Bearing device

Abstract

In a bearing device in which a sensor unit holder is fitted to the first raceway ring of a rolling bearing, the deformation of both the first raceway ring and the holder due to the fitting is reduced. [Solution] The inner circumference 17 of either the inner or outer circumference 17 or 18 of the first raceway ring 4 has a raceway surface 17a, a stepped surface 17b that restricts the axial inward movement of the holder 10, a support surface 17c that fits into the fitting portion 12 of the holder 10, and a recess 17d formed at a position further axially outward than the stepped surface 17b. The retaining member 37 further has a fitting portion 38 that is fitted into the recess 17d and whose axial outward movement is restricted by the recess 17d, and a restricting portion 39 which is a portion that protrudes from the recess 17d toward the second raceway ring 5, and the holder 10 has a side end portion 40 that engages with the restricting portion 39 axially outward.

Description

Technical Field

[0001] This invention relates to a bearing device including a rolling bearing and a sensor unit.

Background Art

[0002] Conventionally, a sensor or the like for detecting the state of a rolling bearing is mounted on a substrate to form a circuit board with a sensor, and the circuit board is held by a holder and assembled into a sensor unit, and the sensor unit is fixed to a race ring. A bearing device is known. The state of a rolling bearing is generally detected by detecting temperature and vibration.

[0003] When a stator of a generator that supplies power to the circuit board is provided in the sensor unit, the holder may have a yoke function. Also, in some cases where it is preferable to detect the vibration of a bearing, etc., it may be preferable to arrange the holder coaxially with the race ring in the bearing state detection. In such a case, the holder is formed as an annular body and is fitted to be arranged coaxially with the race ring. And, as a fixing means between the holder and the race ring, fitting and fixing of the holder to one of the inner and outer circumferences of the race ring is adopted.

[0004] Also, there may be cases where it is desired to increase the area of the circuit board in order to enhance the functionality of the sensor unit, such as mounting a power circuit for AC-DC conversion on the substrate, mounting a wireless communication circuit on the substrate, or mounting a plurality of sensors on the substrate. In such a case, the holder is provided with a side plate portion extending in the radial direction and an annular plate portion extending in the axial direction from the race ring side of the side plate portion, the circuit board is attached to the side plate portion, and a structure in which the annular plate portion is press-fitted into the race ring is adopted, so that while increasing the area of the circuit board, the axial width of the sensor unit is also suppressed.

[0005] The above-described holder is generally formed of a metal plate in order to ensure a strength suitable for purposes such as press-fitting into the race ring and stable positioning of the sensor. In particular, when the holder has a yoke function, it is made of an iron-based magnetic material.

[0006] For example, in the bearing device of Patent Document 1, an L-shaped holder is attached to the raceway. The holder also serves as a yoke in the stator of the generator. The circuit board is a control board that includes multiple sensors such as a temperature sensor. The annular plate portion of the holder is fitted to the circumferential surface of the stepped end formed on the raceway, and the rolling element side of the holder abuts axially against the stepped surface of the stepped end. As a result, the holder and the raceway are arranged coaxially, and the displacement of the holder toward the rolling element side is restricted. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2003-307435 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] However, when the holder is fixed to the raceway ring by press-fitting the annular plate portion of the holder with the circumferential surface of the stepped end of the raceway ring, in order to ensure the pull-out strength of the holder against the circumferential surface of the stepped end by press-fitting, it is necessary to ensure a sufficient radial interference fit between the circumferential surface of the stepped end and the annular plate portion of the holder. The metal plate forming the holder also needs to have a plate thickness suitable for purposes such as sensor positioning and press-fitting. For these reasons, if the aforementioned radial interference fit is excessive, it becomes difficult to press-fit the parts together, and the pressing load during press-fitting may cause deformation of the raceway surface or the holder, potentially adversely affecting the performance of the rolling bearing and sensor unit. In particular, when the holder is press-formed from a metal plate, the tolerance width of the holder becomes larger compared to machined holders, increasing concerns that the press-fitting operation will be difficult.

[0009] In light of the above background, the problem that this invention aims to solve is to reduce the deformation of both the first raceway ring and the holder in a bearing device in which the holder of a sensor unit is fitted to the first raceway ring of a rolling bearing. [Means for solving the problem]

[0010] As a first means to solve the above problems, this invention provides a rolling bearing comprising a first raceway, a second raceway, and a plurality of rolling elements disposed between the first raceway and the second raceway; a sensor unit comprising a substrate, a sensor mounted on the substrate, and a metal plate holder supporting the substrate, wherein the holder has an annular side portion extending in the radial direction and fitting portions protruding axially from the outer and inner edges of the annular side portion, and the first raceway has an inner circumference portion and an outer circumference portion, and the circumference portion of either the inner circumference portion or the outer circumference portion is The bearing device has a raceway surface, a stepped surface that restricts the axial inward movement of the holder, and a support surface that fits into the fitting portion, wherein one of the circumferential portions has a recess formed at a position closer to the axial outward position than the stepped surface, and further comprises a retaining member having a fitting portion that is fitted into the recess and whose axial outward movement is restricted by the recess, and a regulating portion which is a portion that protrudes from the recess toward the second raceway ring, and the holder has a side end that engages with the regulating portion toward the axial outward direction, the bearing device adopts a configuration 1.

[0011] According to the above configuration 1, one circumference of the first raceway has a recess located axially outward from the stepped surface that restricts the axial inward movement of the holder. This makes it possible to fit another member into the recess and restrict the axial movement of the other member relative to the first raceway. As the other member, a retaining member is employed which has a fitting portion that is fitted into the recess and whose axial outward movement is restricted by the recess, and a restricting portion that is a portion that protrudes from the recess toward the second raceway. The holder has a side end that engages with the retaining member axially outward, so that the retaining member can restrict the axial outward movement of the sensor unit relative to the first raceway. As a result, it becomes unnecessary to prevent the sensor unit from coming off by press-fitting the support surface of the first raceway and the fitting portion of the holder, and it becomes possible to loosen the fit between the support surface and the fitting portion.

[0012] Furthermore, since the retaining member's fitting portion is fitted into a recess formed on one periphery including the raceway surface of the first raceway ring, and the sensor unit is axially supported by a restricting portion that protrudes from this recess toward the second raceway ring, it is also possible to house the retaining member inside the rolling bearing so that the retaining member does not get in the way when assembling the rolling bearing between the shaft and the housing.

[0013] In the above configuration 1, a configuration 2 can be adopted in which the fitting portion of the retaining member is fitted into the recess of the first raceway ring such that its circumferential movement is restricted by the recess, and the holder has a first opposing end that engages with the restricting portion of the retaining member toward one side in the circumferential direction, and a second opposing end that engages with the restricting portion toward the other side in the circumferential direction.

[0014] According to the above configuration 2, the circumferential movement of the fitting portion of the retaining member is restricted by the recess of the first raceway ring, and the corresponding first opposing end or second opposing end of the holder can engage with the restricting portion of the retaining member toward one or the other side in the circumferential direction, thereby restricting the circumferential movement of the holder relative to the first raceway ring. This makes it possible to keep the sensor in an appropriate circumferential position relative to the rolling bearing.

[0015] In the above configuration 2, a configuration 3 can be adopted in which the recess of the first raceway intersects the support surface in the circumferential direction, the fitting portion of the holder has a notched edge that forms a space at a position facing radially to the recess, and the notched edge includes the side end, the first opposing end, and the second opposing end of the holder.

[0016] According to the above configuration 3, the recess of the first raceway ring intersects the support surface in the circumferential direction, and the fitting portion of the holder has a notched edge that forms a space at a position facing the recess radially. Therefore, without reducing the overall width of the support surface and the fitting portion, it becomes possible to position the restricting portion of the retaining member so that it protrudes radially into the space formed by the notched edge. Since the notched edge includes the side end of the holder and the first and second opposing ends, it becomes possible to engage the restricting portion protruding into that space with the notched edge to prevent the holder from coming off or rotating.

[0017] In the above configuration 3, a configuration 4 can be adopted in which the sensor unit has an opening provided so that the fitting portion of the retaining member can be fitted into the recess of the first raceway when the fitting portion of the holder is fitted into the support surface of the first raceway, and the notched edge of the holder is shaped to be open toward the axial outward.

[0018] According to the above configuration 4, the retaining member is fitted into the recess from the outside of the rolling bearing through the opening of the sensor unit while the fitting portion of the holder is fitted to the support surface of the first raceway ring. As a result, the shape of the notched edge of the fitting portion is not complicated, and since the notched edge is open toward the axial outward direction, the fitting portion does not get in the way when inserting the retaining member into the recess.

[0019] In the above configuration 3 or 4, a configuration 5 can be adopted in which the sensor unit has an opening provided so that the fitting portion of the retaining member can be fitted into the recess of the first raceway when the fitting portion of the holder is fitted into the support surface of the first raceway, and a cover portion that closes the opening and radially supports the restricting portion of the retaining member.

