a magnetic powder, and then adhering the mixture onto the core 31. Preferably, an adhesive is applied to the core 31 in advance to adhere the magnetic rubber 32. For example, NBR, HNBR, FKM, ACM, etc. are used as the rubber material. For example, ferrite-based, neodymium-based, or samarium-based magnetic powder is used as the magnetic powder.

[0057] The magnetic rubber 32 is magnetized with N poles and S poles alternately arranged in the circumferential direction. There is no particular limitation on the number of magnetic poles magnetized on the magnetic rubber 32. The magnetic rubber 32 faces the power generation coil 22 with a gap therebetween in the radial direction.

[0058] After the core metal 31 and the magnetic rubber 32 are integrated, the magnetic ring 30 is attached to a rotating chuck (mounting jig) of a magnetizing device. The magnetizing device rotates the rotating chuck to alternately magnetize the magnetic rubber 32 with north and south poles. At this time, a magnetizing coil and a yoke are arranged to face the magnetic rubber 32. By alternately switching the direction of the current flowing through the magnetizing coil in synchronization with the rotation of the rotating chuck, the magnetic rubber 32 is alternately magnetized with north and south poles.

[0059] The first fastener 40 is, for example, a circlip. That is, the first fastener 40 extends in the circumferential direction and has opposite ends spaced apart in the circumferential direction. The first fastener 40 is placed in the groove 12ac while being reduced in diameter, with the stator 21 attached to the outer ring 12. When the first fastener 40 is placed in the groove 12ac, the first fastener 40 attempts to return to its original shape and comes into contact with the outer ring 12. The radial elastic repulsive force generated at this time attaches the first fastener 40 to the outer ring 12, making it impossible to remove the stator 21 (sensor unit 20) from the outer ring 12. On the other hand, if the first fastener 40 is reduced in diameter again and removed from the groove 12ac, the stator 21 (sensor unit 20) can be removed from the outer ring 12. In this way, the sensor unit 20 is detachably attached to the outer ring 12 by the elastic repulsive force of the first fastener 40 (see FIG. 1B).

[0060] The second fastener 50 is annular and extends in the circumferential direction. The second fastener 50 has a plurality of biasing portions 51. The biasing portions 51 are arranged at intervals in the circumferential direction. The biasing portions 51 are, for example, leaf springs. A groove 11db is formed in the outer peripheral surface 11d. The groove 11db extends in the circumferential direction. The groove 11db is located between the inner ring raceway surface 11da and the first end face 11a in the axial direction. The second fastener 50 is disposed in the groove 11db.

[0061] A step portion 11aa is formed on the first end face 11a. The step portion 11aa extends in the circumferential direction. The step portion 11aa is continuous with the outer peripheral surface 11d. With the inner peripheral surface of the first portion 31a and the outer peripheral surface 11d facing each other, the magnetic ring 30 is pushed from one axial side (the right side in FIG. 1A) to the other axial side (the left side in FIG. 1A) against the elastic repulsive force from the biasing portion 51 until the second portion 31b contacts the step portion 11aa. This elastic repulsive force attaches the magnetic ring 30 to the inner ring 11.

[0062] On the other hand, by pulling out the magnetic ring 30 against the elastic repulsive force, the magnetic ring 30 is removed from the inner ring 11. In this way, the magnetic ring 30 is detachably attached to the inner ring 11 by the elastic repulsive force of the second fastener 50 (see FIG. 1B).

[0063] As described above, the magnetic ring 30 is detachably attached to the inner ring 11, and therefore rotates together with the inner ring 11. The magnetic ring 30 faces the generator coil 22 in the radial direction with a gap between them, and has magnetic rubber 32 that is magnetized with alternating north and south poles along the circumferential direction. As the inner ring 11 rotates, an alternating magnetic flux is generated around the generator coil 22, and an induced voltage is generated in the generator coil 22.

[0064] FIG. 4A is a first enlarged view of IV in FIG. 3. FIG. 4B is a second enlarged view of IV in FIG. 3. FIG. 4B shows the state when the magnetic ring 30 has rotated from FIG. 4A. In FIGS. 4A and 4B, magnetic flux is indicated by dotted arrows. FIG. 5 is a cross-sectional view taken along VV in FIG. 4A. FIG. 6 is a cross-sectional view taken along VI-VI in FIG. 4B. In FIGS. 5 and 6, magnetic flux is indicated by dotted arrows. As shown in FIGS. 4A, 4B, 5, and 6, magnetic flux generated from the magnetic poles magnetized in the magnetic rubber 32 passes from the comb tooth portion 28 through the stator 21 around the generating coil 22. This generates an induced voltage in the generating coil 22.

