Bearing device

Abstract

To suppress the degradation of radio communication performance using an antenna for a circuit board while protecting the circuit board of a sensor unit provided for a bearing device.SOLUTION: The bearing device includes a bearing 2 rotatably supporting a rotary member 1, a mating member 3 arranged coaxially with the rotary member 1, and a sensor unit 4 mounted on the mating member 3, the sensor unit 4 having a circuit board 11 including a board 12, at least one sensor 13, and a radio communication circuit 14, the radio communication circuit 14 having an antenna 14a, the circuit board 11 being covered as a whole with a resin coat 15.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Conventionally, a bearing device has been known in which a sensor for detecting the condition of a bearing and a wireless communication circuit are mounted on a substrate to form a circuit board, this circuit board is held in a holder and assembled into a sensor unit, and the holder of this sensor unit is connected to the raceway of a rolling bearing (Patent Document 1).

[0003] The bearing device disclosed in Patent Document 1 has a circuit board including a substrate, a sensor, a wireless communication circuit, etc. The wireless communication circuit has an antenna, and the antenna is located on the substrate. The sensor, wireless communication circuit, etc. are protected by being covered. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-72170 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, when covering the sensor, wireless communication circuit, etc. with a cover as in Patent Document 1, if condensation occurs inside the cover due to the temperature difference between the air layer trapped inside the cover and the outside, or if lubricating oil seeps inside the cover, the water or lubricating oil may adhere to the sensor, wireless communication circuit, board, etc., and affect the operation of the circuit board.

[0006] If a resin mold is used instead of a cover, it is possible to embed the circuit board in the resin mold to prevent condensation water and lubricating oil from adhering to the circuit board, but the antenna will come into contact with the resin mold. When resin, which is a dielectric, comes into contact with the antenna, the wavelength of the radio waves becomes shorter due to its dielectric constant, and wireless communication performance deteriorates.

[0007] Therefore, an object of the present invention is to protect the circuit board of a sensor unit provided in a bearing device while suppressing a decrease in the performance of wireless communication using the antenna of the circuit board. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention employs Configuration 1, which is a bearing device comprising a rotating member, a bearing which rotatably supports the rotating member, a mating member which is arranged coaxially with the rotating member, and a sensor unit which is attached to the mating member, wherein the sensor unit has a circuit board which includes a substrate, at least one sensor, and a wireless communication circuit, and the wireless communication circuit has an antenna, and wherein the entire circuit board is covered with a resin coating.

[0009] According to the above-mentioned configuration 1, since the entire circuit board is covered with a resin coating, there is no concern that water or lubricating oil will adhere to the circuit board, and the entire circuit board can be protected, regardless of whether a cover is used or not. In addition, the antenna included in the circuit board is covered with a resin coating, but is not covered with a thick layer of resin as in the case where the circuit board is embedded in a resin molded section. Therefore, the wavelength of the radio wave is prevented from being shortened due to contact between the antenna and the resin coating. Therefore, it is also possible to prevent a decrease in the performance of wireless communication using the antenna.

[0010] In the above configuration 1, configuration 2 can be adopted in which the resin coating has a thickness of 200 μm or less. According to this configuration 2, the thickness of the resin coating can be made sufficiently thinner than that of a resin mold, and the deterioration of wireless communication performance described above can be effectively suppressed.

[0011] In the above configuration 1 or 2, a configuration 3 can be adopted in which the sensor unit has a cover that covers the circuit board, and a gap is provided between the cover and the resin coating. According to this configuration 3, the contact between the antenna and the dielectric can be limited to the resin coating while the circuit board is further protected by the cover, and even if the above-mentioned condensation or intrusion of lubricating oil occurs, the resin coating has liquid repellency, so that the operation of the circuit board is not affected.

[0012] In the above configuration 3, a configuration 4 can be adopted in which the sensor unit has a board storage section that is open on one side, the circuit board is stored in the board storage section, the cover closes the board storage section, and a portion of at least one of the board storage section and the cover that faces the antenna is formed of a nonmetallic material. According to this configuration 4, at least one of the board storage section and the cover has a nonmetallic portion that is radio wave permeable in a portion that faces the antenna, making it possible to perform wireless communication between the antenna and the outside of the sensor unit.

[0013] In any one of the above configurations 1 to 4, a configuration 5 can be adopted in which at least one of a group consisting of an acceleration sensor, a temperature sensor, and an AE sensor is included in the at least one sensor.

[0014] In any one of the above configurations 1 to 5, a configuration 6 can be adopted in which the rotating member is a first raceway, the mating member is a second raceway, and the bearing is a rolling bearing having rolling elements between the rotating member and the mating member.

[0015] In the above configuration 6, a configuration 7 can be adopted in which the sensor unit is housed between the rotating member and the mating member so as not to protrude from the mating member in the axial direction.

[0016] In the above configuration 6, a configuration 8 can be adopted in which the sensor unit is fixed to an end surface located at one end of the width of the counterpart member.

[0017] In any one of the above configurations 1 to 5, a configuration 9 can be adopted in which the sensor unit is a spacer adjacent to the bearing in the axial direction.

[0018] In any one of the above configurations 1 to 8, a configuration 10 can be adopted in which the sensor unit has at least a part of a power source that supplies power to the circuit board.

[0019] In the above configuration 10, a configuration 11 can be adopted in which the power source is a storage battery.

[0020] In the above configuration 10, configuration 12 can be adopted in which the power source comprises a power supply device having a power receiving circuit and a power transmitting circuit that transmits power to the power receiving circuit in a non-contact manner, and the power receiving circuit is provided in the sensor unit.

[0021] In the above configuration 10, a configuration 13 can be adopted in which the power supply comprises a generator having a magnetic ring that rotates integrally with the rotating member and a stator that faces the magnetic ring, the stator is provided in the sensor unit, and the circuit board has a power supply circuit that converts AC power generated by the stator as the magnetic ring rotates into DC power used by the circuit board. Effect of the Invention

[0022] As described above, by employing configuration 1 above, the present invention can protect the circuit board of the sensor unit provided in the bearing device, while suppressing degradation in wireless communication performance using the antenna of the circuit board. [Brief description of the drawings]