[0020] According to the above configuration 5, the retaining member is fitted into the recess from the outside of the rolling bearing through the opening of the sensor unit while the fitting portion of the holder is fitted to the support surface of the first raceway ring. Therefore, the shape of the notched edge of the fitting portion does not become complicated. Furthermore, by closing the opening with the cover portion, the inside of the sensor unit is protected, and by supporting the restricting portion radially with the cover portion, it is possible to prevent the retaining member from coming out of the recess. For this reason, it becomes unnecessary to fix the retaining member with adhesive or the like.

[0021] In the above configuration 5, a configuration 6 can be adopted in which the holder has a bent portion that sandwiches the cover portion with the annular side portion in the axial direction.

[0022] According to the above configuration 6, the cover can be sandwiched in the axial direction between the annular side and the bent part of the holder, making it possible to prevent the cover from falling off or shifting in the axial direction.

[0023] As a second means to solve the above problems, this invention provides a rolling bearing comprising a first raceway, a second raceway, and a plurality of rolling elements disposed between the first and second raceway, and a sensor unit comprising a substrate, a sensor mounted on the substrate, and a metal plate holder supporting the substrate, wherein the holder has an annular side portion extending in the radial direction and a fitting portion protruding axially from the annular side portion, and the first raceway has an inner circumference portion and an outer circumference portion, and the circumference portion of either the inner circumference portion or the outer circumference portion is a raceway surface and regulated the axial inward movement of the holder The bearing device has a stepped surface that controls movement and a support surface that fits into the fitting portion, and the first raceway ring has a recess that is continuous with the inner circumference and the other circumference of the outer circumference opposite to one of the circumferences and with both axial ends of the first raceway ring, and the retaining member further has a fitting portion that is fitted into the recess and whose movement outward in the axial direction is restricted by the recess, and a restricting portion which is a portion that protrudes from the recess toward the second raceway ring, and the sensor unit has a side end that engages with the restricting portion outward in the axial direction, thus the bearing device configuration 7 is adopted.

[0024] According to the above configuration 7, since the first track wheel has a concave portion continuous with both axial ends of the first track wheel and the other circumferential portion opposite to one circumferential portion including the track surface, it is possible to fit another member into the concave portion and restrict the axial movement of the other member. As the other member, an anti-drop member having a fitting portion fitted into the concave portion and restricted from moving axially outward by the concave portion, and a restricting portion protruding from the concave portion toward the second track wheel is adopted. Since the sensor unit has a side end portion that engages with the restricting portion axially outward, it becomes possible to restrict the sensor unit from moving axially outward with respect to the first track wheel by the anti-drop member. As a result, it becomes unnecessary to prevent the sensor unit from dropping by press-fitting the support surface of the first track wheel and the fitting portion of the holder, and it becomes possible to loosen the fitting between the support surface and the fitting portion.

[0025] In addition, since the fitting portion of the anti-drop member is arranged in a state of straddling the concave portion outside the rolling bearing, it becomes possible to easily perform the fitting process to the first track wheel as compared with the case of arranging it inside the rolling bearing.

[0026] Moreover, since the fitting portion of the anti-drop member is fitted into the concave portions located at the other circumferential portion and both axial ends of the first track wheel, and the sensor unit is axially received by the restricting portion protruding from the concave portion toward the second track wheel, it is also possible to reduce or eliminate the protrusion of the anti-drop member with respect to the cross-sectional height of the rolling bearing and the bearing width, and to prevent the anti-drop member from becoming an obstacle when assembling between the shaft and the housing.

[0027] In the above configuration 7, the configuration 8 can be adopted in which the fitting portion of the anti-drop member is fitted into the concave portion so as to be restricted from circumferential movement by the concave portion of the first track wheel, and the sensor unit has a first opposing end portion that engages with the restricting portion of the anti-drop member toward one side in the circumferential direction and a second opposing end portion that engages with the restricting portion toward the other side in the circumferential direction.

[0028] According to the above configuration 8, the circumferential movement of the fitting portion of the retaining member is restricted by the recess of the first raceway, and the corresponding first opposing end or second opposing end of the sensor unit can engage with the restricting portion of the retaining member toward one or the other side in the circumferential direction, thereby restricting the circumferential movement of the sensor unit relative to the first raceway. This makes it possible to keep the sensor in an appropriate circumferential position relative to the rolling bearing.

[0029] In the above configuration 8, a configuration 9 can be adopted in which the recess of the first raceway intersects the support surface in the circumferential direction, the fitting portion of the holder has a notched edge that forms a space at a position facing radially to the recess, and the notched edge includes the side end, the first opposing end, and the second opposing end of the sensor unit.

[0030] According to the above configuration 9, the recess of the first raceway ring intersects the support surface in the circumferential direction, and the fitting portion of the holder has a notched edge that forms a space at a position facing radially into the recess. Therefore, it is possible to position the restricting portion of the retaining member so that it protrudes radially from the recess into the space without reducing the overall width of the support surface and the fitting portion. Since the notched edge includes the side end of the sensor unit and the first and second opposing ends, it is possible to engage the restricting portion protruding into the space with the notched edge to prevent the sensor unit from coming loose or rotating.

[0031] In the above configuration 9, a configuration 10 can be adopted in which the retaining member has a hook portion that protrudes from the restricting portion and overlaps the fitting portion radially at a position that protrudes from the notched edge of the holder toward the second raceway ring.

[0032] According to the above configuration 10, the hooking portion of the retaining member can engage radially with the fitting portion of the holder from the second raceway side toward the first raceway, thereby keeping the fitting portion fitted into the recess of the first raceway and preventing the retaining member from falling out or shifting.

[0033] In the above configuration 10, a configuration 11 can be adopted in which the restricting portion of the retaining member protrudes from the fitting portion in a cantilevered manner so as to elastically press the notched edge of the holder in the circumferential direction.

[0034] According to the above configuration 11, since the restricting portion of the retaining member protrudes from the fitting portion in a cantilevered manner, when fitting the fitting portion into the recess of the first raceway ring, it becomes easier to forcibly pass the catching portion between the first and second opposing ends of the notched edge of the holder and elastically deform the restricting portion in the circumferential direction. Consequently, the elastic restoring force pushes the notched edge in the circumferential direction, further preventing circumferential displacement of the retaining member, and making it easier to attach and detach the retaining member to and from the first raceway ring.

[0035] In any one of the above configurations 7 to 11, configuration 12 can be adopted in which the retaining member is provided such that the fitting portion elastically grips the recess of the first raceway in the axial direction, or the fitting portion and the regulating portion elastically grip the recess and the side end of the sensor unit in the axial direction.

[0036] According to the above configuration 12, the fitting portion of the retaining member can elastically grip the recess of the first raceway ring, or the fitting portion and regulating portion of the retaining member can elastically grip the recess and the side end of the sensor unit in the axial direction, thereby preventing the retaining member from falling out or shifting.

[0037] In any one of the above configurations 7 to 12, configuration 13 can be adopted in which the fitting portion of the retaining member and the recess of the first raceway ring are shaped such that the entire fitting portion fits into the recess, and the restricting portion does not protrude axially outward from the fitting portion.

[0038] According to the above configuration 13, the entire fitting portion of the retaining member is housed in the recess of the first raceway ring, so the entire fitting portion is positioned within the range of the rolling bearing's cross-sectional height and bearing width. Furthermore, since the restricting portion does not protrude axially outward from the fitting portion, the entire restricting portion is also positioned within the range of the rolling bearing's cross-sectional height and bearing width. Therefore, it becomes possible to eliminate any protrusion of the retaining member relative to the rolling bearing's cross-sectional height and bearing width.

[0039] In any one of the above configurations 7 to 13, configuration 14 can be adopted in which the sensor unit has an opening provided so as to accommodate the substrate on the side surface of the annular side of the holder, and a cover portion that closes the opening, and the restricting portion of the retaining member is provided so as to sandwich the cover portion with the annular side in the axial direction.