[0065] <Effects of the Sensor-Equipped Bearing 100> The effects of the sensor-equipped bearing 100 will be described below.

[0066] In the sensor-equipped bearing 100, if a rolling abnormality or the like occurs in the rolling bearing 10 during use, the rolling bearing 10 must be replaced. In the sensor-equipped bearing 100, the sensor unit 20 is detachably attached to the outer ring 12 and the magnetic ring 30 is detachably attached to the inner ring 11, so even when the rolling bearing 10 is replaced, the sensor unit 20 and magnetic ring 30 can be removed from the rolling bearing 10 and reused. As a result, the sensor-equipped bearing 100 can reduce costs associated with continued use.

[0067] <Variation 1> The following describes the sensor-equipped bearing 100 according to Modification 1. Here, differences from the sensor-equipped bearing 100 will be mainly described, and overlapping descriptions will not be repeated.

[0068] Fig. 7A is a first enlarged cross-sectional view of the sensor-equipped bearing 100 according to Modification 1 in the vicinity of the biasing portion 51. Fig. 7B is a second enlarged cross-sectional view of the sensor-equipped bearing 100 according to Modification 1 in the vicinity of the biasing portion 51. As shown in Figs. 7A and 7B, in the sensor-equipped bearing 100 according to Modification 1, the leaf spring shape of the biasing portion 51 is different from that of the sensor-equipped bearing 100. In other words, the leaf spring shape of the biasing portion 51 is not particularly limited as long as it can generate an elastic repulsive force along the radial direction.

[0069] In the sensor-equipped bearing 100 according to variant example 1, the sensor unit 20 is removably attached to the outer ring 12, and the magnetic ring 30 is removably attached to the inner ring 11. Therefore, even when the rolling bearing 10 is replaced due to a rolling abnormality or the like, the sensor unit 20 and the magnetic ring 30 can be removed from the rolling bearing 10 and reused.

[0070] <Variation 2> The following describes the sensor-equipped bearing 100 according to Modification 2. Here, differences from the sensor-equipped bearing 100 will be mainly described, and overlapping descriptions will not be repeated.

[0071] FIG. 8 is a cross-sectional view of the sensor-equipped bearing 100 according to Modification 2. FIG. 8 shows a cross-section corresponding to FIG. 1A. FIG. 9 is an enlarged view of IX in FIG. 8. As shown in FIGS. 8 and 9, the sensor-equipped bearing 100 according to Modification 2 does not have a groove 11db formed in the outer peripheral surface 11d. Furthermore, the sensor-equipped bearing 100 according to Modification 2 has a groove 11ab formed in the stepped portion 11aa. The groove 11ab extends in the circumferential direction. The groove 11ab is formed at the end of the stepped portion 11aa on the radially opposite side from the outer peripheral surface 11d.

[0072] In the sensor-equipped bearing 100 according to the second modification, the core metal 31 further includes a third portion 31c. The third portion 31c extends axially in a cylindrical shape from the end of the second portion 31b opposite the first portion 31a. The outer peripheral surface of the third portion 31c faces the inner peripheral surface of the first portion 31a in the radial direction with a gap therebetween. The third portion 31c is disposed in the groove 11ab.

[0073] In the sensor-equipped bearing 100 according to Modification 2, the second fastener 50 is attached to the side surface of the groove 11ab on the outer circumferential surface 11d side. More specifically, the second fastener 50 is disposed between the side surface of the groove 11ab on the outer circumferential surface 11d side and the outer circumferential surface of the third portion 31c. Furthermore, in the sensor-equipped bearing 100 according to Modification 2, the elastic repulsive force from the biasing portion 51 is applied to the third portion 31c in a radially inward direction. That is, in the sensor-equipped bearing 100 according to Modification 2, the direction of the elastic repulsive force applied from the biasing portion 51 to the second fastener 50 is opposite to that in the sensor-equipped bearing 100.

[0074] In the sensor-equipped bearing 100 according to variant example 2, the sensor unit 20 is detachably attached to the outer ring 12, and the magnetic ring 30 is detachably attached to the inner ring 11. Therefore, even when the rolling bearing 10 is replaced due to a rolling abnormality or the like, the sensor unit 20 and the magnetic ring 30 can be removed from the rolling bearing 10 and reused.

