Bearing device

Abstract

To provide a bearing device which can detect temperature change of a bearing ring of a rolling bearing early and accurately.SOLUTION: A sensor unit 2 has a holder 9 for holding a circuit board 8. A temperature sensor 10 is mounted on one surface of a substrate 23 of the circuit board 8. A rear surface part 23a including at least a portion, which faces the temperature sensor 10 in a substrate thickness direction, of the other surface of the substrate 23 is in contact with the holder 9. The substrate 23 has at least one of a penetration metal part 28a which penetrates through the substrate 23 from the rear surface part 23a in the thickness direction of the substrate 23, a rear side metal foil part 28b disposed at the rear surface part 23a, and a front side metal foil part 28c disposed at a front surface part 23b located on the one surface of the substrate 23 and facing the rear surface part 23a in the substrate thickness direction.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Conventionally, a bearing device has been known in which sensors for detecting the condition of a rolling bearing are mounted on a substrate to form a circuit board, the circuit board is held in a holder and assembled into a sensor unit, and the sensor unit is fixed to a raceway ring.

[0003] For example, in the bearing device of Patent Document 1, a holder with an L-shaped cross section is attached to the raceway. The holder has an annular side portion extending in the radial direction and a fitting portion protruding in the axial direction from the raceway side of the annular side portion. The holder also serves as a yoke in the stator of the generator. The fitting portion of the holder is fitted to the circumferential surface portion of the raceway, and the protruding end face of the fitting portion is abutted against the step portion of the raceway in the axial direction. The circuit board is a control board including a plurality of sensors such as a temperature sensor. This circuit board is fixed on the side surface of the annular side portion on the rolling element side. The circumferential surface portion and the step portion of the raceway are included in the inner circumference of the raceway, and are formed between the raceway surface portion of the inner circumference and an end face located at one end that defines the width of the raceway. The sensor unit is arranged so as not to protrude from the raceway in the axial direction. The rolling bearing generates heat as the rolling bearing rotates. This heat is generated at the contact portion between the raceway surface portion and the rolling element. When the temperature change due to this heat generation is detected by a temperature sensor, it can be used as information indicating the condition of the bearing. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2003-307435 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the bearing device of Patent Document 1, heat generated at the contact area between the raceway surface and the rolling elements is thermally conducted from the raceway ring through the holder to one side of the circuit board, and then further through the board to reach the temperature sensor. There is a large amount of insulating base material and resist inside and on both sides of the board, and the thermal conductivity from the holder to the temperature sensor is poorer than the thermal conductivity between the holder and the raceway ring, so there is a large delay in detecting the above-mentioned heat generated in the raceway surface, and there is also concern that accurate temperature measurement will be difficult.

[0006] In view of the above background, an object of the present invention is to provide a bearing device capable of quickly and accurately detecting a temperature change in the raceway of a rolling bearing. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention adopts a configuration 1 of a bearing device comprising a rolling bearing having a first raceway, a second raceway, and a plurality of rolling elements arranged between the first raceway and the second raceway, a sensor unit having a circuit board and a holder for holding the circuit board, wherein the circuit board has a substrate and a temperature sensor mounted on the substrate, the substrate is attached to the holder, and the holder is attached to the first raceway, wherein the temperature sensor is made of an electronic component surface-mounted on one side of the substrate, and a back side portion of the other side of the substrate opposite to the one side, the back side portion including at least a portion facing the temperature sensor in the thickness direction of the substrate, is in contact with the holder, and the substrate has at least one of a penetrating metal portion that penetrates in the thickness direction of the substrate from the back side portion to the one side of the substrate, a back side metal foil portion arranged on the back side, and a front side metal foil portion arranged on a surface portion located on the one side of the substrate and facing the back side portion in the thickness direction of the substrate.

[0008] As in the above configuration 1, when the temperature sensor is surface-mounted on one side of the board, the other side of the board, which is the opposite side, can have a flat back surface including at least a portion facing the temperature sensor in the thickness direction of the board, and this back surface can be brought into contact with the holder. The temperature sensor is located on one side of the board and on a front surface facing the back surface in the thickness direction of the board. Therefore, by improving at least one of the thermal conduction between the back surface and front surface of the board, the thermal conduction between the holder and the back surface of the board, and the thermal conduction between the front surface of the board and the temperature sensor, the thermal conduction from the holder to the temperature sensor can be improved, and the heat generated at the contact portion between the raceway surface of the first raceway and the rolling element can be quickly transmitted from the first raceway to the holder and the board to the temperature sensor by thermal conduction, so that the temperature change of the raceway can be quickly and accurately detected. Specifically, by using a through metal portion that penetrates the substrate in the thickness direction from the substrate's back surface to one surface, a heat conduction path is provided from the substrate's back surface through the through metal portion, which has good thermal conductivity, to the substrate's front surface, improving heat conduction between the substrate's back surface and front surface. By using a back metal foil portion disposed on the substrate's back surface, improving heat conduction between the holder and the substrate's back surface. By using a front metal foil portion disposed on the substrate's front surface, improving heat conduction between the substrate's front surface and the temperature sensor.

[0009] In addition, by adopting an embodiment in which the through metal portion and the metal foil portion on the back side are continuous, it is possible to improve the thermal conductivity from the back side of the substrate to the through metal portion. In addition, by adopting an embodiment in which the through metal portion and the metal foil portion on the front side are continuous, it is possible to improve the thermal conductivity from the through metal portion to the front side of the substrate. In addition, by adopting an embodiment in which the through metal portion and the metal foil portion on the back side are continuous, and the through metal portion and the metal foil portion on the front side are continuous, it is possible to improve the thermal conductivity from the back side of the substrate to the front side of the substrate via the through metal portion.

[0010] In the above configuration 1, configuration 2 can be adopted in which the holder has an annular side portion extending radially and an engagement portion protruding axially from the annular side portion, the first raceway has an inner or outer circumference including a raceway surface portion, a peripheral surface portion that engages with the engagement portion, and a step portion that axially receives the side surface of the annular side portion on the rolling body side, the substrate is positioned on the side surface of the annular side portion on the reversing body side, and the back surface of the substrate is in contact with the side surface of the annular side portion on the reversing body side.

[0011] As in the above configuration 2, when the holder has an annular side portion extending in the radial direction and a fitting portion protruding from the annular side portion in the axial direction, and the first raceway ring has an inner or outer circumference including a raceway surface portion, a circumferential surface portion that fits with the fitting portion, and a step portion that axially receives the side surface of the annular side portion on the rolling body side, the annular side portion of the holder can be arranged near the raceway surface portion. When a substrate is arranged on the side surface of the annular side portion on the reversible moving body side, and the back surface of the substrate is in axial contact with the side surface of the annular side portion on the reversible moving body side, heat can be conducted directly from the step portion near the raceway surface portion, and from the annular side portion to the back surface of the substrate. Therefore, the heat conduction path from the first raceway ring to the back surface of the substrate can be made shorter than the case where the heat conduction path is from the first raceway ring to the back surface of the substrate via the fitting portion of the holder and the annular side portion to the back surface of the substrate.