[0023] [Figure 1]FIG. 1 is a cross-sectional view showing a bearing device according to a first embodiment of the present invention; [Diagram 2] FIG. 2 is a partial cross-sectional view showing a cross section of the wireless communication circuit of the circuit board of FIG. 1 taken along the circumferential direction. [Diagram 3] FIG. 4 is a cross-sectional view showing a bearing device according to a second embodiment of the present invention. [Figure 4] FIG. 11 is a cross-sectional view showing a bearing device according to a third embodiment of the present invention. [Diagram 5] FIG. 11 is a cross-sectional view showing a bearing device according to a fourth embodiment of the present invention. [Figure 6] FIG. 13 is a cross-sectional view showing a bearing device according to a fifth embodiment of the present invention. [Figure 7] FIG. 13 is a perspective view showing a main part of a bearing device according to a sixth embodiment of the present invention; [Figure 8] FIG. 13 is a perspective view showing a main part of a bearing device according to a seventh embodiment of the present invention; [Figure 9] FIG. 13 is a cross-sectional view showing a main part of a bearing device according to an eighth embodiment of the present invention. [Figure 10] FIG. 10 is a perspective view of the bearing device of FIG. [Figure 11] FIG. 10 is a side view showing the bearing device of FIG. 9 with a cover partially cut away. [Figure 12] FIG. 10 is an exploded perspective view of the sensor unit of FIG. [Figure 13] FIG. 10 is a perspective view showing an assembly stage of the sensor unit of FIG. [Figure 14] FIG. 13 is a cross-sectional view showing a main part of a bearing device according to a ninth embodiment of the present invention. [Figure 15] FIG. 13 is a cross-sectional view showing a main part of a bearing device according to a tenth embodiment of the present invention. [Figure 16] FIG. 23 is a cross-sectional view showing a main part of a bearing device according to an eleventh embodiment of the present invention. [Figure 17] FIG. 17 is an enlarged view showing the vicinity of a substrate housing portion of the bearing device of FIG. 16; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] A bearing device according to a first embodiment of the present invention (hereinafter simply referred to as "the bearing device") will be described with reference to the accompanying drawings, FIGS. 1 and 2. FIG.

[0025] The bearing device shown in FIGS. 1 and 2 includes a rotating member 1, a bearing 2, a mating member 3 arranged coaxially with the rotating member 1, a sensor unit 4 attached to the mating member 3, and a power source 5.

[0026] Here, the circumferential direction centered on the central axis of rotation of the rotating member 1 is referred to as the "circumferential direction," the direction along the central axis of rotation is referred to as the "axial direction," and the direction perpendicular to the central axis of rotation is referred to as the "radial direction."

[0027] The rotating member 1 is a member that rotates relatively to the mating member 3 in the circumferential direction.

[0028] The bearing 2 is a mechanism that supports the rotating member 1 so as to be rotatable in the circumferential direction.

[0029] The counter member 3 is a member disposed coaxially with the rotating member 1 .

[0030] The rotating member 1 is made of a first raceway ring arranged as a rotating ring. The mating member 3 is made of a second raceway ring arranged as a stationary ring. The bearing 2 is a rolling bearing having two or more rolling elements 8 between a raceway surface 6 formed on the rotating member 1 and a raceway surface 7 formed on the mating member 3. These rolling elements 8 are held at equal intervals in the circumferential direction by a cage 9.

[0031] Bearing 2 is a radial bearing. Rolling elements 8 consist of balls. Cage 9 is a crown-shaped cage that has a ring portion only on the side opposite sensor unit 4 from rolling elements 8 (the side farther from sensor unit 4, the left side in FIG. 1). In order to avoid interference between sensor unit 4 and cage 9, cage 9 does not have a portion closer to sensor unit 4 than rolling elements 8. Note that, although a deep groove ball bearing has been shown as an example of bearing 2, bearing 2 is not limited to a deep groove ball bearing.

[0032] Bearing 2 is a standard bearing that complies with a specific standard. Here, a standard bearing refers to a bearing that satisfies the dimensions specified in the ISO or JIS standard. For example, the dimensions of radial bearings other than tapered roller bearings are specified in ISO15 or JIS B 1512-1.

[0033] The sensor unit 4 is a unit that incorporates an electric circuit that can detect at least one of a physical quantity and a chemical quantity related to the state of the bearing 2 and wirelessly transmit the detection result to the outside.

[0034] The sensor unit 4 has a board storage section 10 that opens on one side of the sensor unit 4, and a circuit board 11 accommodated in the board storage section 10.

[0035] The substrate storage section 10 is composed of a recess that opens at one axial end (the right end in FIG. 1) of the sensor unit 4 and closes at the other axial end (the left end in FIG. 1) of the sensor unit 4. The substrate storage section 10 extends around the entire circumferential direction, seamlessly and integrally with a side plate portion extending along the radial direction and first and second annular plate portions extending in the axial direction from the inner and outer circumferential sides of the side plate portion.

[0036] The circuit board 11 is a printed circuit board on which the above-mentioned electric circuits are formed. The circuit board 11 includes a substrate 12, one or more sensors 13, and a wireless communication circuit 14. The wireless communication circuit 14 has an antenna 14a.

[0037] The power source 5 is a source of power supply for operating the circuit board 11. In the illustrated example, the power source 5 is a storage battery. Both sides of the power source 5 extend along the circumferential and radial directions. The power source 5 is connected to the board 12 via electric wires (not shown).

[0038] The circuit board 11 and the power supply 5 are housed in the board storage unit 10 in a radially opposed arrangement. The circuit board 11 and the power supply 5 are each arranged on a side plate of the board storage unit 10 through an opening of the board storage unit 10, and are fixed to the side plate of the board storage unit 10 by fixing one plate surface of the board 12 and one side surface of the power supply 5 to the surface of the side plate by appropriate means such as adhesive or screwing.

[0039] The entire circuit board 11 is covered with a resin coating 15 .

[0040] The sensor unit 4 has a cover 16 that covers the circuit board 11 .

[0041] The sensor unit 4 is fitted into the stepped end 17 of the mating member 3 so as not to protrude from the mating member 3 in the axial direction. By fixing the sensor unit 4 to the stepped end 17 of the mating member 3, the mating member 3 and the sensor unit 4 are arranged coaxially. The stepped end 17 of the mating member 3 is a portion for securing an annular space capable of accommodating the sensor unit 4 between the one ends of the rotating member 1 and the mating member 3, and has a shape that expands the space between the one ends of the rotating member 1 and the mating member 3 in the radial direction.

[0042] A predetermined distance is ensured between the sensor unit 4 and the rolling elements 8 and the cage 9. This distance is set so that the sensor unit 4 does not come into contact with the rolling elements 8 and the cage 9 even if there is axial displacement due to the internal bearing gap of the bearing 2.

[0043] The substrate 12 is made of a printed wiring board. The substrate 12 is in the shape of an arc plate that is short in the radial direction and long in the circumferential direction. At least one sensor 13, a wireless communication circuit 14, etc. are mounted on one side of the substrate 12 (the right side in FIG. 1).

