Bearing device

Abstract

To provide a bearing device for suppressing the deformation of both a bearing ring of a rolling bearing and a holder of a sensor unit while fixing the sensor unit to the bearing ring at their peripheral parts without fixing both of them at their peripheral parts with adhesive agent.SOLUTION: A rolling bearing 1 has a first peripheral part 12 on one of the inner and outer peripheries of a first raceway ring 4. A holder 20 of a sensor unit 2 holds a circuit board 19. The holder 20 has a second peripheral part 21 opposed to the radial direction of the first peripheral part 12. The sensor unit 2 is fixed to the first bearing ring 4 between the first peripheral part 12 and the second peripheral part 21 by pressing a fixing member 22 between the first peripheral part 12 and the second peripheral part 21.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] When the stator of a generator that supplies power to the circuit board is provided in the sensor unit, the holder may function as a yoke for the stator. Also, when detecting the vibration of a bearing, it may be preferable to arrange the holder coaxially with the raceway to detect the condition of the bearing. In such cases, the holder is made into an annular body and is fixed coaxially to the raceway. The fixing means employed is to fit the holder to one of the inner and outer circumferences of the raceway.

[0004] Also, there are cases where it is desired to increase the area of ​​the circuit board in order to improve the functionality of the sensor unit, such as by mounting an AC / DC conversion power circuit on the board, mounting a wireless communication circuit on the board, mounting multiple sensors on the board, etc. In such cases, the holder is provided with an annular side portion extending in the radial direction and a fitting peripheral portion extending in the axial direction from the raceway side of the annular side portion, and a structure is adopted in which the circuit board is attached to the annular side portion and the fitting portion is press-fitted into the raceway, thereby increasing the area of ​​the circuit board while reducing the axial width of the sensor unit.

[0005] The holder as described above is generally made of metal in order to ensure the strength to withstand press-fitting, and in particular, when the holder is to have a yoke function, it is made of an iron-based magnetic material.

[0006] For example, the sensor-equipped bearing device (bearing device) of Patent Document 1 has a yoke function given to a yoke member (holder), and is configured as a control board (circuit board) with a vibration sensor, temperature sensor, power supply circuit, wireless communication circuit, etc. mounted on a circumferentially long board, and the control board (circuit board) is attached to the side of the mounting part (annular side part) of the yoke member (holder) facing the rolling element, and the fitting part of the yoke member (holder) and the raceway are fitted and fixed with each other's cylindrical surfaces. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2003-307435 A Summary of the Invention [Problem to be solved by the invention]

[0008] When the cylindrical surfaces of the yoke member (holder) and the raceway ring are fitted and fixed together as in the sensor-equipped bearing device (bearing device) of Patent Document 1, if an adhesive is used for fixing, a degreasing process is required before bonding, which makes assembly of the bearing device complicated.

[0009] Although it is possible to fix the yoke component (holder) and raceway ring together more easily by pressing them together than by using adhesives, if the radial interference between the raceway ring and the yoke component (holder) becomes too large, it becomes difficult to press them together, and the pressure load applied during press-fitting can cause deformation of the raceway surface and the yoke component (holder), which can adversely affect the performance of the rolling bearing and sensor unit. In particular, when the yoke component (holder) is manufactured by pressing, etc., the tolerance width of the yoke component (holder) is larger than when it is machined, which increases concerns that the press-fitting process will become more difficult.

[0010] In view of the above background, the problem that this invention aims to solve is to suppress deformation of both the raceway of a rolling bearing and the holder of a sensor unit while fixing the sensor unit to the raceway between the two peripheral portions without fixing the peripheral portions of the two holders to each other with adhesive. [Means for solving the problem]

[0011] In order to solve the above problems, the present invention adopts configuration 1, which is a bearing device comprising a rolling bearing having a first raceway, a second raceway, and two or more 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 a first circumferential portion is formed on either the inner or outer periphery of the first raceway, the holder has a second circumferential portion radially opposed to the first circumferential portion, and the sensor unit is fixed to the first raceway at a position between the first circumferential portion and the second circumferential portion, and wherein the sensor unit is fixed to the first raceway by pressing a fixing member between the first circumferential portion and the second circumferential portion.

[0012] According to the above configuration 1, the sensor unit is fixed to the first raceway by pressing the fixing member between the first circumferential portion of the first raceway and the second circumferential portion of the holder, so there is no need to fix the first circumferential portion and the second circumferential portion together with an adhesive. In addition, since the fixing member presses the first circumferential portion and the second circumferential portion radially at points distributed in the circumferential direction, it is possible to suppress the pressing load at each pressing point while ensuring a predetermined holding force required to fix the sensor unit and the first raceway. In addition, it is also possible to press the fixing member by appropriately selecting the dimensions, etc. according to the size of the gap between the first circumferential portion and the second circumferential portion. As a result, it is possible to prevent the pressing load from becoming excessive at each pressing point and suppress the deformation of the first raceway and the holder of the sensor unit.

[0013] In the above configuration 1, configuration 2 can be adopted in which the fixing member is made of a hollow body elastically compressed in the radial direction between the first circumferential portion and the second circumferential portion. According to this configuration 2, it becomes easy to elastically press both circumferential portions in the radial direction with the fixing member press-fitted between the first circumferential portion and the second circumferential portion, and even if the tightening margin between the first circumferential portion and the second circumferential portion with respect to the fixing member is large, it can be absorbed by the elastic deformation of the fixing member and deformation of the first race and the holder can be suppressed.

[0014] In the above configuration 2, configuration 3 can be adopted in which the fixing member is a spring pin. According to this configuration 3, since the fixing member easily undergoes elastic deformation according to the interference between the first circumferential portion and the second circumferential portion, it becomes possible to easily press-fit even if the interference is large, which is advantageous for fixing and suppressing deformation of the first raceway, etc.

[0015] In the above configuration 3, a configuration 4 can be adopted in which the fixing member has a female threaded hole portion that can be screwed in the axial direction. According to this configuration 4, the fixing member can be removed from between the first circumferential portion and the second circumferential portion by utilizing the female threaded hole portion. This makes it possible to replace the sensor unit or reuse the sensor unit separated from the first raceway.

[0016] In any one of the above configurations 1 to 4, a configuration 5 can be adopted in which one of the first circumferential portion and the second circumferential portion has grooves extending in the axial direction at multiple locations in the circumferential direction, and the fixing member is press-fitted between the other circumferential portion opposite to the one and the groove. According to this configuration 5, the circumferential position of the fixing member can be appropriately determined by the groove.