[0012] In the above configuration 2, configuration 3 can be adopted in which the back surface portion of the base plate is disposed at a position axially opposite to the step portion of the first raceway ring.

[0013] According to the above configuration 3, the heat conduction path between the step portion of the first race and the back surface of the base plate can be minimized in the axial direction.

[0014] In the above configuration 3, a configuration 4 can be adopted in which the raceway surface portion, the step portion, the back surface portion of the substrate, and the temperature sensor are arranged in positions facing each other in the axial direction.

[0015] According to the above-mentioned configuration 4, the heat conduction path from the raceway surface portion through the step portion, the annular side portion, and the substrate to the temperature sensor can be made a linear path in the axial direction, and thus the heat generated at the contact portion between the raceway surface portion of the first raceway ring and the rolling element can reach the temperature sensor particularly quickly.

[0016] In any one of the above configurations 1 to 4, a configuration 5 can be adopted in which the metal penetrating portion is provided at a position facing the temperature sensor in the axial direction.

[0017] According to the above configuration 5, the heat conduction path from the rear surface of the substrate to the temperature sensor via the penetrating metal portion can be particularly short.

[0018] In any one of the above configurations 1 to 5, configuration 6 can be adopted in which at least one of the back-side metal foil portion and the front-side metal foil portion extends from a position facing the temperature sensor in the thickness direction of the substrate to a position not facing the temperature sensor in the thickness direction of the substrate. The "position facing the thickness direction of the substrate" refers to the position where the substrate and the temperature sensor are in contact, and the "position not facing the thickness direction of the substrate" refers to a portion on the surface of the substrate opposite to where the temperature sensor is disposed.

[0019] According to the above-mentioned configuration 6, at least one of the metal foil portion on the back side of the substrate and the metal foil portion on the front side of the substrate extends not only to a position facing the temperature sensor in the thickness direction of the substrate but also to a non-facing position, thereby improving thermal conductivity between the holder and the surface portion of the substrate.

[0020] In any one of the above configurations 1 to 6, configuration 7 can be adopted, in which the penetrating metal portion is hollow, and the back-side metal foil portion and the front-side metal foil portion each extend from the penetrating metal portion.

[0021] According to the above-mentioned configuration 7, a printed wiring board having a penetrating metal portion, a metal foil portion on the back side, and a metal foil portion on the front side arranged in the form of through holes can be used as the substrate, and these penetrating metal portions etc. can improve the thermal conductivity from the back side of the substrate to the temperature sensor.

[0022] In any one of the above configurations 1 to 6, a configuration 8 can be adopted in which the penetrating metal portion is made of a solid portion that closes the through hole of the substrate.

[0023] According to the above configuration 8, since the cross-sectional area of ​​the penetrating metal portion is larger than that of the hollow penetrating metal portion, the thermal conductivity of the penetrating metal portion can be improved.

[0024] In any one of the above configurations 1 to 8, configuration 9 can be adopted in which the substrate has a heat conduction path portion including at least one of the penetrating metal portion and the back-side metal foil portion, the heat conduction path portion is an electrically non-conductive portion, and the holder is formed from a metal plate.

[0025] According to the above-mentioned configuration 9, the metal plate holder can have better thermal conductivity than a resin holder, and it is not necessary to insulate between the heat conduction path portion of the board and the metal plate holder so as not to affect the electrical circuit of the circuit board, and the heat conduction path portion can be in contact with the metal plate holder. Effect of the Invention

[0026] As described above, by employing the above configuration 1, the present invention can provide a bearing device that is capable of quickly and accurately detecting temperature changes in the raceways of a rolling bearing. [Brief description of the drawings]

[0027] [Figure 1] FIG. 1 is a vertical sectional front view showing a main portion of a bearing device according to a first embodiment of the present invention; [Diagram 2] An enlarged view of the sensor unit and its surroundings in Figure 1. [Diagram 3] FIG. 2 is a perspective view showing the bearing device of FIG. [Figure 4] FIG. 2 is a side view showing the bearing device of FIG. 1 with a cover partially cut away; [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 an assembly stage of the sensor unit of FIG. 1; [Figure 7] FIG. 11 is a longitudinal sectional front view showing a main portion of a bearing device according to a second embodiment of the present invention; [Figure 8] 13 is a side view of the temperature sensor according to the third embodiment; [Figure 9] FIG. 13 is a longitudinal sectional front view showing the vicinity of a temperature sensor of a bearing device according to a third embodiment; [Figure 10] Side view of the temperature sensor in Figure 9 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] 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 to 6. FIG.

[0029] As shown in FIGS. 1 to 3, the bearing device includes a rolling bearing 1, a sensor unit 2, and a generator 3. The rolling bearing 1 has a cylindrical shape and a cylindrical surface.

[0030] Here, the circumferential direction centered on the central axis of the rolling bearing 1 (not shown) is referred to as the "circumferential direction," the direction along the central axis of the bearing is referred to as the "axial direction," and the direction perpendicular to the central axis of the bearing is referred to as the "radial direction." In Figures 1 and 2, the axial direction corresponds to the left-right direction, and the radial direction corresponds to the up-down direction.

[0031] 1, the rolling bearing 1 has a first raceway 4, a second raceway 5, and a plurality of rolling elements 6 arranged between the first raceway 4 and the second raceway 5. These rolling elements 6 are held at equal intervals in the circumferential direction by a cage 7.

[0032] The sensor unit 2 is a unit in which a circuit board 8 and a holder 9 for holding the circuit board 8 are integrated together.

[0033] The circuit board 8 has a temperature sensor 10 .

[0034] The holder 9 has an annular side portion 11 extending in the radial direction and a fitting portion 12 protruding from the annular side portion 11 in the axial direction.

[0035] The generator 3 consists of a magnetic ring 13 arranged so as to be rotatable integrally with the second raceway 5, and a stator 14 facing the magnetic ring 13, and the relative rotational motion between the first raceway 4 and the second raceway 5 is electromagnetically converted into alternating current by the magnetic ring 13 and the stator 14.

[0036] The rolling bearing 1 is a radial bearing. The rolling bearing 1 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 standard or the JIS standard. For example, the dimensions of radial bearings other than tapered roller bearings are specified in ISO15 or JIS B 1512-1.

[0037] Although the rolling bearing 1 is configured as a deep groove ball bearing in the above example, the rolling bearing 1 is not limited to a deep groove ball bearing.

