Bearing device

Abstract

To provide a bearing device where a holder of a sensor unit is fitted to the inner periphery or the outer periphery on the raceway surface side of a first bearing ring out of the first bearing ring and a second bearing ring of a rolling bearing, for reducing the deformation of both the first bearing ring and the holder when fitted to each other.SOLUTION: The bearing device includes a rolling bearing 1 having a first bearing ring 4, a second bearing ring 5, and a plurality of rolling elements 6 arranged between the first bearing ring 4 and the second bearing ring 5, and a sensor unit 2 having a sensor 10 and a holder 9 holding the sensor 10, the holder 9 having an annular side part 11 extending in the radial direction, and a fitting part 12 protruding from the annular side part 11 in the axial direction, the holder 9 being formed of a metal plate, the first bearing ring 4 having an inner periphery 16 or an outer periphery including a raceway surface part 15, a step part 18 receiving the holder 9 at its rolling element 6 side in the axial direction, and a peripheral face part 19 fitted to the fitting part 12. Herein, a weld part 22 is provided for welding the holder 9 and the first bearing ring 4 to each other.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

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

[0003] When the stator of a generator that supplies power to the circuit board is provided in the sensor unit, the holder may function as a yoke for the stator. Also, when detecting the vibration of a bearing, it may be preferable to arrange the holder coaxially with the raceway to detect the condition of the bearing. In such cases, the holder is made annular and is fitted to the raceway so as to be arranged coaxially. The means for fixing the holder and the raceway is to fit the holder to one of the inner and outer circumferences of the raceway.

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

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

[0006] For example, in the bearing device of Patent Document 1, a holder with an L-shaped cross section is attached to a raceway. The holder also serves as a yoke in the stator of the generator. The circuit board is a control board including a plurality of sensors such as a temperature sensor. The annular plate part of the holder is fitted to the peripheral surface of the stepped end part formed on the raceway, and the rolling element side of the holder is butted against the step surface of the stepped end part in the axial direction. This allows the holder and the raceway to be arranged coaxially, and also restricts the displacement of the holder towards the rolling element side. [Prior art documents] [Patent documents]

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

[0008] However, when the holder is fixed to the raceway by press-fitting the annular plate of the holder with the peripheral surface of the stepped end of the raceway, in order to ensure the pull-out strength of the holder against the peripheral surface of the stepped end by press-fitting, it is necessary to ensure a suitable radial interference between the peripheral surface of the stepped end and the annular plate of the holder. The metal plate forming the holder also needs to have a plate thickness suitable for purposes such as positioning and press-fitting the sensor. For these reasons, if the radial interference is excessive, it becomes difficult to press-fit each other, and the pressing load during press-fitting may cause deformation of the raceway surface and deformation of the holder, which may adversely affect the performance of the rolling bearing and the sensor unit. In particular, when a metal plate holder is press-formed, the tolerance width of the holder is larger than that of a machined holder, which increases the concern that the press-fitting operation will be difficult.

[0009] In view of the above-mentioned background, the problem that this invention aims to solve is to reduce deformation of both the first raceway ring and the holder due to the fitting of the first raceway ring and the holder in a bearing device in which a sensor unit holder is fitted against the inner or outer periphery of the orbital surface side of the first raceway ring of a rolling bearing. [Means for solving the problem]

[0010] As a first means for solving the above problems, the present invention adopts configuration 1, which is a bearing device comprising: a rolling bearing having a first raceway, a second raceway, and a plurality of rolling elements arranged between the first raceway and the second raceway; a sensor unit having a holder for holding the sensor; the holder having an annular side portion extending radially and an engagement portion protruding axially from the annular side portion; the holder is formed of a metal plate; and the first raceway has an inner or outer periphery including a raceway surface portion, a step portion axially receiving the rolling element side of the holder, and a peripheral surface portion that engages with the engagement portion, wherein a weld portion is provided to join the holder and the first raceway.

[0011] According to the above configuration 1, since the welded joint prevents the holder from being pulled out of the first raceway, it is possible to set a looser fit between the peripheral surface portion and the mating portion of the holder, thereby reducing deformation of both the first raceway and the holder due to their mating.

