Bearing device

Abstract

The bearing arrangement comprises a bearing and a sensor unit (6). A sensor unit (6) is fixed to a fixed ring (3) of a bearing and holds a sensor (15) for monitoring the state of the bearing. The sensor unit (6) includes a holding member (12) having a side plate portion (12A) and a peripheral portion. The holding member (12) and the fixing ring (3) are fitted at the periphery thereof. A part of a first fitting surface (12Ca) of the peripheral part, which is fitted to the fixed ring (3), and a part of a second fitting surface (3a) of the fixed ring (3), which is fitted to the peripheral part, are arranged so as to be spaced apart from each other.

Description

Technical Field

[0001] The present disclosure relates to a bearing device. Background Art

[0002] For the purpose of monitoring the state of a rolling bearing for the purpose of maintaining the device, a bearing device is known in which a sensor is provided at a position adjacent to the bearing. The bearing device includes a generator and a sensor. In addition, for the purpose of transmitting data detected by the sensor with high convenience, the bearing device may have a structure capable of wirelessly transmitting the data.

[0003] Japanese Patent Publication No. 2003-269477 (Patent Document 1) proposes a rolling bearing with a generator that can be applied to a wheel bearing device. Japanese Patent Publication No. 2003-269477 discloses a structure in which the outer peripheral surface of a stator (magnetic ring) that accommodates the coil of the generator has a step. That is, in Japanese Patent Publication No. 2003-269477, the outer peripheral surface of the stator is bent in a manner having a portion extending in the radial direction and a portion extending in the axial direction intersecting therewith, so as to be able to fit with the shape of the inner peripheral surface of the outer member of the wheel bearing. Due to this bending, in the cross section, the portion of the outer peripheral surface of the stator extending in the axial direction forms a step like a staircase. Prior art literature Patent Literature

[0004] Patent Document 1: Japanese Patent Application Publication No. 2003-269477 Summary of the invention Technical problem to be solved by the invention

[0005] In Japanese Patent Publication No. 2003-269477, at least the outer peripheral surface of the stator extends in the axial direction. The portion where the outer peripheral surface of the stator contacts the inner peripheral surface of the outer member does not have a step, and the contacting portion is generally flat as a whole. In other words, the portion where the outer peripheral surface of the stator contacts contacts the outer member as a whole. Therefore, for example, when the stator is fixed to the outer member by press-fitting, the pressing load is too large, and the stator may be deformed in a manner inclined relative to the outer member. In this way, the desired characteristics of the bearing device may not be obtained.

[0006] The present disclosure is made in view of the above technical problems. An object of the present disclosure is to provide a bearing device that suppresses excessive pressing load when a sensor unit including a stator is pressed in, and that allows the sensor unit to be easily installed without deformation. Technical solutions adopted to solve technical problems

[0007] The bearing device according to the present disclosure includes a bearing and a sensor unit. The bearing includes an outer ring, an inner ring and rolling elements. The sensor unit is fixed to a fixed ring as either the outer ring or the inner ring, and holds a sensor that monitors the state of the bearing. The sensor unit includes a retaining member having a side plate portion and a peripheral portion extending in a manner intersecting the side plate portion. The retaining member is engaged with the fixed ring at the peripheral portion. A first engaging surface in the peripheral portion engaged with the fixed ring and a second engaging surface in the fixed ring engaged with the peripheral portion are partially in contact with each other, and other portions other than the portion are arranged at intervals from each other. Effects of the Invention

[0008] According to the present disclosure, it is possible to provide a bearing device that suppresses an excessive pressing load when a sensor unit including a stator is press-fitted and that allows the sensor unit to be easily installed without deformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a perspective view of the entire bearing device according to the first embodiment. Figure 2 This is a cross-sectional view of the bearing according to the first embodiment taken along a plane including the rotation axis. Figure 3 yes Figure 2 In particular, the enlarged cross-sectional view of the sensor unit and the magnetic ring is shown. Figure 4 This is a diagram showing the bearing device according to the first embodiment as viewed from the sensor unit side. Figure 5 This is an exploded perspective view of the sensor unit according to the first embodiment. Figure 6 This is a perspective view of the sensor unit after assembly according to the first embodiment. Figure 7 This is a cross-sectional view of a bearing according to the second embodiment taken along a plane including the rotation axis. Figure 8 yes Figure 7 In particular, the enlarged cross-sectional view of the sensor unit and the magnetic ring is shown. Fig. 9 This is a cross-sectional view of a bearing according to a third embodiment taken along a plane including the rotation axis. Fig.10 yes Fig. 9 In particular, the enlarged cross-sectional view of the sensor unit and the magnetic ring is shown. Fig.11 This is an enlarged cross-sectional view of the fourth embodiment, particularly the sensor unit and the magnetic ring. Fig.12 This is an enlarged cross-sectional view of the fifth embodiment, particularly the sensor unit and the magnetic ring. DETAILED DESCRIPTION

[0010] Hereinafter, embodiments will be described in detail based on the drawings. (Implementation Method 1) <Structure of bearing member> Figure 1 2 is a perspective view of the entire bearing device according to the first embodiment. Figure 1 The bearing device 1 of this embodiment includes a bearing 2, a sensor unit 6, and a magnetic ring 7. The bearing 2 includes an outer ring 3 and an inner ring 4. In the bearing 2, for example, the outer ring 3 is a fixed ring, and the inner ring 4 is a rotating ring. The bearing 2 is described using a deep groove ball bearing as an example, but the type of the bearing 2 is not limited to a deep groove ball bearing.

[0011] Here, the bearing 2 is a standard bearing whose main dimensions (inner diameter, outer diameter, width, etc.) are recorded in a specific specification. A standard bearing is a bearing whose dimensions are recorded in, for example, ISO specifications or JIS specifications. The bearing 2 is a radial bearing, and the main dimensions of the bearing 2 are the dimensions specified in ISO15 or JISB1512-1. Hereinafter, the bearing 2 is also referred to as a standard bearing 2.

[0012] The sensor unit 6 includes a stator 5 and a cover 14. The structure of the stator 5 will be described in detail later. The cover 14 protects the interior of the sensor unit 6. The magnetic ring 7 is a magnetic member in which the N pole and the S pole are alternately magnetized in the circumferential direction. The stator 5 is fixed to the outer ring 3, and the magnetic ring 7 is fixed to the inner ring 4. The generator G is formed by the stator 5 and the magnetic ring 7. The generator G is a claw pole generator, but it can also be a generator of other structures. Figure 1 The dot-dash line is the rotation axis O of the bearing 2 .

[0013] Figure 2 This is a cross-sectional view of the bearing according to the first embodiment taken along a plane including the rotation axis. Figure 3 yes Figure 2 In particular, the sensor unit and the magnetic ring are enlarged cross-sectional views. Figure 2 and Figure 3 In addition to the outer ring 3 and the inner ring 4, the bearing 2 also includes rolling elements 8, retainers 9 and seals 10. Figure 2 The distance W between the end face 11 and the rolling element 8 in the left-right direction (in the right-left direction) can be selected from the size of the standard bearing model that can accommodate the sensor unit 6 and the magnetic ring 7. The end face 11 is also the end face of the outer ring 3.