[0017] In the above configuration 5, a configuration 6 can be adopted in which the other peripheral portion has a cylindrical surface that faces the groove in the radial direction and extends in the circumferential direction. According to this configuration 6, compared with the case where radially facing grooves are formed in both the first peripheral portion and the second peripheral portion, the cylindrical surface, which has a simple form, can be made less susceptible to large tolerances, and circumferential phase alignment of the first peripheral portion and the second peripheral portion is not required in the fitting process of the two portions.

[0018] In any one of the above configurations 1 to 6, a configuration 7 can be adopted in which the first circumferential portion and the second circumferential portion are entirely clearance-fitted to each other. According to this configuration 7, in the fitting process of the first circumferential portion and the second circumferential portion, a large pressing load such as that in the case of press-fitting cylindrical surfaces is not applied, so that deformation of the first raceway, etc. can be suppressed.

[0019] In any one of the above configurations 1 to 7, a configuration 8 can be adopted in which the fixing member is press-fitted only in a part of an axial region that faces the second circumferential portion in the radial direction. According to this configuration 8, the axial region that forms a radial interference with the fixing member can be shortened, thereby reducing the pressing load required to press-fit the fixing member between the first circumferential portion and the second circumferential portion, and suppressing deformation of the first raceway, etc.

[0020] In any one of the above configurations 1 to 8, a configuration 9 can be adopted in which the holder has an annular side portion extending radially from the second circumferential portion, the fixing members are arranged at equal intervals in the circumferential direction, and the circuit board is attached to the annular side portion in a non-contact state with the second circumferential portion. According to this configuration 9, it is possible to equalize the deformation of the holder and the first race caused by the press-fitting of the fixing member in the circumferential direction, and to avoid interference between the second circumferential portion and the circuit board, which are deformed during the press-fitting, and to prevent any effect on the performance of the sensor unit and the rolling bearing.

[0021] In any one of the above configurations 1 to 9, a configuration 10 can be adopted in which the sensor unit is disposed only in an area radially opposed to the first bearing ring.

[0022] In any one of the above configurations 1 to 10, a configuration 11 can be adopted, further comprising a generator having a magnetic ring fixed to the second raceway and a stator facing the magnetic ring, the stator being provided in the sensor unit, and the circuit board having a substrate, a sensor mounted on the substrate, a wireless communication circuit mounted on the substrate, and 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.

[0023] In the above configuration 11, a configuration 12 can be adopted in which the magnetic ring, the stator, and the circuit board are arranged to face each other only in the radial direction. Effect of the Invention

[0024] As described above, by adopting the above configuration 1, the present invention makes it possible to fix the sensor unit to the raceway of the rolling bearing and the holder of the sensor unit between the two peripheral portions without fixing the peripheral portions of the raceway of the rolling bearing and the holder of the sensor unit together with an adhesive, while suppressing deformation of both. [Brief description of the drawings]

[0025] [Figure 1] FIG. 1 is a perspective view showing a bearing device according to a first embodiment of the present invention; [Diagram 2] FIG. 2 is a perspective view showing the sensor unit and the rolling bearing in FIG. 1 in a separated state. [Diagram 3] FIG. 2 is a longitudinal sectional front view showing the bearing device of FIG. [Figure 4] Enlarged view of the sensor unit in Figure 3 [Diagram 5] FIG. 2 is a right side view showing the bearing device of FIG. 1 with a cover partially cut away. [Figure 6] FIG. 2 is an exploded perspective view of the sensor unit of FIG. 1; [Figure 7] Schematic diagram showing the clamping margin of the fixing member in Figure 1 [Figure 8] FIG. 2 is a schematic diagram showing a modification of the cross-sectional shape of the groove in FIG. 1; [Figure 9] FIG. 2 is a perspective view showing the sensor unit of FIG. 1 with the cover removed; [Figure 10] 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 11] FIG. 13 is a longitudinal sectional front view showing a main portion of a bearing device according to a third embodiment of the present invention; [Figure 12] FIG. 13 is a vertical sectional front view showing a bearing device according to a fourth embodiment of the present invention; [Figure 13] FIG. 13 is a side view similar to FIG. 5 showing the bearing device of FIG. [Figure 14] FIG. 6 is a side view similar to FIG. 5 showing a bearing device according to a fifth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] 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.

[0027] The bearing device shown in FIGS. 1 to 3 includes a rolling bearing 1, a sensor unit 2, and a generator 3. The bearing device shown in FIGS.

[0028] Here, the circumferential direction centered on the central axis of the rolling bearing 1 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".

[0029] The rolling bearing 1 has a first raceway 4, a second raceway 5, and two or more rolling elements 6 arranged between the first raceway 4 and the second raceway 5. These rolling elements 6 are held by a cage 7 at equal intervals in the circumferential direction.

[0030] The sensor unit 2 is a unit incorporating an electric circuit that detects at least one of a physical quantity and a chemical quantity related to the state of the rolling bearing 1 and outputs the detection result to a predetermined destination.

[0031] The generator 3 comprises a magnetic ring 8 arranged so as to be rotatable integrally with the second raceway 5, and a stator 9 facing the magnetic ring 8 across a magnetic gap. The relative rotational motion between the first raceway 4 and the second raceway 5 is electromagnetically converted into alternating current by the magnetic ring 8 and the stator 9.

[0032] 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.

[0033] The sensor unit 2 is fixed to the first bearing ring 4 .

[0034] 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.

[0035] As shown in Fig. 3, the first raceway 4 is an outer race having a raceway surface 10 on its inner circumference. The second raceway 5 is an inner race having a raceway surface 11 on its outer circumference. Each rolling element 6 is a ball that rolls between the raceway surfaces 10, 11.

[0036] 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.

[0037] As shown in FIG. 2, the first bearing ring 4 has a first circumferential portion 12 on its inner circumference, which faces the sensor unit 2 in the radial direction. The first circumferential portion 12 has a plurality of grooves 13 extending in the axial direction. The grooves 13 are provided at equal intervals in a plurality of locations in the circumferential direction of the first circumferential portion 12. Between each pair of grooves 13 adjacent in the circumferential direction in the first circumferential portion 12, an arc surface 14 extending in the circumferential direction is formed. The first circumferential portion 12 is made up of a plurality of grooves 13 and arc surfaces 14 that are equally spaced in the circumferential direction. It is preferable that such grooves 13 are provided in three or more locations.