[0044] The sensor 13 is composed of a circuit that converts the above-mentioned physical quantity or chemical quantity into an electric signal. The type of each sensor 13 is not particularly limited. At least one of the group consisting of an acceleration sensor, a temperature sensor, and an AE (Acoustic Emission) sensor is included in at least one sensor 13. If an acceleration sensor is used, it is possible to detect radial or axial acceleration for monitoring the vibration of the bearing 2. If a temperature sensor is used, it is possible to monitor the temperature of the bearing 2. If an AE sensor is used, it is possible to detect an elastic wave (AE wave) emitted when an acoustic wave generated when a part of an object such as a component of the bearing 2 is deformed or broken or when an impact is applied. In addition, an electronic component including an acceleration sensor and a temperature sensor may be mounted as the sensor 13, or the acceleration sensor and the temperature sensor may be mounted as separate electronic components. When a temperature sensor is used as a sensor, a through hole may be formed in the side plate part of the board storage part 10, and the temperature sensor may be mounted on one side of the rolling element 8 side of the circuit board 11 so as to be close to or in contact with the mating member 3, which is a raceway ring, through the through hole, thereby making it possible to measure the temperature of the bearing 2 more accurately.

[0045] The wireless communication circuit 14 is a communication circuit that converts predetermined information, such as the detection result by the sensor 13, into radio waves and radiates the radio waves from the antenna 14a. The wireless communication circuit 14 complies with a predetermined communication protocol and is generally modular. The antenna 14a in the illustrated example is formed on one side of the substrate 12 (the right side in FIG. 1). The type of the antenna 14a is not particularly limited as long as it is located on the substrate 12.

[0046] The resin coating 15 is made of a resin that is fixed to cover the entire circuit board 11. The resin coating 15 is provided by coating the board 12 and each electronic component, terminal, etc. connected to the board 12 with resin. The coating method may be any suitable method such as application or immersion. For example, the resin may be applied to cover all exposed surfaces of the board 12 configured as a printed circuit board, all exposed surfaces of each electronic component (i.e., the sensor 13, the wireless communication circuit 14, etc.) mounted on the board 12, and all connection parts exposed on the board 12 (i.e., the soldered parts between the electronic components and the board 12, and the soldered parts between the board 12 and the electric wires, etc.), or the board 12 may be immersed in a resin coating liquid, and then dried to fix the resin coating 15 to a predetermined thickness or more. If the resin coating obtained by one application is thin, multiple applications may be performed. Examples of the coating material that can be used as the resin coating 15 include urethane-based, acrylic-based, silicon-based, olefin-based, and fluorine-based coatings.

[0047] The thickness and material of the resin coating 15 may be determined according to the required performance of the resin coating 15, such as liquid repellency (water repellency, oil repellency), insulation, moisture resistance, and adverse effects on the radio wave characteristics of the antenna 14a. Here, since the resin coating 15 is a dielectric, the thicker the resin coating 15 that contacts the antenna 14a, the stronger the adverse effects on the radio wave characteristics, that is, the shorter the wavelength of the radio wave in the wireless communication using the antenna 14a, or the lower the radio wave intensity. In order to suppress the adverse effects on the radio wave characteristics, the thickness of the resin coating 15 is preferably 200 μm or less, more preferably less than 100 μm, and even more preferably several tens of μm or less. If the thickness of the resin coating 15 is 200 μm or less, the adverse effects on the radio wave characteristics caused by covering the antenna 14a with the resin coating 15 are small, and the adverse effects on the radio wave characteristics can be sufficiently reduced compared to the case where the antenna 14a is covered with a resin mold that fills the substrate storage unit 10 with resin.

[0048] From the viewpoint of radio wave characteristics, it is preferable to make the thickness of resin coating 15 as thin as possible. On the other hand, from the viewpoint of protecting circuit board 11 so that water or lubricating oil does not adhere to circuit board 11 and adversely affect the operation of circuit board 11, it is sufficient to ensure that resin coating 15 has a thickness equal to or greater than a predetermined value so that resin coating 15 has the required liquid repellency.

[0049] The cover 16 is a lid that fits into the board storage section 10 without making contact with the circuit board 11. The cover 16 is provided in an annular shape extending in the circumferential direction, and fits around the entire circumferential direction between the outer peripheral wall and the inner peripheral wall of the board storage section 10. There is no particular limit to the means for fixing the cover 16, but in order to improve the airtightness of the fitting portion between the cover 16 and the board storage section 10, an adhesive or a resin filler may be applied to the fitting portion.

[0050] There is a gap between the entire circuit board 11 and the cover 16. In order to prevent the antenna 14a from coming into contact with a dielectric as much as possible, the antenna 14a is not in contact with any tangible object other than the resin coating 15. Furthermore, at least the portion of the resin coating 15 that covers the antenna 14a is not in contact with any tangible object, and is usually in contact with an air layer that fills the gap between the cover 16 and the board storage unit 10.

[0051] In addition, when an acceleration sensor is used as sensor 13, if the acceleration sensor is pressed by a tangible object such as cover 16 or a resin molding material, the distortion of the acceleration sensor due to the pressure will cause an output offset. However, if there is an air layer around the acceleration sensor on circuit board 11, the acceleration sensor will not be pressed, and the output offset will be reduced.

[0052] The board storage unit 10 is formed of a metal plate. Because the board storage unit 10 is made of metal, it can hold the circuit board 11 with high rigidity. Therefore, even if the board storage unit 10 is fixed directly to the vibrating bearing 2, it is possible to suppress malfunction of the sensor 13, which is advantageous for stably monitoring the state of the bearing 2 using the detection results of the sensor 13.

[0053] In order to ensure insulation of the circuit board 11 and power supply 5 from the board storage section 10, an insulating sheet such as a polyimide film may be sandwiched between the board 12 and the board storage section 10 and between the power supply 5 and the board storage section 10.

[0054] The entire cover 16 is made of a non-metallic material that does not block radio waves in order to improve radio wave transmission between the outside of the sensor unit 4 and the antenna 14a as much as possible. The cover 16 is made of, for example, a resin that does not contain metal. Even if the board storage section 10 is made of metal, since the cover 16 is made of a resin that has radio wave transmission properties, wireless communication using the antenna 14a is possible.

[0055] The fixing means for the sensor unit 4 to the counterpart member 3 and the fixing means for the cover 16 to the substrate housing section 10 can be one or more suitable means such as press-fitting, adhesion, welding, etc.

[0056] In the illustrated example, the power supply 5 is not covered with a resin coating, so the power supply 5 housed in the substrate storage section 10 is covered with a cover 16; however, if the power supply 5 is protected by being covered with a resin coating, the cover 16 can be omitted.

