Bearing device

Abstract

To prevent deterioration of radio communication performance due to a sealing material while performing sealing between a substrate storage part and a cover of a sensor unit provided in a bearing device with a sealing material.SOLUTION: A sensor unit 4 is attached to a mating member 3 arranged coaxially with a rotary member 1. A substrate storage part 8 opening to one face of the sensor unit 4 stores a circuit board 9 mounting a radio communication circuit 29 or the like on a substrate 26. A cover 10 covering the circuit board 9 is formed by a lid body mated with the substrate storage part 8 in a state being in no contact with the circuit board 9. The cover 10 and the substrate storage part 8 have gap forming surfaces 20a, 20b facing each other with a space at positions closer to an anti-circuit board 9 side with respect to mutual mating surfaces 19a, 19b. A sealing material 11 for performing sealing between the cover 10 and the substrate storage part 8 is filled in between the mutual gap forming surfaces 20a, 20b of the cover 10 and the substrate storage part 8.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 module 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 sensor-equipped bearing (bearing device) disclosed in Patent Document 1 has a circuit board attached to the inside of a cover member (substrate housing section) that has an opening on one side, a cover that covers a wireless module mounted on the circuit board, and a resin (potting material) is filled between the cover and the cover member (substrate housing section) from the opening side to seal the open gap between the outside of the cover, the plate surface of the circuit board, and the cover member (substrate housing section), and an air layer is provided between the antenna of the wireless module mounted on the circuit board and the inside of the cover. When a dielectric such as resin comes into contact with the antenna, wireless communication performance is reduced. By using a cover to prevent contact between the antenna and the sealing resin and providing a space (air layer) between the inside of the cover and the antenna, the reduction in wireless communication performance can be suppressed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-63591 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the sensor-equipped bearing (bearing device) of Patent Document 1 is structured so that the board surface on the wireless module mounting side of the circuit board is butted against the periphery of the cover around the wireless module, and the sealant is filled into the filled space surrounded by the cover, board surface, and lid member (board storage section).For this reason, if care is not taken in how the periphery of the cover is butted against the board surface when assembling the sensor unit, a gap will form between them, and the sealant will leak from the gap to the inside of the cover and immediately spread over the board surface, potentially covering the antenna of the wireless module on the board surface and reducing wireless communication performance.

[0006] Therefore, the problem that the present invention aims to solve is to seal the space between a substrate housing section and a cover of a sensor unit provided in a bearing device with a sealant, while preventing a decrease in wireless communication performance due to the sealant. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention employs a configuration 1 of a bearing device comprising a rotating member, a bearing for rotatably supporting the rotating member, a mating member arranged coaxially with the rotating member, and a sensor unit attached to the mating member, wherein the sensor unit has a board storage section that is open on one side, a circuit board contained in the board storage section, a cover that covers the circuit board, and a sealant that seals between the board storage section and the cover, and the circuit board has a board, a sensor mounted on the board, and a wireless communication circuit mounted on the board, wherein the cover is a lid that fits into the board storage section without contacting the circuit board, the cover and the board storage section have gap-forming surfaces that face each other with a gap between them at positions closer to the anti-circuit board side with respect to their respective fitting surfaces, and the sealant is filled between the gap-forming surfaces of the cover and the board storage section.

[0008] As in the above configuration 1, if the sealant is filled between the gap-forming surfaces of the cover and the substrate housing section at a position closer to the opposite side of the circuit board with respect to the mating surfaces of the cover and the substrate housing section, the mating portion of the cover and the substrate housing section can prevent the sealant from leaking into the internal space surrounded by the cover and the substrate housing section. If the cover is kept out of contact with the circuit board, even if the sealant leaks from the mating portion into the internal space, it cannot immediately spread onto the substrate surface, making it difficult for the sealant to reach the antenna of the wireless communication circuit. In this way, it is possible to prevent the sealant from deteriorating wireless communication performance.

[0009] In the above configuration 1, a configuration 2 can be adopted in which the cover is made of a non-metal material and the sealing material is made of a resin. According to this configuration 2, a radio wave path that passes through the cover and the sealing material can be secured to perform wireless communication.

[0010] In the above configuration 1 or 2, a configuration 3 can be adopted in which the cover has a gap forming surface recessed with respect to the fitting surface of the cover so as to form a gap for filling with the sealant between the gap forming surface of the substrate storage section and the gap forming surface of the substrate storage section. According to this configuration 3, the gap for filling is provided by the gap forming surface of the cover, and it is possible to avoid a complicated shape of the substrate storage section.

[0011] In the above configuration 3, a configuration 4 can be adopted in which the cover has a partition wall that protrudes toward the circuit board side beyond a portion facing the circuit board in a direction in which the cover is assembled with the board housing section, and a part of the gap forming surface of the cover and a fitting surface of the cover are provided on the partition wall. According to this configuration 4, compared to the above configuration 3, the length of the partition wall that protrudes at a position that does not affect the securing of the distance between the cover and the board surface of the circuit board can be utilized to fill the sealant to a recessed position, thereby further improving the sealing performance.

[0012] In any one of the above configurations 1 to 4, a configuration 5 can be adopted in which the cover has a partition wall abutted against the substrate housing section in a direction in which the cover is assembled to the substrate housing section. According to this configuration 5, during the assembly process of the cover and the substrate housing section, the assembly position of the substrate housing section and the cover can be appropriately determined by the abutment of the partition wall of the cover with the substrate housing section, and it is also possible to prevent the sealant leaking from the fitting portion between the cover and the substrate housing section to the circuit board side from spreading toward the circuit board side.

[0013] In any one of the above configurations 1 to 5, a configuration 6 can be adopted in which the sensor unit is fixed to the mating member by press-fitting the sensor unit into the mating member in the axial direction, and a press-fit portion of the sensor unit and the mating member is provided only in an axial region where the sensor unit and the mating member face each other in the radial direction, where the gap forming surfaces of the cover and the substrate housing section are not present. According to this configuration 6, it is possible to prevent a pressing load when the sensor unit and the mating member are pressed into each other from acting between the gap forming surfaces of the substrate housing section and the cover, thereby preventing the sealant from overflowing or cracking, and it is possible to reduce the region where the press-fit portions of the sensor unit and the mating member are present, thereby reducing the pressing load and suppressing deformation of the sensor unit.

[0014] Configuration 7 can be adopted in any one of configurations 1 to 6 above, further comprising a generator having a magnetic ring that rotates integrally with the rotating member and a stator that faces the magnetic ring, the stator being provided in the sensor unit, and the circuit board having a power supply circuit that converts AC power generated by the stator as the magnetic ring rotates into DC power to be used on the circuit board.