[0040] According to the above configuration 14, after placing the substrate on the annular side of the holder through the opening of the sensor unit, the opening can be closed with the cover to protect the inside of the sensor unit. Since the cover can be sandwiched axially between the annular side of the holder and the restricting portion of the retaining member, it is possible to prevent the cover from falling off or shifting in the axial direction. [Effects of the Invention]

[0041] As described above, by adopting configuration 1 or 7, this invention makes it possible to reduce the deformation of both the first raceway ring and the holder due to the fitting of the sensor unit in a bearing device in which the holder of the sensor unit is fitted to the first raceway ring of the rolling bearing. [Brief explanation of the drawing]

[0042] [Figure 1] Cross-sectional view showing a bearing device according to the first embodiment of this invention. [Figure 2] Right side view showing a partially cut-out section of the bearing device cover in Figure 1. [Figure 3] Enlarged view of the area around the substrate in Figure 1 [Figure 4] Partial perspective view of the bearing device in Figure 1. [Figure 5] Figure 1: Exploded perspective view of the sensor unit [Figure 6] Figure 1 is a perspective view showing the assembly unit during the manufacturing stage of the sensor unit. [Figure 7] Partial perspective view showing the inner circumference of the first raceway ring in Figure 1. [Figure 8] Partial perspective view of the holder in Figure 1. [Figure 9] Perspective view of the retaining member in Figure 1. [Figure 10] A partial cross-sectional view showing the assembly unit in Figure 6 fitted onto the first raceway. [Figure 11] Partial cross-sectional view showing the state in which the retaining member is fitted into the recess, as in the state shown in Figure 10. [Figure 12] Partial cross-sectional view showing the state with the cover attached, as shown in Figure 11. [Figure 13] Partial perspective view of the holder of the bearing device according to the second embodiment of this invention [Figure 14] Partial cross-sectional view showing the state corresponding to Figure 10 of the second embodiment. [Figure 15] Cross-sectional view showing a bearing device according to the third embodiment of this invention. [Figure 16] Partial perspective view showing the outer circumference of the first raceway ring in Figure 15. [Figure 17] Perspective view of the bearing device in Figure 15. [Figure 18] Perspective view of the retaining member in Figure 15. [Figure 19] Enlarged view of the area around the substrate in Figure 15. [Figure 20] Figure 15: Partial right side view of the bearing device [Figure 21] A perspective view showing the assembly unit corresponding to Figure 6 of the sensor unit in Figure 15. [Figure 22] Partial perspective view of the retaining member of the bearing device according to the fourth embodiment of this invention. [Figure 23] Partial right side view of the bearing device in Figure 22. [Modes for carrying out the invention]

[0043] As an example relating to the first means of this invention, a bearing device according to the first embodiment (hereinafter referred to as "this bearing device") will be described based on Figures 1 to 12 of the attached drawings.

[0044] The bearing device shown in Figure 1 comprises a rolling bearing 1, a sensor unit 2, and a generator 3.

[0045] Here, the circumferential direction around the bearing central axis (not shown) of the rolling bearing 1 is called the "circumferential direction," the direction along that bearing central axis is called the "axial direction," and the direction perpendicular to that bearing central axis is called the "radial direction." In Figure 1, the axial direction corresponds to the left-right direction, and the radial direction corresponds to the up-down direction. The outer axial side means the side that moves away from the center of the width (total length in the axial direction) of the rolling bearing 1 in the axial direction, and the inner axial side means the side that approaches the center of the width of the rolling bearing 1 in the axial direction.

[0046] The rolling bearing 1 includes a first raceway 4, a second raceway 5, and a plurality of rolling elements 6 positioned between the first raceway 4 and the second raceway 5. The rolling elements 6 are held at equal intervals in the circumferential direction by a cage 7.

[0047] The sensor unit 2 is fixed to the first raceway 4.

[0048] The first raceway wheel 4 is usually positioned as a stationary wheel. The second raceway wheel 5 is usually positioned as a rotating wheel.

[0049] As shown in Figures 1 and 2, the sensor unit 2 comprises a substrate 8, one or more sensors 9a and 9b mounted on the substrate 8, and a metal plate holder 10 that supports the substrate 8. The substrate 8 with sensors 9a and 9b and the holder 10 are integrated into a single unit. The sensor unit 2 can output the detection results of sensors 9a and 9b to a predetermined destination.

[0050] Sensors 9a and 9b detect at least one of a physical quantity and a chemical quantity related to the state of the rolling bearing 1. The holder 10 has an annular side portion 11 that extends radially and a fitting portion 12 that protrudes axially from the outer and inner edges of the annular side portion 11. In its mounted state fitted to the first raceway 4, the holder 10 is an annular body that positions the substrate 8 and sensors 9a and 9b in predetermined positions relative to the first raceway 4.

[0051] The generator 3 consists of a magnetic ring 13 that is rotatably integrated with the second raceway 5, and a stator 14 that faces the magnetic ring 13. The relative circumferential rotation between the magnetic ring 13 and the stator 14 is electromagnetically converted into electricity.

[0052] The sensor unit 2 and the magnetic ring 13 are fixed to one axial end (the right end in Figure 1; hereinafter referred to as the "right end") of the corresponding first or second raceway 4 or second raceway 5, respectively. The other axial end (the left end in Figure 1; hereinafter referred to as the "left end") of the first raceway 4 and the second raceway 5 are sealed by a seal 15 fixed to the left end of the first raceway 4 and a sealing surface 16 formed on the second raceway 5.

[0053] Rolling bearing 1 is a radial bearing. Furthermore, rolling bearing 1 is a standard bearing conforming to 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 ISO 15 or JIS B 1512-1.

[0054] The first raceway ring 4 is an outer ring having an inner circumference 17 including a raceway surface 17a, an outer circumference 18 including a fitting surface 18a, and two width surfaces 19 that define the width (overall length in the axial direction) of the first raceway ring 4.

[0055] The second raceway ring 5 is an inner ring having an outer circumference 20 including a raceway surface 20a, an inner circumference 21 including a fitting surface 21a, and two width surfaces 22 that define the width of the second raceway ring 5.

[0056] The raceway surfaces 17a and 20a form the track for the rolling elements 6. Each mating surface 18a and 21a is curved along the circumferential direction. Each mating surface 18a and 21a defines the outer or inner diameter of the corresponding raceway ring 4 or 5. Each mating surface 18a and 21a is fitted into the corresponding shaft or housing. Each width surface 19 and 22 is flat along the radial and circumferential directions.

[0057] The first raceway 4 and the second raceway 5 are provided with the same width. The sensor unit 2 and the magnetic ring 13 do not have any parts that protrude to the right (outward in the axial direction) of the width surfaces 19 and 22 on the right end sides of both raceway 4 and 5.

[0058] The rolling element 6 rolls between the raceway surfaces 17a and 20a. The rolling element 6 is ball-shaped.

[0059] The cage 7 is a crown-shaped cage with a ring portion only on the side opposite the sensor unit 2 (the side away from the sensor unit 2, the left side in Figure 1) relative to each rolling element 6. A predetermined distance is maintained between the rolling elements 6, cage 7 and the sensor unit 2 so that the sensor unit 2 does not come into contact with the rolling elements 6 and cage 7 during the operation of the rolling bearing 1.

[0060] Although the example given uses a deep groove ball bearing as the rolling bearing 1, the rolling bearing is not limited to a deep groove ball bearing and can be changed to various other bearings such as angular contact ball bearings and self-aligning bearings.

[0061] The circuit board 8 consists of a printed circuit board. The circuit board 8 is shaped like a circular arc, being shorter in the radial direction and longer in the circumferential direction. Sensors 9a and 9b, a wireless communication circuit 23, and a power supply circuit 24 are mounted on the right side of the circuit board surface of the circuit board 8.

[0062] As shown in Figure 1, the substrate 8 is positioned opposite the stepped surface 17b of the inner circumference 17 in the axial direction. As shown in Figures 2 and 5, the substrate 8 is fastened in the axial direction to the annular side portion 11 by a plurality of screws 25.

[0063] The sensor 9a consists of a circuit that converts temperature into an electrical signal (hereinafter referred to as temperature sensor 9a as appropriate). The temperature sensor 9a is positioned opposite the raceway surface 17a in the axial direction. One of the main causes of heat generation in the rolling bearing 1 is the heat generated at the contact point between the rolling elements 6 and the first raceway ring 4. The faster this heat reaches the temperature sensor 9a, the faster and more accurately the temperature change of the first raceway ring 4 can be detected. Therefore, it is preferable to provide a heat conduction path consisting of a solid portion that is continuous in the axial direction from the raceway surface 17a to the substrate 8, preferably to the temperature sensor 9a. Alternatively, a hole may be formed in the substrate 8, the temperature sensor may be embedded in this hole, and the temperature sensor may be in contact with the right side surface of the annular side portion 11.

[0064] Sensor 9b consists of a circuit that converts physical or chemical quantities other than temperature into electrical signals. Sensor 9b is, for example, at least one of the group consisting of an acceleration sensor and an AE sensor (Acoustic Emission). If an acceleration sensor is used, radial and axial acceleration can be detected to monitor vibrations of the rolling bearing 1. If an AE sensor is used, when sound is emitted as an elastic wave (AE wave) when a part of an object such as a component of the rolling bearing 1 is deformed or damaged, or when an impact is applied, the sound generated can be detected. The number of sensors mounted on the substrate 8 is not particularly limited, and for example, electronic components including a temperature sensor and an acceleration sensor may be used.

[0065] The wireless communication circuit 23 consists of a communication circuit that converts predetermined information, such as detection results from sensors 9a and 9b, into radio waves and radiates them from an antenna. The wireless communication circuit 23 conforms to a predetermined communication protocol and is generally modular. To avoid a decrease in wireless communication performance, no other components such as sealing materials are in contact with the antenna of the wireless communication circuit 23.

[0066] The power supply circuit 24 consists of a circuit that converts the AC power generated by the stator 14 of the generator 3 into DC power used by the circuit board 8.

[0067] The sensor unit 2 is a wireless unit that can transmit the detection results of sensors 9a and 9b via the wireless communication circuit 23 using the AC power generated by the stator 14, without requiring wired connections to other communication devices or external power sources other than this bearing device.

[0068] The holder 10 is formed from a single, seamless metal plate. The annular side portion 11 is a ring-shaped plate extending radially. The fitting portion 12 is a cylindrical shape extending axially from the radial end of the annular side portion 11 closer to the first raceway ring 4.