[0014] The rolling element 8 is located in the circumferential direction of the bearing 2 ( Figure 2 The plurality of rolling elements 8 are arranged at intervals in the depth direction. The retainer 9 retains these plurality of rolling elements 8. The axial direction of the retainer 9 is Figure 1 The end surface side of one side in the left and right direction ( Figure 2 The other end face side ( Figure 2 Therefore, Figure 2In FIG. 1 , the cage 9 is arranged only in a region substantially on the left side of the center of the rolling element 8 , and the cage 9 is not arranged in a region substantially on the right side of the center of the rolling element 8 .

[0015] The sensor unit 6 constituting the bearing device 1 of the present embodiment includes a holding member 12 and a circuit board 13 in addition to the stator 5 and the cover 14. The holding member 12 is arranged on the end surface side ( 10 ) of the retainer 9 closer to one side than the rolling element 8. Figure 2 That is, the holding member 12 is arranged in the axial direction on the side where the retainer 9 is open and the retainer 9 is not arranged. The holding member 12 is arranged at the position where the retainer 9 should be arranged.

[0016] The retaining member 12 has a side plate portion 12A, an outer peripheral portion 12C and an inner peripheral portion 12D. The outer peripheral portion 12C and the inner peripheral portion 12D are collectively referred to as a peripheral portion. The side plate portion 12A extends in the circumferential direction, that is, extends in a manner that describes a circular ring. That is, the side plate portion 12A extends continuously in the circumferential direction (one circle). The peripheral portion extends in a manner that intersects with the side plate portion 12A.

[0017] The side plate portion 12A is arranged adjacent to the rolling element 8 at a position closest to the rolling element 8 in the axial direction in the retaining member 12 (inside the bearing 2). The side plate portion 12A has a back surface 12b on the side opposite to the rolling element 8 and a front surface 12f on the side opposite to the back surface 12b (i.e., the side not opposite to the rolling element 8). In other words, the back surface 12b faces the inside of the bearing 2, and the front surface 12f faces the outside of the bearing 2. The area on the front surface 12f of the side plate portion 12A of the retaining member 12 is surrounded by the side plate portion 12A, the outer peripheral portion 12C, and the inner peripheral portion 12D through the side plate portion 12A, the outer peripheral portion 12C, and the inner peripheral portion 12D. Here, the area surrounded by the side plate portion 12A, the outer peripheral portion 12C, and the inner peripheral portion 12D is considered to be the inside of the sensor unit 6. The retaining member 12 is a ring member having a C-shaped (or U-shaped) cross-sectional shape composed of the side plate portion 12A, the outer peripheral portion 12C, and the inner peripheral portion 12D.

[0018] The circuit board 13 is fixed to the front surface 12f of the side plate portion 12A of the holding member 12. One or more sensors for monitoring and detecting the state of the bearing 2 are mounted on the circuit board 13. Figure 2 As shown, an acceleration sensor 15 is installed as a sensor. The acceleration sensor 15 detects the vibration of the bearing 2. The circuit substrate 13 is fixed in a manner close to, for example, a relatively radially outer region (region close to the outer peripheral portion 12C) in the front surface 12f. A portion of the outer edge of the circuit substrate 13 may also be in contact with the inner wall of the outer peripheral portion 12C.

[0019] The outer peripheral portion 12C of the holding member 12 is connected to the outer ring 3 on one end surface side ( Figure 2The retaining member 12 is fitted and fixed to the first cutout portion 3a formed on the inner circumferential surface of the outer ring 3). In addition, the retaining member 12 can be fixed to the outer ring 3 by both press-fitting and bonding, or by methods other than these. The fixation here is not limited to a firm fixation that does not separate from each other, and includes, for example, a state in which it can be easily removed as when pressed in but has a pulling force of a certain level or more. When the retaining member 12 is fixed to the first cutout portion 3a, a certain gap is ensured between the rolling element 8 and the retaining member 12. As a result, even if the rolling element 8 and the retaining member 12 are axially displaced, the gap can prevent the rolling element 8 and the retaining member 12 from contacting each other.

[0020] As described above, the circuit substrate 13 and the holding member 12 that fixes the circuit substrate 13 both constitute the sensor unit 6. Therefore, the sensor such as the acceleration sensor 15 mounted on the circuit substrate 13 is held by the sensor unit 6. In addition, since the holding member 12 is fixed to the outer ring 3, the sensor unit 6 is fixed to the outer ring 3.

[0021] exist Figure 2 and Figure 3 In the embodiment, the first mating surface as the surface where the retaining member 12 is mated with the outer ring 3 and the second mating surface as the surface where the outer ring 3 is mated with the retaining member 12 have a step. Due to the step, a part of the first mating surface and the second mating surface are in contact with each other, and the other parts are not in contact and are arranged at a distance from each other. Here, it is more preferred that the area of ​​the part where the first mating surface and the second mating surface are not in contact is larger (the size is longer in the cross-sectional view) than the part where the first mating surface and the second mating surface are in contact. For example, the area of ​​the part where the first mating surface and the second mating surface are in contact is preferably less than 45% of the area of ​​the first mating surface, and more preferably less than 40%. However, from the viewpoint of fixing the retaining member 12 to the fixing ring, the area of ​​the above-mentioned contacting part is preferably more than 20% of the area of ​​the first mating surface, and more preferably more than 25%. In addition, the first mating surface is the part of the circumference of the retaining member 12 that is mated with the outer ring 3 as the fixing ring, and is Figure 2 and Figure 3 The second fitting surface refers to the portion of the outer ring 3 that fits with the outer peripheral portion 12C of the retaining member 12. Figure 2 and Figure 3 The first cutout portion 3a.

[0022] Specifically, the outer peripheral mating surface 12Ca has a step that is axially spaced from the rolling element 8 side ( Figure 2 , Figure 3 Compared with the left side of the opening 12g on the opposite side ( Figure 2 , Figure 3The distance from the radially outermost part of the outer ring 3, i.e., the outermost surface 3c, becomes smaller (on the right side). The peripheral mating surface 12Ca has a mating surface 12Ca1 and a mating surface 12Ca2. The mating surface 12Ca1 is formed on the rolling element 8 side, and the mating surface 12Ca2 is formed on the opening 12g side. They both extend in the axial direction, but their boundary portions have steps in the radial direction. In the case of forming the retaining member 12 by stamping as described later, the stamping process is facilitated by making the mating surface 12Ca2 a straight surface. Preferably, the axial dimension of the mating surface 12Ca2 is longer than the cutout portion 3a2 described later.

[0023] The step portion between the mating surface 12Ca1 and the mating surface 12Ca2, that is, the boundary portion is as follows. Figure 3 As shown, the angle between the boundary portion and the mating surfaces 12Ca1 and 12Ca2 may be an obtuse angle (e.g., greater than 120° and less than 150°). However, the obtuse angle may be greater than 100° and less than 120°. It can be considered that the boundary portion does not belong to any of the mating surfaces 12Ca1 and 12Ca2.