[0015] In any one of the above configurations 1 to 7, a configuration 8 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.

[0016] In any one of the above configurations 1 to 8, a configuration 9 can be adopted, further comprising a spacer adjacent to the bearing in the axial direction, and the substrate storage section is provided on the spacer. Effect of the Invention

[0017] As described above, by employing the above configuration 1, the present invention can seal the space between the substrate housing section and the cover of the sensor unit provided in the bearing device with a sealant while preventing a decrease in wireless communication performance caused by the sealant. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a cross-sectional view showing a bearing device according to a first embodiment of the present invention; [Diagram 2] 2 is a perspective view of the bearing device of FIG. 1 from diagonally above on the right [Diagram 3] An enlarged view of the sensor unit and its surroundings in Figure 1. [Figure 4] FIG. 2 is a side view showing the bearing device of FIG. 1 with a part cut away from the right side; [Diagram 5] FIG. 2 is an exploded perspective view of the sensor unit of FIG. 1; [Figure 6] FIG. 2 is a perspective view showing a first stage of assembly of the sensor unit of FIG. 1; [Figure 7] FIG. 7 is a perspective view showing a state in which the cover and the board storage unit are combined from the state shown in FIG. [Figure 8] A partial cross-sectional view showing the inside between the cover and the board storage section in the state shown in FIG. [Figure 9] FIG. 8 is a perspective view showing the positional relationship when the completed sensor unit is press-fitted from the state shown in FIG. [Figure 10] FIG. 4 is a cross-sectional view showing a main part of a bearing device according to a second embodiment of the present invention. [Figure 11] FIG. 11 is a cross-sectional view showing a main part of a bearing device according to a third embodiment of the present invention. [Figure 12] FIG. 11 is a cross-sectional view showing a bearing device according to a fourth embodiment of the present invention. [Figure 13] Enlarged view of the sensor unit in Figure 12 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] A bearing device according to a first embodiment (hereinafter simply referred to as "the bearing device") as one example of the present invention will be described with reference to FIGS. 1 to 9 of the accompanying drawings.

[0020] 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 generator 5.

[0021] 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."

[0022] The rotating member 1 is a member that is rotated in the circumferential direction.

[0023] The bearing 2 is a mechanism that supports the rotating member 1 so as to be rotatable in the circumferential direction.

[0024] The counter member 3 is a member that is arranged rotatably relative to the rotating member 1 in the circumferential direction, and is generally a stationary member.

[0025] The sensor unit 4 is a unit that incorporates an electric circuit that detects at least one of a physical quantity and a chemical quantity related to the state of the bearing 2 and outputs the detection result to a predetermined destination.

[0026] The generator 5 comprises a magnetic ring 6 arranged so as to be rotatable integrally with the rotating member 1, and a stator 7 facing the magnetic ring 6 across a magnetic gap, and the rotational motion of the rotating member 1 is electromagnetically converted into alternating current by the magnetic ring 6 and the stator 7.

[0027] The sensor unit 4 has a board storage section 8 that is open on one side, a circuit board 9 housed in the board storage section 8, a cover 10 that covers the circuit board 9, and a sealant 11 that seals between the board storage section 8 and the cover 10.

[0028] The board storage section 8 is formed of a recess that opens on one side of the sensor unit 4 and has a depth and bottom area sufficient to accommodate the entire circuit board 9.

[0029] The circuit board 9 is made of a printed circuit board on which the above-mentioned electric circuit is formed.

[0030] The cover 10 is a lid that fits into the board storage section 8 without making contact with the circuit board 9. Therefore, there is a space between the cover 10 and the entire circuit board 9, and this space forms an air layer.

[0031] The sealing material 11 is in a liquid state and fills the gap between the opening edge of the substrate storage section 8 and the cover 10 up to the fitting portion between the two 8, 10, and then solidifies and becomes fixed to both 8, 10.

[0032] The aforementioned rotating member 1 is made up of a first raceway ring arranged as a rotating ring. The mating member 3 is made up of a second raceway ring arranged as a stationary ring. The bearing 2 is a rolling bearing having two or more rolling elements 14 between a raceway surface 12 formed on the rotating member 1 and a raceway surface 13 formed on the mating member 3. These rolling elements 14 are held at equal intervals in the circumferential direction by a cage 15. The cage 15 is a crown-shaped cage having a ring portion only on the side opposite the sensor unit 4 (the side away from the sensor unit 4, the left side in FIG. 1) with respect to the rolling elements 14.

[0033] Bearing 2 is a radial bearing. Bearing 2 is also 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.

[0034] Although the above embodiment shows an example in which the bearing 2 is configured as a deep groove ball bearing, the bearing 2 is not limited to a deep groove ball bearing. Furthermore, the rotating member and the mating member are not limited to raceways, and can be, for example, an inner ring spacer, an outer ring spacer, a housing shoulder, a housing lid, etc.

[0035] 1, 3 and 4, the substrate storage section 8 is made up of a first annular wall 16 and a second annular wall 17 that face the mating member 3 in the radial direction, and a side wall 18 that connects one axial end (left end in FIG. 1) of both the annular walls 16 and 17. The annular walls 16 and 17 are each cylindrical and extend in the circumferential direction. The edges of the other axial ends (right end in FIG. 1) of the annular walls 16 and 17 form the opening end of the substrate storage section 8. The side wall 18 closes the space between the one axial ends of the annular walls 16 and 17, and forms the inner bottom surface of the substrate storage section 8.

[0036] The side wall 18 axially supports the circuit board 9. The radial distance between the first annular wall 16 and the second annular wall 17 is greater than the overall radial width of the circuit board 9, and the height by which these annular walls 16, 17 protrude from the side wall 18 in the axial direction (corresponding to the depth of the board storage section 8) is greater than the overall axial thickness of the circuit board 9.

[0037] The cover 10 is provided in an annular shape extending in the circumferential direction, and is fitted between a first annular wall 16 and a second annular wall 17 around the entire circumference.

[0038] The cover 10 and the first annular wall 16 have first mating surfaces 19a, 19b that mate with each other, and first gap-forming surfaces 20a, 20b that face each other radially and are spaced apart from each other at a position closer to the anti-circuit board 9 side (i.e., the side away from the circuit board 9, the right side in Figure 1) than the first mating surfaces 19a, 19b.