[0012] In the above configuration 1, a configuration 2 can be adopted in which the circumferential surface portion of the first race and the fitting portion of the holder are clearance-fitted.

[0013] According to the above configuration 2, since there is no radial interference between the peripheral surface of the first raceway and the fitting portion of the holder, deformation of both the first raceway and the holder due to fitting between them can be particularly reduced.

[0014] In the above configuration 1 or 2, a configuration 3 can be adopted in which the first raceway has a chamfered portion that continues from the circumferential surface portion to one end of the width of the first raceway, and the welded portion joins the chamfered portion to the holder and is arranged so as not to protrude beyond the one end of the width toward the one end in the axial direction.

[0015] The welded portion joining the holder and the first race is for preventing the holder from being pulled out of the peripheral surface, so a small welded portion is sufficient. Therefore, as in configuration 3 above, it is possible to use the space created by the chamfered portion to provide the welded portion so that it does not protrude beyond one end of the width of the first race toward one axial end, and this makes it possible to prevent the welded portion from interfering when the bearing device is inserted between the housing and the shaft.

[0016] In any one of the above configurations 1 to 3, a configuration 4 can be adopted in which the fitting portion of the holder has a plate end that is positioned closer to the rolling element side than one end of the width of the first raceway, and the welded portion joins the plate end and the first raceway and is arranged so as not to protrude beyond the one end of the width toward the one end in the axial direction.

[0017] When it is possible to get by with a small weld as described above, as in configuration 4 above, it is possible to utilize the space between the plate end of the fitting portion and one end of the width of the first raceway so that the weld does not extend beyond one end of the width of the first raceway toward the one end in the axial direction, thereby preventing the weld from interfering when the bearing device is accommodated between the housing and the shaft.

[0018] In the above configuration 1 or 2, a configuration 5 can be adopted in which the first raceway has an end face portion extending radially at one end of the width of the first raceway, and a notch portion that is recessed axially from the end face portion and intersects with the inner circumference or outer circumference including the peripheral surface portion, the holder has a protruding portion extending radially from the fitting portion and fitting into the notch portion, and the welded portion joins the protruding portion and the notch portion and is arranged so as not to protrude toward the one axial end side beyond the end face portion.

[0019] According to the above-mentioned configuration 5, it is possible to use the space of the notch recessed in the axial direction from the end face at one end of the width of the first raceway ring to provide the protruding plate portion and the welded portion of the holder so that they do not protrude beyond the one end of the width of the first raceway ring toward the one end in the axial direction, thereby making it possible to prevent the protruding plate portion and the welded portion from interfering with each other when the bearing device is accommodated between the housing and the shaft. Also, it is possible to provide a margin in the notch recessed in the axial direction from the end face at one end of the width of the first raceway ring so that the welded portion can be cut off with a cutting tool or the like. Therefore, by cutting off the welded portion, the sensor unit can be pulled out of the first raceway ring without any significant damage, and the removed sensor unit can be reused.

[0020] As a second means for solving the above-mentioned problems, the present invention provides a sensor unit comprising a rolling bearing having a first raceway, a second raceway, and a plurality of rolling elements arranged between the first raceway and the second raceway, a sensor, and a holder for holding the sensor, the holder having an annular side portion extending in a radial direction and a fitting portion protruding in an axial direction from the annular side portion, the holder being formed of a metal plate, the first raceway having an inner or outer circumference including a raceway surface portion, a step portion for axially receiving the rolling element side of the holder, and a peripheral surface portion that fits into the fitting portion, In a bearing device having a circumference, the first raceway has an end face portion extending radially at one end of the width of the first raceway, and a notch portion that is recessed axially from the end face portion and intersects with the inner circumference or outer circumference including the peripheral surface portion, the fitting portion has a concave plate edge recessed in the axial direction in the same phase as the notch portion, a pressure plate that axially overlaps the concave plate edge and the notch portion, and a weld portion is provided that joins the notch portion to the pressure plate, and the pressure plate and the weld portion are arranged so as not to protrude beyond the end face portion toward one end in the axial direction.