[0024] The peripheral mating surface 12Ca has a step as described above, but the radial thickness of the peripheral portion 12C is generally constant as a whole, and there is not much difference between regions. Therefore, not limited to the peripheral mating surface 12Ca, the peripheral portion 12C including both the peripheral mating surface 12Ca and the portion other than the peripheral mating surface 12Ca also has a step. Specifically, the peripheral portion 12C has: a first peripheral portion 12C1 including the mating surface 12Ca1; and a second peripheral portion 12C2 including the mating surface 12Ca2. The second peripheral portion 12C2 has a step in such a way that the overall distance from the outermost surface 3c in the radial direction becomes smaller than that of the first peripheral portion 12C1.

[0025] In addition, the first cutout portion 3a has a step that is axially spaced from the rolling element 8 side ( Figure 2 , Figure 3 Compared with the left side of the opening 12g on the opposite side ( Figure 2 , Figure 3 The distance from the outermost surface 3c increases on the right side of the rolling element 8 and the end surface 11 side. The first cutout portion 3a has a cutout portion 3a1 and a cutout portion 3a2. The cutout portion 3a1 is formed on the rolling element 8 side, and the cutout portion 3a2 is formed on the opening 12g side. They both extend in the axial direction, but their boundary portions have a step in the radial direction.

[0026] The step portion between the cutout portion 3a1 and the cutout portion 3a2, that is, the boundary portion, may be as follows: Figure 3 As shown, the angles formed by the boundary portion and the cutouts 3a1 and 3a2 are obtuse angles (for example, 120° or more and 150° or less). However, the obtuse angles may be 100° or more and less than 120°.

[0027] In the radial direction, the fitting surface 12Ca1 and the cutout portion 3a1 are arranged at a distance from each other, and the fitting surface 12Ca2 and the cutout portion 3a2 are in contact with each other. According to the above, when the outermost surface 3c in the radial direction is used as a reference, the distance to the fitting surface 12Ca1 is set as L1, the distance to the fitting surface 12Ca2 and the cutout portion 3a2 that are in contact with each other is set as L2, and the distance to the cutout portion 3a1 is set as L3, then L1>L2>L3.

[0028] L2 can be larger than L3 by 3% to 5% of L3, and L1 can be larger than L2 by 3% to 5% of L2. Due to such a shape, the radial interval L3-L1 between the fitting surface 12Ca1 and the cutout portion 3a1 is larger than, for example, the interval L2-L1 when the first cutout portion 3a does not have a step. The increase in the interval L3-L1 is due to the formation of an inner chamfer 3n in a manner that the first cutout portion 3a avoids the cutout portion 3a1 radially outward. The inner chamfer 3n is formed on the rolling element 8 side of the first cutout portion 3a and the radially outermost side ( Figure 2 , Figure 3 The upper left part of the outer ring 3 is formed after a larger amount of material is removed than that in other areas. Figure 2 , Figure 3 In the example shown, an inner chamfer 3n is formed. However, the inner chamfer 3n may not be formed.

[0029] Here, the first distance between the surface forming the first notch portion 3a (the surface in contact with the back surface 12b) and the end surface 11 is, for example, 10% to 20% of the axial dimension of the outer ring 3, excluding the inner chamfer 3n. The second distance between the first notch portion 3a and the inner diameter surface 3d of the outer ring 3 closest to the inner ring 4 (radially inner side), for example, 20% to 30% of the radial dimension of the outer ring 3, excluding the inner chamfer 3n. The first distance and the second distance may be equal, or the first distance may be larger, or the second distance may be larger.

[0030] The stator 5 includes a stator 5A and a stator 5B. On the other hand, from a different point of view, the stator 5 includes two magnetic body components 21, 22, a bobbin 23 and a coil 24. A part of the retaining member 12 is used as the magnetic body component 21 of the stator 5A in the stator 5. The stator 5B in the stator 5 is used as the magnetic body component 22. That is, the stator 5A is equivalent to the retaining member 12, which is equivalent to the magnetic body component 21. The stator 5B is equivalent to the magnetic body component 22. In other words, the stator 5A, the retaining member 12 and the magnetic body component 21 are the same, and the stator 5B and the magnetic body component 22 are the same.

[0031] Inside the stator 5A, that is, in the relatively radially inner area of ​​the area surrounded by the side plate portion 12A, the outer peripheral portion 12C, and the inner peripheral portion 12D, there is arranged a coil 24 wound on a bobbin 23. At least a portion of the surface of the bobbin 23 and the coil 24 may be in contact with the inner peripheral portion 12D or the side plate portion 12A. The bobbin 23 and the coil 24 are covered by the magnetic body component 22 which is the stator 5B from the axial end face 11 side (the side opposite to the rolling element 8). Figure 2 and Figure 3 In the cross section shown, the magnetic member 22 has an outer peripheral portion 22B and an end surface portion 22C. Figure 2 and Figure 3 Although not shown in the figure, the magnetic member 22 actually has an inner peripheral portion 22D described later in addition to the above. The outer peripheral portion 22B and the end surface portion 22C are substantially orthogonal to each other. Figure 2 and Figure 3 The outer peripheral portion 22B divides the interior of the stator 5A into a radially outer area (an area where the circuit substrate 13 is arranged) and an inner area (an area where the coil 24 is arranged). The end surface portion 22C covers the interior of the stator 5A in parallel with the cover 14. The end surface portion 22C covers the radially inner area of ​​the interior of the stator 5A. With the two arranged in parallel, the interior of the stator 5A is covered from the end surface 11 side. The bobbin 23 and the coil 24 are surrounded by a portion of the side plate portion 12A (the radially inner area) and the inner peripheral portion 12D of the stator 5A, as well as the outer peripheral portion 22B and the end surface portion 22C of the stator 5B.

[0032] In other words, the above is as follows. With respect to the magnetic body member 21 occupying the entire holding member 12, the magnetic body member 22 is arranged in the radially inner region of the holding member 12. The radially inner region of the U-shaped cross section of the magnetic body member 21 and the U-shaped cross section of the magnetic body member 22 are opposite to each other. Between the magnetic body members 21 and 22 facing each other, the coil 24 including the bobbin 23 is installed in a manner surrounded by the magnetic body members 21 and 22.

[0033] Cover 14 as Figure 3 As shown, in the stator 5 , in particular, in a region radially outward of the stator 5B except for a portion of the stator 5A surrounding the coil 24 and the stator 5B, the cover 14 covers the region inside the stator 5A.

[0034] On one end surface side of the inner ring 4 ( Figure 2 On the outer peripheral surface of the bearing 2 (on the right side), a second notch portion 4a with a step is formed in a manner opposite to the first notch portion 3a. In the axial direction of the bearing 2, from the outer ring 3 to the inner ring 4, an annular recessed portion cut toward the rolling element 8 is formed by the first notch portion 3a and the second notch portion 4a.

[0035] The second cutout portion 4a extends axially from the end face 11 by a size of, for example, 5% to 10% of the axial dimension of the inner ring 4. The second cutout portion 4a extends radially from the surface of the inner ring 4 closest to the outer ring 3 (radially outer side) by a size of, for example, 10% to 20% of the radial dimension of the inner ring 4. The radial dimension and axial dimension of the second cutout portion 4a may be equal, or the radial dimension may be larger, or the axial dimension may be larger.