[0038] As shown in Figures 2 and 4, the first raceway 4 has a width surface portion 15 located at one end of the axial width of the first raceway 4 (the right end in Figure 4), a chamfered portion 16 that removes the corner between the width surface portion 15 and the first circumferential portion 12, a step portion 17 that supports the sensor unit 2 in the axial direction, and a recessed portion 18 that is recessed in the axial direction between the step portion 17 and the first circumferential portion 12.

[0039] The chamfered portion 16 is included in the first circumferential portion 12, and is also formed at the intersection of the width surface portion 15 and the groove 13. The width surface portion 15 and the step portion 17 each have a flat surface that extends around the entire circumferential direction and in the radial direction.

[0040] The step portion 17 abuts against the side surface at the other axial end (the left end in Figure 4) of the sensor unit 2, appropriately determining the axial positional relationship between the sensor unit 2 and the first bearing ring 4 and preventing the sensor unit 2 from tilting in the radial direction.

[0041] Groove 13 extends straight from the edge intersecting with chamfered portion 16 toward the other axial end (the left end in FIG. 4). Groove 13 does not reach the region radially opposed to raceway surface 10 to avoid adverse effects on the radial load bearing capacity of first bearing ring 4. Groove 13 is therefore closed at the other axial end of groove 13 and is open toward one axial end (the right end in FIG. 4), leading directly to the outside of the bearing.

[0042] As shown in Fig. 3, a certain distance is ensured between the sensor unit 2 and the rolling elements 6. This distance is set so that the sensor unit 2 and the rolling elements 6 do not come into contact with each other 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 Fig. 3) with respect to each rolling element 6. The sensor unit 2 does not have any part that protrudes from the rolling bearing 1 in the axial direction.

[0043] 4, the recessed portion 18 forms a space for reliably avoiding interference with the sensor unit 2. It is also possible to omit the formation of the recessed portion 18.

[0044] The sensor unit 2 has a circuit board 19 and a holder 20 that holds the circuit board 19 .

[0045] The circuit board 19 is made of a printed circuit board on which the above-mentioned electric circuits are formed.

[0046] As shown in Figures 2 and 5, the holder 20 has a second circumferential portion 21 radially opposed to the first circumferential portion 12, and is fixed between the first circumferential portion 12 and the second circumferential portion 21 by pressing a plurality of fixing members 22 into the space between the first circumferential portion 12 and the second circumferential portion 21. In this fixed state, the holder 20 is made of an annular body that determines a predetermined position of the circuit board 19 relative to the first raceway 4.

[0047] The second circumferential portion 21 has a cylindrical surface 23 that faces the groove 13 of the first circumferential portion 12 in the radial direction and extends in the circumferential direction.

[0048] As shown in FIGS. 3 and 5, the holder 20 has an annular side portion 24 extending radially from the other axial end (the left end in FIG. 3) of the second circumferential portion 21.

[0049] The entire holder 20 is formed as a single unit without any seams. As shown in Fig. 6, the holder 20 is composed of a holding member 25. The holding member 25 is made of a single metal plate and is formed by pressing.

[0050] 4 and 6, the annular side portion 24 is in the shape of an annular plate extending straight in the radial direction around the entire circumferential direction. The side surface at one axial end (the right end in FIG. 4) of the annular side portion 24 forms a surface portion for supporting the circuit board 19 in the axial direction. The side surface at the other axial end (the left end in FIG. 4) of the annular side portion 24 forms a surface portion for abutting against the step portion 17 of the first race 4 in the axial direction.

[0051] As shown in FIG. 2, when the rolling bearing 1 and the sensor unit 2 are separated and the sensor unit 2 is in an independent state, the diameter of the imaginary cylindrical surface circumscribing the second circumferential portion 21 is defined as the circumscribing circle diameter D, and the diameter of the imaginary cylindrical surface inscribing the first circumferential portion 12 is defined as the inscribing circle diameter d. The circumscribing circle diameter D corresponds to the diameter of the cylindrical surface 23. The inscribing circle diameter d corresponds to the diameter of the imaginary cylindrical surface inscribing the multiple arc surfaces 14. The circumscribing circle diameter D is set smaller than the inscribing circle diameter d. This ensures a slight radial gap (not shown) between the first circumferential portion 12 and the second circumferential portion 21. In other words, the entire surfaces of the two circumferential portions 12 and 21 are loosely fitted to each other.

[0052] The sensor unit 2 does not have a portion that is provided with a diameter larger than the circumscribed circle diameter D. The sensor unit 2 shown in Fig. 1 and Fig. 3 is fixed to the first race 4 only by press-fitting a plurality of fixing members 22 between the plurality of grooves 13 of the first circumferential portion 12 and the cylindrical surface 23 of the second circumferential portion 21.

[0053] The cross-sectional shape of the groove 13 is U-shaped with the bottom of the groove facing the radial direction as shown in FIG. 7. On the other hand, the fixing member 22 is a round bar with the longitudinal direction as the axial direction. The surface portion of the fixing member 22 that contacts the groove 13 and the cylindrical surface 23 forms a cylindrical surface when the fixing member 22 is in an independent state without contacting another object (the cylindrical surface is shown by a two-dot chain line in FIG. 7). As shown by the two-dot chain line in the figure, the diameter of the cylindrical surface is larger than the radial gap g between the groove 13 and the cylindrical surface 23 and larger than the circumferential width of the groove 13. Therefore, the fixing member 22 has a circumferential interference with the groove 13 and a radial interference with the radial gap between the groove 13 and the cylindrical surface 23.

[0054] The cross-sectional shape of groove 13 is not limited to a U-shape, and may be any shape as long as it provides at least a radial tightening margin between groove 13 and second circumferential portion 21 with respect to fixed member 22 and can determine the circumferential position of fixed member 22. For example, as shown in Fig. 8, the cross-sectional shape of groove 13 may be changed to a substantially arc shape having a diameter larger than the aforementioned diameter of fixed member 22.

[0055] 2 and 4, the fixed member 22 is a hollow body having a central hole that penetrates the fixed member 22 in the axial direction. Since the fixed members 22 are press-fitted between the grooves 13 and the cylindrical surface 23 based on the aforementioned interference, each fixed member 22 is elastically compressed and deformed in the radial direction compared to when it is in an independent state, and exerts an elastic force that presses the grooves 13 and the cylindrical surface 23 in the radial direction (towards the central axis of the bearing). Therefore, each fixed member 22 is fixed between the grooves 13 and the cylindrical surface 23, and the sensor unit 2 is firmly fixed coaxially to the first race 4.