[0039] The cover 10 and the second annular wall 17 have second mating surfaces 21a, 21b that mate with each other, and second gap-forming surfaces 22a, 22b that face each other radially with a gap between them at a position closer to the side of the circuit board 9 than the second mating surfaces 21a, 21b.

[0040] The first mating surface 19b and the first gap forming surface 20b of the first annular wall 16 are located on the inner circumference of the first annular wall 16 and are axially continuous so as to form the same plane, and both 19b and 20b are located on the same cylindrical surface.

[0041] The second mating surface 21b and the second gap forming surface 22b of the second annular wall 17 are located on the outer periphery of the second annular wall 17 and are axially continuous so as to form the same plane, and both 21b and 22b are located on the same cylindrical surface.

[0042] The first gap forming surface 20a of the cover 10 is provided in a notch shape recessed in the radial direction with respect to the first fitting surface 19a of the cover 10. In the illustrated example, the notch shape is a chamfered shape that radially expands the distance between the first gap forming surface 20b of the board housing section 8 and the first gap forming surface 20b to the side opposite the circuit board 9, but it may be changed to another shape.

[0043] The second gap forming surface 22a of the cover 10 is provided in a notch shape recessed in the radial direction with respect to the second fitting surface 21a of the cover 10. In the illustrated example, the notch shape is a chamfered shape that radially expands the distance between the second gap forming surface 22b of the board storage section 8 and the notch shape so that it is positioned on the side opposite to the circuit board 9, but it may be changed to another shape.

[0044] The cover 10 has an end face 23 that is continuous with the edge of the other axial end (the right end in Figure 1) of the first gap forming surface 20a (first chamfered portion) and the edge of the other axial end of the second gap forming surface 22a (second chamfered portion) and is located on the same radial plane as the edges of the other axial ends of the first annular wall 16 and the second annular wall 17.

[0045] Furthermore, using a portion of the cover 10 facing the circuit board 9 in the axial direction, which is the direction in which the cover 10 is assembled with the board storage section 8, as a reference, the cover 10 has a first partition wall 24 that protrudes from that portion in the axial direction toward the circuit board 9 (i.e., the side approaching the circuit board 9, the left side in FIG. 1) and a second partition wall 25 that protrudes from that reference portion toward the circuit board 9. These partition walls 24, 25 are each continuous around the entire periphery, and their tips are abutted in the axial direction against the side wall 18 that forms the inner bottom surface of the board storage section 8.

[0046] The first fitting surface 19a of the cover 10 is a cylindrical surface that defines the outer diameter of the first partition wall 24. The second fitting surface 21a of the cover 10 is a cylindrical surface that defines the inner diameter of the second partition wall 25.

[0047] The entire cover 10 is made of a non-metallic material, for example, a resin that does not contain metal.

[0048] A sealant 11 is filled between the first gap forming surfaces 20a, 20b of the cover 10 and the first annular wall 16. Also, a sealant 11 is filled between the second gap forming surfaces 22a, 22b of the cover 10 and the second annular wall 17. The sealant 11 is not intentionally filled between the first mating surfaces 19a, 19b or between the second mating surfaces 21a, 21b.

[0049] Any known resin sealing material or potting material can be used as the sealing material 11, as long as it can be filled in liquid form by coating or injection, has a fixed shape due to hardening of the resin component, and is fixed to the cover 10 and the substrate storage section 8. For example, epoxy adhesive, silicon sealant, liquid gasket, epoxy resin, urethane resin, or the like can be used as the sealing material 11.

[0050] In the mating portion between the cover 10 and the board storage portion 8 (between the first mating surfaces 19a, 19b; between the second mating surfaces 21a, 21b), the fit tolerance can be set to any of an intermediate fit, an interference fit, and a clearance fit. From the viewpoint of sufficiently preventing the sealing material 11 from leaking from the mating portion to the circuit board 9 side, it is preferable to set the mating portion to an interference fit. On the other hand, when setting the mating portion to an intermediate spring or clearance fit that allows a small gap, the first mating surfaces 19a, 19b and the second mating surfaces 21a, 21b are evenly bonded together with an adhesive, respectively, to sufficiently prevent the sealing material 11 from leaking.

[0051] As shown in Figures 4 to 6, the aforementioned circuit board 9 has a substrate 26, one or more sensors 27, 28 mounted on the substrate 26, a wireless communication circuit 29 mounted on the substrate 26, and a power supply circuit 30 mounted on the substrate 26.

[0052] The substrate 26 is made of a printed wiring board. The substrate 26 is in the shape of an arc plate that is short in the radial direction and long in the circumferential direction. As shown in Figures 3 and 4, the substrate 26 is fixed at a position radially away from both annular walls 16, 17 of the substrate storage section 8 and both partition walls 24, 25 of the cover 10. Sensors 27, 28, a wireless communication circuit 29, etc. are mounted on the substrate surface on the other axial end side of the substrate 26 (the right side in Figure 3).

[0053] The substrate 26 is fixed to the side wall 18 of the substrate storage section 8 by a plurality of screws 31. It is also possible to fix the substrate 26 and the side wall 18 by adhesion using an adhesive, an adhesive sheet, or the like.

[0054] The sensors 27 and 28 are each composed of a circuit that converts the above-mentioned physical or chemical quantities into an electric signal. The sensor 27 is, for example, an acceleration sensor that detects radial or axial acceleration to monitor vibration of the bearing 2. In this case, since the sensor 27 is not in contact with other members such as a sealant, the sensor 27 can accurately detect vibrations caused by the bearing 2. The sensor 28 is, for example, a temperature sensor to monitor the temperature of the bearing 2.

[0055] The wireless communication circuit 29 is a communication circuit that converts predetermined information, such as the detection results of the sensors 27 and 28, into radio waves and radiates the radio waves from the antenna 32. The wireless communication circuit 29 complies with a predetermined communication protocol and is generally modular. To avoid a decrease in wireless communication performance, the antenna 32 is not in contact with other members, such as a sealant.

[0056] The power supply circuit 30 is made up of a circuit that converts AC power generated by the stator 7 as the magnetic ring 6 shown in FIGS. 1 and 4 rotates into DC power used by the circuit board 9.

[0057] The magnetic ring 6 of the generator 5 described above is a rotor that generates a rotating magnetic field relative to the stator 7. The magnetic ring 6 is fixed to the rotating member 1. The stator 7 is provided in the sensor unit 4 so as to face the magnetic ring 6 with an air gap between them. As shown in Figs. 3 and 4, the magnetic ring 6 has a magnet 33 magnetized with N poles and S poles alternately arranged in the circumferential direction, and a core metal 34. The magnet 33 is formed of magnetic rubber extending in the circumferential direction. The magnet 33 is bonded to the core metal 34 all around in the circumferential direction. Vulcanization bonding can be used as the bonding method. The core metal 34 has a flange portion for increasing its rigidity.