[0036] The magnetic ring 7 includes a core shaft 7a and a multi-pole magnet 7b. The multi-pole magnet 7b is a magnet formed by, for example, vulcanizing and bonding a magnetic material made by mixing magnetic powder and rubber to the core shaft 7a, and then alternately magnetizing the N pole and the S pole in the circumferential direction of the magnetic ring 7. The core shaft 7a of the magnetic ring 7 has a flange portion 7c to improve rigidity. The magnetic ring 7 is fixed to the outer diameter surface 4b of the inner ring 4 by pressing or bonding. The flange portion 7c is accommodated in the second cutout portion 4a formed on the inner ring 4.

[0037] The holding member 12 is pressed or bonded so as not to protrude axially outward from the end face 11 of the outer ring 3. By arranging the holding member 12 so as not to protrude axially outward from the end face 11 of the outer ring 3, the circuit board 13 fixed to the holding member 12 is also arranged so as not to protrude axially outward from the end face 11 of the outer ring 3. Thus, the sensor unit 6 is fixed to the outer ring 3 so as not to protrude axially outward from the end face 11 of the outer ring 3. In addition, the magnetic ring 7 is arranged so as not to protrude from the end face 20 of the inner ring 4. Furthermore, the sensor unit 6 and the magnetic ring 7 do not protrude to the axially open side of the holder 9. As described above, the sensor unit 6 (holding member 12 and circuit board 13) and the magnetic ring 7 are fixed (arranged) so as not to protrude axially outward from the end face 11 of the outer ring 3 and the end face 20 of the inner ring 4. In this way, the sensor unit 6 can be made thinner in the axial direction, and the bearing device 1 with the same size as the standard bearing can be provided.

[0038] like Figure 3 As shown, inside the annular recess formed by the first cutout portion 3a and the second cutout portion 4a, the magnetic ring 7, the coil 24 and the circuit substrate 13 are arranged in a manner spaced apart from each other on an imaginary straight line L extending in the radial direction of the bearing 2. In other words, they are arranged in a manner not spaced apart from each other on an imaginary straight line extending in the axial direction of the bearing 2. Figure 3In the embodiment, the magnetic ring 7, the coil 24, and the circuit board 13 are arranged in order from the radial inside to the outside of the bearing 2. As a result, each component can be arranged inside the annular recess, so the axial thickness of the bearing 2 can be suppressed. In addition, in the bearing device 1, for example, the magnetic ring 7 is fixed to the inner ring 4, and the stator 5 (especially the area where the stator 5A and the stator 5B surround the bobbin 23 and the coil 24) is fixed to the outer ring 3 at a relative position. Since the radial gap between the stator 5 and the magnetic ring 7 changes little, a stable amount of power generation can be ensured by the generator G.

[0039] Next, the materials of each component are described. The holding component 12 (stator 5A, magnetic component 21) and the magnetic component 22 (stator 5B) are magnetic materials and are made of metal. The cover 14 is a non-metallic resin component. A resin sealing material can also be used instead of the cover 14 to seal the circuit board 13.

[0040] Figure 4 This is a diagram of the bearing device according to the first embodiment as viewed from the sensor unit side. Figure 4 In the figure, a part of the cover 14 is omitted to make the interior of the sensor unit 6 clear. Figure 4 In addition to the acceleration sensor 15, a temperature sensor 16 is mounted on the circuit board 13 as a sensor. The acceleration sensor 15 can detect, for example, radial acceleration of the bearing 2. In addition, the temperature sensor 16 can accurately measure the temperature of the bearing 2.

[0041] A power supply circuit 17 and a wireless communication circuit 18 are also mounted on the circuit substrate 13. The power supply circuit 17 rectifies the AC power generated by the generator G through the rotation of the inner ring 4 and converts it into DC power. That is, the power supply circuit 17 is completely different from the power supply, that is, the generator G (electromagnetic induction generator) in this embodiment. The DC power converted by the power supply circuit 17 is used in the acceleration sensor 15, the temperature sensor 16 and the wireless communication circuit 18. The terminal 25 is arranged on the circuit substrate 13. The ends (not shown) of the winding start and the winding end of the coil 24 included in the stator 5 and led out therefrom are connected to the terminal 25.

[0042] The circuit board 13 is fixed to a part of the annular side plate 12A, and thus has a substantially arc shape. The acceleration sensor 15 and the temperature sensor 16 are mounted in the circumferential direction of the arc shape of the circuit board 13. Screws 19 are arranged on both sides of the acceleration sensor 15 in a manner spaced apart from the acceleration sensor 15. Figure 4 As shown, the wireless communication circuit 18 , the acceleration sensor 15 , the power supply circuit 17 , and the terminal 25 may be sequentially arranged with intervals therebetween from one end to the other end in the circumferential direction of the circuit board 13 .

[0043] The wireless communication circuit 18 includes an antenna portion 18a. The wireless communication circuit 18 uses the antenna portion 18a to wirelessly transmit the outputs of the acceleration sensor 15 and the temperature sensor 16 that monitor the state of the bearing 2 to the outside. The circuit substrate 13 is fixed to the retaining member 12 by a plurality of screws 19. In addition, the circuit substrate 13 can also be adhesively fixed relative to the retaining member 12. The circuit substrate 13 on which the wireless communication circuit 18 is installed is arranged relative to the resin cover 14. As a result, the wireless communication circuit 18 becomes a structure that is not sealed by conductive materials such as metal. Therefore, wireless communication can be performed using the antenna portion 18a in the wireless communication circuit 18. Therefore, the bearing of the bearing device 1 is a bearing with a wireless sensor.

[0044] Figure 5 This is an exploded perspective view of the sensor unit according to the first embodiment. Figure 6 FIG. 1 is a perspective view of the sensor unit after assembly according to the first embodiment. Figure 5 and Figure 6 The cover 14 is omitted. Figure 5 and Figure 6 , in the magnetic member 21 ( Figure 5 A plurality of claws 21a are formed on the inner circumference 12D of the magnetic member 22. A plurality of claws 22a are formed on the inner circumference 22D of the magnetic member 22. A coil 24 obtained by winding the electromagnetic wire multiple times is arranged in the groove provided along the circumferential direction of the bobbin 23. The bobbin 23 may also be omitted.

[0045] <Assembly Method of Stator 5> The following describes the assembly method of the stator 5. Figure 5 and Figure 6 First, the bobbin 23 wound with the coil 24 is inserted into the magnetic member 22, and the plurality of claws 21a of the magnetic member 21 and the plurality of claws 22a of the magnetic member 22 are assembled in a manner of being alternately arranged with gaps in the circumferential direction. Next, the outer peripheral portion 22B of the magnetic member 22 is fixed so that its end surface (except for the convex portion 22e described later) contacts the front surface 12f of the side plate portion 12A of the magnetic member 21. At this time, the openings of the magnetic member 21 and the magnetic member 22 are opposite to each other, and the bobbin 23 and the coil 24 are accommodated in the openings.