[0021] According to the above-mentioned configuration 6, the holder is prevented from being pulled out from the first race by the pressing plate welded to the first race, and therefore it is possible to set the fit between the peripheral surface and the fitting portion of the holder loosely, and therefore it is possible to reduce the deformation of both the first race and the holder due to the fitting. In addition, it is possible to provide the pressing plate and the welded portion so that they do not protrude from the one end of the width of the first race toward the one end in the axial direction by utilizing the space of the notch portion recessed in the axial direction from the end face portion at one end of the width of the first race, and this makes it possible to prevent the pressing plate and the welded portion from interfering with each other when the bearing device is accommodated between the housing and the shaft. In addition, it is possible to provide a margin in the notch portion recessed in the axial direction from the end face portion at one end of the width of the first race so that the welded portion can be cut off with a router or the like. Therefore, if the welded portion is cut off and the pressing plate is removed, the sensor unit can be pulled out from the first race without any particular damage, and the removed sensor unit can be reused.

[0022] In the above configuration 6, configuration 7 can be adopted in which the peripheral surface of the first raceway and the mating portion of the holder are clearance-fitted, and the holder is prevented from rotating by circumferential engagement between the pressure plate and the concave plate edge.

[0023] According to the above configuration 7, since there is no radial interference between the peripheral surface of the first raceway and the mating portion of the holder, deformation of both the first raceway and the holder due to their mating can be particularly reduced, and the holder can be prevented from rotating by utilizing a pressure plate fixed to the first raceway by welding, thereby realizing the fixation of the sensor unit to the first raceway. Effect of the Invention

[0024] As described above, by adopting the above configurations 1 or 6, the present invention can reduce deformation of both the first raceway ring and the holder due to the fitting of the first raceway ring and the holder in a bearing device in which the sensor unit holder is fitted against the inner or outer circumference of the raceway surface side of the first raceway ring of the first and second raceway rings of a rolling bearing. [Brief description of the drawings]

[0025] [Figure 1] FIG. 1 is a vertical sectional front view showing a main portion of a bearing device according to a first embodiment of the present invention; [Diagram 2] An enlarged view of the sensor unit and its surroundings in Figure 1. [Diagram 3] FIG. 2 is a perspective view showing the bearing device of FIG. [Figure 4] FIG. 2 is a side view of the bearing device of FIG. 1 with the cover of the sensor unit partially cut away; [Diagram 5] FIG. 2 is an exploded perspective view of the sensor unit of FIG. 1; [Figure 6] FIG. 2 is a perspective view showing an assembly stage of the sensor unit of FIG. 1; [Figure 7] FIG. 11 is a longitudinal sectional front view showing a main portion of a bearing device according to a second embodiment of the present invention; [Figure 8] FIG. 13 is a longitudinal sectional front view showing a main portion of a bearing device according to a third embodiment of the present invention; [Figure 9] FIG. 9 is a side view of the bearing device of FIG. 8 with the cover of the sensor unit partially cut away. [Figure 10] FIG. 13 is a vertical sectional front view showing a bearing device according to a fourth embodiment of the present invention; [Figure 11] FIG. 11 is a side view showing the bearing device of FIG. 10 with the cover of the sensor unit partially cut away. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] A bearing device according to a first embodiment of the present invention (hereinafter simply referred to as "the bearing device") will be described with reference to the accompanying drawings, FIGS. 1 to 6. FIG.

[0027] As shown in FIGS. 1 to 3, the bearing device includes a rolling bearing 1, a sensor unit 2, and a generator 3. The rolling bearing 1 has a cylindrical shape and a cylindrical surface.

[0028] Here, the circumferential direction centered on the central axis of the rolling bearing 1 (not shown) is referred to as the "circumferential direction," the direction along the central axis of the bearing is referred to as the "axial direction," and the direction perpendicular to the central axis of the bearing is referred to as the "radial direction." In Figures 1 and 2, the axial direction corresponds to the left-right direction, and the radial direction corresponds to the up-down direction.

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

[0030] The sensor unit 2 is a unit that integrates a circuit board 8 and a holder 9 that holds the circuit board 8. The circuit board 8 includes a temperature sensor 10 and the like.