[0075] <Variation 3> The following describes the sensor-equipped bearing 100 according to Modification 3. Here, differences from the sensor-equipped bearing 100 according to Modification 2 will be mainly described, and overlapping descriptions will not be repeated.

[0076] FIG. 10 is a cross-sectional view of the sensor-equipped bearing 100 according to Modification 3. FIG. 10 shows a cross section corresponding to FIG. 8. FIG. 11 is an enlarged view of XI in FIG. 10. As shown in FIGS. 10 and 11, in the sensor-equipped bearing 100 according to Modification 3, the second fastener 50 is attached to the side surface of the groove 11ab on the inner circumferential surface 11c side. More specifically, the second fastener 50 is disposed between the side surface of the groove 11ab on the inner circumferential surface 11c side and the inner circumferential surface of the third portion 31c. In addition, in the sensor-equipped bearing 100 according to Modification 3, the elastic repulsive force from the biasing portion 51 is applied to the third portion 31c in a radially outward direction. That is, in the sensor-equipped bearing 100 according to Modification 3, the direction of the elastic repulsive force applied from the biasing portion 51 to the second fastener 50 is the same as in the sensor-equipped bearing 100.

[0077] In the sensor-equipped bearing 100 according to variant example 3, the sensor unit 20 is detachably attached to the outer ring 12, and the magnetic ring 30 is detachably attached to the inner ring 11. Therefore, even when the rolling bearing 10 is replaced due to a rolling abnormality or the like, the sensor unit 20 and the magnetic ring 30 can be removed from the rolling bearing 10 and reused.

[0078] <Variation 4> The following describes the sensor-equipped bearing 100 according to Modification 4. Here, differences from the sensor-equipped bearing 100 according to Modification 2 will be mainly described, and overlapping descriptions will not be repeated.

[0079] Figure 12 is a cross-sectional view of the sensor-equipped bearing 100 according to Modification 4. Figure 12 shows a cross section corresponding to Figure 8. Figure 13 is an enlarged view of XIII in Figure 12. As shown in Figures 12 and 13, in the sensor-equipped bearing 100 according to Modification 4, the second fastener 50 is a circlip.

[0080] In the sensor-equipped bearing 100 according to Variation 4, the second fastening member 50 is expanded in diameter and then placed in the groove 11ab. Therefore, the second fastening member 50 is attached to the side surface of the groove 11ab on the inner circumferential surface 11c side due to the elastic repulsive force that tries to reduce the diameter. In the sensor-equipped bearing 100 according to Variation 4, the magnetic ring 30 can be removed from the inner ring 11 when the second fastening member 50 is removed, but the magnetic ring 30 cannot be removed from the inner ring 11 when the second fastening member 50 is attached. Therefore, even in the sensor-equipped bearing 100 according to Variation 4, the magnetic ring 30 is detachably attached to the inner ring 11.

[0081] In the sensor-equipped bearing 100 relating to variant example 4, the sensor unit 20 is detachably attached to the outer ring 12, and the magnetic ring 30 is detachably attached to the inner ring 11. Therefore, even when the rolling bearing 10 is replaced due to a rolling abnormality or the like, the sensor unit 20 and magnetic ring 30 can be removed from the rolling bearing 10 and reused.

[0082] (Second embodiment) A sensor-equipped bearing according to a second embodiment (hereinafter referred to as "sensor-equipped bearing 100A") will be described. Here, differences from the sensor-equipped bearing 100 will be mainly described, and overlapping descriptions will not be repeated.

[0083] <Configuration of sensor-equipped bearing 100A> The configuration of the sensor-equipped bearing 100A will be described below.

[0084] Fig. 14 is a cross-sectional view of the sensor-equipped bearing 100A. Fig. 14 shows a cross section passing through the central axis A and parallel to the axial direction. Fig. 15 is an enlarged view of XV in Fig. 14. As shown in Figs. 14 and 15, the sensor-equipped bearing 100A has a rolling bearing 10, a sensor unit 20, a magnetic ring 30, and a first fastening member 40. In this respect, the configuration of the sensor-equipped bearing 100A is common to the configuration of the sensor-equipped bearing 100.

[0085] The sensor-equipped bearing 100A does not have a second fastening member 50. Furthermore, in the sensor-equipped bearing 100A, the magnetic ring 30 is attached to the inner ring 11 by press-fitting. In other words, in the sensor-equipped bearing 100A, the magnetic ring 30 is not detachably attached to the inner ring 11. In these respects, the configuration of the sensor-equipped bearing 100A differs from the configuration of the sensor-equipped bearing 100.