[0038] The sensor unit 2 is fixed to the first bearing ring 4 .

[0039] The first bearing ring 4 is usually arranged as a stationary ring, and the second bearing ring 5 is usually arranged as a rotating ring.

[0040] The first raceway 4 is an outer ring having an inner circumference 16 including a first raceway surface portion 15. The second raceway 5 is an inner ring having an outer circumference including a second raceway surface portion 17. Each rolling element 6 is a ball that rolls between the raceway surface portions 15, 17. The raceway surface portions 15, 17 are the surfaces of the raceways 4, 5 that form the rolling path of the rolling elements 6, and in the illustrated example, are continuous around the entire circumferential direction with a cross-sectional shape that forms a raceway groove corresponding to the ball diameter of the rolling elements 6.

[0041] A predetermined distance is ensured between the rolling elements 6, the cage 7, and the sensor unit 2. This distance is set so that the sensor unit 2 will not come into contact with the rolling elements 6 and the cage 7 even if there is axial displacement due to the internal bearing gap of the rolling bearing 1. The cage 7 is a crown-shaped cage that has a ring portion only on the side opposite the sensor unit 2 (the side going away from the sensor unit 2, the left side in Figure 1) with respect to each rolling element 6. To avoid interference between the sensor unit 2 and the cage 7, the cage 7 has no portion that is closer to the sensor unit 2 than the rolling elements 6. The sensor unit 2 has no portion that protrudes from the rolling bearing 1 in the axial direction.

[0042] The inner circumference 16 of the first race 4 includes a step portion 18 that axially receives the annular side portion 11 of the holder 9, and a peripheral surface portion 19 that fits with the fitting portion 12 of the holder 9. The step portion 18 extends in the radial direction over the entire circumferential direction. The step portion 18 and the peripheral surface portion 19 form a cylindrical surface that extends in the circumferential direction.

[0043] 1 and 2, the first raceway ring 4 has a width surface portion 20 located at one end of the axial width of the first raceway ring 4 (the right end in FIGS. 1 and 2). The width surface portion 20 is aligned along the radial direction. The step portion 18 and the peripheral surface portion 19 are formed at a position closer to the first raceway surface portion 15 in the axial direction than the width surface portion 20 is.

[0044] The step portion 18 faces the first raceway surface portion 15 in the axial direction.

[0045] The peripheral surface portion 19 intersects with the step portion 18 at the other axial end of the peripheral surface portion 19 (the left end in Figs. 1 and 2).

[0046] In addition, the inner circumference 16 of the first raceway 4 may include at least one of a recessed portion between the step portion 18 and the circumferential surface portion 19 to facilitate processing, and a chamfered portion that removes the corners between the circumferential surface portion 19 and the width surface portion 20.

[0047] The holder 9 is an annular body that, when attached to the first bearing ring 4 , determines a predetermined position of the circuit board 8 relative to the first bearing ring 4 .

[0048] The entire holder 9 is formed from a single metal plate, and has a seamless, integral annular side portion 11 and a fitting portion 12. The entire holder 9 is formed by press working.

[0049] The annular side portion 11 is in the shape of an annular plate having both side surfaces 21, 22 extending along the radial direction over the entire circumference in the circumferential direction. The fitting portion 12 extends along the axial direction from the end portion of the annular side portion 11 that is closer to the first race 4.

[0050] The fitting portion 12 is fitted to a peripheral surface portion 19 of the first bearing ring 4. As a result, the holder 9 is disposed coaxially with the first bearing ring 4.

[0051] A side surface 21 of the annular side portion 11 on the rolling element 6 side (the side closer to the rolling element 6, the left side in FIG. 2) is butted against the step portion 18 of the first raceway 4 in the axial direction. This brings the side surface 21 of the annular side portion 11 on the rolling element 6 side into axial contact with the step portion 18. The step portion 18 properly determines the axial positional relationship between the fitted sensor unit 2 and the first raceway 4, and also restricts the sensor unit 2 from falling in the radial direction.

[0052] A side surface 22 of the annular side portion 11 on the reversible moving body 6 side (the side farther from the rolling body 6, the right side in FIG. 2) serves as a surface portion that supports the circuit board 8 in the axial direction.

[0053] As shown in Figures 2, 4 and 5, the circuit board 8 is a printed circuit board including a substrate 23, a temperature sensor 10 mounted on the substrate 23, a wireless communication circuit 24 mounted on the substrate 23, a power supply circuit 25 mounted on the substrate 23, and one or more other sensors 26 mounted on the substrate 23.

[0054] The substrate 23 is made of a printed wiring board and has an arc-shaped plate shape that is short in the radial direction and long in the circumferential direction.

[0055] As shown in Figures 1 and 2, both surfaces of the substrate 23 are oriented in the axial direction. Therefore, the thickness direction of the substrate 23, which is the direction that defines the plate thickness between both surfaces of the substrate 23, corresponds to the axial direction (the left-right direction in Figures 1 and 2). The temperature sensor 10, the wireless communication circuit 24, the power supply circuit 25, and one or more other sensors 26 are each mounted on one surface of the substrate 23. This one surface of the substrate 23 is the one surface on the side of the reversing body 6 of the substrate 23 (the right side in Figures 1 and 2).

[0056] The substrate 23 has a back surface 23a located on the other side (the left side in Figs. 1 and 2) opposite to the aforementioned one surface on which the temperature sensor 10 etc. are mounted, and in contact with the side surface 22 on the reversible body 6 side of the annular side portion 11. The back surface 23a of the substrate 23 includes at least a portion of the other surface of the substrate 23 that faces the temperature sensor 10 in the thickness direction of the substrate 23 (the left-right direction in Figs. 1 and 2). In other words, the temperature sensor 10 is located on a front surface 23b that faces the back surface 23a in the thickness direction of the substrate 23 on the one surface on which the substrate 23 is mounted.

[0057] The back surface portion 23a and the front surface portion 23b of the substrate 23 are disposed at positions facing the first raceway surface portion 15 in the axial direction.

[0058] 4 and 5, the substrate 23 is fixed to the annular side portion 11 by a plurality of screws 27. As a result, the back surface 23a of the substrate 23 is fastened in the axial direction to the side surface 22 of the annular side portion 11 on the side of the reversible moving body 6, and is in contact with the side surface 22 without any gaps.

[0059] The temperature sensor 10 includes a circuit that converts temperature into an electrical signal, and is made of an electronic component (SMD) surface-mounted on one surface of the substrate 23. Pads P1 and P2 of both electrodes are formed on the surface portion 23b of the substrate 23, as shown in Fig. 4. The temperature sensor 10 is soldered to the pads P1 and P2.