[0046] Here, if Figure 5As shown, a hole portion 12e is formed on the side plate portion 12A of the stator 5A (retaining member 12, magnetic member 21) and passes through it. The hole portion 12e is formed in the radially inner region of the side plate portion 12A. In addition, a convex portion 22e is formed on the end portion of the outer peripheral portion 22B of the stator 5B (magnetic member 22) that is axially close to the side plate portion 12A side of the retaining member 12. In the convex portion 22e, the end portion on the side of the side plate portion 12A close to the retaining member 12 protrudes further toward the side plate portion 12A side than other portions. A plurality of hole portions 12e and convex portions 22e are formed at intervals in the circumferential direction. For example, the hole portion 12e and the convex portion 22e are as follows: Figure 5 As shown, four are formed each, but preferably, three or more are formed each. Each hole portion 12e and convex portion 22e has an arc shape along the circumference of the annular shape of the retaining member 12. The convex portion 22e is inserted into the hole portion 12e so that the two are fitted together. Figure 6 As shown, the plurality of claws 21a and the plurality of claws 22a are assembled in a manner of being alternately arranged with gaps in the circumferential direction. The magnetic member 22 is mounted on the inner circumference 12D of the holding member 12. The end surface 22C is oriented toward the outermost portion ( Figure 5 The stator 5B is combined with the stator 5A in such a manner that the stator 5B is on the rightmost side of the stator 5A. At this time, the magnetic body member 21 and the magnetic body member 22 are combined in such a manner that the end of the outer peripheral portion 22B (excluding the protrusion 22e) abuts against the side plate portion 12A. In addition, the hole portion 12e and the protrusion 22e are fixed in a mutually restrained manner by pressing, bonding, welding (for example, laser welding), etc. It is also possible to select a plurality of the above-mentioned fixing means and use them in combination.

[0047] By fitting the hole 12e and the convex part 22e, the axis of the magnetic body component 21 and the magnetic body component 22 can be aligned without using a clamp, and the assembly of the two becomes easy. In addition, the claws 21a and the claws 22a can be phase-aligned in a manner of alternating in the circumferential direction. However, the hole 12e and the convex part 22e can also be omitted. In the case of omitting both, the Figure 5 and Figure 6 The axes of the magnetic members 21 and 22 are aligned and the phases of the claws 21a and 22a are aligned by a jig (not shown). At this time, the side plate 12A and the outer peripheral portion 22B are abutted and fixed by welding (eg, laser welding).

[0048] Then, the circuit substrate 13 is fixed to the front surface 12f of the side plate portion 12A by screws 19, and the circuit substrate 13 is protected by the cover 14 or the resin sealing material. In addition, an insulating sheet (e.g., a polyimide film) not shown in the figure may be inserted between the circuit substrate 13 and the side plate portion 12A to ensure the insulation between the circuit substrate 13 and the holding member 12.

[0049] The plurality of claws 21a and the plurality of claws 22a ensure that Figure 3The stator 5 and the magnetic ring 7 are arranged relative to each other in a state of gaps between the multipolar magnets 7b shown in the magnetic ring 7. The plurality of claws 21a of the magnetic member 21 in the stator 5, the plurality of claws 22a of the magnetic member 22, and the magnetic ring 7 constitute a radial claw-pole generator G. The total number of the plurality of claws 21a and 22a is equal to the number of poles (the total number of N poles and S poles) of the multipolar magnet 7b. The stator 5 and the magnetic ring 7 face each other in the radial direction of the bearing 2.

[0050] The magnetic flux emitted from the N pole of the multipolar magnet 7b enters the magnetic member 21 (or the magnetic member 22) from the plurality of claws 21a (or the plurality of claws 22a) as the magnetic poles, and returns to the S pole of the multipolar magnet 7b via the adjacent plurality of claws 22a (or the plurality of claws 21a) around the coil 24. When the positions of the N pole and the S pole of the multipolar magnet 7b are exchanged due to the rotation of the inner ring 4, the direction of the magnetic flux is reversed. The alternating magnetic field thus generated generates AC power at both ends of the coil 24.

[0051] <Effects> The bearing device 1 disclosed in the present invention includes: a bearing 2 including an outer ring 3, an inner ring 4 and rolling elements 8; and a sensor unit 6 fixed to a fixed ring as one of the outer ring 3 and the inner ring 4, and holding a sensor for monitoring the state of the bearing 2. The sensor unit 6 includes a retaining member 12 having a side plate portion 12A and a peripheral portion (an outer peripheral portion 12C and an inner peripheral portion 12D) extending in a manner intersecting the side plate portion 12A. The retaining member 12 is fitted with the fixed ring at the peripheral portion. A first fitting surface (an outer peripheral fitting surface 12Ca) in the peripheral portion that is fitted with the fixed ring and a second fitting surface (a first notch portion 3a) in the fixed ring that is fitted with the peripheral portion are partially in contact with each other, and other portions other than the portion are arranged at intervals from each other.

[0052] Since the first fitting surface and the second fitting surface are in contact with each other only in a part of the axial area, for example, the axial length (pressing width) of the fitting between the first fitting surface and the second fitting surface is shortened compared to the case where the first fitting surface and the second fitting surface are in contact with each other in the entire axial direction. Therefore, the area pressing the fixing ring when pressing the retaining member 12 is reduced, which can prevent the pressing load from becoming excessive during the press-in. Therefore, deformation of the retaining member 12 can be prevented.

[0053] As described above, it is possible to provide a bearing device that suppresses an excessive pressing load when the sensor unit 6 including the stator 5 is press-fitted, and that allows the sensor unit 6 to be easily installed without deformation.

[0054] In the above-mentioned bearing device 1, the outer peripheral mating surface 12Ca has a step, so that the distance between the opening 12g side on the axial side opposite to the side plate portion 12A side and the surface (outermost surface 3c) on the radial side opposite to the surface of the fixed ring (outer ring raceway surface 3b) that contacts the rolling element 8 is smaller than that of the side plate portion 12A side.

[0055] In the above-mentioned bearing device 1, the first notch portion 3a has the following step: in the axial direction, the side opposite to the rolling element 8 side (end face 11 side) is radially farther away from the surface of the fixing ring opposite to the surface in contact with the rolling element 8 (outermost surface 3c) than the rolling element 8 side.

[0056] Thus, as described above, an excessive pressing load at the time of press-fitting can be suppressed, and the sensor unit 6 can be easily installed without deformation.

[0057] For example, in Figure 3 When the sensor unit 6 is pressed into the first cutout portion 3a of the outer ring 3, the first outer peripheral portion 12C1 of the retaining member 12 can be inserted while maintaining a gap with the cutout portion 3a2 (not in contact with the cutout portion 3a2). The first outer peripheral portion 12C1 is at a greater distance from the outermost surface 3c, L1, than the second outer peripheral portion 12C2. In addition, if the distance between the cutout portion 3a2 and the outermost surface 3c is set to L2, L1>L2. Therefore, the first outer peripheral portion 12C1 can be inserted without contacting the cutout portion 3a2. In this way, the retaining member 12 is inserted without being interfered by the cutout portion 3a2. Therefore, the sensor unit 6 including the retaining member 12 can be pressed straightly along the cutout portion 3a2 without being tilted relative to the cutout portion 3a2. Therefore, the posture of the sensor unit 6 can be stabilized.