[0086] <Effects of the 100A Sensor-Equipped Bearing> In the sensor-equipped bearing 100A, the sensor unit 20 is detachably attached to the outer ring 12, so that even when the rolling bearing 10 is replaced, the sensor unit 20 can be removed from the rolling bearing 10 and reused. Typically, the cost of the sensor unit 20 is higher than the cost of the magnetic ring 30. Therefore, with the sensor-equipped bearing 100A, the sensor unit 20 can be reused, so that even if the magnetic ring 30 cannot be reused, the cost associated with continued use can be reduced.

[0087] <Variation 1> The following describes a sensor-equipped bearing 100A according to Modification 1. Here, differences from the sensor-equipped bearing 100A will be mainly described, and overlapping descriptions will not be repeated.

[0088] Fig. 16 is a cross-sectional view of a sensor-equipped bearing 100A according to Modification 1. Fig. 16 shows a cross-section corresponding to Fig. 14. Fig. 17 is an enlarged view of XVII in Fig. 16. As shown in Figs. 16 and 17, the sensor-equipped bearing 100A according to Modification 1 uses a rubber member 60 instead of the first fastening member 40. The rubber member 60 is ring-shaped. The rubber member 60 is, for example, an O-ring.

[0089] In the sensor-equipped bearing 100A according to the first modification, a groove 21c is formed in the outer peripheral surface of the stator 21. The groove 21c extends annularly in the circumferential direction. Furthermore, in the sensor-equipped bearing 100A according to the first modification, a groove 12cc is formed in a portion of the inner peripheral surface 12c that is continuous with the step portion 12aa and faces the outer peripheral surface of the stator 21. The groove 12cc faces the groove 21c in the radial direction and extends annularly in the circumferential direction.

[0090] The rubber member 60 is disposed in the groove 12cc and the groove 21c. The outer diameter of the stator 21 in the groove 21c is larger than the inner diameter of the rubber member 60. Therefore, the rubber member 60 is compressed in the radial direction in the groove 12cc and the groove 21c, and the elastic repulsive force from the rubber member 60 in the radial direction due to this compression allows the sensor unit 20 (stator 21) to be detachably attached to the outer ring 12.

[0091] In the sensor-equipped bearing 100A according to the first modification, the sensor unit 20 is also detachably attached to the outer ring 12, so that the sensor unit 20 can be removed from the rolling bearing 10 and reused.

[0092] <Variation 2> The following describes the sensor-equipped bearing 100A according to Modification 2. Here, differences from the sensor-equipped bearing 100A according to Modification 1 will be mainly described, and overlapping descriptions will not be repeated.

[0093] Fig. 18 is a cross-sectional view of a sensor-equipped bearing 100A according to Modification 2. Fig. 18 shows a cross section corresponding to Fig. 16. Fig. 19 is an enlarged view of XIX in Fig. 18. As shown in Figs. 18 and 19, in the sensor-equipped bearing 100A according to Modification 2, multiple plungers 70 are used instead of the rubber member 60.

[0094] The plunger 70 is attached to the sensor unit 20 by being inserted into a hole formed in the outer peripheral surface of the stator 21. The multiple plungers 70 are arranged at intervals along the circumferential direction. The plunger 70 has a pin 71 and a compression coil spring 72. When the plunger 70 is attached to the sensor unit 20, the pin 71 is positioned so as to protrude radially outward from the outer peripheral surface of the stator 21. When the pin 71 is moved radially inward, the compression coil spring 72 generates an elastic repulsive force on the pin 71 that acts radially outward.

[0095] With the pin 71 pressed radially inward, the plunger 70 is connected to the stepped portion 12aa and is in contact with a portion of the inner circumferential surface 12c that faces the outer circumferential surface of the stator 21. Therefore, the sensor unit 20 is detachably attached to the outer ring 12 by the elastic repulsive force acting radially outward on the pin 71 from the compression coil spring 72.

[0096] In the sensor-equipped bearing 100A according to the second modification, the sensor unit 20 is also detachably attached to the outer ring 12, so that the sensor unit 20 can be removed from the rolling bearing 10 and reused.

[0097] <Variation 3> The following describes the sensor-equipped bearing 100A according to Modification 3. Here, differences from the sensor-equipped bearing 100A according to Modification 1 will be mainly described, and overlapping descriptions will not be repeated.