[0056] As shown in Figures 1 and 2, the fixing member 22 is a spring pin. Here, the spring pin is formed by bending a thin metal plate into a cylindrical shape and breaking it at one point around the cylindrical axis. For this reason, the fixing member 22 can be easily compressed in the pin radial direction and the pin circumferential direction, compared to a cylindrical pin that is unbroken around the cylindrical axis. Therefore, when the fixing member 22 is press-fitted into the groove 13, the fixing member 22 easily elastically deforms in the radial direction and the circumferential direction according to the interference between the groove 13 and the cylindrical surface 23, and exerts spring elasticity in these directions, making it easy to press-fit.

[0057] In this bearing device, as shown in Figs. 2 and 4, the grooves 13 and the fixing members 22 are arranged at three equal intervals in the circumferential direction as described above, but the present invention is not limited thereto. By appropriately selecting the dimensions (radial length, circumferential length, diameter, etc.), cross-sectional shape (solid, hollow, round, square, etc.), total axial length, and material (metal, resin, spring steel, etc.) of each fixing member 22, it is possible to adjust the elastic force exerted by each fixing member 22 pressed between the first circumferential portion 12 and the second circumferential portion 21. In addition, by selecting the number of fixing members 22 and the circumferential arrangement, it is possible to adjust the holding force of the sensor unit 2 against the first raceway 4 (static friction force obtained at the contact portion between the first raceway 12 and the second raceway 21 and the multiple fixing members 22). Therefore, it is possible to suppress deformation of the first raceway 4 (particularly the raceway surface 10) and the sensor unit 2 (particularly the holder 20) by selecting each fixing member 22 so that the elastic force and holding force of each fixing member 22 described above are not excessive. For example, on the premise that a holding force of a predetermined level or more is ensured, the deformation of the track surface 10 must be within a predetermined range, and the distortion or tilt of the holder 20 of the sensor unit 2 must be within a predetermined range.

[0058] The first circumferential portion 12 is formed on the first raceway 4 by machining. Therefore, the dimensional tolerance of the inscribed circle diameter d shown in FIG. 2 is relatively small. On the other hand, since the holder 20 is made of the retaining member 25 which is a press-formed product, it is difficult to control the dimensional tolerance of the circumscribed circle diameter D of the second circumferential portion 21 to be smaller than that in the case of machining. From the viewpoint of reducing the tolerance of the radial gap between the first circumferential portion 12 and the second circumferential portion 21, it is preferable to form the groove 13 on the first circumferential portion 12 by machining and to make the surface shape of the second circumferential portion 21 facing the groove 13 a simple cylindrical surface 23.

[0059] In addition, in order to guide the fixing member 22 in the axial direction when the fixing member 22 is initially inserted between the groove 13 and the cylindrical surface 23, the corners on the other axial end (the left end in Figure 4) of the fixing member 22 and the corners on the one axial end (the right end in Figure 4) of the second peripheral portion 21 are also chamfered.

[0060] As shown in FIG. 6, the aforementioned circuit board 19 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.

[0061] 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 4 and 5, the substrate 26 is fixed at a position radially away from the second circumferential portion 21. Sensors 27, 28, a wireless communication circuit 29, etc. are mounted on the substrate surface on one axial end side of the substrate 26 (the right end in Figure 4).

[0062] 6 and 9, the substrate 26 is fixed to the annular side portion 24 by a plurality of screws 31. It is also possible to fix the substrate 26 and the annular side portion 24 by adhesion using an adhesive, an adhesive sheet, or the like.

[0063] The sensors 27 and 28 each consist 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 rolling bearing 1. The sensor 28 is, for example, a temperature sensor to monitor the temperature of the rolling bearing 1.

[0064] 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.

[0065] The power supply circuit 30 is a circuit that converts AC power generated by the stator 9 as the magnetic ring 8 shown in FIGS. 1 and 3 rotates into DC power used by the circuit board 19 .

[0066] The magnetic ring 8 is a rotor that generates a rotating magnetic field for the stator 9. The magnetic ring 8 is fixed to the second race 5.

[0067] As shown in Figures 4 and 5, the magnetic ring 8 has a magnet 33 magnetized with alternating north and south poles 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 to increase its rigidity.

[0068] The magnetic ring 8 shown in Fig. 3 is fixed to the outer periphery of the second raceway 5. The fixing means is press-fitting, adhesive bonding, or a combination of both. A notch 35 that is recessed in the axial and radial directions is formed around the entire periphery of the outer periphery of the second raceway 5 at one axial end (the right end in Fig. 3). The flange portion of the magnetic ring 8 is contained within the area radially opposed to the notch 35, and the magnetic ring 8 does not have a portion that protrudes axially from the rolling bearing 1.

[0069] Stator 9 is a stator that guides the magnetic flux emitted from magnetic ring 8 with a yoke structure and induces an AC voltage in coil 36 shown in Fig. 4 within the yoke structure. As shown in Figs. 3 and 5, stator 9 is provided in sensor unit 2 so as to face magnetic ring 8 with an air gap therebetween. The yoke structure is composed of holding member 25 and yoke member 37 combined with holding member 25, as shown in Figs. 4 to 6.

[0070] In order to allow the holding member 25 and the yoke member 37 to function as a yoke, the holding member 25 and the yoke member 37 are each made of a magnetic material such as a steel plate.

[0071] The retaining member 25 has an extended side portion 38 extending radially from the annular side portion 24 toward the second raceway 5, and a first claw pole portion 39 extending from the extended side portion 38 toward one axial end side (the right side in Figure 4) at a regular interval in the circumferential direction, which are integrally formed without any seams.

[0072] The yoke member 37 has, seamlessly and integrally, an annular portion 40 facing the second circumferential portion 21 at a radial distance, a side circumferential portion 41 extending radially from one axial end portion (the right end portion in FIG. 4) of the annular portion 40 toward the second race 5, and a second claw pole portion 42 extending circumferentially from the side circumferential portion 41 toward the other axial end portion (the left side portion in FIG. 4) at a constant interval. The overall shape of the yoke member 37 is formed by press molding.