[0058] In addition, the second peripheral portion 12C2 side of the holding member 12 has an opening 12g at the end, so the rigidity is lower than that of the first peripheral portion 12C1 side. Therefore, even if the cutout portion 3a2 is farther away from the outermost surface 3c than the cutout portion 3a1, and the cutout portion 3a2 contacts the second peripheral portion 12C2 during press-in, the second peripheral portion 12C2 is more easily deformed by press-in than the first peripheral portion 12C1. Therefore, the above structure can prevent the pressing load during press-in from becoming too large.

[0059] In addition, the second outer peripheral portion 12C2 of the retaining member 12, which is easily deformed, is arranged at a position farther away from the outer ring raceway surface 3b in the axial direction than the first outer peripheral portion 12C1. Therefore, it is possible to suppress the deformation of the outer ring raceway surface 3b accompanying the deformation of the second outer peripheral portion 12C2 when the retaining member 12 is pressed in. Therefore, it is possible to suppress the influence of the change in the characteristics of the bearing 2 caused by the deformation of the outer ring raceway surface 3b.

[0060] The bearing device 1 may further include a magnetic ring 7, a stator 5, a wireless communication circuit 18, a power supply circuit 17, and a circuit substrate 13. The magnetic ring 7 is fixed to a rotating ring as either the outer ring 3 or the inner ring 4, and the N pole and the S pole are magnetized alternately. The stator 5 includes a retaining member 12 fixed to the fixed ring in a manner radially opposite to the magnetic ring 7 and the bearing 2 as a structural component, and accommodates a coil 24. The wireless communication circuit 18 transmits the output of the sensor to the outside in a wireless manner. The power supply circuit 17 can adjust the output from the generator G formed by the magnetic ring 7 and the stator 5. The circuit substrate 13 is installed with a sensor, a wireless communication circuit 18, and a power supply circuit 17. Due to the above characteristics, the bearing device 1 can generate electricity using the generator G as a power source, and can adjust the power generated by the generator G through the power supply circuit 17. The output of the sensor can be transmitted to the outside in a wireless manner through the wireless communication circuit 18 and the sensor installed on the circuit substrate 13.

[0061] The fact that the power circuit 17 can adjust the output from the generator G means, for example, rectifying the AC power generated by the generator G and converting it into DC power as described above. Alternatively, the above-mentioned ability to adjust may also mean controlling the voltage value to a target value by stepping up or down.

[0062] (Supplement to Implementation Method 1) Alternatively, in the bearing device 1, a portion of the stator 5 (stator 5A) may be the retaining member 12, and the circuit board 13 may be fixed to the retaining member 12. By making the retaining member 12 also function as the stator 5A (magnetic member 21), the number of components can be reduced, and stamping of each component becomes easier.

[0063] (Implementation Method 2) In the description of the bearing device of each embodiment below, the same components as those of the bearing device of the conventional embodiment are denoted by the same reference numerals, and when there is no difference in structure or function, the description thereof will not be repeated. Figure 7 This is a cross-sectional view of a bearing according to the second embodiment taken along a plane including the rotation axis. Figure 8 yes Figure 7 In particular, the enlarged cross-sectional view of the sensor unit and the magnetic ring. That is, Figure 7 , Figure 8 Corresponding to the first embodiment Figure 2 , Figure 3 . Reference Figure 7 and Figure 8In this embodiment, the inner ring 4 is basically the same as the first embodiment, but the inner ring 4 is a fixed ring and the outer ring 3 is a rotating ring. Therefore, the sensor unit 6 including the stator 5 is fixed to the inner ring 4. Therefore, a second cutout portion 4a having the same form as the first cutout portion 3a of the first embodiment is formed on the inner ring 4. The second cutout portion 4a as the second fitting surface has a cutout portion 4a1 on the rolling element 8 side and a cutout portion 4a2 on the opening 12g side. In the cutout portion 4a1 of the inner ring 4, an inner chamfer 4n is formed in a manner of avoiding radially outward.

[0064] The magnetic ring 7 is fixed to the outer ring 3. Therefore, the first cutout portion 3a and the inner diameter surface 3d of the same form as the second cutout portion 4a and the outer diameter surface 4b of the first embodiment are formed on the outer ring 3. In addition, the inner peripheral portion 12D of the retaining member 12 is formed in the same form as the outer peripheral portion 12C of the first embodiment. The inner peripheral portion 12D of the retaining member 12 is connected to the inner ring 4 on one end surface side ( Figure 2 The second cutout portion 4a formed on the outer peripheral surface (on the right side) is fitted and fixed.

[0065] The inner peripheral portion 12D of the present embodiment has an inner peripheral portion fitting surface 12Da as a first fitting surface. The inner peripheral portion fitting surface 12Da has a fitting surface 12Da1 and a fitting surface 12Da2. The fitting surface 12Da1 is formed on the rolling element 8 side, and the fitting surface 12Da2 is formed on the opening 12g side. The inner peripheral portion 12D has a first inner peripheral portion 12D1 including the fitting surface 12Da1 and a second inner peripheral portion 12D2 including the fitting surface 12Da2.

[0066] In the above-mentioned bearing device 1, the inner peripheral mating surface 12Da has the following step: in the axial direction, the distance between the opening 12g side on the opposite side of the side plate portion 12A and the surface (innermost surface 4c) on the opposite side of the surface of the fixed ring (inner ring raceway surface 4b2) that contacts the rolling element 8 in the radial direction becomes smaller than that on the side of the side plate portion 12A.

[0067] In the bearing device 1, the second notch portion 4a has a step such that the distance from the surface (innermost surface 4c) on the opposite side to the rolling element 8 side (end surface 20 side) in the radial direction to the surface (innermost surface 4c) on the opposite side to the rolling element 8 side in the radial direction becomes larger than that on the rolling element 8 side. According to the above, when the innermost surface 4c in the radial direction is used as a reference, if the distance to the fitting surface 12Da1 is set as L1, the distance to the fitting surface 12Da2 and the notch portion 4a2 that contact each other is set as L2, and the distance to the notch portion 4a1 is set as L3, then L1>L2>L3. In this way, the fixing ring may be either the outer ring 3 or the inner ring 4. As long as the first fitting surface and the second fitting surface have the feature that a part of them contact each other and the other parts do not contact each other, this embodiment also has the same effect of stabilizing the posture of the sensor unit 6 as the first embodiment.

[0068] (Implementation Method 3) Fig. 9 This is a cross-sectional view of a bearing according to a third embodiment taken along a plane including the rotation axis. Fig.10 yes Fig. 9 In particular, the enlarged cross-sectional view of the sensor unit and the magnetic ring. That is, Fig. 9 , Fig.10 Corresponding to the first embodiment Figure 2 , Figure 3 . Reference Fig. 9 and Fig.10 In this embodiment, the first notch 3a is substantially the same as the first embodiment. However, in the bearing device 1 of this embodiment, the first notch 3a has the following step: in the axial direction, the first notch 3a is parallel to the rolling element 8 side ( Figure 2 , Figure 3 Compared with the left side of the end face 11 on the opposite side ( Figure 2 , Figure 3 The distance from the outermost surface 3c to the right side of the outermost surface 3c becomes smaller. In addition, the outer peripheral mating surface 12Ca has no step between the mating surface 12Ca1 and the mating surface 12Ca2, and is flat in the entire axial direction. In this respect, the present embodiment is different from the first embodiment.