[0069] As shown in Figures 1 and 3, the inner circumference 17 of the first raceway 4 includes a stepped surface 17b that restricts the axial inward movement of the holder 10 (to the left in Figure 1), and a support surface 17c that engages with the fitting portion 12 of the holder 10. The stepped surface 17b and the support surface 17c are formed at a position where the axial distance to the raceway surface 17a is closer than the width surface portion 19 on the right end. The stepped surface 17b extends radially along the entire circumference. The support surface 17c is formed in an annular shape along the axial and circumferential directions. The stepped surface 17b intersects with the left end of the support surface 17c. The inner circumference 17 of the first raceway 4 may also include a recess between the stepped surface 17b and the support surface 17c to facilitate machining.

[0070] The left side of the annular side portion 11 is abutted axially against the stepped surface 17b. This ensures that the axial positional relationship between the holder 10 and the first raceway ring 4 is properly determined, and the tilt of the sensor unit 2 in the radial direction is restricted by the stepped surface 17b.

[0071] The outer circumference of the fitting portion 12 is located on the outer circumference of the sensor unit 2. The fitting portion 12 is fitted onto the support surface 17c. As a result, the holder 10 is positioned with a predetermined degree of coaxiality with the first raceway ring 4.

[0072] As shown in Figures 1 and 4, the magnetic ring 13 has a magnet portion 26a that is alternately magnetized with north and south poles in the circumferential direction, and a core metal portion 26b that supports the magnet portion 26a. The magnet portion 26a is formed of magnetic rubber that extends in the circumferential direction. The magnet portion 26a is bonded to the core metal portion 26b. The inner circumference of the core metal portion 26b is fitted onto the outer circumference 20 of the second raceway ring 5, so that the magnetic ring 13 and the second raceway ring 5 are arranged at a predetermined degree of coaxiality. The core metal portion 26b has a flange portion to increase its rigidity. The outer circumference 20 of the second raceway ring 5 includes a stepped end portion 20b that forms a space for arranging the flange portion of the core metal portion 26b.

[0073] The stator 14 guides the magnetic flux emitted from the magnetic ring 13 through a yoke structure, inducing an AC voltage in the coil 27 within the yoke structure. The stator 14 is installed in the sensor unit 2. As shown in Figures 3 and 5, the yoke structure of the stator 14 consists of a holder 10 and a yoke member 28.

[0074] The holder 10 and the yoke member 28 are each made of a magnetic material such as a steel plate.

[0075] The holder 10 has a first claw pole portion 29 that extends axially on the same side as the fitting portion 12 (right side in Figure 3) from the radial end of the annular side portion 11 furthest from the first raceway ring 4, at regular intervals in the circumferential direction.

[0076] The yoke member 28 has an annular plate portion 30 facing radially opposite the fitting portion 12, a side plate portion 31 extending radially from the side opposite the annular portion 11 (right side in Figure 3) of the annular plate portion 30 toward the side opposite the fitting portion 12 (downward side in Figure 3), and a second claw pole portion 32 extending from the side plate portion 31 at regular intervals in the circumferential direction toward the side opposite the annular portion 11 (left side in Figure 3).

[0077] As shown in Figures 3, 4, and 6, the yoke structure of the stator 14 is formed of a first claw pole section 29, an annular side section 11, an annular plate section 30, a side plate section 31, and a second claw pole section 32. Both claw pole sections 29 and 32 are located on the inner circumference of the sensor unit 2. Both claw pole sections 29 and 32 face each other radially with an air gap between them and the magnet section 26a. Both claw pole sections 29 and 32 are arranged in opposite directions axially and alternately in the circumferential direction. There is a circumferential air gap between the first claw pole section 29 and the second claw pole section 32 that are adjacent in the circumferential direction. The total number of both claw pole sections 29 and 32 is equal to the number of poles of the magnet section 26a (total number of N poles and S poles).

[0078] As shown in Figures 3 and 5, multiple arc-shaped holes 11a are formed in the circumferential direction, penetrating the annular side portion 11 in the axial direction. Projections 33 that fit into the inner surface of the holes 11a protrude axially from the annular plate portion 30. As shown in Figure 6, the annular plate portion 30 abuts axially against the right side surface of the annular side portion 11 in almost all areas except for the regions where these projections 33 are located.

[0079] The coil 27 is wound on a bobbin. The coil 27 is arranged around the entire circumference in the space enclosed by the annular side portion 11, the side plate portion 31, the annular plate portion 30, and the rows of both claw pole portions 29 and 32. As shown in Figure 6, both ends 27a of the coil 27 are connected to the substrate 8 through wiring holes slightly formed in the annular plate portion 30. The bobbin can be omitted.

[0080] Furthermore, at least a portion of the surface of the coil 27 and bobbin shown in Figures 3 and 5 may be in contact with the aforementioned claw pole portions 29 and 32, the annular side portion 11, and the side plate portion 31. To protect the magnet wire forming the coil 27 for the purposes of insulation, heat resistance, dustproofing, moisture resistance, and abrasion prevention, a varnish treatment may be employed, in which the coil 27 is immersed in varnish or coated by dripping varnish onto the coil 27. It is also possible to omit the bobbin.

[0081] During operation of the rolling bearing 1, the magnetic ring 13 and stator 14 function as a radial-type claw-pole generator. That is, the magnetic flux emanating from the north pole of the magnet section 26a shown in Figures 1 and 4 travels around the coil 27, for example, entering the annular side section 11 (or side plate section 31) from the first claw-pole section 29 (or second claw-pole section 32), passing through the annular plate section 30 to the side plate section 31 (or annular side section 11), and returning to the south pole of the magnet section 26a via the adjacent second claw-pole section 32 (or first claw-pole section 29). As the second raceway 5 rotates relative to the first raceway 4, the positions of the north and south poles of the magnet section 26a are reversed, and the direction of the magnetic flux is reversed. The alternating magnetic field generated in this way generates an alternating voltage at both ends 27a (see Figure 6) of the coil 27, at the beginning and end of the winding.

[0082] In this bearing device, Figure 1 shows an example where the stator 14 of the generator is provided on the sensor unit 2 as its power source. However, a battery may be added to supply power to the circuit board 8 as an emergency power source, or the sensor unit's power source may be configured solely with a battery. Furthermore, when the sensor unit is equipped with a power generation function, a power generation method other than the claw-pole type may be adopted. For example, a receiving antenna for wireless power supply, such as an electromagnetic induction type, may be provided on the sensor unit.

[0083] The sensor unit 2 is provided with an opening 35 for positioning the substrate 8 on the annular side portion 11. The opening 35 is formed by the inner circumference of the fitting portion 12, the right side of the annular side portion 11, and the outer circumference of the annular plate portion 30. As shown in Figures 1, 2, and 3, the sensor unit 2 is provided with a cover portion 36 that covers the opening 35 to protect the substrate 8 from the outside.

[0084] The holder 10 and yoke member 28 shown in Figures 5 and 6 are each formed from a single, seamless metal plate. The overall shape of each of the holder 10 and yoke member 28 is press-formed.

[0085] The cover portion 36 is a ring-shaped body made of resin that does not contain metal. Even if the holder 10 etc. are made of metal, wireless communication using the wireless communication circuit 23 is possible because the cover portion 36 is radio wave transparent.

[0086] As shown in Figures 1 and 3, the metal plate forming the holder 10 should be thick enough to stably hold the position of the substrate 8 relative to the first raceway ring 4 with the holder 10. For example, when forming the holder 10 with an iron-based metal plate that has weldability and press-formability, it is preferable to make the plate thickness greater than 0.4 mm, and more preferably 0.6 mm or more. When manufacturing a holder 10 of this thickness by press forming, mold wear must be taken into consideration, so the tolerance range of the diameter dimension of the fitting portion 12 becomes larger, for example, to 0.2 mm.

[0087] On the other hand, the support surface 17c is formed by machining. In the case of machining, the tolerance range for the diameter dimension of the support surface 17c is relatively small, for example, the tolerance range is 0.03 mm.

[0088] If the fitting portion 12 and the support surface 17c were press-fitted, the tolerance range of the holder 10, which is a pressed part, would be large, resulting in a large radial interference fit during press-fitting (for example, a maximum interference fit of 0.2 mm). This would make the press-fitting process difficult and raise concerns about deformation of the holder 10 and the first raceway ring 4. To avoid these problems, the support surface 17c and the fitting portion 12 are clearance-fitted. That is, the minimum inner diameter of the support surface 17c is greater than the maximum outer diameter of the fitting portion 12.

[0089] When the support surface 17c and the fitting portion 12 are fitted with a clearance, it is required to ensure the pull-out resistance of the holder 10 to the right relative to the support surface 17c. Furthermore, depending on the required specifications for the arrangement of sensors 9a, 9b, etc., to be held by the holder 10, it is also required to prevent the holder 10 from rotating in the circumferential direction relative to the first raceway 4. To satisfy these requirements, it is advisable to adopt a restrictive structure to prevent the clearance-fitted holder 10 and the first raceway 4 from coming loose and from rotating.