[0058] Stator 7 shown in Fig. 1 is a stator that guides magnetic flux emitted from magnetic ring 6 with a yoke structure and induces an AC voltage in coil 35 in the yoke structure shown in Fig. 3. The yoke structure and substrate storage section 8 are composed of a first holding member 36 and a second holding member 37 combined with the first holding member 37, as shown in Figs. 3, 5 and 6.

[0059] The yoke structure of the stator 7 and the substrate storage section 8 are composed of a first holding member 36 and a second holding member 37 combined with the first holding member 36 .

[0060] In order to allow these holding members 36, 37 to function as a yoke, these holding members 36, 37 are each made of a magnetic material. Each of these holding members 36, 37 is formed from a single metal plate such as a steel plate. The overall shape of each of the holding members 36, 37 is press-formed. Even if the board storage section 8 is made of metal, since the cover 10 and the sealing material 11 are made of a resin having radio wave transparency, wireless communication using the antenna 32 is possible.

[0061] The first holding member 36 has, seamlessly and integrally, the first annular wall 16, the side wall 18, a first extended side wall 38 extending radially from the side wall 18 toward the side opposite the first annular wall 16 (the side going away from the first annular wall 16), and a first claw pole portion 39 extending circumferentially from the first extended side wall 38 toward the other axial end side (the right side in FIGS. 3 and 5) at a constant interval. The outer circumferential surface of the first holding member 36 includes the outer circumferential surface of the first annular wall 16 and forms the outer periphery of the sensor unit 4.

[0062] The second retaining member 37 has a second annular wall 17, a second extended side wall 40 extending radially from the other axial end of the second annular wall 17 toward the side opposite the first annular wall 16, and a second claw pole portion 41 extending from the second extended side wall 40 toward one axial end side (left side in Figures 3 and 5) at a regular interval in the circumferential direction, all of which are seamlessly integrated together.

[0063] As shown in Figures 3 and 4, the first claw pole portion 39 and the second claw pole portion 41 face each other in the radial direction with an air gap between them and the magnet 33. The first claw pole portion 39 and the second claw pole portion 41 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 39 and the second claw pole portion 41 that are adjacent in the circumferential direction. The total number of the first claw pole portions 39 and the second claw pole portions 41 is equal to the number of poles of the magnet 33 (the total number of north poles and south poles).

[0064] As shown in Fig. 5, arc-shaped holes 42 penetrating between both side surfaces of the first holding member 36 are formed at a plurality of locations in the circumferential direction. The second annular wall 17 has protrusions 43 fitted into the inner surfaces of the holes 42. As shown in Fig. 6, most of the second annular wall 17 except for the protrusions 43 is abutted against the side wall 18 in the axial direction.

[0065] 3 and 5, the coil 35 is wound around a bobbin 44. The coil 35 and the bobbin 44 are arranged all around the circumference in a space surrounded by the first extended side wall 38, the second extended side wall 40, the second annular wall 17, the first claw pole portion 39, and the second claw pole portion 41.

[0066] At least a portion of the surface of the coil 35 and the bobbin 44 may be in contact with the claw pole portions 39, 41 and the extended side walls 38, 40. When protecting the coil 35 for the purposes of insulation, heat resistance, dust resistance, moisture resistance, and chafing prevention, a varnish treatment may be adopted in which the coil 35 is coated by immersing the coil 35 in varnish or by dripping varnish onto the coil 35. Also, the bobbin 44 may be omitted.

[0067] The magnetic flux from the N pole of the magnet 33 shown in FIG. 4, for example, enters the first extended side wall 38 (or the second extended side wall 40) from the first claw pole portion 39 (or the second claw pole portion 41) which is a magnetic pole, passes through the second annular wall 17, goes around the coil 35 to reach the second extended side wall 40 (or the first extended side wall 38), passes through the adjacent second claw pole portion 41 (or the first claw pole portion 39), and returns to the S pole of the magnet 33. When the positions of the N pole and the S pole of the magnet 33 are exchanged with the rotation of the rotating member 1, the direction of the magnetic flux is reversed. The alternating magnetic field thus generated generates an AC voltage at both ends of the start and end of the winding of the coil 35. Although a radial type claw pole type generator has been exemplified as the generator 5, it is possible to change to another type of generator.

[0068] Both ends of the coil 35 are drawn out to the inside of the circuit board storage section 8 through a wiring groove (not shown) formed slightly in the second annular wall 17, and are connected to a terminal 45 provided on the circuit board 26. The input end of the power supply circuit 30 is the terminal 45. The power supplies of the sensors 27, 28 and the wireless communication circuit 29 are each the output end of the power supply circuit 30. An emergency battery may be mounted on the circuit board 26.

[0069] The sensor unit 4 and magnetic ring 6 shown in Fig. 1 are arranged so that they do not have any portions that protrude in the axial direction relative to the bearing 2. The sensor unit 4 is fixed to the mating member 3 by press-fitting the first annular wall 16 of the substrate storage section 8 and the mating member 3 into each other in the axial direction. This press-fitting causes the mating member 3 and the sensor unit 4 to be arranged coaxially. And, since the mating member 3 and the rotating member 1 form the bearing 2, the sensor unit 4 is also arranged coaxially with the rotating member 1.

[0070] As shown in Figure 3, the mating member 3 has a width surface 46 located on the other axial end (the right end in Figure 3) of the entire width of the mating member 3, a non-contact surface 47 facing the sensor unit 4 at a radial distance, a radial contact surface 48 having a radial interference between it and the first annular wall 16, an axial contact surface 49 that axially receives the side surface of the sensor unit 4 at one axial end, and a clearance surface 50 that is recessed toward the one axial end between the radial contact surface 48 and the axial contact surface 49.

[0071] The non-contact surface 47 includes a chamfered portion that removes the corners of the width surface 46. In the axial region W where the sensor unit 4 and the mating member 3 face each other in the radial direction, the non-contact surface 47 is provided in the entire region where the gap forming surfaces 20a, 20b, 22a, 22b of the substrate storage section 8 and the cover 10 exist. There is a space between the non-contact surface 47 and the sensor unit 4. In the non-contact surface 47, an end region that is connected to the radial contact surface 48 has a tapered surface shape in which the diameter difference with the radial contact surface 48 becomes smaller the closer to the radial contact surface 48.