[0073] As shown in Fig. 4 and Fig. 5, the first claw pole portion 39 and the second claw pole portion 42 face each other in the radial direction with an air gap between them and the magnet 33. As shown in Fig. 6, the first claw pole portion 39 and the second claw pole portion 42 are arranged in opposite directions in the axial direction and alternately arranged in the circumferential direction. A circumferential air gap is formed between the first claw pole portion 39 and the second claw pole portion 42 that are adjacent in the circumferential direction. The total number of the first claw pole portions 39 and the second claw pole portions 42 is equal to the number of poles (the total number of N poles and S poles) of the magnet 33 shown in Fig. 1.

[0074] As shown in Fig. 6, arc-shaped holes 43 penetrating between both side surfaces of the retaining member 25 are formed at multiple locations in the circumferential direction. The annular portion 40 has protrusions 44 that fit into the inner surfaces of the holes 42. As shown in Figs. 4 and 9, most of the annular portion 40, except for the protrusions 44, is abutted against the extended side portion 38 in the axial direction.

[0075] As shown in Fig. 6, the coil 36 is wound around a bobbin 45. As is clear from Figs. 4, 6 and 9, the coil 36 and the like are arranged all around the circumference in the space surrounded by the extended side portion 38, the peripheral side portion 41, the annular portion 40, the first claw pole portion 39 and the second claw pole portion 42.

[0076] At least a portion of the surface of the coil 36 and the bobbin 45 may be in contact with the claw pole portions 39, 41, the extended side portion 38, and the peripheral side portion 41. When protecting the coil 36 for the purposes of insulation, heat resistance, dust resistance, moisture resistance, and chafing prevention, a varnish treatment may be employed in which the coil 36 is immersed in varnish or coated by dripping varnish onto the coil 36. Also, the bobbin 45 may be omitted.

[0077] The magnetic flux from the N pole of the magnet 33 shown in FIG. 4 and FIG. 5, for example, enters the extended side portion 38 (or the circumferential side portion 41) from the first claw pole portion 39 (or the second claw pole portion 42) which is a magnetic pole, goes around the coil 36 to reach the circumferential side portion 41 (or the extended side portion 38) via the annular portion 40, and returns to the S pole of the magnet 33 via the adjacent second claw pole portion 42 (or the first claw pole portion 39). When the positions of the N pole and the S pole of the magnet 33 are exchanged with the relative rotation of the first race 4 and the second race 5, 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 36. Although a radial type claw pole type generator has been exemplified as the generator 3, it is possible to change to another type of generator.

[0078] As shown in Fig. 9, the annular side portion 24, the second peripheral portion 21, and the annular portion 40 form an opening for accommodating the circuit board 19. This opening is closed by a cover 46 as shown in Figs. 1 and 4. The cover 46 is fixed to the circuit board 19 in a non-contact state. The internal space between the cover 46 and the circuit board 19 is filled with air. The spaces between the cover 46 and the second peripheral portion 21 and between the cover 46 and the annular portion 40 may be sealed with a sealant, respectively.

[0079] The cover 46 is made of resin that does not contain metal. Even if the holding member 25 and the yoke member 37 shown in FIG. 6 are made of metal, the cover 46 shown in FIG. 1 and FIG. 4 has radio wave transparency, so wireless communication using the antenna 32 shown in FIG. 9 is possible. The cover 46 may be made of metal, and a part of the area facing the antenna 32 may be made of non-metal (for example, resin). It is also possible to seal the circuit board 19 by filling the above-mentioned opening with a sealant without using the cover 46 shown in FIG. 4. In this case, the antenna 32 shown in FIG. 9 is covered with the sealant, so it is preferable to use a sealant with a small relative dielectric constant, such as a resin, to suppress the deterioration of the radio wave characteristics of the antenna 32 due to the sealant.

[0080] When the circuit board 19 is covered with a cover 46 as shown in Figure 4 and the antenna 32 shown in Figure 9 is put in a state of no contact with other members, it is possible to obtain good radio wave characteristics of the antenna 32. In this case, when the vibration caused by the rolling bearing 1 is detected by the sensor 27, the sensor 27 is not in contact with other members such as a sealant, so that the vibration can be easily detected accurately by the sensor 27.

[0081] Both ends of the coil 36 are connected to terminals 47 provided on the substrate 26 through small wiring holes formed in the annular portion 40. The input end of the power supply circuit 30 is the terminal 47. The power sources for the sensors 27, 28 and the wireless communication circuit 29 are each the output end of the power supply circuit 30. This bearing device is capable of performing detection and wireless communication by the circuit board 19 using the generator 3 as a power source, so that the sensor unit 2 can be made wireless. An emergency battery may be mounted on the substrate 26.

[0082] In assembling the sensor unit 4, as shown in FIG. 6, the bobbin 45 around which the coil 36 is wound is placed between the extended side portion 38 and the peripheral side portion 41, and the holding member 25 and the yoke member 37 are assembled in the axial direction, and at this time, each protrusion 44 of the yoke member 37 is inserted into the corresponding hole 43 of the holding member 25. This insertion ensures that the holding member 25 and the yoke member 37 are coaxial with each other, and the first claw pole portion 39 and the second claw pole portion 42 are arranged alternately in a predetermined phase with a gap in the circumferential direction. Therefore, the holding member 25 and the yoke member 37 can be assembled appropriately without using a jig. It is preferable that the holes 43 and the protrusions 44 are each formed in three or more places.

[0083] After this assembly, protrusion 44 is fixed to the inner surface of hole 43. This fixing means may be, for example, press-fitting, bonding, laser welding, or a combination of these. It is also possible to omit protrusion 44 and hole 43. In this case, after coaxial alignment and phase alignment of holding member 25 and yoke member 37 are performed using a jig (not shown), annular portion 40 of yoke member 37 and the butting portion of holding member 25 may be bonded, or laser welded from the outer periphery of annular portion 40, or a combination of these may be used for fixing.

[0084] After the holding member 25 and the yoke member 37 are combined as described above, a process for mounting the circuit board 19 is performed as shown in Fig. 9. Here, the circuit board 19 is fixed onto the annular side portion 24 using a plurality of screws 31. At this time, the board surface opposite the mounting surface for electronic components such as the sensor 27 faces the annular side portion 24. To insulate the holding member 25 and the circuit board 19 shown in Fig. 6 from each other, an insulating sheet such as a polyimide film (not shown) may be interposed between the circuit board 19 and the annular side portion 24.