[0090] Therefore, in this bearing device, in order to provide the aforementioned restrictive structure, a recess 17d is formed in the inner circumference 17 of the first raceway ring 4, and a retaining member 37 that fits into the recess 17d is employed.

[0091] As shown in Figures 3 and 7, the recess 17d is located to the right (outward in the axial direction) of the stepped surface 17b and inward in the axial direction of the width surface portion 19 on the right end, and is groove-shaped with a groove depth in the radial direction from the support surface 17c and extending in the circumferential direction.

[0092] The recesses 17d are formed at multiple locations spaced apart in the circumferential direction (two locations 180° symmetrical in the illustrated example). Both ends of the recesses 17d in the circumferential direction intersect with the support surface 17c in the circumferential direction.

[0093] As shown in Figures 3 and 8, the fitting portion 12 of the holder 10 has a notched edge 12a that forms a space at a position facing radially into the recess 17d. The notched edge 12a penetrates radially between the inner and outer circumference of the fitting portion 12 at the middle of the width of the fitting portion 12, forming a slit-shaped space that is long in the circumferential direction and short in the axial direction. The space formed by the notched edge 12a is in a positional relationship that allows it to communicate radially with the groove space formed by the recess 17d.

[0094] As shown in Figure 3, the retaining member 37 has a fitting portion 38 that fits into the recess 17d and a restricting portion 39 that protrudes radially from the recess 17d. One retaining member 37 is placed in each recess 17d.

[0095] As shown in Figure 9, the retaining member 37 is shaped like a circular arc plate that is long in the circumferential direction and short in the radial direction.

[0096] As shown in Figures 1 and 3, the left and right sides of the fitting portion 38 and the inner surfaces of the grooves on both the left and right sides of the recess 17d can engage with each other in the axial direction. In addition, the circumferential ends of the fitting portion 38 and the recess 17d can engage with each other in the circumferential direction. Therefore, in the state shown in Figures 1 and 3, the circumferential and axial movement of the retaining member 37 relative to the first raceway ring 4 can be restricted by the engagement of the fitting portion 38 and the recess 17d.

[0097] The restricting portion 39 can abut radially against the outer circumferential wall of the cover portion 36 through the space formed by the notched edge 12a. Since the outer circumferential wall of the cover portion 36 is annular in shape that fits with the inner circumference of the fitting portion 12, it has sufficient strength to restrict the radial movement of the retaining member 37. Therefore, by supporting the restricting portion 39 radially with the cover portion 36, the fitting portion 38 can be fitted into the recess 17d and the restricting portion 39 can be kept protruding radially from the recess 17d. No adhesive or other joining means are used to fix the retaining member 37 to the recess 17d or the notched edge 12a.

[0098] As shown in Figure 3, the sensor unit 2 has a side end portion 40 located axially inward from the regulating portion 39, and as shown in Figure 8, a first opposing end portion 41 that is continuous with one circumferential end of the side end portion 40, and a second opposing end portion 42 that is continuous with the other circumferential end of the side end portion 40.

[0099] The side end portion 40 is formed from the left end of the notched edge 12a and is an arc-shaped plate edge extending in the circumferential direction. The side end portion 40 can engage with the regulating portion 39 toward the right side (axially outward).

[0100] The first opposing end 41 consists of an edge portion that extends axially at one circumferential end of the notch edge 12a. The first opposing end 41 can engage with the restricting portion 39 shown in Figure 3 toward one side in the circumferential direction (counterclockwise direction in Figure 2).

[0101] The second opposing end 42 shown in Figure 8 consists of an edge portion that extends axially at the other circumferential end of the notched edge 12a. The second opposing end 42 can engage with the restricting portion 39 shown in Figure 3 toward the other circumferential direction (clockwise direction in Figure 2).

[0102] As long as the cover portion 36 shown in Figures 1 and 3 does not detach from the fitting portion 12, the cover portion 36, the retaining member 37 positioned in the recess 17d, the restricting portion 39, and the holder 10 are maintained in a positional relationship that allows them to engage in the axial and circumferential directions. To prevent the cover portion 36 from falling off the fitting portion 12, the holder 10 has a bent portion 44 that overlaps the side recess 43 of the cover portion 36 in the axial direction. The bent portion 44 extends from the fitting portion 12 and is formed at multiple locations spaced apart in the circumferential direction. The side recess 43 has an axial depth greater than or equal to the thickness of the bent portion 44, and can accommodate the bent portion 44 without it protruding to the right (outward in the axial direction). Furthermore, by providing the side recess 43 and the bent portion 44 to be engageable in the circumferential direction, it is also possible to restrict the rotation of the cover portion 36 relative to the fitting portion 12.

[0103] The work involved in assembling the sensor unit 2 and attaching it to the first raceway 4 can be broadly divided into two parts: an assembly process in which the necessary components are attached to the holder 10, and an attachment process in which the remaining parts are assembled and fixed while the assembled unit is fitted onto the first raceway 4.

[0104] In the assembly process, as shown in Figure 5, a holder 10 is used in which the bent portion 44 extends axially from the fitting portion 12. A coil with a bobbin 27 is placed between the annular side portion 11 of the holder 10 and the side plate portion 31 of the yoke member 28, and the holder 10 and the yoke member 28 are combined axially. At this time, each protrusion 33 of the yoke member 28 is fitted into the corresponding hole 11a of the annular side portion 11, thereby ensuring coaxiality between the holder 10 and the yoke member 28, as shown in Figure 6, and the first claw pole portion 29 and the second claw pole portion 32 are arranged alternately in a predetermined phase with a gap in the circumferential direction. For this reason, the holder 10 and the yoke member 28 can be properly combined without using a jig. It is preferable that three or more holes 11a and protrusions 33 are formed.

[0105] After this assembly, the projection 33 is fixed to the inner surface of the hole 11a, as shown in Figures 3 and 6. This fixing method may be, for example, press-fitting, bonding, laser welding, or a combination of these.

[0106] The protrusion 33 and hole 11a can be omitted. In this case, the abutting portion between the annular side portion and the annular plate portion may be bonded together, laser-welded from the outer circumference of the annular plate portion, or fixed using a combination of these methods, while the holder and the yoke member are coaxially and phase-aligned using a jig (not shown).

[0107] When the holder 10 and the yoke member 28 are fixed in the assembled state as described above, the stator 14 is completed as shown in Figure 6, and the opening 35 formed by the annular side portion 11, the fitting portion 12, and the annular plate portion 30 is completed. In this example, the annular plate portion 30 of the yoke member 28 is shown as a partition between the housing space of the substrate 8 and the stator 14, but it is also possible to provide a partition wall that divides the annular side portion of the holder into two regions in the radial direction, and to place the stator on the radially inner side of that partition wall, separate from the annular plate portion.

[0108] The circuit board 8, on which sensors 9a, 9b, etc. are mounted, is inserted through the opening 35 onto the annular side portion 11. The circuit board 8 is then fixed to the annular side portion 11 using multiple screws 25, and the holder 10, circuit board 8, etc. are assembled into the unit shown in Figure 6 by performing the necessary soldering. When inserting the circuit board 8, the side of the circuit board opposite to the side on which sensors 9a, etc. are mounted should face the annular side portion 11. Here, in order to insulate the holder 10 from the circuit board 8, an insulating sheet such as a polyimide film may be interposed between the circuit board 8 and the annular side portion 11. The circuit board 8 and the annular side portion 11 can also be fixed by bonding using an adhesive, adhesive sheet, etc., or by a combination of bonding and screw fastening. If the adhesive, adhesive sheet, or insulating sheet becomes a component of the heat conduction path, it is preferable to use one with good thermal conductivity.

[0109] In the aforementioned mounting process, as shown in Figure 10, the fitting portion 12 of the assembly unit is fitted onto the support surface 17c of the first raceway 4, and the annular side portion 11 is brought into contact with the stepped surface 17b. At this time, the phases of the fitting portion 12 and the first raceway 4 are aligned so that the recess 17d and the space formed by the notched edge 12a communicate radially. In this state, as shown in Figure 11, the retaining member 37 is inserted from the opening 35 to a position facing the recess 17d radially, and the fitting portion 38 of the retaining member 37 is fitted into the recess 17d from the space formed by the notched edge 12a. In this state, as shown in Figure 12, the cover portion 36 is fitted between the fitting portion 12 and the annular plate portion 30. As a result, the cover portion 36 closes the opening 35 without contacting the substrate 8, the gap between the cover portion 36 and the substrate 8 is filled with air, and the outer peripheral wall of the cover portion 36 supports the restricting portion 39 of the retaining member 37 in the radial direction.

[0110] Furthermore, the radial length of the retaining member 37 is set to be greater than the radial depth of the recess 17d, and less than the sum of the radial depth of the recess 17d and the radial thickness of the notched edge 12a. This ensures that the restricting portion 39 of the retaining member 37 faces the side end 40 of the notched edge 12a in the axial direction, while the restricting portion 39 can be supported radially by the cover portion 36 fitted into the fitting portion 12. If the retaining member 37 is not supported by the cover portion, it can be fixed to the recess 17d or notched edge 12a with adhesive or the like.