[0060] 1 and 2, the temperature sensor 10 is disposed at a position axially facing the first raceway surface portion 15. The entire temperature sensor 10 is disposed at a position radially facing the fitting portion 12 of the holder 9 and the peripheral surface portion 19 of the first race 4.

[0061] The substrate 23 has a heat conductive path 28 that continues from the back surface 23a to the front surface 23b. The heat conductive path 28 is formed of a penetrating metal portion 28a that penetrates in the thickness direction of the substrate 23 (the left-right direction in FIG. 2) from the back surface 23a to one surface (front surface 23b) of the substrate 23, a rear-side metal foil portion 28b disposed on the back surface 23a, and a front-side metal foil portion 28c disposed on the front surface 23b.

[0062] The heat conduction path portion 28 is provided in the form of a through hole. That is, the penetrating metal portion 28a is hollow and forms the inner surface of a hole penetrating the substrate 23 in the thickness direction (left-right direction in FIG. 2). The metal foil portion 28b on the back side is not covered with the resist of the substrate 23 and extends from the penetrating metal portion 28a. The metal foil portion 28c on the front side is not covered with the resist of the substrate 23 and extends from the penetrating metal portion 28a.

[0063] The back-side metal foil portion 28b and the penetrating metal portion 28a form the same plane on the back surface 23a, and are in contact with the side surface 22 on the reversible body 6 side of the annular side portion 11. The front-side metal foil portion 28c and the penetrating metal portion 28a form the same plane on the front surface portion 23b, and are opposed to the temperature sensor 10 in the axial direction, and are preferably in contact with the temperature sensor 10 in the axial direction.

[0064] As described above, the heat conductive path portion 28 is provided in the form of a through hole in the substrate 23, but is not used for soldering the temperature sensor 10, does not belong to the circuit pattern formed on the substrate 23, and is not an element constituting the electric circuit of the circuit board 8. In other words, the heat conductive path portion 28 is an electrically non-conductive portion. Therefore, even if the heat conductive path portion 28 is brought into contact with the holder 9 or the temperature sensor 10 made of a metal plate, it does not adversely affect the electric circuit of the circuit board 8.

[0065] The heat conductive path portion 28 may be made of a metal having excellent thermal conductivity, but is preferably made of copper. In a printed wiring board, a circuit pattern including a through hole is generally formed using a copper foil or copper plating layer having a thickness of 18 μm to 70 μm. Therefore, if a through-hole-shaped heat conductive path portion 28 is used, a printed wiring board provided with the heat conductive path portion 28 by a general processing technique can be used as the substrate 23.

[0066] The entire heat conduction path portion 28 is disposed at a position facing the temperature sensor 10, the first raceway surface portion 15, and the step portion 18 in the axial direction. That is, a heat conduction path is provided that is continuous in the axial direction from the first raceway surface portion 15 to the substrate 23, preferably to the temperature sensor 10. In this heat conduction path, the path portion from the first raceway surface portion 15 to the step portion 18 is made of an iron-based metal such as the bearing steel that forms the first race 4, and therefore has good heat conductivity. In addition, the path portion from the step portion 18 to the side surface 22 of the annular side portion 11 on the side of the reversible body 6 is also made of metal, and therefore has good heat conductivity. In addition, since the penetrating metal portion 28a and the metal foil portion 28b on the back side are present at the contact portion between the side surface 22 of the annular side portion 11 on the side of the reversible body 6 and the back surface portion 23a of the substrate 23, this contact portion also has good heat conductivity. In addition, since the path portion from the penetrating metal portion 28a to the surface portion 23b of the substrate 23 is also made of metal, it has good heat conductivity. The path from the surface portion 23b of the substrate 23 to the temperature sensor 10 surface-mounted on this surface portion 23b has good thermal conductivity because the surface portion 23b has the penetrating metal portion 28a and the front-side metal foil portion 28c.

[0067] The rolling bearing 1 generates heat as it rotates. One of the main causes of this heat generation is heat generated at the contact portion between the rolling element 6 and the first raceway ring 4. This heat is transferred from the first raceway surface portion 15 through the step portion 18, the annular side portion 11 of the holder 9, and the board 23 of the circuit board 8 (particularly the back surface portion 23a, the front surface portion 23b, and the heat conduction path portion 28) to the temperature sensor 10 by the phenomenon of thermal conduction. Therefore, the temperature sensor 10 can detect the temperature change of the first raceway ring 4. At this time, the side surface 21 of the annular side portion 11 on the rolling element 6 side is supported in the axial direction by the step portion 18 close to the first raceway surface portion 15, the back surface portion 23a of the board 23 is brought into contact with the side surface 22 of the annular side portion 11 on the reversible moving body 6 side, and the temperature sensor 10 is surface-mounted on the front surface portion 23b of the board 23. Therefore, the heat of the first raceway surface portion 15 is transferred to the board 23 and the temperature sensor 10 in the axial direction via a particularly short heat conduction path. Therefore, the heat mentioned above reaches the temperature sensor 10 more quickly than when a space is formed between the step 18 of the first raceway 4 and the circuit board 8, or between the step 18 and the temperature sensor 10, making it possible to detect temperature changes in the first raceway 4 quickly and accurately.

[0068] The technical significance of axially opposing the temperature sensor 10 to the first raceway surface portion 15 is to shorten the path of heat conduction between the first raceway surface portion 15 and the temperature sensor 10 in the axial direction in order to reduce delays in temperature detection and improve accuracy. Therefore, although it is of course preferable to axially oppose the entire temperature sensor 10 to the first raceway surface portion 15, it is considered effective in achieving the above-mentioned objective if at least the temperature sensing portion (circuit portion that converts temperature into an analog electrical signal) of the temperature sensor 10 is axially opposed to the first raceway surface portion 15 and the surface portion 23b of the substrate 23.

[0069] The one or more other sensors 26 are made of a circuit that converts a physical quantity or a chemical quantity other than temperature into an electric signal. The type of the other sensor 26 is not particularly limited. For example, at least one of a group consisting of an acceleration sensor and an AE (Acoustic Emission) sensor is included in the one or more other sensors 26. When an acceleration sensor is used, it is possible to detect radial or axial acceleration for monitoring vibration of the rolling bearing 1. When an AE sensor is used, it is possible to detect elastic waves when sound generated when a part of an object such as a component of the rolling bearing 1 is deformed or broken or when an impact is applied is emitted as an elastic wave (AE wave).

[0070] In addition, electronic components including a temperature sensor and an acceleration sensor may be adopted and placed in the virtual projection area A.

[0071] The wireless communication circuit 24 shown in Figures 4 and 5 is composed of a communication circuit that converts predetermined information, such as the results of detection by the temperature sensor 10 and one or more other sensors 26, into radio waves and radiates them from an antenna. The wireless communication circuit 24 complies with a predetermined communication protocol and is generally modular. To avoid a decrease in wireless communication performance, the antenna of the wireless communication circuit 24 is not in contact with other members, such as a sealant.