[0098] Fig. 20 is a cross-sectional view of a sensor-equipped bearing 100A according to Modification 3. Fig. 20 shows a cross-section corresponding to Fig. 16. Fig. 21 is an enlarged view of XXI in Fig. 20. As shown in Figs. 20 and 21, the sensor-equipped bearing 100A according to Modification 3 uses a first fastener 40 instead of the rubber member 60. However, in the sensor-equipped bearing 100A according to Modification 3, the first fastener 40 is not a circlip, and the first fastener 40 has a plurality of biasing portions 41.

[0099] The multiple biasing portions 41 are arranged at intervals along the circumferential direction. The biasing portions 41 are, for example, leaf springs. In the sensor-equipped bearing 100A according to the third modification, the first fastening member 40 is disposed between the portion of the inner circumferential surface 12c that is continuous with the stepped portion 12aa and the outer circumferential surface of the stator 21, and an elastic repulsive force is applied to the outer circumferential surface of the stator 21 in a radially inward direction from the biasing portion 41. This allows the sensor unit 20 to be detachably attached to the outer ring 12.

[0100] In the sensor-equipped bearing 100A according to the third modification, the sensor unit 20 is also detachably attached to the outer ring 12, so that the sensor unit 20 can be removed from the rolling bearing 10 and reused.

[0101] (Third embodiment) A sensor-equipped bearing according to a third embodiment (hereinafter referred to as "sensor-equipped bearing 100B") will be described. Here, differences from the sensor-equipped bearing 100A will be mainly described, and overlapping descriptions will not be repeated.

[0102] <Configuration of sensor-equipped bearing 100B> The configuration of the sensor-equipped bearing 100B will be described below.

[0103] FIG. 22 is a cross-sectional view of the sensor-equipped bearing 100B. FIG. 22 shows a cross section passing through the central axis A and parallel to the axial direction. FIG. 23 is an enlarged view of XXIII in FIG. 22. As shown in FIGS. 22 and 23, the sensor-equipped bearing 100B has a rolling bearing 10, a sensor unit 20, and a magnetic ring 30. The sensor-equipped bearing 100B does not have a second fastening member 50, and the magnetic ring 30 is not detachably attached to the inner ring 11. In these respects, the configuration of the sensor-equipped bearing 100B is common to the configuration of the sensor-equipped bearing 100A.

[0104] The sensor-equipped bearing 100B does not have a first fastening member 40, and the sensor unit 20 is not detachably attached to the outer ring 12. More specifically, in the sensor-equipped bearing 100B, the stator 21 is crimped to the outer ring 12, thereby attaching the sensor unit 20 to the outer ring 12. In this respect, the configuration of the sensor-equipped bearing 100B differs from the configuration of the sensor-equipped bearing 100A. Note that in the sensor-equipped bearing 100B, the magnetic ring 30 may be attached to the inner ring 11 by crimping the core metal 31 to the inner ring 11.

[0105] <Effects of the sensor-equipped bearing 100B> The effects of the sensor-equipped bearing 100B will be described below.

[0106] In the sensor-equipped bearing 100B, the sensor unit 20 is not detachably attached to the outer ring 12, and the magnetic ring 30 is not detachably attached to the inner ring 11, so when replacing the rolling bearing 10, the sensor unit 20 and magnetic ring 30 cannot be removed from the rolling bearing 10 and reused. However, in the sensor-equipped bearing 100B, the sensor unit 20 can detect a tendency for abnormalities in the rolling bearing 10 (for example, peeling or micro-peeling on the rolling surface). Therefore, with the sensor-equipped bearing 100B, the rolling bearing 10 can be replaced before it malfunctions (for example, becomes unable to rotate due to seizure).

[0107] <Variation 1> The following describes a sensor-equipped bearing 100B according to Modification 1. Here, differences from the sensor-equipped bearing 100B will be mainly described, and overlapping descriptions will not be repeated.

[0108] Fig. 24 is a cross-sectional view of a sensor-equipped bearing 100B according to Modification 1. Fig. 24 shows a cross-section corresponding to Fig. 22. Fig. 25 is an enlarged view of XXV in Fig. 24. As shown in Figs. 24 and 25, in the sensor-equipped bearing 100B according to Modification 1, the stator 21 is fixed to the outer ring 12 at a weld 81, thereby attaching the sensor unit 20 to the outer ring 12. Furthermore, in the sensor-equipped bearing 100B according to Modification 1, the core metal 31 is fixed to the inner ring 11 at a weld 82, thereby attaching the magnetic ring 30 to the inner ring 11.