[0085] After the circuit board 19 is fixed onto the annular side portion 24 as shown in Fig. 9, a sealing process is performed to protect the circuit board 19. Here, as shown in Figs. 1 and 4, the outer periphery of the cover 46 is fitted onto the inner periphery of the second circumferential portion 21, and the inner periphery of the cover 46 is fitted onto the outer periphery of the annular portion 40. There is no particular limit to the means for fixing the cover 46, but an adhesive, for example, can be used as the fixing means.

[0086] When the sealing of the circuit board 19 is completed, the sensor unit 2 is assembled and can be fixed to the first race 4, as shown in FIG. 2. In this state, the sensor unit 2 and the first race 4 are arranged coaxially, and a fitting process is performed in which the first circumferential portion 12 of the first race 4 and the second circumferential portion 21 of the sensor unit 2 are inserted into each other in the axial direction. Here, the fitting process is completed when the annular side portion 24 abuts against the step portion 17 in the axial direction as shown in FIG. 4, whereby the axial position of the sensor unit 2 relative to the first race 4 is determined at a predetermined position, and the first race 4 and the sensor unit 2 are arranged approximately coaxially. In this fitting process, the first circumferential portion 12 and the second circumferential portion 21 are loosely fitted to each other, and the sensor unit 2 is not press-fitted into the first race 4, so that the first race 4 and the sensor unit 2 do not suffer from deformation problems.

[0087] As shown in Figures 1, 3 and 4, after the fitting step, a press-fitting step is performed in which fixing members 22 are axially inserted between each groove 13 of the first circumferential portion 12 and the cylindrical surface 23 of the second circumferential portion 21. Here, for each fixing member 22, a member having dimensions such as a diameter appropriate for the radial gap g (see Figure 8) between the groove 13 to be inserted and the cylindrical surface 23 and capable of exerting an elastic force within a predetermined range can be adopted. When this press-fitting step is completed, the above-mentioned predetermined holding force can be obtained between the first circumferential portion 12 and the second circumferential portion 21 without fixing them to each other with an adhesive, and the sensor unit 2 can be firmly fixed to the first race 4.

[0088] In this press-fitting step, since the fixing member 22 is made of a hollow body as described above, the fixing member 22 can be easily compressed and deformed by the amount of interference with the radial gap g described above during press-fitting, thereby exerting elastic force. Therefore, the fixing member 22 can be easily press-fitted, and even if the interference between the first circumferential portion 12 and the second circumferential portion 21 with respect to the fixing member 22 is large, it can be absorbed by the elastic deformation of the fixing member 22 and deformation of the first race 4 and the holder 20 can be suppressed.

[0089] In this press-fitting step, since the fixing members 22 are easily pressed in, the pressing load required for the press-fitting is not as large as that required for pressing cylindrical surfaces together, but if the fixing members 22 are pressed in one by one, or if two or more fixing members 22 are pressed in simultaneously and unevenly spaced in the circumferential direction, a pressing load that is uneven in the circumferential direction acts on the first circumferential portion 12 and the second circumferential portion 21, which may cause eccentricity or inclination of the sensor unit 2 relative to the first race 4. In order to prevent this and to complete the press-fitting step in one go, it is preferable to press-fit all of the fixing members 22 between the multiple grooves 13 and the cylindrical surface 23 simultaneously.

[0090] In this way, the fitting process and the press-fitting process can be performed without applying an excessive pressing load between the first circumferential portion 12 of the first race 4 and the second circumferential portion 21 of the sensor unit 2, and even if the dimensional tolerance of the holder 20 is larger than that of a machined product, deformation of the first race 4 and the sensor unit 2 is suppressed. In other words, adverse effects on the performance of the rolling bearing 1 and the sensor unit 2 are suppressed. For example, it is possible to prevent adverse effects such as the raceway surface 10 of the first race 4 being distorted and deforming, shortening the life of the rolling bearing 1 from the rated life, increasing the operating noise of the rolling bearing 1, and deforming the holder 20 of the sensor unit 2, reducing the detection accuracy of the sensors 27 and 28.

[0091] When the sensor unit 2 and the first race 4 are fixed between the first circumferential portion 12 and the second circumferential portion 21 by the press-fitting process, the sensor unit 2 and the first race 4 are arranged more coaxially than in the fitting process. Then, the first race 4 and the second race 5 constitute the rolling bearing 1, so that the sensor unit 2 is also arranged coaxially with the second race 5.

[0092] In the ring-shaped space radially sandwiched between the first raceway 4 and the second raceway 5, the circuit board 19, the stator 9, and the magnetic ring 8 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. This makes it possible to provide a bearing device of the same size as the rolling bearing 1 configured as a standard bearing.

[0093] In addition, since the radial gap fluctuation between the magnetic ring 8 fixed to the second raceway 5 of the radial bearing and the stator 9 of the sensor unit 2 similarly fixed to the first raceway 4 is small, a stable amount of power generation can be ensured by the generator 3.

[0094] This bearing device (see Figures 1, 3, and 8) is as described above, and comprises a rolling bearing 1 having a first raceway 4, a second raceway 5, and two or more rolling elements 6 arranged between the first raceway 4 and the second raceway 5, and a sensor unit 2 having a circuit board 19 and a holder 20 for holding the circuit board 19, wherein a first circumferential portion 12 is formed on the inner circumference of the first raceway 4, the holder 20 has a second circumferential portion 21 radially opposed to the first circumferential portion 12, and the sensor unit 2 is fixed to the first raceway 4 at a position between the first circumferential portion 12 and the second circumferential portion 21.

[0095] In particular, in this bearing device, the sensor unit 2 is fixed to the first raceway 4 by pressing the fixing member 22 between the first circumferential portion 12 and the second circumferential portion 21 of the holder 20. Therefore, the sensor unit 2 is fixed to the first raceway 4 by pressing the fixing member 22 between the first circumferential portion 12 and the second circumferential portion 21. Therefore, it is not necessary to press the first circumferential portion 12 and the second circumferential portion 21 directly together or to fix them with an adhesive. In addition, the fixing member 22 is fixed between the first circumferential portion 12 and the second circumferential portion 21 at points distributed in the circumferential direction. Since 21 is pressed radially, it is possible to reduce the pressing load at each pressing point while ensuring a predetermined holding force required to fix the sensor unit 2 and the first raceway 4. Also, it is possible to appropriately select and press-fit the dimensions of the fixing member 22 according to the dimension of the gap g between the groove 13 of the first circumferential portion 12 and the cylindrical surface 23 of the second circumferential portion 21. Therefore, it is possible to prevent the pressing load from becoming excessive at each pressing point and suppress deformation of the first raceway 4 and the holder 20 of the sensor unit 2.