[0072] The power supply circuit 25 is a circuit that converts the AC power generated by the stator 14 of the generator 3 into DC power used on the circuit board 8 .

[0073] The magnetic ring 13 shown in FIG. 1 has a magnet 29 magnetized with alternating north and south poles in the circumferential direction, and a core metal 30, as shown in FIGS. 2 and 4. The magnet 29 is formed of magnetic rubber extending in the circumferential direction. The magnet 29 is bonded to the core metal 30 all around in the circumferential direction. Vulcanization bonding can be used as the bonding method. The core metal 30 has a flange portion for increasing its rigidity. Although the magnet 29 is exemplified by a magnetic material magnetized with multiple poles, it may be composed of a plurality of permanent magnets.

[0074] 1, the magnetic ring 13 is fixed to the stepped end 31 of the second raceway 5 so as not to protrude from the second raceway 5 in the axial direction. By fitting the magnetic ring 13 to the stepped end 31 of the second raceway 5, the second raceway 5 and the magnetic ring 13 are arranged coaxially. The stepped end 31 of the second raceway 5 is a portion for securing an annular space capable of accommodating the sensor unit 2 and the magnetic ring 13 between the circumferential surface portion 19 of the first raceway 4 and the second raceway 5, and has a shape that radially expands the space between the circumferential surface portion 19 and the end of the second raceway 5 that faces the stepped end 31 in the radial direction.

[0075] 1 and 2 guides the magnetic flux emitted from the magnetic ring 13 with a yoke structure, and induces an AC voltage in the coil 32 within the yoke structure. The stator 14 is provided in the sensor unit 2.

[0076] The yoke structure of the stator 14 is made up of a holder 9 and a yoke member 33 combined with annular side portion 11 of the holder 9, as shown in FIGS.

[0077] The holder 9 and the yoke member 33 are each made of a magnetic material such as a steel plate. The yoke member 33 is formed from a single metal plate. The overall shape of the yoke member 33 is formed by press molding.

[0078] The holder 9 has a first claw pole portion 34 which is seamlessly and integrally formed and extends from the side of the annular side portion 11 opposite the mating portion 12 (the side farther from the mating portion 12, the lower side in Figure 2) to the same side as the mating portion 12 (the right side in Figure 2) in the axial direction at regular intervals in the circumferential direction.

[0079] The yoke member 33 has, integrally and seamlessly, an annular plate portion 35 radially opposed to the fitting portion 12, a side plate portion 36 extending radially from the anti-annular side portion 11 side of the annular plate portion 35 (the side farther from the annular side portion 11, the lower side in Figure 2) to the anti-fitting portion 12 side (the side farther from the annular side portion 11, the right side in Figures 2 and 5), and a second claw pole portion 37 extending axially from the side plate portion 36 at a regular interval in the circumferential direction toward the annular side portion 11 side (the left side in Figure 5).

[0080] The yoke structure of the stator 14 is formed by a first claw pole portion 34, an annular side portion 11, an annular plate portion 35, a side plate portion 36, and a second claw pole portion 37. The fitting portion 12 of the holder 9 forms the outer periphery of the sensor unit 2. The first claw pole portion 34 and the second claw pole portion 37 are located on the inner periphery of the sensor unit 2.

[0081] As shown in Figures 2 and 4, the first claw pole portion 34 and the second claw pole portion 37 face each other in the radial direction with an air gap between them and the magnet 29. The first claw pole portion 34 and the second claw pole portion 37 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 34 and the second claw pole portion 37 that are adjacent in the circumferential direction. The total number of the first claw pole portions 34 and the second claw pole portions 37 is equal to the number of poles of the magnet 29 (the total number of north poles and south poles).

[0082] As shown in Fig. 5, arc-shaped holes 38 axially penetrating the annular side portion 11 are formed at multiple locations in the circumferential direction. Protrusions 39 that fit into the inner surfaces of the holes 38 protrude in the axial direction from the annular plate portion 35. As shown in Fig. 6, the annular plate portion 35 is abutted in the axial direction against the annular side portion 11 at substantially all portions except for the areas where these protrusions 39 are present.

[0083] 2 and 5, the coil 32 is wound around a bobbin 40. The coil 32 and the bobbin 40 are arranged all around the circumference in a space surrounded by the annular side portion 11, the side plate portion 36, the annular plate portion 35, the first claw pole portion 34, and the second claw pole portion 37.

[0084] At least a portion of the surface of the coil 32 and the bobbin 40 may be in contact with the claw pole portions 34, 37, the annular side portion 11, and the side plate portion 36. When protecting the magnet wire constituting the coil 32 for the purposes of insulation, heat resistance, dust resistance, moisture resistance, and chafing prevention, a varnish treatment may be adopted in which the coil 32 is coated by dipping the coil 32 in varnish or by dripping varnish onto the coil 32. Also, the bobbin 40 may be omitted.

[0085] The magnetic flux emanating from the N pole of the magnet 29 shown in Fig. 4, for example, enters the annular side portion 11 (or side plate portion 36) from the first claw pole portion 34 (or the second claw pole portion 37), passes through the annular plate portion 35, goes around the coil 32 to the side plate portion 36 (or the annular side portion 11), and returns to the S pole of the magnet 29 via the adjacent second claw pole portion 37 (or the first claw pole portion 34). When the positions of the N pole and the S pole of the magnet 29 are interchanged with the rotation of the second race 5 relative to the first race 4, the direction of the magnetic flux is reversed. The alternating magnetic field thus generated generates an AC voltage at both ends 41, 41 of the start and end of the winding of the coil 32.

[0086] Both ends 41, 41 of the coil 32 are connected to terminals 42, 42 provided on the substrate 23 through wiring holes formed slightly in the annular plate portion 35.

[0087] In assembling the sensor unit 2, as shown in FIG. 5, the bobbin 40 around which the coil 32 is wound is placed between the annular side portion 11 of the holder 9 and the side plate portion 36 of the yoke member 33, and the holder 9 and the yoke member 33 are assembled in the axial direction, and at this time, each protrusion 39 of the yoke member 33 is inserted into the corresponding hole 38 of the annular side portion 11. This insertion ensures that the holder 9 and the yoke member 33 are coaxial with each other, and the first claw pole portion 34 and the second claw pole portion 37 are alternately arranged in a predetermined phase with a gap in the circumferential direction. Therefore, the holder 9 and the yoke member 33 can be assembled appropriately without using a jig. It is preferable that the holes 38 and the protrusions 39 are each formed in three or more places.