[0109] The welded portions 81 and 82 are formed by beam welding. Beam welding includes, for example, laser welding and electron beam welding. Specific examples of lasers used for laser welding include YAG lasers and CO2 lasers.

[0110] In the sensor-equipped bearing 100B according to the first modification, the sensor unit 20 can also detect any tendency for abnormality in the rolling bearing 10, allowing the rolling bearing 10 to be replaced before it reaches a malfunction. Furthermore, because the welded portions 81 and 82 are formed by beam welding, the sensor-equipped bearing 100B according to the first modification can minimize the thermal effects on the inner ring 11 and outer ring 12.

[0111] <Variation 2> The following describes a sensor-equipped bearing 100B according to Modification 2. Here, differences from the sensor-equipped bearing 100B will be mainly described, and overlapping descriptions will not be repeated.

[0112] Fig. 26 is a cross-sectional view of a sensor-equipped bearing 100B according to Modification 2. Fig. 26 shows a cross-section corresponding to Fig. 22. Fig. 27 is an enlarged view of XXVII in Fig. 26. As shown in Figs. 26 and 27, in the sensor-equipped bearing 100B according to Modification 2, the stator 21 is fixed to the outer ring 12 with adhesive 83, thereby attaching the sensor unit 20 to the outer ring 12. Furthermore, in the sensor-equipped bearing 100B according to Modification 2, the core metal 31 is fixed to the inner ring 11 with adhesive 84, thereby attaching the magnetic ring 30 to the inner ring 11.

[0113] The adhesives 83 and 84 are, for example, anaerobic adhesives or epoxy resin-based, urethane resin-based, silicone-based or phenol resin-based adhesives. The adhesives 83 and 84 are not particularly limited.

[0114] In the sensor-equipped bearing 100B according to the second modification, the sensor unit 20 can also detect a tendency for abnormality in the rolling bearing 10, so that the rolling bearing 10 can be replaced before it becomes malfunctioning.

[0115] <Variation 3> The following describes a sensor-equipped bearing 100B according to Modification 3. Here, differences from the sensor-equipped bearing 100B will be mainly described, and overlapping descriptions will not be repeated.

[0116] In the sensor-equipped bearing 100B according to the third modification, although this is not shown, the stator 21 is fixed to the outer ring 12 by press-fitting, thereby attaching the sensor unit 20 to the outer ring 12. In the sensor-equipped bearing 100B according to the third modification, the sensor unit 20 can also detect any tendency for abnormality in the rolling bearing 10, so that the rolling bearing 10 can be replaced before it malfunctions.

[0117] (Fourth embodiment) A sensor-equipped bearing according to a fourth embodiment (hereinafter referred to as "sensor-equipped bearing 100C") will be described. Here, differences from the sensor-equipped bearing 100 will be mainly described, and overlapping descriptions will not be repeated.

[0118] <Configuration of sensor-equipped bearing 100C> The configuration of the sensor-equipped bearing 100C will be described below.

[0119] FIG. 28 is a cross-sectional view of the sensor-equipped bearing 100C. FIG. 28 shows a cross-section passing through the central axis A and parallel to the axial direction. FIG. 29 shows a cross-section taken along line XXIX-XXIX in FIG. 28. FIG. 30 is a view showing the lid 26 superimposed on FIG. 29. As shown in FIGS. 28, 29, and 30, the sensor-equipped bearing 100C has a rolling bearing 10, a sensor unit 20, a magnetic ring 30, a first fastening member 40, and a second fastening member 50. In this respect, the configuration of the sensor-equipped bearing 100C is common to the configuration of the sensor-equipped bearing 100.

[0120] In the sensor-equipped bearing 100C, the sensor 24 is a vibration sensor. In the sensor-equipped bearing 100C, the sensor unit 20 is detachably attached to the outer ring 12 so that the vibration detection direction of the sensor 24 (dotted arrow in FIG. 29) coincides with the load application direction of the rolling bearing 10 (solid arrow in FIG. 29).

[0121] In the sensor-equipped bearing 100C, a mark 26a is provided on the cover 26. When viewed in the axial direction, the mark 26a overlaps the sensor 24. In the example shown in Fig. 30, the mark 26a is provided by drawing a circle, but the method of providing the mark 26a is not limited to this. Note that if the molded resin 27 is also disposed on the circuit board 23, the mark 26a may be provided on the molded resin 27.

[0122] <Effects of the 100C sensor-equipped bearing> The effects of the sensor-equipped bearing 100C will be described below.