[0072] The radial contact surface 48 has a cylindrical surface extending in the circumferential direction. The press-fit portion between the sensor unit 4 and the mating member 3 is only the fitting portion between the first annular wall 16 of the substrate housing portion 8 and the radial contact surface 48. Since the sensor unit 4 and the mating member 3 are press-fitted only in a part of the axial region W, the pressing load during the press-fitting is reduced, making the press-fitting easier and advantageous for suppressing deformation of the mating member 3 and the sensor unit 4, for example, advantageous for suppressing deformation of the raceway surface 13 of the mating member 3 made of a raceway ring and suppressing deformation of the substrate housing portion 8 to suppress the effect on the fit with the cover 10.

[0073] Further, the press-fit portion of the sensor unit 4 and the mating member 3 is provided only in a region of the axial region W where the gap forming surfaces 20a, 20b, 22a, and 22b of the substrate housing section 8 and the cover 10 do not exist. This prevents the sealing material 11 from being pressurized by the above-mentioned pressing load. The press-fit portion of the sensor unit 4 and the mating member 3 is provided in a region of the axial region W where the mating surfaces 19a, 19b, 21a, and 21b of the substrate housing section 8 and the cover 10 exist.

[0074] The axial contact surface 49 abuts against the side surface (side wall 18) at one axial end (the left end in FIG. 3) of the sensor unit 4 when the sensor unit 4 and the mating member 3 are press-fitted, appropriately determining the axial positional relationship between the sensor unit 4 and the mating member 3 and restricting the sensor unit 4 from falling in the radial direction. The sensor unit 4 does not have a portion that protrudes from the mating member 3 in the axial direction.

[0075] The flank 50 forms a space for reliably avoiding interference between the sensor unit 4 and the counterpart member 3. It is also possible to omit the formation of the flank 50.

[0076] A certain distance is ensured between the sensor unit 4 and the rolling elements 14. This distance is set so that the sensor unit 4 and the rolling elements 14 do not come into contact with each other even if there is axial displacement due to the internal bearing gap of the bearing 2.

[0077] If the sealing material 11 is exposed to the lubricant stirred inside the bearing 2, the sealing material 11 will be easily deteriorated, and if the sealing material 11 peels off, it will undesirably become mixed as a foreign object into the bearing 2. Therefore, when the sensor unit 4 is fixed to the mating member 3, which is a component of the bearing 2, it is preferable that one surface of the sensor unit 4 including the cover 10 and the sealing material 11 is arranged facing the outside of the bearing 2 (the side of the reversible moving body 14).

[0078] The magnetic ring 6 shown in FIG. 1 is fixed to the outer periphery of the rotating member 1. The fixing means is press-fitting, adhesive bonding, or a combination of these. In order to prevent the magnetic ring 6 from protruding from the rotating member 1, which is a component of the bearing 2, a notch 51 that is recessed in the axial and radial directions is formed around the entire periphery of the outer periphery of the rotating member 1 at the other axial end (the right end in FIG. 1). The flange portion of the magnetic ring 6 fits within the area that faces the notch 51 in the radial direction, and the magnetic ring 6 does not have a portion that protrudes axially from the rotating member 1.

[0079] In the ring-shaped space radially sandwiched between the rotating member 1 of the bearing 2 and the mating member 3, the circuit board 9, the stator 7, and the magnetic ring 6 are arranged in this order in a radially opposing relationship so as not to overlap in the axial direction, allowing these to be arranged thinly in the axial direction. Therefore, it can be provided as a bearing device of the same size as the bearing 2 configured as a standard bearing.

[0080] Since there is small variation in the radial gap between the magnetic ring 6 fixed to the rotating member 1, which is a component of the radial bearing, and the stator 7 of the sensor unit 4 fixed to the mating member 3, which is a component of the bearing 2, a stable amount of power generation can be ensured by the generator 5.

[0081] In assembling the sensor unit 4, as shown in FIG. 5, the bobbin 44 around which the coil 35 is wound is placed between the first extended side wall 38 and the second extended side wall 40, and the first holding member 36 and the second holding member 37 are assembled in the axial direction, and at this time, each protrusion 43 of the second holding member 37 is fitted into the corresponding hole 42 of the first holding member 36. This fitting ensures that the first holding member 36 and the second holding member 37 are coaxial, and the first claw pole portion 39 and the second claw pole portion 41 are alternately arranged in a predetermined phase with a gap in the circumferential direction. Therefore, the first holding member 36 and the second holding member 37 can be assembled appropriately without using a jig. It is preferable that the holes 42 and the protrusions 43 are each formed in three or more places.

[0082] After this assembly, the protrusion 43 is fixed to the inner surface of the hole 42. This fixing may be performed by, for example, press fitting, bonding, laser welding, or a combination of these.

[0083] It is also possible to omit the protrusion 43 and the hole 42. In this case, after the first holding member 36 and the second holding member 37 are coaxially aligned and phase-aligned using a jig (not shown), the butting portions of the second annular wall 17 and the side wall 18 may be bonded or laser-welded from the outer periphery of the second annular wall 17, or these may be fixed using a combination of these.

[0084] When the first retaining member 36 and the second retaining member 37 are combined as described above, the first annular wall 16, the second annular wall 17, and the side wall 18 form a substrate storage section 8 that is open on the side surface on the other axial end side (the right side in FIG. 6), as shown in FIG. 6.

[0085] Next, the circuit board 9 is inserted onto the side wall 18 through the opening of the board storage section 8. The circuit board 9 is fixed to the side wall 18 using a plurality of screws 31. At this time, the surface of the board opposite to the mounting surface for electronic components such as the sensor 27 faces the side wall 18. To insulate the first holding member 36 from the circuit board 9, an insulating sheet such as a polyimide film (not shown) may be interposed between the circuit board 9 and the side wall 18.