[0096] In this way, this bearing device can fix the sensor unit 2 to the first raceway 4 between the first raceway 4 of the rolling bearing 1 and the peripheral portions 12, 21 of the holder 20 of the sensor unit 2 without fixing the two portions 12, 21 together with an adhesive, while suppressing deformation of both the first raceway 4, 20.

[0097] In addition, since the first raceway 4 and the sensor unit 2 are not fixed by adhesive and the sensor unit 2 can be removed, the sensor unit 2 can be reused, making this bearing device considerate of sustainability.

[0098] Furthermore, in this bearing device, the fixing member 22 consists of a hollow body elastically compressed radially between the first circumferential portion 12 and the second circumferential portion 21, so that the fixing member 22 pressed between the first circumferential portion 12 and the second circumferential portion 21 can easily elastically press both circumferential portions 12, 21 radially. Even if the clamping margin between the first circumferential portion 12 (groove 13) and the second circumferential portion 21 (cylindrical surface 23) relative to the fixing member 22 is large, this can be absorbed by the elastic deformation of the fixing member 22, and deformation of the first raceway 4 and the holder 20 can be suppressed.

[0099] Furthermore, in this bearing device, since the fixing member 22 consists of a spring pin, the fixing member 22 easily undergoes elastic deformation according to the clamping margin between the first circumferential portion 12 (groove 13) and the second circumferential portion 21 (cylindrical surface 23), making it possible to easily press-fit even if the clamping margin is large, which is advantageous for fixation and for suppressing deformation of the first raceway 4, etc.

[0100] In addition, this bearing device has a first circumferential portion 12 and a second circumferential portion 21, and one of the circumferential portions 12 has grooves 13 extending in the axial direction at multiple locations in the circumferential direction, and a fixing member 22 is pressed between the other circumferential portion 21 opposite the one and the grooves 13, so that the circumferential position of the fixing member 22 can be appropriately determined by the grooves 13.

[0101] In addition, in this bearing device, the other peripheral portion 21 mentioned above has a cylindrical surface 23 that is radially opposed to the groove 13 and extends circumferentially. Therefore, compared to the case where radially opposed grooves are formed in both the first peripheral portion 12 and the second peripheral portion 21, the cylindrical surface 23, which has a simple shape, is less likely to have large tolerances, and circumferential phase alignment of the first peripheral portion 12 and the second peripheral portion 21 is not required during the fitting process of the first peripheral portion 12 and the second peripheral portion 21.

[0102] Furthermore, since the first circumferential portion 12 and the second circumferential portion 21 of this bearing device are entirely clearance-fitted to each other, there is no need to apply a large pressing load, as occurs when cylindrical surfaces are pressed together, during the fitting process of the first circumferential portion 12 and the second circumferential portion 21, and deformation of the first raceway 4 and the sensor unit 2 can be suppressed.

[0103] Furthermore, in this bearing device, the holder 20 has an annular side portion 24 extending radially from the second circumferential portion 21, the fixing members 22 are arranged at equal intervals in the circumferential direction, and the circuit board 19 is attached to the annular side portion 24 without contacting the second circumferential portion 21. Therefore, the deformation of the holder 20 and the first raceway 4 caused by the pressing of the fixing member 22 is made circumferentially equal, and interference between the second circumferential portion 21 and the circuit board 19, which deform when pressed in, is avoided, thereby preventing any impact on the performance of the sensor unit 2 and the rolling bearing 1.

[0104] Furthermore, since the sensor unit 2 is disposed only in the region radially opposed to the first race 4, this bearing device can be provided as a bearing device within the dimensions of the rolling bearing 1.

[0105] In addition, this bearing device further includes a generator 3 having a magnetic ring 8 fixed to the second raceway 5 and a stator 9 facing the magnetic ring 8, the stator 9 being provided on the sensor unit 2, and the circuit board 19 having a substrate 26, sensors 27, 28 mounted on the substrate 26, a wireless communication circuit 29 mounted on the substrate 26, and a power supply circuit 30 that converts the AC power generated by the stator 9 as the magnetic ring 8 rotates into DC power for use on the circuit board 19, so that the sensor unit 2 can be made wireless.

[0106] Furthermore, in this bearing device, the magnetic ring 8, the stator 9, and the circuit board 19 are arranged so as to face each other only in the radial direction, so that the dimensions of the axial area required for arranging these can be reduced.

[0107] A second embodiment as another example of the present invention is shown in Fig. 10. Note that, in the following, only the differences from the first embodiment will be described.

[0108] In the bearing device according to the second embodiment, the shape of the second circumferential portion 51 of the sensor unit 50 is changed. The cylindrical surface 52 of the second circumferential portion 51 is provided only on one axial end side (the right end in the figure) of the second circumferential portion 51. A radial gap is provided between the fixed member 22 and a portion 53 of the second circumferential portion 51 from the cylindrical surface 52 to the other axial end (the left end in the figure). Therefore, the axial contact length between the fixed member 22 and the second circumferential portion 51 is shorter than that of the first embodiment. That is, the axial region that forms a radial interference with the fixed member 22 is shorter. Therefore, in the press-fitting process of the fixed member 22, the pressing load required to press-fit the fixed member 22 between the second circumferential portion 51 and the groove 13 of the first circumferential portion is reduced.

[0109] In this way, in the bearing device according to the second embodiment, the fixed member 22 is press-fitted only in a portion of the axial region W that faces the second circumferential portion 51 in the radial direction, and therefore the axial region that forms a radial interference with the fixed member 22 can be shortened to reduce the pressing load required to press the fixed member 22 between the groove 13 of the first circumferential portion and the second circumferential portion 51, thereby suppressing deformation of the first race 4 and the sensor unit 50. Note that it is also possible to shorten the groove 13 in the axial direction in a similar manner.

[0110] A third embodiment as yet another example of the present invention is shown in FIG.