[0057] This bearing device is as described above and comprises a rotating member 1, a bearing 2 that rotatably supports the rotating member 1, a mating member 3 that is arranged coaxially with the rotating member 1, and a sensor unit 4 that is attached to the mating member 3, wherein the sensor unit 4 has a circuit board 11 that includes a substrate 12, at least one sensor 13, and a wireless communication circuit 14, and the wireless communication circuit 14 has an antenna 14a.

[0058] In particular, in this bearing device, since the entire circuit board 11 is covered with the resin coating 15, there is no concern that water or lubricating oil will adhere to the circuit board 11, and the entire circuit board 11 can be protected, regardless of whether the cover 16 is used or not. In addition, the antenna 14a included in the circuit board 11 is covered with the resin coating 15, but is not covered with a thick layer of resin as in the case where the circuit board 11 is embedded in a resin molded portion. Therefore, the wavelength of the radio wave is prevented from being shortened due to contact between the antenna 14a and the resin coating 15. Therefore, it is also possible to prevent a decrease in the wireless communication performance using the wireless communication circuit 14. In this way, this bearing device can prevent a decrease in the wireless communication performance of the circuit board 11 while protecting the circuit board 11 of the sensor unit 4 provided in the bearing device.

[0059] Furthermore, since the thickness of resin coating 15 of this bearing device is 200 μm or less, the thickness of resin coating 15 can be made much thinner than in the case of resin molding, thereby effectively suppressing the deterioration of wireless communication performance described above.

[0060] In addition, in this bearing device, the sensor unit 4 has a cover 16 that covers the circuit board 11, and a gap (air layer) is provided between the cover 16 and the resin coating 15, so that the cover 16 can protect the circuit board 11 better, while the contact between the antenna 14a and the dielectric can be limited to the resin coating 15. Here, the moisture contained in the air layer may condense due to the temperature difference between the air layer and the outside of the sensor unit 4. In addition, if there is a gap in the fitting portion between the cover 16 and the board storage section 10, lubricating oil may infiltrate from the outside of the sensor unit 4 through the gap and reach the circuit board 11. Even if such condensation or infiltration of lubricating oil occurs, the condensed water and lubricating oil are repelled by the resin coating 15, which has liquid repellency. Therefore, this bearing device can prevent the condensed water and lubricating oil from affecting the operation of the circuit board 11.

[0061] In addition, this bearing device has a board storage section 10 with the sensor unit 4 opening on one side, a circuit board 11 is housed in the board storage section 10, and a cover 16 closes the board storage section 10. At least one of the board storage section 10 and the cover 16, that is, a portion of the cover 16 that faces the antenna 14a is formed from a non-metallic material, so that at least one of the board storage section 10 and the cover 16 has a portion made of a non-metallic material that is permeable to radio waves, located opposite the antenna 14a, making it possible to perform wireless communication between the antenna 14a and the outside of the sensor unit 4.

[0062] In addition, since at least one of the group consisting of an acceleration sensor, a temperature sensor and an AE sensor is included in at least one sensor 13, this bearing device can monitor the condition of the bearing 2 using one or more of acceleration, temperature and vibration (AE waves), which are correlated with the condition of the bearing 2.

[0063] In addition, this bearing device can be configured as a unit consisting of the sensor unit 4 and a rolling bearing, since the rotating member 1 consists of a first raceway, the mating member 3 consists of a second raceway, and the bearing 2 is a rolling bearing having rolling elements 8 between the rotating member 1 and the mating member 3.

[0064] Furthermore, because the sensor unit 4 is housed between the rotating member 1 and the mating member 3 so that it does not protrude axially from the mating member 3, the width of the bearing device can be made equal to or smaller than the width of the bearing 2, and the circuit board 11 is positioned in close proximity to the bearing 2, enabling the sensor 13 to detect abnormalities in the bearing 2 with high accuracy.

[0065] Furthermore, since this bearing device has at least a portion of the power supply 5 that supplies power to the circuit board 11, it is not necessary to connect the sensor unit 4 to an external power supply with an electric wire, and the sensor unit 4 can be made wireless to the outside.

[0066] Furthermore, in this bearing device, since the power supply 5 is made up of a storage battery, the entire power supply 5 can be provided in the sensor unit 4 .

[0067] In this bearing device, the circuit board 11 and the like are disposed on the reversible moving body 8 side of the side plate of the sensor unit 4, but this can also be disposed in reverse. As an example, a bearing device according to a second embodiment is shown in Fig. 3. Note that here, only the differences from the first embodiment will be described, and the same reference numerals will be used to designate the same components as in the first embodiment.

[0068] The sensor unit 4 according to the second embodiment is attached to the mating member 3 with the orientation of the sensor unit 4 relative to the mating member 3 reversed in the axial direction from that of the first embodiment. Therefore, the opening of the board storage section 10 faces the inside of the bearing 2. Accordingly, the circuit board 11 and the like accommodated in the board storage section 10 are arranged on the rolling elements 8 side of the side plate section of the board storage section 10. A cover 16 closes the opening of the board storage section 10 inside the bearing 2.

[0069] In the above-described embodiments, examples have been shown in which the entire substrate storage section 10 is made of a metal plate and the entire cover 16 is made of a non-metallic material, but it is also possible to form the entire cover from metal. As an example, a third embodiment is shown in Fig. 4. Note that since the third embodiment is a further modification of the second embodiment, only the differences from the second embodiment will be described here, and the same components as those in the second embodiment will be denoted by the same reference numerals.

[0070] In the sensor unit 20 according to the third embodiment, the side plate portion of the substrate housing portion 21 facing the antenna 14a is made of a non-metallic material 22, the other portions are made of a metal plate, and the entire cover 23 is made of a metal material. The non-metallic material 22 forms an opening in the metal plate in a range including the area where the antenna 14a is projected in the axial direction, and is fixed to the metal plate so as to close the opening. Radio waves can pass through the non-metallic material 22 between the antenna 14a and the outside of the sensor unit 20. Therefore, even if the entire cover 23 is made of metal, radio waves can be transmitted and received between the antenna 14a and the outside of the sensor unit 20.

[0071] In addition, even when the entire cover is formed from a non-metallic material as in the first or second embodiment, the portion of the substrate storage section facing the antenna may be formed from a non-metallic material as in the third embodiment, thereby increasing the number of paths through which radio waves can pass.

[0072] In each of the above-mentioned embodiments, the sensor unit is accommodated in the annular space between the rotating member as the first raceway of the bearing and the mating member as the second raceway, but the sensor unit can also be disposed outside the bearing. As an example of such a case, a fourth embodiment is shown in FIG.