[0088] After this assembly, the protrusion 39 is fixed to the inner surface of the hole 38. This fixing may be performed by, for example, press fitting, bonding, laser welding, or a combination of these.

[0089] It is also possible to omit the protrusions 39 and the holes 38. In this case, after the holder and the yoke member are coaxially aligned and phase-aligned using a jig (not shown), the butting portions of the annular side portion and the annular plate portion may be bonded or laser-welded from the outer periphery of the annular plate portion, or these may be fixed using a combination of these methods.

[0090] When holder 9 and yoke member 33 are fixed in the assembled state as described above, stator 14 is completed as shown in Figures 1 and 6. Note that, although an example has been shown in which annular plate portion 35 of yoke member 33 serves as a partition between the storage space for circuit board 8 and stator 14, it is also possible to provide a partition wall separate from the annular plate portion that divides the annular side portion of the holder into two regions in the radial direction, and to place the stator on the radial inside of that partition wall.

[0091] Next, the circuit board 8 is inserted onto the annular side portion 11, and the board 23 is fixed to the annular side portion 11 using a plurality of screws 27. At this time, the back surface 23a of the board 23, which is the opposite surface to the mounting surface of the temperature sensor 10, faces the annular side portion 11. Here, as long as the back surface 23a of the board 23 and the annular side portion 11 can be brought into contact with each other in the axial direction, an insulating sheet such as a polyimide film may be interposed between the board 23 and the annular side portion 11 to insulate the holder 9 from the circuit board 8, or the board 23 and the annular side portion 11 may be fixed to each other by bonding using an adhesive, an adhesive sheet, or the like, or by a combination of bonding and screwing. It is preferable to use an adhesive, adhesive sheet, or insulating sheet with as good thermal conductivity as possible.

[0092] After the circuit board 8 is fixed to the annular side portion 11, an assembly process is performed in which the cover 43 is fitted between the fitting portion 12 and the annular plate portion 35 as shown in Figures 2 and 4. As a result, the cover 43 closes the opening between the fitting portion 12 and the annular plate portion 35 without contacting the circuit board 8, and the gap between the cover 43 and the circuit board 8 becomes filled with air. Note that there is no particular limit to the means for fixing the cover 43, but in order to improve the airtightness of the fitting portions between the cover 43 and the fitting portion 12 and between the cover 43 and the annular plate portion 35, an adhesive or a resin filler may be applied to the fitting portions.

[0093] The cover 43 is made of resin that does not contain metal. Even if the holder 9 and the yoke member 33 are made of metal, the cover 43 has radio wave permeability, so wireless communication using the antenna 24a is possible. It is also possible to seal the circuit board 8 by filling the opening between the fitting portion 12 and the annular plate portion 35 with a sealant without using the cover 43. In this case, since the antenna 24a is covered with the sealant, it is advisable to use a sealant with a low relative dielectric constant, such as a resin, to suppress shortening of the wavelength of radio waves due to the dielectric constant of the sealant.

[0094] After the cover 43 is fixed, as shown in Figures 1 and 2, the sensor unit 2 is fixed to the peripheral surface portion 19 of the first raceway 4 at the fitting portion 12. Meanwhile, the magnetic ring 13 is fixed to the outer periphery of the second raceway 5. The fixing means for them is press-fitting, bonding, or a combination of these. Since the first raceway 4 and the second raceway 5 are arranged coaxially, the sensor unit 2 and the magnetic ring 13 are also arranged coaxially.

[0095] Since the variation in the radial gap between the magnetic ring 13 fixed to the second raceway 5, which is a component of the radial bearing, and the stator 14 of the sensor unit 2 fixed to the first raceway 4, which is also a component of the radial bearing, is small, a stable amount of power can be generated by the generator 3 composed of the magnetic ring 13 and the stator 14, compared to the case where a magnetic ring is provided on the cage. Since the detection and wireless communication can be performed by the circuit board 8 using the generator 3 as a power source, the sensor unit 2 can be made wireless. Note that a storage battery may be mounted on the annular side portion 11 or the board 23 as an emergency power source. Also, the power source for making it wireless is not limited to a generator, and may be a storage battery that can be mounted on the sensor unit or a power receiving circuit of a wireless power supply device.

[0096] This bearing device (see Figures 1 and 2) is as described above and comprises a rolling bearing 1 having a first raceway 4, a second raceway 5 and a plurality of rolling elements 6 arranged between the first raceway 4 and the second raceway 5, and a sensor unit 2 having a circuit board 8 and a holder 9 for holding the circuit board 8, wherein the circuit board 8 has a substrate 23 and a temperature sensor 10 mounted on the substrate 23, the substrate 23 being attached to the holder 9, and the holder 9 being attached to the first raceway 4.

[0097] In particular, in this bearing device, since temperature sensor 10 is an electronic component surface-mounted on one side of substrate 23, back surface 23a including at least a portion facing temperature sensor 10 in the thickness direction of substrate 23 (left-right direction in FIGS. 1 and 2) on the opposite side of substrate 23 is provided flat, making it possible to bring back surface 23a into contact with holder 9, and temperature sensor 10 is located on front surface 23b located on one side of substrate 23 and facing back surface 23a in the thickness direction of substrate 23. In other words, the distance from the contact point between holder 9 and back surface 23a to front surface 23b and temperature sensor 10 can be shortened to approximately the thickness of substrate 23.

[0098] Furthermore, in this bearing device, the back surface 23a of the substrate 23 is in contact with the holder 9, and the substrate 23 has at least one of a penetrating metal portion 28a that penetrates the substrate 23 in the thickness direction from the back surface 23a to one surface of the substrate 23, a back-side metal foil portion 28b arranged on the back surface 23a, and a front-side metal foil portion 28c that is located on one surface of the substrate 23 and arranged on a surface portion 23b that faces the back surface 23a in the thickness direction of the substrate 23. Therefore, at least one of the thermal conduction between the back surface 23a and the surface portion 23b of the substrate 23, the thermal conduction between the holder 9 and the back surface 23a of the substrate 23, and the thermal conduction between the surface portion 23b of the substrate 23 and the temperature sensor 10 is improved, and the thermal conductivity from the holder 9 to the temperature sensor 10 can be improved. As a result, this bearing device allows heat generated at the contact area between the raceway surface portion 15 of the first raceway 4 (raceway) and the rolling element 6 to quickly reach the temperature sensor 10 by thermal conduction from the first raceway 4 (raceway) through the holder 9 and the substrate 23, so that temperature changes in the first raceway 4 (raceway) can be detected quickly and accurately.

[0099] Furthermore, in this bearing device, since the substrate 23 has the penetrating metal portion 28a, a heat conduction path is provided from the back surface 23a of the substrate 23 through the penetrating metal portion 28a, which has good thermal conductivity, to the front surface 23b of the substrate 23, resulting in good heat conduction between the back surface 23a and the front surface 23b of the substrate 23.