[0111] After fitting the cover portion 36 onto the fitting portion 12, the bent portion 44 is bent radially so that it overlaps with the side recess 43 of the cover portion 36. As a result, as shown in Figures 1, 3, and 4, the annular side portion 11 and the multiple bent portions 44 sandwich the cover portion 36 in the axial direction, preventing the cover portion 36 from falling out of the fitting portion 12.

[0112] The means of attaching the cover portion 36 is not particularly limited, but in order to improve the airtightness of the fitting portions between the cover portion 36 and the fitting portion 12, and between the cover portion 36 and the annular plate portion 30, adhesive or a resin-based filler may be applied to the fitting portions.

[0113] Once the cover portion 36 is attached to the assembly unit, as shown in Figures 1 and 2, the assembly of the sensor unit 2 is completed, and the holder 10 is secured to the first raceway 4 in the axial direction and secured to the circumferential direction. The cover portion 36 is held by the holder 10 in such a state that the positional relationship between the retaining member 37 and the recess 17d is maintained, thus completing the attachment of the sensor unit 2 to the first raceway 4.

[0114] It is also possible to seal the substrate 8 by filling the opening 35 with a sealing material instead of using the cover portion 36. In this case, the radial movement of the retaining member 37 can also be restricted by the sealing material. Furthermore, it is possible to eliminate the need for the bent portion 44 of the holder 10. Since the antenna of the wireless communication circuit 23 will be covered with the sealing material, it is preferable to suppress the shortening of the wavelength of radio waves due to the dielectric constant of the sealing material, and it is advisable to use a sealing material with a low relative permittivity, such as resin.

[0115] As described above, this bearing device (see Figures 1 to 4, 7 to 9) comprises a rolling bearing 1 having a first raceway 4, a second raceway 5, and a plurality of rolling elements 6 arranged between the first raceway 4 and the second raceway 5; a sensor unit 2 having a substrate 8, sensors 9a and 9b mounted on the substrate 8, and a metal plate holder 10 supporting the substrate 8. The holder 10 has an annular side portion 11 extending radially, and fitting portions 12 protruding axially from the outer and inner edges of the annular side portion 11. The first raceway 4 has an inner circumference portion 17 and an outer circumference portion 18, and the inner circumference portion 17, which is the circumference of either the inner circumference portion 17 or the outer circumference portion 18, has a raceway surface 17a, a stepped surface 17b that restricts the axial inward movement of the holder 10, and a support surface 17c that fits into the fitting portion 12.

[0116] In particular, this bearing device has a recess 17d formed on the inner circumference 17 as one of the circumferential parts, which is located axially outward from the stepped surface 17b. The bearing device further includes a retaining member 37 having a fitting portion 38 that fits into the recess 17d and whose axial outward movement is restricted by the recess 17d, and a restricting portion 39 which is a portion that protrudes from the recess 17d toward the second raceway 5. The holder 10 has a side end portion 40 that engages with the restricting portion 39 axially outward. As a result, the retaining member 37 can restrict the axial outward movement of the holder 10 relative to the first raceway 4. Therefore, it becomes unnecessary to prevent the sensor unit 2 from coming off by press-fitting the support surface 17c and the fitting portion 12, and it becomes possible to loosen the fit between the support surface 17c and the fitting portion 12. Consequently, this bearing device can reduce the deformation of both the first raceway 4 and the holder 10 due to the fitting of the two.

[0117] Furthermore, this bearing device has a structure in which the retaining member 37's fitting portion 38 is fitted into a recess 17d formed in the inner circumference 17, which is the first circumference including the raceway surface 17a of the first raceway ring 4, and the sensor unit 2 is supported in the axial direction by a restricting portion 39 that protrudes from this recess 17d toward the second raceway ring 5. Therefore, the retaining member 37 can be housed inside the rolling bearing 1 so that the retaining member 37 does not become an obstacle when assembling the rolling bearing 1 between the shaft (not shown) and the housing (not shown).

[0118] Furthermore, in this bearing device, the fitting portion 38 of the retaining member 37 is fitted into the recess 17d of the first raceway ring 4 such that its circumferential movement is restricted by the recess 17d of the first raceway ring 4. The holder 10 has a first opposing end 41 that engages with the restricting portion 39 of the retaining member 37 toward one side in the circumferential direction, and a second opposing end 42 that engages with the restricting portion 39 toward the other side in the circumferential direction. This restricts the circumferential movement of the holder 10 relative to the first raceway ring 4, thereby keeping the sensors 9a and 9b in the appropriate circumferential position relative to the rolling bearing 1.

[0119] Furthermore, in this bearing device, the recess 17d of the first raceway ring 4 intersects the support surface 17c in the circumferential direction, and the fitting portion 12 of the holder 10 has a notched edge 12a that forms a space at a position radially facing the recess 17d. Since the notched edge 12a includes the side end 40, the first opposing end 41, and the second opposing end 42 of the sensor unit 2, the restricting portion 39 of the retaining member 37 is positioned to protrude radially from the recess 17d into the space formed by the notched edge 12a without reducing the overall width of the support surface 17c and the fitting portion 12, and the restricting portion 39 can be engaged with the notched edge 12a to prevent the sensor unit 2 from coming loose or rotating. It is also possible to form the recess on one side of the circumference so that it does not intersect the support surface of the first raceway ring in the circumferential direction, but in this case, it is necessary to secure the total width of the support surface and the recess, and in standard rolling bearings with a defined bearing width, it may be difficult to secure the aforementioned total width without reducing the overall width of the support surface. Reducing the overall width of the support surface also reduces the overall width of the contact area where the support surface and the holder's fitting portion interlock, making the holder more prone to tilting, which is undesirable.

[0120] Furthermore, this bearing device has an opening 35 provided so that the fitting portion 38 of the retaining member 37 can be fitted into the recess 17d of the first raceway 4 when the sensor unit 2 has fitted the fitting portion 12 of the holder 10 onto the support surface 17c of the first raceway 4, and a cover portion 36 that closes the opening 35 and radially supports the restricting portion 39 of the retaining member 37. As a result, the fitting portion 38 of the retaining member 37 can be fitted into the recess 17d from the outside of the rolling bearing 1 through the opening 35 when the fitting portion 12 is fitted onto the support surface 17c, so the shape of the notched edge of the fitting portion 12 is not complicated, and the opening 35 can be closed by the cover portion 36 to protect the inside of the sensor unit 2, and the restricting portion 39 can be radially supported by the cover portion 36 to prevent the retaining member 37 from coming out of the recess 17d. For this reason, it is not necessary to fix the fitting portion 38 to the recess 17d with adhesive or the like. It is also conceivable to have a structure in which the fitting portion of the retaining member is fixed to the recess of the first raceway ring, and then the fitting portion of the holder is fitted to the support surface. However, in this case, the notched edge of the fitting portion and the restricting portion of the retaining member would be combined in a bayonet manner, which would complicate the shape of the notched edge and the fitting operation of the first raceway ring and the holder, so this is undesirable.

[0121] Furthermore, this bearing device has a bent portion 44 in the holder 10 that sandwiches the cover portion 36 axially with the annular side portion 11, thereby preventing the cover portion 36 from falling off or shifting in the axial direction.

[0122] The bearing device according to the second embodiment is shown in Figures 13 and 14. In the following descriptions of each embodiment, only the differences from the first embodiment will be described, and the same reference numerals will be used for corresponding components as appropriate.

[0123] The bearing device according to the second embodiment has a modified shape in which the notched edge of the holder is partially altered. Specifically, the notched edge 12a of the holder 10 is concave, opening outwards to the right (axially outward), and does not have a portion that faces the side end 40 in the axial direction. In this way, the bearing device according to the second embodiment has a notched edge 12a that opens outwards to the axial direction, so that the fitting portion 12 does not get in the way when fitting the retaining member 37 into the recess 17d through the opening 35 during the aforementioned mounting process.

[0124] Although the retaining member 37 and recess 17d are shown as examples with arc-shaped extensions, the shapes of the retaining member and recess can be changed to other shapes. For example, the retaining member can be made of a cylindrical pin, and the recess can be made into a corresponding pin hole.

[0125] As an example relating to the second means of this invention, a bearing device according to the third embodiment will be described based on Figures 15 to 21 of the attached drawings. In the bearing device according to the third embodiment, the position and shape of the recess of the first raceway ring and the retaining member are changed from those of the first embodiment.

[0126] That is, as shown in Figures 15, 16, and 17, the first raceway 50 according to the third embodiment has recesses 52 that are continuous with the outer periphery 51 and both axial ends of the first raceway 50. The recesses 52 consist of a radial recess 52a that traverses the outer periphery 51 in the axial direction, and two axial recesses 52b that extend radially from both the left and right ends of the radial recess 52a. The recesses 52 are formed at multiple locations spaced apart in the circumferential direction, and the figures show an example where they are arranged at two locations 180° apart. The mating surface 51a of the outer periphery 51 is distributed in the circumferential region other than the radial recesses 52a. Each width surface 53 of the first raceway 50 is distributed in the circumferential region other than the axial recesses 52b.