[0073] The bearing 30 according to the fourth embodiment is a double-seal bearing in which a pair of seals 33, 34 seals between the rotating member 31 and the mating member 32. Since the seals 34, 34 are housed between the rotating member 31 and the mating member 32, the sensor unit 4 cannot be housed inside the bearing 30. For this reason, the sensor unit 4 is fixed to an end face 35 located at one end of the width of the mating member 32.

[0074] In the fourth embodiment, the circuit board 11 and the like are arranged on the reversible moving body 8 side of the side plate portion of the sensor unit 4, but this can also be arranged in reverse. As an example, a bearing device according to a fifth embodiment is shown in Fig. 6. Note that since the fifth embodiment is a further modification of the fourth embodiment, only the differences from the fourth embodiment will be described here, and the same components as those in the fourth embodiment will be given the same reference numerals.

[0075] The sensor unit 40 according to the fifth embodiment is fixed to the end face 35 of the mating member 32 with the opening of the board storage section 41 facing the rolling element 8 side. Therefore, the circuit board 11 and the like housed in the board storage section 41 are disposed on the rolling element 8 side of the side plate section of the board storage section 41. Since a part of the cover 16 faces the end face 35 of the mating member 32 in the axial direction, the area available for fixing the end face 35 of the mating member 32 and the sensor unit 40 is reduced compared to the fourth embodiment. To compensate for this reduction, the outer periphery of the board storage section 41 is expanded, and the expanded outer periphery section 42 is fixed to the end face 35 of the mating member 32. The fixing means for the sensor unit 40 to the end face 35 of the mating member 32 may be any suitable means such as welding, adhesive, or mechanical joining.

[0076] In the above-described embodiments, as an example of reducing the axial width of the sensor unit by arranging the circuit board and the power supply radially opposite to each other, the circuit board is arranged close to the outer peripheral wall of the board storage section, and the power supply is arranged between the circuit board and the inner peripheral wall of the board storage section, but it is possible to realize an arrangement in which the circuit board and the power supply radially oppose each other in other arrangements. As an example, a sixth embodiment is shown in FIG. 7. Note that, here, only the differences from the first embodiment are described, and the same components as those in the first embodiment are given the same reference numerals.

[0077] FIG. 7 is an oblique view showing the board storage section 10 according to the sixth embodiment with the cover (see FIG. 1) removed, and in particular shows the circuit board 50 and other components fixed onto the side panel of the board storage section 10.

[0078] A circuit board 50 according to the sixth embodiment has a board 51 provided with a finite length in the circumferential direction. On one surface of the board 51, a plurality of sensors 52, 53, a power supply circuit 54, and a wireless communication circuit 14 with an antenna 14a are mounted at intervals in the circumferential direction. The sensor 52 is an acceleration sensor, and the sensor 53 is a temperature sensor.

[0079] Power source 55 is an arc-shaped storage battery with a finite length in the circumferential direction. Power source 55 and circuit board 50 are arranged on the same circumference. In this arrangement, circuit board 50 and power source 55 are arranged in the same axial position, while the radial width of board 51 and power source 55 can be made large.

[0080] Terminals 56, 56 provided on the substrate 51 are connected to a power source 55 via electric wires 57, 57. The power supply circuit 54 increases or decreases the voltage of the power input from the power supply 55 between the terminals 56, 56 of the substrate 51, and controls the voltage to a target voltage value. The power supply circuit 54 supplies output power of the target voltage value to the corresponding sensors 52, 53 and wireless communication circuit 14.

[0081] The entire circuit board 50 may be resin-coated either before or after the terminals 56, 56 and the electric wires 57, 57 are connected, but if resin-coating is performed before connection, it is preferable to reapply a coating agent to the connection portions of the terminals 56, 56 and the electric wires 57, 57. This is because when the terminals 56, 56 and the electric wires 57, 57 are connected by soldering or the like, the resin coating portion covering the terminals 56, which was generated by the previous resin coating, may be damaged.

[0082] In each of the above-mentioned embodiments, a storage battery is used as a power source for making the sensor unit wireless to the outside, and an example has been shown in which the sensor unit has the entire power source, but as long as the above-mentioned wireless connection can be realized, it is not necessary to provide the entire power source in the sensor unit. As an example, a seventh embodiment is shown in Fig. 8. Note that the seventh embodiment is a further modification of the sixth embodiment, so here, only the differences from the sixth embodiment will be described, and the same components as those in the sixth embodiment will be given the same reference numerals.

[0083] FIG. 8 is an oblique view showing the board storage section 10 according to the seventh embodiment with the cover (see FIG. 1) removed, and in particular shows the circuit board 50 and other components fixed onto the side panel of the board storage section 10.

[0084] The power supply according to the seventh embodiment is a wireless power supply device having a power receiving circuit 60 and a power transmitting circuit 61 that transmits power to the power receiving circuit 60 in a non-contact manner. The power transmitting circuit 61 is a circuit that electromagnetically transmits primary power into the air. The power receiving circuit 60 is a circuit that converts the electromagnetic signal S transmitted from the power transmitting circuit 61 into secondary power. The power receiving circuit 60 is an arc plate with a finite length in the circumferential direction. The power receiving circuit 60 is fixed to the side plate of the board storage section 10 so as to be located on the same circumference as the circuit board 50. The power receiving circuit 60 and the power transmitting circuit 61 may be appropriately selected from known wireless power supply devices. In the seventh embodiment, an electromagnetic signal S is sent from the power transmission circuit 61 to the power receiving circuit 60 at a required timing, whereby the power receiving circuit 60 provided in the substrate housing section 10 (sensor unit) as part of the power source converts the signal into secondary power, and this secondary power is input between the terminals 56, 56. Note that, in the seventh embodiment, if the power receiving circuit 60 is covered with a resin coating, the cover can be omitted.

[0085] When the sensor unit has a storage battery as a power source as in the above-described embodiments, or when the sensor unit has a power receiving circuit as part of the power source, the storage battery and the power receiving circuit may be located outside the board, or may be mounted on the board. If one or more power sources such as a storage battery, a power receiving circuit, and a power storage element are mounted on the board, it becomes difficult to reduce the axial width of the circuit board because the thick power source overlaps with the board, which is disadvantageous in terms of completely accommodating the sensor unit inside the bearing, and therefore it is preferable to locate the storage battery and the power receiving circuit outside the board.

[0086] It is also possible to use a generator as a power source and provide part of it in the sensor unit. An eighth embodiment as an example is shown in Figures 9 to 13. Note that only the differences from the first embodiment are described here, and the same components as those in the first embodiment are denoted by the same reference numerals.