[0031] The holder 9 has an annular side portion 11 extending in the radial direction and a fitting portion 12 protruding from the annular side portion 11 in the axial direction.

[0032] The generator 3 consists of a magnetic ring 13 arranged so as to be rotatable integrally with the second raceway 5, and a stator 14 facing the magnetic ring 13, and the relative rotational motion between the first raceway 4 and the second raceway 5 is electromagnetically converted into alternating current by the magnetic ring 13 and the stator 14.

[0033] The rolling bearing 1 is a radial bearing. The rolling bearing 1 is also a standard bearing that complies with a specific standard. Here, a standard bearing refers to a bearing that satisfies the dimensions specified in the ISO standard or the JIS standard. For example, the dimensions of radial bearings other than tapered roller bearings are specified in ISO15 or JIS B 1512-1.

[0034] Although the rolling bearing 1 is configured as a deep groove ball bearing in the above example, the rolling bearing 1 is not limited to a deep groove ball bearing.

[0035] The sensor unit 2 is fixed to the first bearing ring 4 .

[0036] The first bearing ring 4 is usually arranged as a stationary ring, and the second bearing ring 5 is usually arranged as a rotating ring.

[0037] The first raceway 4 is an outer ring having an inner circumference 16 including a first raceway surface portion 15. The second raceway 5 is an inner ring having an outer circumference including a second raceway surface portion 17. Each rolling element 6 is a ball that rolls between the raceway surface portions 15, 17. The raceway surface portions 15, 17 are the surfaces of the raceways 4, 5 that form the rolling path of the rolling elements 6, and in the illustrated example, are continuous around the entire circumferential direction with a cross-sectional shape that forms a raceway groove corresponding to the ball diameter of the rolling elements 6.

[0038] A predetermined distance is ensured between the rolling elements 6, the cage 7, and the sensor unit 2. This distance is set so that the sensor unit 2 will not come into contact with the rolling elements 6 and the cage 7 even if there is axial displacement due to the internal bearing gap of the rolling bearing 1. The cage 7 is a crown-shaped cage that has a ring portion only on the side opposite the sensor unit 2 (the side going away from the sensor unit 2, the left side in Figure 1) with respect to each rolling element 6. To avoid interference between the sensor unit 2 and the cage 7, the cage 7 has no portion that is closer to the sensor unit 2 than the rolling elements 6. The sensor unit 2 has no portion that protrudes from the rolling bearing 1 in the axial direction.

[0039] The inner circumference 16 of the first race 4 includes a step portion 18 that axially receives the annular side portion 11 of the holder 9, and a peripheral surface portion 19 that fits with the fitting portion 12 of the holder 9. The step portion 18 extends completely around the circumference in the radial direction. The peripheral surface portion 19 is a cylindrical surface that extends completely around the circumference in the axial direction.

[0040] As shown in Figs. 1 and 2, the first raceway ring 4 has an end surface portion 20 located at one end of the axial width of the first raceway ring 4 (the right end in Figs. 1 and 2). The end surface portion 20 is along the radial direction. The step portion 18 and the circumferential surface portion 19 are formed at a position closer to the first raceway surface portion 15 in the axial direction than the end surface portion 20. The circumferential surface portion 19 intersects with the step portion 18 at the other axial end of the circumferential surface portion 19 (the left end in Figs. 1 and 2). It is also possible to include a recessed portion between the step portion 18 and the circumferential surface portion 19 on the inner circumference 16 of the first raceway ring 4 to facilitate machining.

[0041] The inner circumference 16 of the first race 4 has a chamfered portion 21 that continues from the circumferential surface portion 19 to the end surface portion 20. The chamfered portion 21 has a cross-sectional shape in which the corners between the circumferential surface portion 19 and the end surface portion 20 are rounded off, and in the illustrated example, is tapered.

[0042] The holder 9 is an annular body that, when attached to the first bearing ring 4 , determines a predetermined position of the circuit board 8 relative to the first bearing ring 4 .

[0043] The entire holder 9 is formed from a single metal plate, and has an annular side portion 11 and a fitting portion 12 that are seamlessly integrated together. The annular side portion 11 is in the shape of an annular plate having both side surfaces 11a, 11b extending in the radial direction over the entire circumferential direction. The fitting portion 12 extends in the axial direction from the end of the annular side portion 11 that is closer to the first race 4.