[0127] The axial recess 52b on the right side intersects with the support surface 54a of the inner circumference 54 of the first raceway ring 50 in both the circumferential and axial directions.

[0128] The retaining member 55 shown in Figure 18 has a fitting portion 56 that fits into the recess 52 and a restricting portion 57 that protrudes from the recess 52 toward the second raceway ring 5, as shown in Figures 15, 17, and 19. The entire retaining member 55 is formed seamlessly from a single metal plate.

[0129] The fitting portion 56 consists of a transverse plate portion 56a along the radial recess 52a and two flat plate portions 56b extending from both the left and right ends of the transverse plate portion 56a along the corresponding axial recesses 52b. The left and right flat plate portions 56b can engage with the corresponding axial recesses 52b in an axially inward direction, and the fitting portion 56 can engage with the recess 52 in a circumferential direction at each edge on both sides of its circumferential direction. Therefore, the fitting portion 56 is fitted into the recess 52 such that its movement in the axially outward direction and movement in the circumferential direction are restricted by the recess 52.

[0130] The radial depth of the radial recess 52a is set to be greater than the thickness of the transverse plate portion 56a, and the axial depth of the axial recess 52b is set to be greater than the thickness of the flat plate portion 56b. As a result, the entire fitting portion 56 is accommodated in the recess 52.

[0131] The restricting portion 57 consists of a plate portion that extends radially from the right-side flat plate portion 56b. Therefore, the restricting portion 57 is positioned so as not to protrude to the right (outward in the axial direction) of the fitting portion 56. The restricting portion 57 protrudes in a flat plate shape at a position on the extension of the right-side axial recess 52b, facing the sensor unit 58 in the axial direction.

[0132] The sensor unit 58 has a side end 59 that engages with the restricting portion 57 in an axially outward direction, a first opposing end 60 that engages with the restricting portion 57 in one direction in the circumferential direction, and a second opposing end 61 that engages with the restricting portion 57 in the other direction in the circumferential direction.

[0133] As shown in Figures 16, 20, and 21, the fitting portion 63 of the holder 62 has a notched edge 63a that forms a space in the right-side axial recess 52b at a position facing radially. The notched edge 63a is concave and opens towards the right side (outward in the axial direction).

[0134] The side end 59 is formed from the left end of the notched edge 63a and is an arc-shaped plate edge extending in the circumferential direction. The side end 59 can engage with the regulating portion 57 toward the right side (outward in the axial direction). The first opposing end 60 is formed from an edge portion extending in the axial direction at one end in the circumferential direction of the notched edge 63a. The first opposing end 60 can engage with the regulating portion 57 toward one side in the circumferential direction. The second opposing end 61 is formed from an edge portion extending in the axial direction at the other end in the circumferential direction of the notched edge 63a. The second opposing end 61 can engage with the regulating portion 57 toward the other side in the circumferential direction.

[0135] As shown in Figures 15 and 19, the side end portion 59 is positioned to overlap radially with or near the right-side axial recess 52b. When the retaining member 55 is in a standalone state, the axial distance between the left and right flat plate portions 56b is set to be smaller than the axial distance between the left and right axial recesses 52b, and also smaller than the axial distance between the left-side axial recess 52b and the side end portion 59. Therefore, the retaining member 55 can elastically clamp the recess 52 in the axial direction with the fitting portion 56, or elastically clamp the recess 52 and the side end portion 59 in the axial direction with the fitting portion 56 and the restricting portion 57.

[0136] As shown in Figures 19 and 20, a side recess 65 for accommodating the restricting portion 57 is formed on the right side (axially outward) of the cover portion 64. The side recess 65 is located in a position that overlaps radially with or near the side end portion 59. Therefore, the cover portion 64 can be sandwiched in the axial direction between the restricting portion 57 and the annular side portion 11 of the holder 62. Furthermore, by providing the side recess 65 and the restricting portion 57 to be engageable in the circumferential direction, it is also possible to restrict the rotation of the cover portion 64 relative to the fitting portion 63.

[0137] The process of fitting the cover portion 64 onto the holder 62 is carried out during the assembly process. At this time, the cover portion 64 may be fixed to the holder 62 to complete the assembly of the sensor unit 58. In the mounting process, with the fitting portion 63 of the assembled unit or the sensor unit 58 fitted onto the support surface 54a of the first raceway ring 50, the retaining member 55 is fitted into the recess 52 so as to straddle it from the radially outside. As a result, the fitting portion 56 elastically clamps the recess 52 or the recess 52 and the side end portion 59 in the axial direction, and the restricting portion 57 clamps the annular side portion 11 and the cover portion 64 in the axial direction.

[0138] The bearing device according to the third embodiment (see Figures 15, 16, 19, and 20) is as described above, and in particular, the first raceway ring 50 has a recess 52 that is continuous with the outer circumference 51, which is the other circumference opposite to the inner circumference 54, which is one circumference, and with both axial ends of the first raceway ring 50. The bearing device further includes a retaining member 55 having a fitting portion 56 that is fitted into the recess 52 and whose movement outward in the axial direction is restricted by the recess 52, and a restricting portion 57 which is a portion that protrudes from the recess 52 toward the second raceway ring 5. The sensor unit 58 has a side end portion 59 that engages with the restricting portion 57 in the outward direction in the axial direction. As a result, the retaining member 55 can restrict the movement of the sensor unit 58 outward in the axial direction relative to the first raceway ring 50. Therefore, it is not necessary to prevent the sensor unit 58 from coming off by press-fitting the support surface 54a and the fitting portion 63, and it becomes possible to loosen the fit between the support surface 54a and the fitting portion 63. Therefore, the bearing device according to the third embodiment can reduce the deformation of both the first raceway ring 50 and the holder 62 due to the fitting of the raceway ring 50 and the holder 62.

[0139] Furthermore, in the bearing device according to the third embodiment, since the fitting portion 56 is positioned outside the rolling bearing 66 and straddles the recess 52, the process of fitting the retaining member 55 onto the first raceway ring 50 can be performed more easily compared to the first embodiment in which the retaining member 55 is positioned inside the bearing.

[0140] Furthermore, in the bearing device according to the third embodiment, the fitting portion 56 is fitted into the recesses 52 located on the other circumference (outer circumference 51) and both axial ends of the first raceway ring 50, and the sensor unit 58 is supported in the axial direction by the restricting portion 57 that protrudes from the recess 52 toward the second raceway ring 5. Therefore, the protrusion of the retaining member 55 relative to the cross-sectional height and bearing width of the rolling bearing 66 can be reduced or eliminated, and the retaining member 55 can be prevented from becoming an obstacle when assembled between the shaft and the housing.

[0141] Furthermore, in the bearing device according to the third embodiment, the fitting portion 56 of the retaining member 55 is fitted into the recess 52 of the first raceway ring 50 such that its circumferential movement is restricted by the recess 52. The sensor unit 58 has a first opposing end 60 that engages with the restricting portion 57 of the retaining member 55 toward one side in the circumferential direction, and a second opposing end 61 that engages with the restricting portion 57 toward the other side in the circumferential direction. This restricts the circumferential movement of the sensor unit 58 relative to the first raceway ring 50, thereby keeping the sensors 9a and 9b in the appropriate circumferential position relative to the rolling bearing 66.

[0142] Furthermore, in the bearing device according to the third embodiment, the recess 52 of the first raceway ring 50 intersects the support surface 54a in the circumferential direction, and the fitting portion 63 of the holder 62 has a notched edge 63a that forms a space at a position facing radially into the recess 52, and the notched edge 63a includes the side end 59, the first opposing end 60, and the second opposing end 61 of the sensor unit 58, so that the restricting portion 57 is positioned to protrude radially from the recess 52 into the space formed by the notched edge 63a without reducing the overall width of the support surface 54a and the fitting portion 63, and the restricting portion 57 can be engaged with the notched edge 63a to prevent the sensor unit 58 from coming off or rotating.

[0143] Furthermore, in the bearing device according to the third embodiment, the retaining member 55 is provided such that the fitting portion 56 elastically grips the recess 52 of the first raceway ring 50 in the axial direction, or the fitting portion 56 and the regulating portion 57 elastically grip the recess 52 and the side end portion 59 of the sensor unit 58 in the axial direction, thereby preventing the retaining member 55 from falling off or shifting. As a result, it also helps to suppress the generation of vibrations of the sensor unit 58 and the like due to external disturbances.

[0144] Furthermore, in the bearing device according to the third embodiment, the fitting portion 56 of the retaining member 55 and the recess 52 of the first raceway ring 50 are shaped such that the entire fitting portion 56 fits into the recess 52, and the regulating portion 57 does not protrude axially outward from the fitting portion 56, thereby eliminating the protrusion of the retaining member 55 relative to the cross-sectional height and bearing width of the rolling bearing 66.

[0145] Furthermore, the bearing device according to the third embodiment has an opening 35 provided so that the substrate 8 can be placed on the side surface of the annular side portion 11 of the holder 62, and a cover portion 64 that closes the opening 35, and the regulating portion 57 of the retaining member 55 is provided so as to sandwich the cover portion 64 axially with the annular side portion 11, thereby protecting the inside of the sensor unit 58 by closing the opening 35 with the cover portion 64, and preventing the cover portion 64 from falling off or moving axially.