[0123] Aligning the vibration detection direction of sensor 24 with the load application direction of rolling bearing 10 improves the reliability of the vibration values ​​detected by sensor 24. With sensor-equipped bearing 100C, by rotating sensor unit 20 around central axis A while checking the position of mark 26a when attaching it to outer ring 12, it is possible to easily align the vibration detection direction of sensor 24 with the load application direction of rolling bearing 10. Therefore, with sensor-equipped bearing 100C, the reliability of the vibration values ​​detected by sensor 24 can be improved.

[0124] (Other embodiments) In the above embodiments, the sensor-equipped bearing is described as having a rotating inner ring and a fixed outer ring, but the inner ring may be a fixed ring and the outer ring may be a rotating ring. In other words, it is sufficient that one of the inner ring and the outer ring is a rotating ring and the other of the inner ring and the outer ring is a fixed ring.

[0125] The embodiments disclosed herein are illustrative in all respects and should not be considered limiting. The scope of the present invention is defined by the claims rather than the above embodiments, and it is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0126] 100, 100A, 100B, 100C Sensor-equipped bearing, 10 Rolling bearing, 11 Inner ring, 11a First end face, 11aa Step portion, 11ab Groove, 11b Second end face, 11c Inner peripheral surface, 11d Outer peripheral surface, 11db Groove, 11da Inner ring raceway surface, 11db Groove, 12 Outer ring, 12a First end face, 12aa, 12ab Step portion, 12ac Groove, 12b Second end face, 12c Inner peripheral surface, 12ca Outer ring raceway surface, 12cb, 12cc Groove, 12d Outer peripheral surface, 13 Rolling element, 14 Cage, 14a Annular portion, 14b Column portion, 15 Seal, 20 Sensor unit, 21 Stator, 21a First member, 21aa First annular portion, 21ab Second annular portion, 21aba first region, 21abb second region, 21b second member, 21c groove, 22 generating coil, 22a coil bobbin, 23 circuit board, 23a electronic component, 24 sensor, 25 wireless communication module, 26 lid, 26a mark, 27 molded resin, 28 comb tooth portion, 30 magnetic ring, 31 core, 31a first portion, 31b second portion, 31c third portion, 32 magnetic rubber, 40 first fastener, 41 biasing portion, 50 second fastener, 51 biasing portion, 60 rubber member, 70 plunger, 71 pin, 72 compression coil spring, 81, 82 welded portion, 83, 84 adhesive, A central axis.

Claims

1. a deep groove ball bearing including a rotating ring, a fixed ring, and a rolling element; A sensor unit; a magnetic ring; The rotating ring has a rotating ring raceway surface extending along a circumferential direction, the fixed ring has a fixed ring raceway surface that extends along the circumferential direction and faces the rotating ring raceway surface in the radial direction with a gap therebetween, the rolling elements are disposed between the rotating ring raceway surface and the fixed ring raceway surface, The sensor unit includes a power generating coil that is detachably attached to the fixed wheel and generates an induced voltage as the rotating wheel rotates, a sensor that outputs a physical quantity or a chemical quantity as an electrical signal, a wireless communication module that wirelessly transmits the output of the sensor to the outside, an annular stator that is detachably attached to the fixed wheel and on which the power generating coil is mounted, and a circuit board on which the wireless communication module and the sensor are mounted, the stator has an inner peripheral surface that extends along the circumferential direction and faces the magnetic ring with a gap in the radial direction, A plurality of comb-tooth portions are formed on the inner peripheral surface of the stator and are arranged at intervals along the circumferential direction, the comb-tooth portion forms a magnetic path for magnetic flux from the magnetic ring, the circuit board is disposed radially outward of the stator, the magnetic ring has a magnetized outer peripheral surface on which north and south poles are alternately magnetized along the circumferential direction, and is detachably attached to the rotating wheel such that the magnetized outer peripheral surface faces the stator inner peripheral surface in the radial direction, The sensor-equipped bearing, wherein the sensor unit is disposed in a space between the rotating ring and the fixed ring.

2. 2. The sensor-equipped bearing according to claim 1, wherein the sensor detects the rotational state of the rotating ring and outputs the detected state as an electric signal.

3. 3. The sensor-equipped bearing according to claim 2, wherein the sensor unit generates an induced voltage in the power generating coil as the magnetic ring rotates, and detects the rotation speed of the rotating ring based on the waveform of the induced voltage generated in the power generating coil.

4. 4. The sensor-equipped bearing according to claim 2, wherein the number of magnetic poles of the magnetic ring is equal to the number of the comb-tooth portions.