[0069] In addition, similarly to the first embodiment, in this embodiment, the inner chamfer 3n may be formed on the outer ring 3, but the inner chamfer 3n may not be formed. Fig.10 As shown, as long as the gap between the fitting surface 12Ca2 and the cutout portion 3a2 can be ensured when the retaining member 12 is fitted into the first cutout portion 3a, the peripheral portion 12C of the present embodiment may also have the following step: the distance from the opening 12g side to the outermost surface 3c becomes smaller than that on the side plate portion 12A side.

[0070] <Effects> In the bearing device 1 of this embodiment, the first notch portion 3a has the following step: in the axial direction, the distance from the side opposite to the rolling element 8 side (end face 11 side) to the surface of the fixing ring on the side opposite to the surface in contact with the rolling element 8 in the radial direction (outermost surface 3c) becomes smaller than that on the rolling element 8 side.

[0071] In the structure of this embodiment, since the first fitting surface and the second fitting surface are in contact with each other only in a part of the axial area, the axial length (pressing width) of the fitting between the first fitting surface and the second fitting surface is shortened compared to the case where the first fitting surface and the second fitting surface are in contact with each other in the entire axial direction. Therefore, the area where the fixing ring is pressed when the retaining member 12 is pressed is reduced, and an excessive pressing load during press-in can be prevented. Therefore, deformation of the retaining member 12 can be prevented.

[0072] For example, in Fig.10When the sensor unit 6 is pressed into the first cutout portion 3a of the outer ring 3, the first outer peripheral portion 12C1 of the retaining member 12 can be inserted while maintaining a gap with the cutout portion 3a2 (not in contact with the cutout portion 3a2). This is because the radial distance between the cutout portion 3a2 and the outermost surface 3c is smaller than that between the cutout portion 3a1 and the retaining member 12. In this way, the retaining member 12 is inserted without being interfered by the cutout portion 3a2. Therefore, the sensor unit 6 including the retaining member 12 can be pressed straightly along the cutout portion 3a2 without being tilted relative to the cutout portion 3a2. Therefore, the posture of the sensor unit 6 can be stabilized.

[0073] As long as the first fitting surface and the second fitting surface have a feature that a part of them contacts each other but the other parts do not contact each other, this embodiment also has the effect of stabilizing the posture of the sensor unit 6 similarly to the first embodiment.

[0074] (Implementation method 4) Fig.11 This is an enlarged cross-sectional view of the sensor unit and the magnetic ring in the fourth embodiment. Fig.11 , in this embodiment, has the basic Figure 3 The same structure as the first embodiment. However, in the present embodiment, the second outer peripheral portion 12C2 of the outer peripheral portion 12C of the retaining member 12 is formed to be thinner in the radial direction than the first outer peripheral portion 12C1. In this regard, Fig.11 The radial thickness of the outer peripheral portion 12C is substantially constant throughout the entire portion. Figure 3 Different in structure. Fig.11 also with Figure 3 Similarly, the outer peripheral fitting surface 12Ca has a step between the fitting surface 12Ca1 and the fitting surface 12Ca2, and the first cutout portion 3a has a step between the cutout portion 3a1 and the cutout portion 3a2.

[0075] When the retaining member 12 is formed by cutting or stamping, the second outer peripheral portion 12C2 may be formed thinner than the first outer peripheral portion 12C1 to reduce the rigidity of the second outer peripheral portion 12C2 and reduce the pressing load applied to the outer ring 3 when the second outer peripheral portion 12C2 is pressed in.

[0076] For example, when the retaining member 12 is formed by stamping, the dimensional tolerance of the second peripheral portion 12C2 is, for example, about 0.2 mm or more, which is relatively large, although it also depends on the accuracy of the stamping. Therefore, the tightening margin when the second peripheral portion 12C2 is engaged with the first cutout portion 3a becomes larger. In this way, the press-fitting process of the retaining member 12 into the first cutout portion 3a may become difficult. Therefore, as described above, when the retaining member 12 is stamped, a thinning process can be performed in a manner that the thickness of the peripheral portion 12C, especially the second peripheral portion 12C2, becomes thinner.

[0077] Although not shown in the figure, in this embodiment, it is also possible to replace Fig.11 The structure makes the entire radial thickness of the outer peripheral portion 12C including the first outer peripheral portion 12C1 thinner than the thickness of the side plate portion 12A. In addition, although not shown, there may be no step between the cutout portion 3a1 and the cutout portion 3a2 of the first cutout portion 3a. Fig.11 The first cutout portion 3a is flat as a whole. In addition, as another example, there may be no step between the fitting surface 12Ca1 and the fitting surface 12Ca2 of the holding member 12. Fig.11 The outer peripheral mating surface 12Ca is flat as a whole.

[0078] When the holding member 12 is formed by press working, it is preferable to Fig.10 The fitting surface 12Ca1 that becomes the press-fit portion in the middle outer peripheral fitting surface 12Ca and Fig.11 The fitting surface 12Ca2 that becomes the press-fitting portion in the middle and outer peripheral fitting surface 12Ca is set as a straight surface. Fig.10 , Fig.11 The middle fitting surface 12Ca1 and the fitting surface 12Ca2 are both straight surfaces. This makes the stamping process easier. Preferably, the portion of the peripheral fitting surface 12Ca that facilitates press-in is longer in the axial direction than the portion of the first cutout portion 3a that facilitates press-in. This is because by lengthening the straight dimension of the peripheral fitting surface 12Ca of the retaining member 12, the shape of the peripheral fitting surface 12Ca is stabilized. Fig.10 , Fig.11 The retaining member 12 of a shape of is suitable for mass production.

[0079] As long as the first fitting surface and the second fitting surface have a feature that a part of them contacts each other but the other parts do not contact each other, this embodiment also has the effect of stabilizing the posture of the sensor unit 6 similarly to the first embodiment.

[0080] (Implementation method five) Fig.12 This is an enlarged cross-sectional view of the sensor unit and the magnetic ring in the fifth embodiment. Fig.12 , in this embodiment, has the basic Figure 3 However, in this embodiment, the first cutout portion 3a has no step between the cutout portion 3a1 and the cutout portion 3a2 and is flat in the entire axial direction. In this respect, this embodiment is different from the first embodiment (one to four) having a step between the cutout portion 3a1 and the cutout portion 3a2. Fig.12 L1, L2 and Figure 3L1 and L2 are basically the same, but L2 not only represents the distance from the outermost surface 3c to the cutout portion 3a2 and the fitting surface 12Ca2, but also represents the distance to the cutout portion 3a1. Figure 3 different.

[0081] As long as the first fitting surface and the second fitting surface have a feature that a part of them contacts each other but the other parts do not contact each other, this embodiment also has the effect of stabilizing the posture of the sensor unit 6 similarly to the first embodiment.

[0082] (Note) The following are examples of embodiments disclosed in this specification.