[0146] Figures 22 and 23 show the main parts of the bearing device according to the fourth embodiment. The bearing device according to the fourth embodiment further modifies the shape of the retaining member from the third embodiment. Therefore, only the changes from the third embodiment will be described here.

[0147] The retaining member 70 according to the fourth embodiment has a pair of restricting portions 72 that protrude from the fitting portion 71 in a cantilevered manner, and a hooking portion 73 that protrudes circumferentially from the restricting portion 72.

[0148] The pair of restricting portions 72 are symmetrical in the circumferential direction and are housed in a side recess 65 of the cover portion 64.

[0149] When the retaining member 70 is in a standalone state, the circumferential width of the pair of restricting portions 72 is set to be wider than the circumferential width of the notched edge 63a of the holder 62, while being on the same circumference as the notched edge 63a. Therefore, when the fitting portion 71 is fitted into the recess 52, the first restricting portion 72 of the pair of restricting portions 72 can elastically push the first opposing end 60 of the notched edge 63a in the circumferential direction, and the second restricting portion 72 can elastically push the second opposing end 61 of the notched edge 63a in the circumferential direction.

[0150] Each hook portion 73 is stepped and overlaps radially with the inner diameter surface of the fitting portion 63. When the fitting portion 71 and the recess 52 attempt to separate radially, each hook portion 73 catches on the inner diameter surface of the fitting portion 63, thereby preventing separation.

[0151] In the bearing device according to the fourth embodiment, the retaining member 70 has a hook portion 73 that protrudes from the restricting portion 72 so as to overlap radially with the fitting portion 63 at a position where it protrudes further toward the second raceway ring (not shown) (corresponding to the downward direction in Figure 23) than the notched edge 63a of the holder 62. As a result, the hook portion 73 can engage radially with the fitting portion 63 from the second raceway ring side toward the first raceway ring 50, thereby keeping the fitting portion 71 fitted in the recess 52 and preventing the retaining member 70 from falling out or shifting.

[0152] Furthermore, in the bearing device according to the fourth embodiment, the restricting portion 72 of the retaining member 70 protrudes from the fitting portion 71 in a cantilevered manner so as to elastically press the notched edge 63a of the holder 62 in the circumferential direction. This makes it easier to forcibly pass the catching portion 73 between the first opposing end 60 and the second opposing end 61 of the notched edge 63a when fitting the fitting portion 71 into the recess 52, thereby elastically deforming the restricting portion 72 in the circumferential direction. Consequently, the elastic restoring force pushes the notched edge 63a in the circumferential direction, further preventing circumferential displacement of the retaining member 70, and also facilitating the attachment and detachment of the retaining member 70 to the first raceway ring 50.

[0153] In the embodiments described above, the first raceway ring was used as the outer ring, and examples were shown where one circumference was the inner circumference and the other circumference was the outer circumference. However, it is also possible to use the first raceway ring as the inner ring. In this case, one circumference of the first raceway ring is considered the outer circumference and the other circumference the inner circumference, and the inside and outside in the radial direction are reversed to form stepped surfaces, support surfaces, and recesses, and retaining members are arranged accordingly. Therefore, illustrations and detailed explanations of these cases are omitted.

[0154] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0155] 1.66 Rolling bearings 2.58 Sensor Unit 4, 50 First orbital ring 5. Second orbital ring 6 Rolling elements 8 circuit boards 9a, 9b sensors 10, 62 holder 11 Annular side 12, 63 Fitting part 12a, 63a Notched edge 18, 51 Outer perimeter (the other perimeter) 17, 54 Inner circumference (one side of the circumference) 17a Raceway surface 17b Step surface 17c, 54a support surface 17d, 52 recess 35 Opening 36, 64 Cover section 37, 55, 70 Retaining members 38, 56, 71 Insertion part 39, 57, 72 Regulatory Department 40, 59 side edge 41, 60 First opposing end 44 Folded section 42, 61 Second opposing end 73. The part that catches

Claims

1. A rolling bearing having a first raceway ring, a second raceway ring, and a plurality of rolling elements disposed between the first raceway ring and the second raceway ring, A sensor unit comprising a substrate, a sensor mounted on the substrate, and a metal plate holder supporting the substrate, The holder has an annular side portion extending in the radial direction, and fitting portions protruding axially from the outer and inner edges of the annular side portion. In a bearing device in which the first raceway ring has an inner circumference and an outer circumference, and one of the inner circumference and outer circumference has a raceway surface, a stepped surface that restricts the axial inward movement of the holder, and a support surface that fits into the fitting portion, The aforementioned one circumferential portion has a recess formed at a position that is axially outward from the stepped surface, The retaining member further comprises a fitting portion that is fitted into the recess and whose movement axially outward is restricted by the recess, and a restricting portion which is a portion that protrudes from the recess toward the second raceway ring, The bearing device is characterized in that the holder has a side end that engages with the restricting portion in an axially outward direction.

2. The fitting portion of the retaining member is fitted into the recess of the first raceway ring such that its circumferential movement is restricted by the recess. The bearing device according to claim 1, wherein the holder has a first opposing end that engages with the restricting portion of the retaining member toward one side in the circumferential direction, and a second opposing end that engages with the restricting portion toward the other side in the circumferential direction.

3. The recess of the first raceway ring intersects the support surface in the circumferential direction. The fitting portion of the holder has a notched edge that forms a space in the recess at a position facing radially, The bearing device according to claim 2, wherein the notched edge includes the side end, the first opposing end, and the second opposing end of the holder.

4. The sensor unit has an opening provided such that the fitting portion of the retaining member can be fitted into the recess of the first raceway when the fitting portion of the holder is fitted into the support surface of the first raceway, The bearing device according to claim 3, wherein the notched edge of the holder has a shape that is open toward the axial outward direction.

5. The bearing device according to claim 3, wherein the sensor unit has an opening provided such that the fitting portion of the retaining member can be fitted into the recess of the first raceway when the fitting portion of the holder is fitted into the support surface of the first raceway, and a cover portion that closes the opening and radially supports the restricting portion of the retaining member.

6. The bearing device according to claim 5, wherein the holder has a bent portion that sandwiches the cover portion with the annular side portion in the axial direction.

7. A rolling bearing having a first raceway ring, a second raceway ring, and a plurality of rolling elements disposed between the first raceway ring and the second raceway ring, A sensor unit comprising a substrate, a sensor mounted on the substrate, and a metal plate holder supporting the substrate, The holder has an annular side portion extending in the radial direction and a fitting portion protruding axially from the annular side portion. In a bearing device in which the first raceway ring has an inner circumference and an outer circumference, and one of the inner circumference and outer circumference has a raceway surface, a stepped surface that restricts the axial inward movement of the holder, and a support surface that fits into the fitting portion, The first raceway has a recess that is continuous with the inner circumference and the outer circumference opposite to one of the outer circumferences, and with both axial ends of the first raceway. The retaining member further comprises a fitting portion that is fitted into the recess and whose movement axially outward is restricted by the recess, and a restricting portion which is a portion that protrudes from the recess toward the second raceway ring, The bearing device is characterized in that the sensor unit has a side end that engages with the restricting portion in an axially outward direction.

8. The fitting portion of the retaining member is fitted into the recess of the first raceway ring such that its circumferential movement is restricted by the recess. The bearing device according to claim 7, wherein the sensor unit has a first opposing end that engages with the restricting portion of the retaining member toward one side in the circumferential direction, and a second opposing end that engages with the restricting portion toward the other side in the circumferential direction.

9. The recess of the first raceway ring intersects the support surface in the circumferential direction. The fitting portion of the holder has a notched edge that forms a space in the recess at a position facing radially, The bearing device according to claim 8, wherein the notched edge includes the side end, the first opposing end, and the second opposing end of the sensor unit.

10. The bearing device according to claim 9, wherein the retaining member has a hook that protrudes from the restricting portion such that it overlaps radially with the fitting portion at a position that protrudes toward the second raceway ring beyond the notched edge of the holder.

11. The bearing device according to claim 10, wherein the restricting portion of the retaining member protrudes from the fitting portion in a cantilevered manner so as to elastically press the notched edge of the holder in the circumferential direction.

12. The bearing device according to any one of claims 7 to 11, wherein the retaining member is provided such that the fitting portion elastically grips the recess of the first raceway ring in the axial direction, or the fitting portion and the regulating portion elastically grip the recess and the side end of the sensor unit in the axial direction.

13. The bearing device according to any one of claims 7 to 11, wherein the fitting portion of the retaining member and the recess of the first raceway ring are shaped to accommodate the entirety of the fitting portion in the recess, and the restricting portion is shaped not to protrude axially outward from the fitting portion.

14. The sensor unit has an opening provided so as to accommodate the substrate on the side surface of the annular side of the holder, and a cover portion that closes the opening. The bearing device according to any one of claims 7 to 11, wherein the restricting portion of the retaining member is provided so as to sandwich the cover portion with the annular side portion in the axial direction.

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