[0086] After the circuit board 9 is fixed on the side wall 18, an assembly process is performed in which the cover 10 is fitted between the inner circumference of the first annular wall 16 and the outer circumference of the second annular wall 17. At this time, the first fitting surface 19a of the cover 10 is guided in the assembly direction by the first gap forming surface 20b of the board storage section 8, and comes into a state of fitting with the first fitting surface 19b of the board storage section 8 (see FIG. 3). Then, when the first partition wall 24 passes between the inner circumference of the first annular wall 16 and the board 26 and butts against the side wall 18, and the second partition wall 25 passes between the outer circumference of the second annular wall 17 and the board 12 in the axial direction and butts against the inner bottom surface (side wall 18) of the board storage section 8 in the axial direction, the axial assembly position of the cover 10 with respect to the board storage section 8 is determined. In this fixed position, as shown in Fig. 3, the end face 23 of the cover 10 and the edges of the other axial ends of the first annular wall 16 and the second annular wall 17 are located on the same radial plane, and as shown in Fig. 7, the first gap forming surfaces 20a, 20b of the cover 10 and the first annular wall 16 form a filling gap g1 that is open toward the other axial end side (the right side in Fig. 7), and the second gap forming surfaces 22a, 22b of the cover 10 and the second annular wall 17 form a filling gap g2 that is also open. At this time, the cover 10 is temporarily fixed to the substrate storage section 8 by frictional force acting on the mating portions (between the first mating surfaces 19a, 19b; between the second mating surfaces 21a, 21b) of the cover 10 and the substrate storage section 8, or by adhesive force when an adhesive is used. As a result, as shown in Figures 3 and 8, an internal space 52 is formed surrounded by the cover 10 and the board storage section 8, the cover 10 is fixed in a position where it does not contact the circuit board 9, and the internal space 52 becomes filled with air except for any placed objects such as the circuit board 9.

[0087] A filling step is performed to fill the filling gaps g1 and g2 shown in FIG. 7 with the sealant 11. At this time, each of the filling gaps g1 and g2 is simply filled by applying the sealant 11. When the sealant 11 solidifies, the cover 10 and the board housing section 8 are sealed, and the cover 10 is fixed, as shown in FIG. 3 and FIG. 8. Since the cover 10 and the board housing section 8 are fitted together to cover the entire circuit board 9 without contact, the filling gaps g1 and g2 are small as shown in FIG. 7, and the sealant 11 can be easily filled by applying the sealant 11. In addition, if the filling gaps g1 and g2 are small, even if there is a difference in the thermal expansion coefficient between the sealant 11 shown in FIG. 3 and the cover 10 or the board housing section 8 that contacts it, the effect of this difference is reduced.

[0088] In addition, during this filling step, the sealant 11 filled between the first gap forming surfaces 20a, 20b and between the second gap forming surfaces 22a, 22b cannot easily escape through the fitting portion between the corresponding first fitting surfaces 19a, 19b and the fitting portion between the second fitting surfaces 21a, 21b to the circuit board 9 side. Therefore, the above-mentioned fitting portion prevents the sealant 11 from leaking into the internal space 52. Even if the sealant 11 leaks to the circuit board 9 side through a small gap in the above-mentioned fitting portion, the sealant 11 cannot enter the internal space 52 unless the sealant 11 escapes through the small gap in the butting portion to the circuit board 9 side. Furthermore, even if a small amount of sealant 11 leaks into internal space 52, because cover 10 and circuit board 9 are arranged so as not to come into contact with each other, sealant 11 cannot immediately spread over the surface of circuit board 9 and is unlikely to reach antenna 32 of wireless communication circuit 29. Since measures to prevent sealant 11 leakage are thus taken, there is no need to maintain the cover 10 and the inner bottom surface of board storage section 8 closely butted against each other in the assembly direction during the filling process, which makes the filling process easier.

[0089] After the sealing material 11 has solidified and been fixed, the sensor unit 4 is attached to the mating member 3 as shown in FIG. 1. Here, as shown in FIG. 3 and FIG. 9, the first annular wall 16 of the substrate storage section 8 is press-fitted into the radial contact surface 48 described above. From the beginning of the combination of the sensor unit 4 and the mating member 3, the first annular wall 16 of the sensor unit 4 is inserted straight up to the radial contact surface 48 without contacting the non-contact surface 47, and then the first annular wall 16 is gradually press-fitted into the radial contact surface 48. In this way, it is possible to prevent the sensor unit 4 from being press-fitted at an angle relative to the radial contact surface 48. It is also possible to adopt other fitting structures.

[0090] This bearing device is as described above (see Figures 1, 3, and 7) 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 board storage section 8 that opens on one side of the sensor unit 4, a circuit board 9 housed in the board storage section 8, a cover 10 that covers the circuit board 9, and a sealant 11 that seals between the board storage section 8 and the cover 10, and the circuit board 9 has a board 26, sensors 27, 28 mounted on the board 26, and a wireless communication circuit 29 mounted on the board 26.

[0091] This bearing device, in particular, comprises a lid body in which the cover 10 fits into the board storage section 8 without contacting the circuit board 9, and the cover 10 and the board storage section 8 have gap-forming surfaces (20a, 20b; 22a, 22b) that face each other with a gap therebetween and are positioned closer to the side opposite the circuit board 9 than the respective fitting surfaces 19a, 19b, 21a, 21b, and a sealant 11 is provided between the gap-forming surfaces (20a, 20b; 22a, 22b) of the cover 10 and the board storage section 8. Since the sealing material 11 is filled between the cover 10 and the board housing section 8, leakage of the sealing material 11 into the internal space 52 surrounded by the cover 10 and the board housing section 8 is prevented by the fitting portions between the cover 10 and the board housing section 8 (between fitting surfaces 19a, 19b; between fitting surfaces 21a, 21b), and even if the sealing material 11 leaks from the fitting portions into the internal space 52, it will not immediately spread over the board surface of the circuit board 9 and will be unlikely to reach the antenna 32 of the wireless communication circuit 29. In this way, this bearing device can seal the space between the board housing section 8 of the sensor unit 4 and the cover 10 with the sealing material 11, while preventing a decrease in wireless communication performance caused by the sealing material 11.

[0092] Furthermore, in this bearing device, the cover 10 is made of a non-metal and the sealant 11 is made of resin, so wireless communication can be performed by securing a radio wave path that passes through the cover 10 and the sealant 11. Note that it is also possible for only a portion of the cover facing the antenna 32 to be made of a non-metal material such as resin, with the remaining area being made of metal.

[0093] In addition, this bearing device has gap forming surfaces (20a; 22a) that are recessed into the mating surface (19a; 21a) of the cover 10 so that the cover 10 forms gaps (g1; g2) for filling with the sealant 11 between the gap forming surface (20b; 22b) of the substrate storage section 8. Therefore, the notched gap forming surface (20a; 22a) of the cover 10 provides the filling gaps (g1; g2), thereby avoiding the shape of the substrate storage section 8 (first annular wall 16; second annular wall 17) from becoming complicated.