[0044] The fitting portion 12 is fitted to a peripheral surface portion 19 of the first bearing ring 4. As a result, the holder 9 is disposed with the first bearing ring 4 at a predetermined coaxiality.

[0045] A side surface 11a of the annular side portion 11 on the rolling element 6 side (the side closer to the rolling element 6, the left side in FIG. 2) is axially butted against a step portion 18 of the first race 4. As a result, the step portion 18 appropriately determines the axial positional relationship between the fitted sensor unit 2 and the first race 4, and also regulates the sensor unit 2 from falling in the radial direction.

[0046] A side surface 11b of the annular side portion 11 on the reversible moving body 6 side (the side farther from the rolling body 6, the right side in FIG. 2) serves as a surface portion that supports the circuit board 8 in the axial direction.

[0047] The entire holder 9 is press-formed. The metal plate forming the holder 9 should have a certain thickness so that the holder 9 can stably hold the position of the circuit board 8 relative to the first race 4. For example, when the holder 9 is formed from an iron-based metal plate having weldability and press formability, the thickness is preferably greater than 0.4 mm, and more preferably 0.6 mm or more. When the holder 9 having such a thickness is produced by press forming, the wear of the mold must be taken into consideration, and therefore the tolerance range of the diameter dimension of the fitting portion 12 becomes large, for example, the tolerance range is 0.2 mm.

[0048] On the other hand, the peripheral surface portion 19 of the first race 4 is formed by cutting. In the case of cutting, the tolerance range of the diameter dimension of the peripheral surface portion 19 is relatively small, for example, the tolerance range is 0.03 mm.

[0049] Here, when the fitting portion 12 and the circumferential surface portion 19 are press-fitted, the tolerance range of the holder 9, which is a pressed part, is large, so the radial interference during press-fitting becomes large (for example, the maximum interference is 0.2 mm), making the press-fitting operation difficult and raising concerns about deformation of the holder 9 and the first race 4. To avoid these problems, the circumferential surface portion 19 and the fitting portion 12 are loosely fitted. That is, in the illustrated example, the minimum inner diameter of the circumferential surface portion 19 is greater than the maximum outer diameter of the fitting portion 12.

[0050] When the peripheral surface portion 19 and the fitting portion 12 are clearance-fitted, it is necessary to ensure the pull-out strength of the holder 9 on one axial end side (the right side in Figs. 1 and 2) relative to the peripheral surface portion 19. In addition, depending on the required specifications for the arrangement of the temperature sensor 10 and the like to be held by the holder 9, it may also be necessary to prevent the holder 9 from rotating in the circumferential direction relative to the first raceway 4. To satisfy these requirements, a weld 22 is provided to join the holder 9 and the first raceway 4.

[0051] As shown in Fig. 2, the welded portion 22 joins the chamfered portion 21 of the first raceway 4 and an outer peripheral portion immediately adjacent to the fitting portion 12 of the holder 9. The welded portion 22 is contained within the axial width of the chamfered portion 21. In other words, the welded portion 22 is provided so as not to protrude toward one axial end side (the right side in Fig. 2) beyond the end face portion 20 located at one end of the width of the first raceway 4. This small welded portion 22 can be provided by laser welding. Although an example in which the welded portion 22 is provided around the entire circumference has been shown (see Figs. 3 and 4), it is also possible to provide the welded portion 22 as spot welded portions at multiple locations evenly spaced around the circumference.

[0052] When the fit between the peripheral surface portion 19 and the fitting portion 12 is a clearance fit, it is possible to ensure the aforementioned pull-out resistance and anti-rotation properties by bonding the first race 4 and the holder 9 with an adhesive, but this requires degreasing before bonding, making assembly of the bearing device more difficult. It is also possible to bond the first race 4 and the holder 9 by friction bonding instead of bonding, but this requires that the friction bonding portion of the first race 4 and the holder 9 be rotated relative to each other in the circumferential direction, and the bonding range becomes larger, which increases the adverse effects of frictional heat, such as thermal strain of the first race 4 and the holder 9.