[0087] As shown in Fig. 9 to Fig. 11, the power supply 70 according to the eighth embodiment is an electromagnetic induction generator having a magnetic ring 72 that rotates integrally with a rotating member 71, and a stator 73 that faces the magnetic ring 72. The power supply 70 electromagnetically converts the rotational motion of the rotating member 71 relative to the mating member 3 into AC power by the magnetic ring 72 and the stator 73. The magnetic ring 72 generates a rotating magnetic field for the stator 73. The stator 73 guides the magnetic flux emitted from the magnetic ring 72 with a yoke structure, and induces an AC voltage in a coil 74 within the yoke structure. The stator 73 is provided in a sensor unit 75.

[0088] 11 shows a state in which the cover 76 is partially cut away and the circuit board 78 is housed in the board storage section 77. The circuit board 78 has a power supply circuit 80 mounted on a board 79, and a plurality of sensors 81, 82, and 83 mounted on the board 79.

[0089] The power supply circuit 80 is a circuit that converts the AC power described above into DC power used on the circuit board 78 .

[0090] Of the multiple sensors 81 to 83, the sensor 81 is a temperature sensor, the sensor 82 is an acceleration sensor, and the sensor 83 is an AE sensor.

[0091] As shown in Figs. 9 and 11, the magnetic ring 72 has a magnet 84 magnetized with alternating N and S poles in the circumferential direction, and a core metal 85. The magnet 84 is formed of magnetic rubber extending in the circumferential direction. The magnet 84 is bonded to the core metal 85 all around in the circumferential direction. Vulcanization bonding can be used as the bonding method. The core metal 85 has a flange portion for increasing its rigidity. Although the magnet 84 is exemplified as a magnetic body magnetized with multiple poles, it may be composed of a plurality of permanent magnets.

[0092] The magnetic ring 72 is fixed to a stepped end 86 of the rotating member 71 so as not to protrude from the rotating member 71 in the axial direction. The rotating member 71 and the magnetic ring 72 are arranged coaxially by fitting the magnetic ring 72 into the stepped end 86 of the rotating member 71. The stepped end 86 of the rotating member 71 is a portion for securing an annular space capable of accommodating the sensor unit 75 and the magnetic ring 72 between the ends of the rotating member 71 and the mating member 3, and has a shape that expands the space between the ends of the rotating member 71 and the mating member 3 in the radial direction.

[0093] Stator 73 faces magnetic ring 72 in the radial direction with an air gap between them. The yoke structure of stator 73 and substrate storage section 77 are composed of a first holding member 87 and a second holding member 88 combined with the first holding member 87, as shown in Figures 9, 12, and 13.

[0094] In order to allow these holding members 87, 88 to function as yokes, these holding members 87, 88 are each made of a magnetic material. Each of these holding members 87, 88 is formed from a single metal plate such as a steel plate. The overall shape of each of the holding members 87, 88 is formed by press molding.

[0095] The first retaining member 87 has, seamlessly and integrally, a side plate portion 89 that extends radially and continuously around the entire circumferential direction, a first annular plate portion 90 that extends from the side plate portion 89 to one side in the axial direction, a first side wall portion 91 that extends further radially from the side plate portion 89 toward the side opposite the first annular plate portion 90 (the side away from the first annular plate portion 90), and a first claw pole portion 92 that extends from the first side wall portion 91 at a regular interval in the circumferential direction to one side in the axial direction (to the right in Figures 9 and 12).

[0096] The second retaining member 88 has, seamlessly and integrally, a second annular plate portion 93 radially opposed to the first annular plate portion 90, a second side wall portion 94 extending radially from one axial side of the second annular plate portion 93 toward the opposite side of the first annular plate portion 90, and a second claw pole portion 95 extending from the second side wall portion 94 circumferentially at a regular interval toward the other axial side (left side in Figures 9 and 12).

[0097] 9 and 13, the substrate storage section 77 is formed of a side plate portion 89, a first annular plate portion 90, and a second annular plate portion 93. The yoke structure of the stator 73 is formed of a first claw pole portion 92, a second claw pole portion 95, a first side wall portion 91, a second side wall portion 94, and the second annular plate portion 93. The outer periphery of the first holding member 87 forms the outer periphery of the sensor unit 75. The first claw pole portion 92 and the second claw pole portion 95 are located on the inner periphery of the sensor unit 75.

[0098] As shown in Fig. 11, the first claw pole portion 92 and the second claw pole portion 95 face each other in the radial direction with an air gap between them and the magnet 84. The first claw pole portion 92 and the second claw pole portion 95 are arranged in opposite directions in the axial direction and are arranged alternately in the circumferential direction. A circumferential air gap is formed between the first claw pole portion 92 and the second claw pole portion 95 that are adjacent in the circumferential direction. The total number of the first claw pole portions 92 and the second claw pole portions 95 is equal to the number of poles of the magnet 84 (the total number of north poles and south poles).

[0099] As shown in Fig. 12, arc-shaped holes 96 penetrating between both side surfaces of the first holding member 87 are formed at a plurality of locations in the circumferential direction. Protrusions 97 that fit into the inner surfaces of the holes 96 protrude in the axial direction from the second annular plate portion 93. As shown in Fig. 9, the second annular plate portion 93 is abutted in the axial direction against the first side wall portion 91 at substantially all portions except for the areas where the protrusions 97 are present.

[0100] 9 and 12, the coil 74 is wound around a bobbin 98. The coil 74 and the bobbin 98 are arranged all around the circumference in a space surrounded by the first side wall portion 91, the second side wall portion 94, the second annular plate portion 93, the first claw pole portion 92, and the second claw pole portion 95.

[0101] At least a portion of the surface of the coil 74 and the bobbin 98 may contact the above-mentioned claw pole portions 92, 95 and side wall portions 91, 94. When protecting the magnet wire constituting the coil 74 for the purposes of insulation, heat resistance, dust resistance, moisture resistance, and chafing prevention, a varnish treatment may be employed in which the coil 74 is coated by dipping the coil 74 in varnish or by dripping varnish onto the coil 74. Also, the bobbin 98 may be omitted.

[0102] 11, the magnetic flux from the N pole of the magnet 84 enters, for example, the first claw pole portion 92 (or the second claw pole portion 95) into the first side wall portion 91 (or the second side wall portion 94), passes through the second annular plate portion 93, goes around the coil 74 to reach the second side wall portion 94 (or the first side wall portion 91), passes through the adjacent second claw pole portion 95 (or the first claw pole portion 92), and returns to the S pole of the magnet 84. When the positions of the N pole and the S pole of the magnet 84 are interchanged with the rotation of the rotating member 71 relative to the counter member 3, the direction of the magnetic flux is reversed. The alternating magnetic field thus generated generates an AC voltage at both ends 99, 99 of the start and end of the winding of the coil 74.