[0094] Furthermore, since this bearing device has the partition walls 24, 25 of the cover 10 abutting against the board storage section 8 in the direction in which the cover 10 is assembled to the board storage section 8, during the assembly process of the cover 10 and the board storage section 8, the abutment of the partition walls 24, 25 of the cover 10 against the board storage section 8 can appropriately determine the assembly position of the board storage section 8 and the cover 10, and can also prevent the sealant 11 that has leaked from the mating portion of the cover 10 and the board storage section 8 to the circuit board 9 side from spreading toward the circuit board 9. If the purpose is not to determine this position and the only purpose is to ensure a sufficient width for the mating surfaces 19a, 21a of the cover 10, it is possible to employ a relatively short partition wall that does not abut against the board storage section 8, or one that omits the partition wall.

[0095] In addition, in this bearing device, the sensor unit 4 is fixed to the mating member 3 by pressing the sensor unit 4 into the mating member 3 in the axial direction, and the press-fit portion of the sensor unit 4 and the mating member 3 (the fitting portion of the first annular wall 16 and the radial contact surface 48) is provided only in the axial region W where the sensor unit 4 and the mating member 3 face each other radially, where the gap-forming surfaces 20a, 20b, 22a, 22b of the cover 10 and the substrate storage section 8 are not present. This prevents the pressing load applied when pressing the sensor unit 4 and the mating member 3 from acting between the gap-forming surfaces (20a, 20b; 22a, 22b) of the cover 10 and the substrate storage section 8, thereby preventing the sealing material 11 from overflowing or cracking, and also reduces the region where the press-fit portions of the sensor unit 4 and the mating member 3 are present, thereby reducing the pressing load and suppressing deformation of the sensor unit 4.

[0096] In addition, this bearing device further includes a generator 5 having a magnetic ring 6 that rotates integrally with the rotating member 1 and a stator 7 facing the magnetic ring 6, the stator 7 being provided in the sensor unit 4, and the circuit board 9 having a power supply circuit 30 that converts the AC power generated by the stator 7 as the magnetic ring 6 rotates into DC power used by the circuit board 9, thereby making it possible to make the sensor unit 4 wireless.

[0097] Furthermore, since the rotating member 1 of this bearing device 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 14 between the rotating member 1 and the mating member 3, it can be configured as a unit consisting of the sensor unit 4 and a rolling bearing.

[0098] A bearing device according to a second embodiment of the present invention is shown in Fig. 10. Note that, in the following, only the differences from the first embodiment will be described.

[0099] The bearing device according to the second embodiment has a cover 60 with a different shape from that of the first embodiment. The cover 60 has a shape in which the dimensions of the chamfered portion 61 on the outer periphery of the cover 60 are smaller than those of the first embodiment, and the outer periphery 63 on the chamfered portion 61 side of the first partition wall 62 has a smaller diameter than the first fitting surface 64, and a width in the axial direction. The first gap forming surface 65 of the cover 60 is composed of the entire chamfered portion 61 on the outer periphery and the outer periphery 63 on the chamfered portion 61 side of the first partition wall 62. The cover 60 has a shape in which the dimensions of the chamfered portion 66 on the inner periphery of the cover 60 are smaller than those of the first embodiment, and the inner periphery 68 on the chamfered portion 66 side of the second partition wall 67 has a larger diameter than the second fitting surface 69, and a width in the axial direction. The second gap forming surface 70 of the cover 60 is composed of the entire chamfered portion 66 on the inner circumferential side and the inner circumferential surface 68 of the second partition wall 67 on the chamfered portion 66 side.

[0100] In the bearing device of the second embodiment, the cover 60 has a partition wall (62; 67) that protrudes toward the circuit board 9 further than the portion facing the circuit board 9 in the direction (axial direction) in which the cover 60 is assembled with the board storage section 8, and the partition wall (62; 67) is provided with a part (outer peripheral surface 63; inner peripheral surface 68) of the gap forming surface (65; 70) of the cover 60 and the mating surface (64; 69) of the cover 60. Therefore, compared to the first embodiment, the protruding length of the partition wall (62; 67) that protrudes at a position that does not affect the distance between the board surfaces of the cover 60 and the circuit board 9 can be utilized to fill the sealing material 71 up to a recessed position, thereby further improving sealing performance.

[0101] FIG. 11 shows a bearing device according to a third embodiment, which is yet another example of the present invention.

[0102] The bearing device according to the third embodiment is modified from the first embodiment in the shape of the cover 81 of the sensor unit 80, the shape of the first annular wall 83 in the substrate housing section 82, and the shape of the mating member 84. The first fitting surface 85 and the first gap forming surface 86 of the cover 81 are continuous in the axial direction so as to be flush with each other, and are located on the same cylindrical surface. The first annular wall 83 has a shape in which the first gap forming surface 87 at the other axial end (the right end in FIG. 11) is provided with a larger diameter than the first fitting surface 88 at the one axial end, and the outer circumferential surface 89 at the other axial end (the right end in FIG. 11) is provided with a larger diameter than the outer circumferential surface 90 at the one axial end. The radial contact surface 91 and the non-contact surface 92 of the mating member 84 are continuous in the axial direction so as to be flush with each other, and are located on the same cylindrical surface.

[0103] In the bearing device according to the third embodiment, an outer circumferential surface 90 at one axial end of the first annular wall 83 is not in contact with the mating member 84 from the beginning of the assembly of the sensor unit 80 and the mating member 84, and an outer circumferential surface 89 at the other axial end of the first annular wall 83 is inserted straight up to the radial contact surface 91 of the mating member 84, and is then gradually press-fitted into the radial contact surface 91. This makes it possible to prevent the sensor unit 80 from being press-fitted at an angle, and also reduces the area where the press-fit portions of the sensor unit 80 and the mating member 84 exist, thereby reducing the pressing load and suppressing deformation of the sensor unit 80.

[0104] In the third embodiment, the pressure load applied during press-fitting acts between the first gap forming surface 86 of the cover 81 and the first gap forming surface 87 of the substrate storage section 82. If the sealing material 93 filled between them is too hard, there is a high concern that cracks may occur due to the pressing load, so it is preferable that the hardness of the sealing material 93 is low. For example, a sealing material 93 having a low hardness of 40 or more and 50 or less in durometer hardness can be used. Here, the durometer hardness is a value in a durometer hardness test type A specified in JIS K 7215 (corresponding to ISO 7619-1).

[0105] In the third embodiment, an example is shown in which the outer peripheral shape of the cover 81 is simplified to a cylindrical surface shape in order to prevent the amount of filling material 93 from becoming large due to the change in the shape of the first annular wall 83, but it is also possible to make the first gap-forming surface 86 of the cover 81 have a notched shape similar to that of the first embodiment.