[0083] (1) A bearing device 1 includes: a bearing 2 including an outer ring 3, an inner ring 4 and rolling elements 8; and a sensor unit 6 fixed to a fixed ring serving as either the outer ring 3 or the inner ring 4 and holding a sensor for monitoring the state of the bearing 2, the sensor unit 6 including a retaining member 12 having a side plate portion 12A and a peripheral portion (an outer peripheral portion 12C and an inner peripheral portion 12D) extending in a manner intersecting the side plate portion 12A, the retaining member being engaged with the fixed ring at the peripheral portion, a first engaging surface (an outer peripheral engaging surface 12Ca and an inner peripheral engaging surface 12Da) in the peripheral portion engaged with the fixed ring and a second engaging surface (a first notch portion 3a and a second notch portion 4a) in the fixed ring engaged with the peripheral portion, partially contact each other, and portions other than the above-mentioned portion are arranged at intervals from each other.

[0084] (2) A bearing device 1 according to (1), wherein the first mating surface has a step as follows: in the axial direction, the distance between the opening 12g side on the opposite side to the side of the side plate portion 12A and the surface (outer ring raceway surface 3b, inner ring raceway surface 4b2) of the fixing ring opposite to the surface in contact with the rolling element 8 in the radial direction (outermost surface 3c, innermost surface 4c) becomes smaller than that on the side of the side plate portion 12A.

[0085] (3) A bearing device 1 according to (1) or (2), wherein the second mating surface has a step as follows: in the axial direction, the distance between the side opposite to the rolling element 8 side (end face 11, 20 side) and the surface of the fixing ring opposite to the surface in contact with the rolling element 8 in the radial direction becomes larger than that on the side opposite to the rolling element 8 side.

[0086] (4) A bearing device 1 according to (1) or (2), wherein the second mating surface has a step as follows: in the axial direction, the distance from the surface of the fixing ring on the side opposite to the rolling element 8 side (end face 11, 20 side) in the radial direction to the surface in contact with the rolling element 8 becomes smaller than that on the rolling element 8 side.

[0087] (5) In the bearing device 1 according to any one of (1) to (4), the sensor unit 6 is fixed to the fixing ring so as not to protrude axially outward from the end faces 11 and 20 of the fixing ring.

[0088] (6) A bearing device 1 according to any one of (1) to (5), further comprising: a magnetic ring 7 fixed to a rotating ring serving as either the outer ring 3 or the inner ring 4, with the N pole and the S pole alternately magnetized; a stator 5 (particularly a portion of the stator 5A and the stator 5B accommodating the coil 24), comprising the retaining member 12 fixed to the fixed ring in a manner opposite to the magnetic ring 7 in the radial direction of the bearing 2 as a structural component, and accommodating the coil 24; a wireless communication circuit 18 which wirelessly transmits the output of the sensor to the outside; a power supply circuit 17 which is capable of adjusting the output of the generator G formed by the magnetic ring 7 and the stator 5; and a circuit substrate 13 on which the sensor, the wireless communication circuit 18 and the power supply circuit 17 are installed.

[0089] (7) In the bearing device 1 according to (6), the magnetic ring 7 , the coil 24 , and the circuit board 13 are arranged to be spaced apart from each other on a virtual straight line L extending in a radial direction of the bearing 2 .

[0090] (at last) The features described in the above-mentioned embodiments (including the examples) may be appropriately combined and applied within the scope of no technical contradiction.

[0091] The embodiments disclosed this time should be considered as illustrative in all aspects and not restrictive. The scope of the present invention is indicated by the claims rather than the above description, and is intended to include all changes within the meaning and scope equivalent to the claims. Explanation of symbols

[0092] 1-bearing device; 2-bearing; 3-outer ring; 3a-first cutout; 3a1, 3a2, 4a1, 4a2-cutout; 3b-outer ring raceway surface; 3c-outermost surface; 3d-inner diameter surface; 3n, 4n-inner chamfer; 4-inner ring; 4a-second cutout; 4b-outer diameter surface; 4b2-inner ring raceway surface; 4c-innermost surface; 5, 5A, 5B-stator; 6-sensor unit; 7-magnetic ring; 7a-core shaft; 7b-multipolar magnet; 7c-flange; 8-rolling element; 9-retainer; 10-seal; 11, 20 end surface; 12-retaining member; 12A-side plate; 12b-back surface; 12C, 22B-outer periphery; 12C1-first outer periphery; 12C2 -Second outer periphery; 12Ca-outer periphery mating surface; 12Ca1, 12Ca2, 12Da1, 12Da2-mating surface; 12D, 22D-inner periphery; 12D1-first inner periphery; 12D2-second inner periphery; 12Da-inner periphery mating surface; 12e-hole; 12f-front; 12g-opening; 13-circuit board; 14-cover; 15-acceleration sensor; 16-temperature sensor; 17-power supply circuit; 18-wireless communication circuit; 18a-antenna; 19-screw; 21, 22-magnetic body component; 21a, 22a-claw; 22C-end face portion; 23-bobbin; 24-coil; 25-terminal; G-generator; O-rotation axis.

Claims

1. A bearing device, characterized in that: include: A bearing comprising an outer ring, an inner ring and rolling elements; as well as a sensor unit fixed to a fixed ring serving as either the outer ring or the inner ring and holding a sensor for monitoring the state of the bearing, The sensor unit includes a holding member, The holding member includes a side plate portion and a peripheral portion extending so as to intersect the side plate portion. The retaining member and the fixing ring are engaged with each other at the periphery. A first fitting surface of the peripheral portion that fits with the fixing ring and a second fitting surface of the fixing ring that fits with the peripheral portion partially contact each other, and portions other than the portions are arranged at a distance from each other.

2. The bearing device according to claim 1, characterized in that: The first fitting surface has a step such that a radial distance from a surface of the fixing ring opposite to a surface contacting the rolling element becomes smaller on an opening side opposite to the side plate side in the axial direction than on the side plate side.

3. The bearing device according to claim 1 or 2, characterized in that: The second fitting surface has a step whose radial distance from a surface of the fixing ring opposite to a surface contacting the rolling element is larger on a side opposite to the rolling element side in the axial direction than on a side opposite to the rolling element side.

4. The bearing device according to claim 1 or 2, characterized in that: The second fitting surface has a step whose radial distance from a surface of the fixing ring opposite to a surface contacting the rolling element is smaller on a side opposite to the rolling element side in the axial direction than on a side opposite to the rolling element side.

5. The bearing device according to claim 1 or 2, characterized in that: The sensor unit is fixed to the fixing ring so as not to protrude axially outward from the end surface of the fixing ring.

6. The bearing device according to claim 1 or 2, characterized in that: Also includes: A magnetic ring, which is fixed to the rotating ring as any one of the outer ring and the inner ring, and has N poles and S poles alternately magnetized; a stator including the holding member fixed to the fixing ring in a manner opposed to the magnetic ring in a radial direction of the bearing as a structural component and accommodating a coil; A wireless communication circuit, which transmits the output of the sensor to the outside in a wireless manner; a power circuit capable of regulating the output from a generator formed by the magnetic ring and the stator; as well as A circuit substrate on which the sensor, the wireless communication circuit, and the power supply circuit are mounted.

7. The bearing device according to claim 6, characterized in that: The magnetic ring, the coil, and the circuit board are arranged so as to be spaced apart from each other on a virtual straight line extending in a radial direction of the bearing.

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