[0103] 11, both ends 99, 99 of the coil 74 are pulled out into the circuit board housing section 77 through a wiring hole formed in the second annular plate portion 93, and are connected to terminals 100, 100 provided on the circuit board 79. A storage battery may be mounted on the side plate portion 89 or the circuit board 79 as an emergency power source.

[0104] In assembling the sensor unit 75, as shown in FIG. 12, the bobbin 98 around which the coil 74 is wound is placed between the first side wall portion 91 and the second side wall portion 94, and the first holding member 87 and the second holding member 88 are assembled in the axial direction, and at this time, each protrusion 97 of the second holding member 88 is fitted into the corresponding hole 96 of the first holding member 87. This fitting ensures that the first holding member 87 and the second holding member 88 are coaxial with each other, and the first claw pole portion 92 and the second claw pole portion 95 are arranged alternately in a predetermined phase with a gap in the circumferential direction. Therefore, the first holding member 87 and the second holding member 88 can be assembled appropriately without using a jig. It is preferable that the holes 96 and the protrusions 97 are each formed in three or more places.

[0105] After this assembly, the protrusion 97 is fixed to the inner surface of the hole 96. This fixing may be performed by, for example, press fitting, adhesion, laser welding, or a combination of these.

[0106] It is also possible to omit the protrusion 97 and the hole 96. In this case, after the first holding member and the second holding member are coaxially aligned and phase-aligned using a jig (not shown), the abutting portion between the second annular plate portion and the first side wall portion may be bonded or laser-welded from the outer periphery of the second annular plate portion, or the two may be used in combination to fix them.

[0107] When the first holding member 87 and the second holding member 88 are combined as described above, the substrate storage section 77 and the stator 73 are completed, as shown in Fig. 13. Note that, although an example has been shown in which the second annular plate portion 93 of the second holding member 88 is used as a partition between the substrate storage section 77 and the stator 73, it is also possible to provide a partition wall that radially divides the first holding member 87 into two regions in addition to the second annular plate portion 93, to make the partition wall the inner periphery of the substrate storage section, and to place the stator radially inside the partition wall.

[0108] Next, the circuit board 78 is inserted onto the side plate portion 89 through the opening of the board storage portion 77. The board 79 is fixed to the side plate portion 89 using a plurality of screws. At this time, the surface of the board opposite to the surface on which the wireless communication circuit 14, the sensor 81, etc. are mounted faces the side plate portion 89. An insulating sheet for insulating the first holding member 87 and the circuit board 78 may be interposed between the board 79 and the side plate portion 89.

[0109] After the circuit board 78 is fixed to the side plate portion 89, an assembly process is performed in which the cover 76 is fitted between the first annular plate portion 90 and the second annular plate portion 93, as shown in Figures 10 and 11. As a result, the cover 76 closes the opening of the board storage portion 77 without contacting the circuit board 78, and the gap between the cover 76 and the circuit board 78 becomes filled with air.

[0110] After the cover 76 is fixed, the sensor unit 75 is fixed to the inner circumference of the mating member 3 at the first annular plate portion 90 of the substrate storage portion 77, as shown in Fig. 9. Meanwhile, the magnetic ring 72 is fixed to the outer circumference of the rotating member 71 at the core metal 85. The fixing means is press-fitting, adhesive bonding, or a combination of these. Since the mating member 3 and the rotating member 71 are arranged coaxially, the sensor unit 75 and the magnetic ring 72 are also arranged coaxially.

[0111] Since there is small fluctuation in the radial gap between the magnetic ring 72 fixed to the rotating member 71, which is a component of the radial bearing, and the stator 73 of the sensor unit 75 fixed to the mating member 3, which is also a component of the radial bearing, a stable amount of power can be generated by the power source 70 configured as a generator by the magnetic ring 72 and the stator 73, compared to the case where a magnetic ring is provided on the retainer.

[0112] Even when a generator is used as the power source, it is possible to place the sensor unit outside the bearing. As an example, a ninth embodiment is shown in Fig. 14. Note that since the ninth embodiment is a further modification of the eighth embodiment, only the differences from the eighth embodiment will be described here, and the same reference numerals will be used to designate the same components as in the eighth embodiment.

[0113] In the ninth embodiment, the sensor unit 75 is fixed to an end surface 102 located at one end of the width of the mating member 101 at its side plate portion 89. The magnet 104 of the magnetic ring 103 is disposed at a position protruding in the axial direction from the rotating member 106 so as to face the stator 73 in the radial direction. Also, in order to provide a predetermined radial air gap between the magnet 104 and the stator 73, the inner and outer diameters of the magnet 104 and the core 105 are enlarged, and the core 105 is fitted into a shoulder outer diameter surface 107 of the rotating member 106 without forming a stepped end portion on the rotating member 106.

[0114] In the eighth and ninth embodiments, the circuit board 78 and the like are arranged on the reversible moving body 8 side of the side plate portion 89 of the sensor unit 75, but this can also be arranged in reverse. Even when a generator is used as the power source, it is possible to form the entire cover from metal. FIG. 15 shows a bearing device according to a tenth embodiment as an example of these. Note that the tenth embodiment is a further modification of the ninth embodiment, so here only the differences from the ninth embodiment will be described, and the same reference numerals will be used to designate the same components as in the ninth embodiment.

[0115] The sensor unit 110 according to the tenth embodiment is fixed to the end surface 102 of the counterpart member 101 with the opening of the board storage section 111 facing the rolling elements 8. Therefore, the circuit board 78 etc. accommodated in the board storage section 111 are disposed on the rolling elements 8 side of the side plate section 112 of the board storage section 111.

[0116] The entire cover 113 is formed of a metal material. Of the side plate portion 112 of the board storage portion 111, the portion facing the antenna 14a is formed of a non-metal material 114, and the other portions are formed of a metal plate. An opening is formed in the first holding member 115 in a range including an area obtained by projecting the antenna 14a in the axial direction, and the non-metal material 114 is fixed to the first holding member 115 so as to close the opening.

[0117] In order to ensure a sufficient fixing area between the end face 102 of the mating member 101 and the sensor unit 110, the inner diameter of the substrate storage section 111 (first holding member 115) is made smaller than in the ninth embodiment, and the substrate storage section 111 is positioned closer to the magnetic ring 117 than in the ninth embodiment, making the solid section from the substrate storage section 111 to the outer diameter of the sensor unit 110 (first holding member 115) radially thicker. As a result, the inner diameter of the sensor unit 110 (stator 116) and the outer diameter of the magnetic ring 117 are made smaller than in the ninth embodiment.