[0106] In the above-mentioned first to third embodiments, an example was shown in which the substrate storage section was arranged on the outer periphery side of the sensor unit and the yoke was arranged on the inner periphery side of the sensor unit, but this arrangement can be reversed. Also, the bearing is a rolling bearing with an outer ring as a stationary ring and an inner ring as a rotating ring, and the sensor unit is attached to the stationary ring. However, since the sensor unit is wireless, the sensor unit can also be attached to the rotating ring. Also, the attachment destination of the sensor unit is not limited to the raceway ring, and it is sufficient to select a mating member that allows the sensor unit to be arranged adjacent to the bearing. As an example of arranging the sensor unit adjacent to the bearing, a bearing device according to a fourth embodiment is shown in Figs. 12 to 13.

[0107] The bearing device of the fourth embodiment is configured as a spindle including a rotating member 100 which also serves as a motor shaft, a mating member 101 which also serves as a bearing housing surrounding the rotating member 100, a pair of bearings 102, 103 incorporated between the rotating member 100 and the mating member 101, a sensor unit 104 and a generator 105 arranged between these bearings 102, 103, and spacers 106, 107, 108 which maintain the axial span between these bearings 102, 103.

[0108] The first bearing 102 and the second bearing 103 are rolling bearings each having an inner ring 109, 110 fitted to the rotating member 100, an outer ring 111, 112 fitted to the mating member 101, and rolling elements 113, 114 arranged between the inner and outer rings (109, 111; 110, 112).

[0109] The first spacer 106 is attached to the rotating member 100 in a state where it is sandwiched between the first inner ring 109 and the second inner ring 110 .

[0110] The second spacer 107 and the third spacer 108 are butted against each other in the axial direction and attached to the mating member 101 in a state where they are sandwiched between the first outer ring 111 and the second outer ring 112. The bearing seat surface of the mating member 101 and the spacers 107 and 108 fitted thereto are arranged coaxially, and are also arranged coaxially with the rotating member 100 via the bearings 102 and 103.

[0111] The magnetic ring 115 of the generator 105 is attached to the outer periphery of the first spacer 106. The stator 116 is attached across the inner periphery of the second spacer 107 and the inner periphery of the third spacer 108.

[0112] The sensor unit 104 is provided with the second spacer 107 as its body. The board storage section 117 is made of an annular groove that opens on one side of the second spacer 107 and extends all around the circumference. The circuit board 118 is arranged with its board surface facing the axial direction, and faces in the axial direction a stator 116 supported on the other side of the second spacer 107. It is also possible to use only one outer ring spacer between the first outer ring 111 and the second outer ring 112, and to use this as the body of the sensor unit.

[0113] The gap between the inner and outer periphery of cover 119 and second spacer 107 is sealed with sealant 120. Cover 119 does not have a portion that protrudes axially from the portion where cover 119 fits with second spacer 107 toward circuit board 118. As a result, the distance between cover 119 and circuit board 118 in internal space 121 is large, so that even if a small amount of sealant 120 leaks from the aforementioned fitting portion into internal space 121, it cannot immediately spread over the board surface of circuit board 118.

[0114] In general, the rotating member 100 of the spindle, the spacers 106-108, the inner rings 109-110, and the outer rings 111-112 are made of metal such as steel. The path that passes through the inside of the first bearing 102 is important for preventing the radio waves that have passed through the cover 119 and the sealing material 120 from escaping to the outside of the bearing device. For this reason, it is preferable that the inside of the first bearing 102 is made of a non-metallic material, and for example, a resin cage and ceramic rolling elements may be used.

[0115] 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]

[0116] 1,100 Rotating parts 2,102,103 Bearings 3,101 Counterpart 4,80,104 Sensor unit 5,105 Generator 6,115 Magnetic Ring 7 Stator 8,82,117 Board storage section 9,118 Circuit Boards 10,60,81,119 Cover 11,120 Encapsulating material 14 Rolling elements 19a, 19b, 21a, 21b, 64, 69, 85, 88 Mating surfaces 20a,20b,22a,22b,65,70,86,87 Void forming surface 24,25 Bulkhead 30 Power circuit 48,91 Radial contact surface 107 Maza g1,g2 Filling gap W axial area

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 board storage section that is open on one side, a circuit board accommodated in the board storage section, a cover that covers the circuit board, and a sealant that seals between the board storage section and the cover, In a bearing device, the circuit board includes a substrate, a sensor mounted on the substrate, and a wireless communication circuit mounted on the substrate, the cover is a lid body that fits into the board storage section without contacting the circuit board, the cover and the board storage section have gap forming surfaces facing each other with a gap therebetween at positions closer to the opposite side of the circuit board than the mating surfaces of each other, A bearing device, characterized in that the sealant is filled between the gap-forming surfaces of the cover and the substrate housing portion.

2. 2. The bearing assembly according to claim 1, wherein the cover is made of a non-metallic material, and the sealing material is made of a resin.

3. 3. The bearing device according to claim 1, wherein the cover has a gap forming surface that is recessed with respect to a fitting surface of the cover so as to form a gap for filling the sealant between the gap forming surface of the substrate storage portion and the gap forming surface of the substrate storage portion.

4. The bearing device according to claim 3, wherein the cover has a partition wall that protrudes toward the circuit board further than the portion facing the circuit board in the direction in which the cover is assembled to the board storage section, and a portion of the gap-forming surface of the cover and a mating surface of the cover are provided on the partition wall.

5. 3. The bearing device according to claim 1, wherein the cover has a partition wall abutting against the substrate housing portion in a direction in which the cover is assembled with the substrate housing portion.

6. The sensor unit is fixed to the mating member by press-fitting into the mating member in an axial direction, 3. A bearing device as described in claim 1 or 2, wherein a press-fit portion for the sensor unit and the mating member is provided only in an axial region where the sensor unit and the mating member are radially opposed to each other, and where the gap-forming surfaces of the cover and the substrate storage section are not present.

7. a generator including 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, 3. The bearing device according to claim 1, 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 in the circuit board.

8. 3. A bearing device according to claim 1 or 2, wherein the rotating member comprises a first raceway, the mating member comprises a second raceway, and the bearing is a rolling bearing having rolling elements between the rotating member and the mating member.

9. Further comprising a spacer adjacent to the bearing in the axial direction, 3. The bearing device according to claim 1, wherein the board storage portion is provided in the spacer.

Images