5. 5. The sensor-equipped bearing according to claim 4, wherein the stator is configured so that magnetic flux from the magnetic ring passes from the comb-tooth portion around the generator coil.

6. Further provided is a ring-shaped first fastener; The sensor-equipped bearing according to any one of claims 1 to 5, wherein the sensor unit is removably attached to the fixed ring by an elastic repulsive force along the radial direction from the first fastener.

7. The first fastener has a plurality of first biasing portions arranged at intervals in the circumferential direction, The sensor-equipped bearing according to claim 6 , wherein the sensor unit is detachably attached to the fixed ring by an elastic repulsive force acting along the radial direction from the first biasing portion.

8. Further provided is a ring-shaped second fastener; The sensor-equipped bearing according to any one of claims 2 to 5, wherein the magnetic ring is detachably attached to the rotating ring by an elastic repulsive force along the radial direction from the second fastener.

9. The second fastener has a plurality of second biasing portions arranged at intervals in the circumferential direction, The sensor-equipped bearing according to claim 8 , wherein the magnetic ring is detachably attached to the rotating ring by an elastic repulsive force acting along the radial direction from the second biasing portion.

10. Further provided with a ring-shaped rubber member, The sensor-equipped bearing according to any one of claims 1 to 5, wherein the sensor unit is detachably attached to the fixed ring by an elastic repulsive force from the rubber member along the radial direction.

11. Further provided with a compression coil spring, The sensor-equipped bearing according to any one of claims 1 to 5, wherein the sensor unit is detachably attached to the fixed ring by an elastic repulsive force from the compression coil spring along the radial direction.

12. The sensor-equipped bearing according to any one of claims 1 to 11, wherein the sensor and the wireless communication module are driven by an induced electromotive force generated in the power generating coil.

13. The sensor-equipped bearing according to any one of claims 1 to 12, wherein the wireless communication module continuously or intermittently modulates a carrier wave with the output from the sensor and wirelessly transmits the modulated carrier wave to the outside.

14. The sensor-equipped bearing according to any one of claims 1 to 13, wherein the open portion of the sensor unit is sealed with a resin material.

15. the sensor is a vibration sensor; the sensor unit is detachably attached to the fixed ring so that the detection direction of the sensor coincides with the load direction of the deep groove ball bearing, The sensor-equipped bearing according to any one of claims 1 to 14, wherein the sensor unit is provided with a mark for aligning the detection direction of the sensor with the load direction of the deep groove ball bearing.

16. a deep groove ball bearing including a rotating ring, a fixed ring, and a rolling element; A sensor unit; a magnetic ring; The rotating ring has a rotating ring raceway surface extending along a circumferential direction, the fixed ring has a fixed ring raceway surface that extends along the circumferential direction and faces the rotating ring raceway surface in the radial direction with a gap therebetween, the rolling elements are disposed between the rotating ring raceway surface and the fixed ring raceway surface, The sensor unit includes a power generating coil that is fixed to the fixed ring by crimping, welding, or adhesive, and generates an induced voltage as the rotating ring rotates; a sensor that outputs a physical quantity or a chemical quantity as an electrical signal; a wireless communication module that wirelessly transmits the output of the sensor to the outside; an annular stator that is attached to the fixed ring by crimping, welding, or adhesive, and on which the power generating coil is mounted; and a circuit board on which the wireless communication module and the sensor are mounted; the stator has an inner peripheral surface that extends along the circumferential direction and faces the magnetic ring with a gap in the radial direction, A plurality of comb-tooth portions are formed on the inner peripheral surface of the stator and are arranged at intervals along the circumferential direction, the comb-tooth portion forms a magnetic path for magnetic flux from the magnetic ring, the circuit board is disposed radially outward of the stator, the magnetic ring has a magnetized outer peripheral surface on which N poles and S poles are alternately magnetized along the circumferential direction, and is attached to the rotating wheel by crimping, welding, or adhesive so that the magnetized outer peripheral surface faces the stator inner peripheral surface in the radial direction; The sensor-equipped bearing, wherein the sensor unit is disposed in a space between the rotating ring and the fixed ring.

17. 17. The sensor-equipped bearing according to claim 16, wherein the sensor detects the rotational state of the rotating ring and outputs the result as an electric signal.

18. Axle and Housing and The sensor-equipped bearing according to any one of claims 1 to 17, one of the rotating ring and the fixed ring is fitted onto the shaft; The other of the rotating ring and the fixed ring is fitted into the housing.

Images