[0100] Furthermore, in this bearing device, since the substrate 23 has the metal foil portion 28b on the rear side, the thermal conduction between the holder 9 and the rear surface 23a of the substrate 23 is improved.

[0101] Furthermore, in this bearing device, since the substrate 23 has the metal foil portion 28c on the front side, the thermal conduction between the surface portion 23b of the substrate 23 and the temperature sensor 10 is improved.

[0102] Furthermore, in this bearing device, since the penetrating metal portion 28a and the metal foil portion 28b on the back side are continuous, it is possible to improve the thermal conductivity from the back surface 23a of the substrate 23 to the penetrating metal portion 28a.

[0103] Furthermore, in this bearing device, since the penetrating metal portion 28a and the metal foil portion 28c on the front side are continuous, the thermal conductivity from the penetrating metal portion 28a to the front surface portion 23b of the substrate 23 can be improved.

[0104] Furthermore, in this bearing device, the penetrating metal portion 28a is continuous with the metal foil portion 28b on the back side, and the penetrating metal portion 28a is continuous with the metal foil portion 28c on the front side, thereby improving the thermal conductivity from the back side 23a of the substrate 23 through the penetrating metal portion 28a to the front side 23b of the substrate 23.

[0105] In addition, in this bearing device, the holder 9 has an annular side portion 11 extending radially and a fitting portion 12 protruding from the annular side portion 11 in the axial direction, the first raceway ring 4 has an inner circumference 16 including a first raceway surface portion 15 (raceway surface portion), a peripheral surface portion 19 that fits with the fitting portion 12, and a step portion 18 that axially receives a side surface 21 of the annular side portion 11 on the rolling element 6 side, and the base plate 23 is disposed on a side surface 22 of the annular side portion 11 on the reversible moving element 6 side, and a back surface portion 23a of the base plate 23 is in contact with the side surface of the annular side portion on the reversible moving element side, thereby The annular side portion 11 can be positioned near the first raceway surface portion 15 (raceway surface portion), and heat can be conducted directly from the step portion 18 near the first raceway surface portion 15 (raceway surface portion) to the annular side portion 11, and then from this annular side portion 11 to the back surface portion 23a of the substrate 23.As a result, the heat conduction path from the first raceway 4 to the back surface portion 23a of the substrate 23 can be made shorter than the heat conduction path from the first raceway 4 via the fitting portion of the holder and the annular side portion to the back surface portion of the substrate as in Patent Document 1.

[0106] Furthermore, since this bearing device is arranged so that the back surface 23a of the base plate 23 is positioned axially opposite the step portion 18 of the first raceway 4, the heat conduction path between the step portion 18 of the first raceway 4 and the back surface 23a of the base plate 23 can be minimized in the axial direction.

[0107] Furthermore, in this bearing device, the first raceway surface portion 15 (raceway surface portion), the step portion 18, the back surface portion 23a of the substrate 23, and the temperature sensor 10 are arranged in opposing axial positions, so that the heat conduction path from the first raceway surface portion 15 (raceway surface portion) through the step portion 18, the annular side portion 11, and the substrate 23 to the temperature sensor 10 can be a linear path in the axial direction, and thus heat generated at the contact portion between the first raceway surface portion 15 (raceway surface portion) and the rolling element 6 can reach the temperature sensor 10 particularly quickly.

[0108] In addition, since the penetrating metal portion 28a of this bearing device is located axially opposite the temperature sensor 10, the heat conduction path from the back surface 23a of the substrate 23 via the penetrating metal portion 28a to the temperature sensor 10 can be particularly short.

[0109] Furthermore, in this bearing device, the through metal portion 28a is hollow, and the back-side metal foil portion 28b and the front-side metal foil portion 28c each extend from the through metal portion 28a, so that a printed wiring board in which the through metal portion 28a, the back-side metal foil portion 28b, and the front-side metal foil portion 28c are arranged in the form of through holes can be used as the substrate 23, and these through metal portions 28a etc. can improve the thermal conductivity from the back side 23a of the substrate 23 to the temperature sensor 10.

[0110] Furthermore, in this bearing device, the substrate 23 has a heat conduction path portion 28 including at least one of the penetrating metal portion 28a and the metal foil portion 28b on the rear side, the heat conduction path portion 28 is an electrically non-conductive portion, and the holder 9 is formed from a metal plate. This allows the metal plate holder 9 to have better thermal conductivity than a resin holder, and eliminates the need for insulation between the heat conduction path portion 28 of the substrate 23 and the metal plate holder 9 so as not to affect the electrical circuit of the circuit board 8, and allows the heat conduction path portion 28 to come into contact with the metal plate holder 9.

[0111] In this bearing device, the heat conduction path portion 28 is a through-hole, and the entire heat conduction path portion 28 faces the temperature sensor in the axial direction, but the form of the heat conduction path portion can be changed as appropriate. As an example, a second embodiment is shown in Figures 7 and 8. Note that the following will only describe the differences from the first embodiment.

[0112] The bearing device of the second embodiment omits the back side metal foil portion and the front side metal foil portion, and the heat conduction path portion of the substrate 23 is formed by a penetrating metal portion 30 that penetrates from the back side portion 23a to the front side portion 23b of the substrate 23.

[0113] The penetrating metal portion 30 is a solid portion that closes the through hole of the substrate 23. The penetrating metal portion 30 does not overlap the connection portion between the temperature sensor 10 and the pads P1 and P2, but extends from a position facing the temperature sensor 10 in the thickness direction of the substrate 23 (left and right direction in FIG. 7) to a position not facing the temperature sensor 10 in the same thickness direction as the temperature sensor 10. Therefore, the penetrating metal portion 30 extends from between the pads P1 and P2 in both directions that do not intersect with both pads P1 and P2. Here, "a position facing in the thickness direction of the substrate" refers to a position where the substrate and the temperature sensor are in contact, and "a position not facing in the thickness direction of the substrate" refers to a portion on the surface of the substrate opposite to where the temperature sensor is disposed.

[0114] In the bearing device of the second embodiment, the through metal portion 30 consists of a solid portion that blocks the through hole of the substrate 23, and therefore the cross-sectional area of ​​the through metal portion 30 is larger than that of the hollow through metal portion of the first embodiment, thereby improving the thermal conductivity of the through metal portion 30.

[0115] Furthermore, in the bearing device of the second embodiment, the penetrating metal portion 30 extends not only to a position facing the temperature sensor 10 in the thickness direction of the substrate 23 but also to a non-facing position, thereby improving the thermal conductivity between the holder 9 and the temperature sensor 10 via the penetrating metal portion 30.

[0116] A third embodiment as another example is shown in Figs.