[0118] In the eighth to tenth embodiments described above, a radial type claw pole generator was used as an example of the generator constituting the power supply, but it is possible to change to another type of generator. Also, although an example was shown in which the substrate storage section was disposed on the outer periphery side of the sensor unit and the stator was disposed on the inner periphery side of the sensor unit, this arrangement can also be reversed.

[0119] In the above-mentioned embodiments, the mating member is the outer ring and the stationary ring, and the rotating member is the inner ring and the rotating ring, but the mating member may be the inner ring and the rotating member may be the outer ring. Also, in the above-mentioned embodiments, since the sensor unit is wireless, it is possible to attach the sensor unit to the rotating ring.

[0120] Furthermore, the attachment of the sensor unit is not limited to the raceway, but any mating member that allows the sensor unit to be disposed adjacent to the bearing may be selected. Furthermore, the rotating member and the mating member are not limited to the raceway, but may be, for example, an inner ring spacer, an outer ring spacer, etc. As an example of disposing the sensor unit adjacent to the bearing and providing it on a spacer, a bearing device according to an eleventh embodiment is shown in Figures 16 and 17.

[0121] The bearing device of the eleventh embodiment is configured as a spindle including a rotating member 120 that also serves as a motor shaft, a mating member 121 that also serves as a bearing housing surrounding the rotating member 120, a pair of bearings 122, 123 incorporated between the rotating member 120 and the mating member 121, a sensor unit 124 and a power source 125 arranged between these bearings 122, 123, and spacers 126, 127, 128 that maintain the axial span between these bearings 122, 123.

[0122] The first bearing 122 and the second bearing 123 are rolling bearings each having an inner ring 129, 130 fitted to the rotating member 120, an outer ring 131, 132 fitted to the mating member 121, and rolling elements 133, 134 arranged between the inner and outer rings (129, 131; 130, 132).

[0123] The first spacer 126 is attached to the rotating member 120 in a state where it is sandwiched between a first inner ring 129 and a second inner ring 130 .

[0124] The second spacer 127 and the third spacer 128 are butted against each other in the axial direction, and are attached to the mating member 121 in a state in which they are sandwiched between the first outer ring 131 and the second outer ring 132. The bearing seat surface of the mating member 121 and the spacers 127, 128 fitted thereto are arranged coaxially, and are also arranged coaxially with the rotating member 120 via the bearings 122, 123.

[0125] The power source 125 is an electromagnetic induction generator, and its magnetic ring 135 is attached to the outer periphery of the first spacer 126. The stator 136 is attached across the inner periphery of the second spacer 127 and the inner periphery of the third spacer 128.

[0126] The sensor unit 124 is provided with the second spacer 127 as its body. The board storage section 137 is made of an annular groove that opens on one side of the second spacer 127 and extends all around the circumference. The circuit board 138 is arranged with its board surface facing the axial direction, and faces in the axial direction a stator 136 supported on the other side of the second spacer 127. It is also possible to use only one outer ring spacer between the first outer ring 131 and the second outer ring 132, and to use this as the body of the sensor unit.

[0127] In general, the rotating member 120 of the spindle, the spacers 126-128, the inner ring 129, and the outer ring 131 are made of metal such as steel. The path that passes through the inside of the first bearing 122 is important for preventing the radio waves that have passed through the cover 139 from escaping to the outside of the bearing device. For this reason, it is preferable that the inside of the first bearing 122 is made of a non-metallic material, and for example, a resin cage and ceramic rolling elements may be used.

[0128] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0129] 1, 31, 71, 106, 120 Rotating members 2, 30, 122, 123 Bearings 3, 32, 101, 121 Mating parts 4, 20, 40, 75, 110, 124 Sensor Unit 5, 55, 70, 125 power supply 8 Rolling elements 10, 21, 41, 77, 111, 137 Circuit board storage area 11, 50, 78, 138 Circuit Board 12, 51, 79 Board 13, 52, 53, 81, 82, 83 Sensors 14 Wireless communication circuits 14a Antenna 15 Resin coating 16, 23, 76, 113, 139 Cover 22, 114 Nonmetallic materials 35, 102 end face 60 Receiving circuit 61 Power transmission circuit 72, 103, 117, 135 Magnetic ring 73, 116, 136 Stator 80 Power circuit 127 Maza

Claims

1. a rotating member, a bearing that rotatably supports the rotating member, a mating member that is arranged coaxially with the rotating member, and a sensor unit that is attached to the mating member; the sensor unit has a circuit board including a substrate, at least one sensor, and a wireless communication circuit; In the bearing assembly, the wireless communication circuit has an antenna, A bearing device according to claim 1, wherein the entire circuit board is covered with a resin coating.

2. 2. The bearing device according to claim 1, wherein the resin coating has a thickness of 200 μm or less.

3. the sensor unit has a cover that covers the circuit board, 3. The bearing device according to claim 1, wherein a gap is provided between the cover and the resin coating.

4. the sensor unit has a substrate storage section that is open on one side, The circuit board is accommodated in the board storage section, the cover closes the substrate storage section, 4. The bearing device according to claim 3, wherein a portion of at least one of the board storage section and the cover, which faces the antenna, is made of a non-metallic material.

5. 3. The bearing device according to claim 1, wherein the at least one sensor includes at least one of a group consisting of an acceleration sensor, a temperature sensor, and an AE sensor.

6. the rotating member comprises a first raceway; the mating member comprises a second raceway; 3. The bearing device according to claim 1, wherein the bearing is a rolling bearing having rolling elements between the rotating member and the mating member.

7. 7. The bearing device according to claim 6, wherein the sensor unit is accommodated between the rotating member and the mating member so as not to protrude from the mating member in the axial direction.

8. 7. The bearing device according to claim 6, wherein the sensor unit is fixed to an end surface located at one end of the width of the mating member.

9. 3. The bearing device according to claim 1, wherein the sensor unit is provided on a spacer that is axially adjacent to the bearing.

10. 3. The bearing device according to claim 1, wherein the sensor unit has at least a part of a power source that supplies power to the circuit board.

11. 11. The bearing assembly of claim 10, wherein the power source comprises a battery.

12. the power source is a power supply device having a power receiving circuit and a power transmitting circuit that transmits power to the power receiving circuit in a non-contact manner; The bearing device according to claim 10, wherein the power receiving circuit is provided in the sensor unit.

13. the power source is a generator having a magnetic ring that rotates integrally with the rotating member and a stator that faces the magnetic ring; The stator is provided in the sensor unit, 11. The bearing device according to claim 10, wherein the circuit board has a power supply circuit for converting AC power generated by the stator as the magnetic ring rotates into DC power for use by the circuit board.

Images