[0111] In the bearing device according to the third embodiment, the shape of the fixed member 60 is changed. A female screw hole 61 is provided on the inner circumference of a hollow body constituting the fixed member 60. The female screw hole 61 is open axially toward the reversible moving body side (the right side in the figure, the outside of the bearing), so that a corresponding male screw member (not shown) can be screwed into the female screw hole 61 from the axial direction. Therefore, the fixed member 60 can be removed from between the first circumferential portion 12 and the second circumferential portion 21 by pulling the screwed male screw member axially toward the reversible moving body side, or by continuing to rotate the male screw member with its tip abutting against the bottom of the groove 13.

[0112] In this way, in the bearing device according to the third embodiment, the fixing member 60 has the female threaded hole portion 61 which can be screwed in the axial direction, so that the fixing member 22 can be removed from between the first circumferential portion 12 and the second circumferential portion 21 by utilizing the female threaded hole portion 61. This makes it possible to reuse the sensor unit 2 by removing all of the fixing members 22, separating the sensor unit 2 from the first bearing ring 4, and replacing it with a new sensor unit 2, or by inspecting the separated sensor unit 2, replacing parts, etc., and then performing the fitting process and press-fitting process again to fix it to the first bearing ring 4.

[0113] A fourth embodiment as yet another example of the present invention is shown in Figs.

[0114] In the bearing device of the fourth embodiment, the first raceway 71 of the rolling bearing 70 is an inner raceway and the second raceway 72 is an outer raceway, and accordingly, the fixing structure of the sensor unit 73, etc. are changed.

[0115] The groove 75 of the first circumferential portion 74 is provided on the outer periphery of the first raceway 71. The second circumferential portion 76 is provided on the inner periphery of the sensor unit 73. By press-fitting a fixing member 77 between the groove 75 and the cylindrical surface of the second circumferential portion 76, the sensor unit 73 can be fixed to the first raceway 71 between the first circumferential portion 74 on the outer periphery of the first raceway 71 and the second circumferential portion 76 of the sensor unit 73. Accordingly, the magnetic ring 78 is fixed to the inner periphery of the second raceway 72, and the stator 79 is provided on the outer periphery of the sensor unit 73.

[0116] A fifth embodiment as yet another example of the present invention is shown in FIG.

[0117] The bearing device according to the fifth embodiment is modified so that a groove 82 is formed in the second circumferential portion 81 of the sensor unit 80, and a fixing member 85 is press-fitted between the groove 82 and the cylindrical surface of the first circumferential portion 84 of the first raceway 83. Since the bearing device according to the fifth embodiment does not form a groove in the first raceway 83, machining of the first raceway 83 is simplified. As with a general raceway, the first raceway 83 can be formed only by rotational processing such as turning and grinding around the center axis of the raceway. The groove 82 of the sensor unit 80 can be formed by pressing a portion of the circumferential direction of the second circumferential portion 81 in the radial direction.

[0118] In the above-described embodiments, the first circumferential portion of the first raceway and the second circumferential portion of the sensor unit are loosely fitted to each other, but these circumferential portions may be intermediately fitted or lightly press-fitted. For example, when the purpose is other than the permanent fixation of the sensor unit to the first raceway, such as temporarily fixing the sensor unit until the press-fitting process of all the fixing members is completed, or as a measure to prevent foreign matter from entering through the gap between the two circumferential portions, intermediate fitting or light press-fitting may be used. With this degree of fit, the deformation of the raceway surface of the first raceway and the deformation of the holder are not excessive, and do not become evident as a negative effect on the performance of the bearing or the performance of the sensor unit.

[0119] 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]

[0120] 1,70 Rolling bearings 2,50,73,80 Sensor unit 3. Generator 4,71,83 First race 5,72 Second raceway 6 Rolling elements 8,78 Magnetic Ring 9,79 Stator 12,74,84 First circumference 13,75,82 groove 19 Circuit Board 20 Holder 21,51,76,81 Second peripheral part 22,60,77,85 Fixing member 23,52 Cylindrical surface 24 Circular side 26 Substrate 27,28 Sensors 29 Wireless communication circuits 30 Power circuit 61 Female thread hole g Gap W axis direction area

Claims

1. a rolling bearing having a first raceway, a second raceway, and two or more 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; a first circumferential portion is formed on either an inner or outer periphery of the first bearing ring, the holder has a second circumferential portion radially opposed to the first circumferential portion, In the bearing device, the sensor unit is fixed to the first bearing ring at a position between the first circumferential portion and the second circumferential portion, A bearing device, characterized in that the sensor unit is fixed to the first race by a fixing member being press-fitted between the first circumferential portion and the second circumferential portion.

2. 2. The bearing device according to claim 1, wherein the fixed member comprises a hollow body elastically compressed in a radial direction between the first circumferential portion and the second circumferential portion.

3. 3. The bearing assembly according to claim 2, wherein the fixing member comprises a spring pin.

4. 3. The bearing device according to claim 2, wherein the fixing member has a female threaded hole portion that can be screwed in an axial direction.

5. A bearing device as described in claim 1 or 2, wherein one of the first circumferential portion and the second circumferential portion has grooves extending in the axial direction at multiple locations in the circumferential direction, and the fixing member is pressed between the other circumferential portion opposite the one and the groove.

6. 6. The bearing device according to claim 5, wherein the other peripheral portion has a cylindrical surface that faces the groove in the radial direction and extends in the circumferential direction.

7. 3. The bearing device according to claim 1, wherein the first circumferential portion and the second circumferential portion are entirely clearance-fitted to each other.

8. The bearing device according to claim 1 or 2, wherein the fixing member is press-fitted into only a part of an axial region that faces the second circumferential portion in the radial direction.

9. the holder has an annular side portion extending radially from the second periphery; The fixing members are arranged at equal intervals in the circumferential direction, 3. The bearing device according to claim 1, wherein the circuit board is attached to the annular side portion in a state of not contacting the second circumferential portion.

10. 3. The bearing device according to claim 1, wherein the sensor unit is disposed only in an area radially opposed to the first raceway ring.

11. a generator having a magnetic ring fixed to the second raceway and a stator facing the magnetic ring; The stator is provided in the sensor unit, 3. The bearing device according to claim 1 or 2, wherein the circuit board comprises a substrate, a sensor mounted on the substrate, a wireless communication circuit mounted on the substrate, and a power supply circuit that converts AC power generated by the stator as the magnetic ring rotates into DC power for use on the circuit board.

12. The bearing device according to claim 11 , wherein the magnetic ring, the stator and the circuit board are arranged to face each other only in the radial direction.

Images