[0117] In the bearing device according to the third embodiment, the metal foil portion 41b on the rear side and the metal foil portion 41c on the front side are expanded more greatly from the penetrating metal portion 41a than in the first embodiment.

[0118] The backside metal foil portion 41b and the frontside metal foil portion 41c each extend from a position facing the temperature sensor 10 and the substrate 23 in the thickness direction (left-right direction in FIG. 9) to a position not facing the temperature sensor 10 in the same thickness direction. In particular, the backside metal foil portion 41b extends relatively widely around the penetrating metal portion 41a because there is no need to consider the electrical environment with the pads P1 and P2. On the other hand, the frontside metal foil portion 41c extends from between the pads P1 and P2 in both directions not intersecting with both pads P1 and P2 to avoid electrical interference with the pads P1 and P2.

[0119] In the bearing device of the third embodiment, the rear-side metal foil portion 41b extends from a position facing the temperature sensor 10 and the substrate 23 in the thickness direction to a position not facing the temperature sensor 10 and the substrate 23 in the thickness direction. This improves the thermal conductivity between the holder 9 (see Figure 2; the same applies below) and the rear-side metal foil portion 41b, and ultimately improves the thermal conductivity between the holder 9 and the surface portion 23b of the substrate 23 (see Figure 2; the same applies below).

[0120] In the bearing device of the third embodiment, the metal foil portion 41c on the front side extends from a position facing the temperature sensor 10 and the substrate 23 in the thickness direction to a position not facing the temperature sensor 10 and the substrate 23 in the thickness direction, thereby improving the thermal conductivity between the penetrating metal portion 41a and the temperature sensor 10, and ultimately improving the thermal conductivity between the holder 9 and the surface portion 23b of the substrate 23.

[0121] In each of the above-mentioned embodiments, the first raceway ring is an outer ring, and the fitting portion of the holder is fitted to the circumferential surface of the inner circumference thereof. However, it is also possible to use the first raceway ring as an inner ring, and to fit the fitting portion of the holder to the circumferential surface of the outer circumference thereof. In this case, the first raceway ring has an outer circumference including a raceway surface portion, a step portion that axially receives the rolling body side of the holder, and a circumferential surface portion that fits with the fitting portion. Therefore, when the first raceway ring is an inner ring in each of the above-mentioned embodiments, it is only necessary to understand the inside and outside in the radial direction inversely, and therefore illustrations and detailed explanations of these cases are omitted. That is, in each of the above-mentioned embodiments, if the cross-sectional structures depicted in the longitudinal front views of Figures 1, 2, and 7 are rotated 180° counterclockwise to be turned upside down, and the upper side of the cross section of the first raceway ring in the upside-down view is the outer circumferential side of the inner ring, and the left side of the first raceway ring in the upside-down view is the axial one end side, then the case where the first raceway ring is an inner ring is shown.

[0122] In each of the above-described embodiments, an example has been given of a substrate having a penetrating metal portion that faces the temperature sensor in the thickness direction of the substrate, but it is also possible for the substrate not to have a penetrating metal portion and for the substrate to have one or both of a metal foil portion on the back side and a metal foil portion on the front side.

[0123] In addition, in each of the above-described embodiments, an example has been shown in which the temperature sensor, the raceway surface portion, and the step portion are positioned opposite each other in the axial direction, but the temperature sensor, the raceway surface portion, etc. do not need to be positioned opposite each other in the axial direction, and it is also possible to arrange the temperature sensor in a position that is not opposite the raceway surface portion, etc. in the axial direction.

[0124] 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]

[0125] 1. Rolling bearings 2 Sensor unit 4 First race 5 Second bearing ring 6 Rolling elements 8 Circuit Board 9 Holder 10 Temperature Sensor 11 Circular side 12 Fitting part 15 First raceway surface section (raceway surface section) 16 Inner Circumference 18 Step section 19 Peripheral part 21 Side surface of the annular portion on the rolling element side 22 Side of the annular part on the inverted moving body side 23 Substrate 23a Back part 23b Surface part 28 Heat conduction path section 28a, 30, 41a Penetrating metal part 28b, 41b Metal foil part on the back 28c, 41c Metal foil part on the front side

Claims

1. a rolling bearing having a first raceway, a second raceway, and a plurality of rolling elements disposed between the first raceway and the second raceway; a sensor unit having a circuit board and a holder for holding the circuit board; the circuit board includes a substrate and a temperature sensor mounted on the substrate; the substrate is attached to the holder; In the bearing device, the holder is attached to the first raceway, the temperature sensor is an electronic component surface-mounted on one side of the substrate, a back surface portion of the other surface of the substrate opposite to the one surface, the back surface portion including at least a portion facing the temperature sensor in a thickness direction of the substrate, is in contact with the holder; A bearing device characterized in that the substrate has at least one of a penetrating metal portion that penetrates in the thickness direction of the substrate from the back surface to one surface of the substrate, a back-side metal foil portion arranged on the back surface, and a front-side metal foil portion that is located on one surface of the substrate and faces the back surface in the thickness direction of the substrate.

2. The holder has an annular side portion extending in a radial direction and a fitting portion protruding in an axial direction from the annular side portion, the first raceway has an inner periphery or an outer periphery including a raceway surface portion, a peripheral surface portion that fits with the fitting portion, and a step portion that axially receives a side surface of the annular side portion on the rolling element side, The substrate is disposed on a side surface of the annular side portion on a side of the inverted moving body, 2. The bearing device according to claim 1, wherein the back surface of the base plate is in contact with a side surface of the annular side portion that faces the reversible moving body.

3. 3. The bearing device according to claim 2, wherein the back surface of the base plate is disposed at a position axially opposite the step of the first race.

4. 4. The bearing device according to claim 3, wherein the raceway surface portion, the step portion, the back surface portion of the base plate, and the temperature sensor are disposed in opposing positions in the axial direction.

5. The bearing device according to claim 1 , wherein the metal penetrating portion is provided at a position axially opposed to the temperature sensor.

6. A bearing device as described in any one of claims 1 to 4, wherein at least one of the rear side metal foil portion and the front side metal foil portion extends from a position facing the temperature sensor in the thickness direction of the substrate to a position not facing the temperature sensor in the thickness direction of the substrate.

7. 5. The bearing device according to claim 1, wherein the through metal portion is hollow, and the back side metal foil portion and the front side metal foil portion each extend from the through metal portion.

8. 5. The bearing device according to claim 1, wherein the through-hole metal portion is a solid portion that closes the through-hole of the substrate.

9. the substrate has a heat conduction path portion including at least one of the through metal portion and the backside metal foil portion, the heat conductive path portion is an electrically non-conductive portion, 5. The bearing device according to claim 1, wherein the holder is formed of a metal plate.

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