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

[0054] The substrate 23 is made of a printed wiring board. The substrate 23 is in the shape of an arc plate that is short in the radial direction and long in the circumferential direction. The temperature sensor 10, the wireless communication circuit 24, the power supply circuit 25, and one or more other sensors 26 are mounted on the substrate surface on the side of the reversible moving body 6 of the substrate 23 (the right side in FIG. 2).

[0055] As shown in Fig. 2, the base plate 23 is disposed at a position facing the first raceway surface portion 15 in the axial direction. As shown in Figs. 4 and 5, the base plate 23 is fixed to the annular side portion 11 by a plurality of screws 27. As a result, the base plate surface of the base plate 23 on the rolling element 6 side (the left side in Fig. 2) is fastened in the axial direction to the side surface 11b of the annular side portion 11 on the reversible moving element 6 side, as shown in Fig. 2.

[0056] The temperature sensor 10 is composed of a circuit that converts temperature into an electric signal. The temperature sensor 10 is disposed at a position facing the first raceway surface portion 15 in the axial direction. The rolling bearing 1 generates heat as the rolling bearing 1 rotates. One of the main causes of this heat generation is heat generated at the contact portion between the rolling element 6 and the first raceway ring 4. The faster this heat reaches the temperature sensor 10, the faster and more accurately the temperature change of the first raceway ring 4 can be detected. Therefore, as shown in the figure, it is preferable to provide a heat conduction path consisting of a solid portion that continues in the axial direction from the first raceway surface portion 15 to the circuit board 8, preferably to the temperature sensor 10. Alternatively, a hole may be formed in the board 23, a temperature sensor may be embedded in the hole, and the temperature sensor may be brought into contact with the side surface 11b of the annular side portion 11 on the side of the reversible moving body 6.

[0057] The one or more other sensors 26 shown in Figs. 4 and 5 are composed of a circuit that converts a physical quantity or a chemical quantity other than temperature into an electric signal. The type of the other sensor 26 is not particularly limited. For example, at least one of a group consisting of an acceleration sensor and an AE (Acoustic Emission) sensor is included in the one or more other sensors 26. When an acceleration sensor is used, it is possible to detect radial or axial acceleration for monitoring vibration of the rolling bearing 1. When an AE sensor is used, it is possible to detect an elastic wave (AE wave) emitted when sound generated when a part of an object such as a component of the rolling bearing 1 is deformed or broken or when an impact is applied. Note that electronic components including a temperature sensor and an acceleration sensor may be used.

[0058] The wireless communication circuit 24 is a communication circuit that converts predetermined information, such as the results of detection by the temperature sensor 10 and one or more other sensors 26, into radio waves and radiates the radio waves from an antenna 24a. The wireless communication circuit 24 complies with a predetermined communication protocol and is generally modular. To avoid a decrease in wireless communication performance, the antenna 24a of the wireless communication circuit 24 is not in contact with other members, such as a sealant.

[0059] The power supply circuit 25 is a circuit that converts the AC power generated by the stator 14 of the generator 3 into DC power used on the circuit board 8 .

[0060] In order to protect the circuit board 8 from exposure to the outside, the sensor unit 2 is provided with a cover 28 that covers an opening for inserting the circuit board 8 onto the annular side portion 11.

[0061] The magnetic ring 13 shown in FIG. 1 has a magnet 29 magnetized with alternating north and south poles in the circumferential direction, and a core metal 30, as shown in FIGS. 2 and 4. The magnet 29 is formed of magnetic rubber extending in the circumferential direction. The magnet 29 is bonded to the core metal 30 all around in the circumferential direction. Vulcanization bonding can be used as the bonding method. The core metal 30 has a flange portion for increasing its rigidity. Although the magnet 29 is exemplified by a magnetic material magnetized with multiple poles, it may be composed of a plurality of permanent magnets.

[0062] As shown in Fig. 1, the magnetic ring 13 is fixed to the outer periphery of the second raceway 5 by utilizing the stepped end 31 of the second raceway 5 so as not to protrude from the second raceway 5 in the axial direction. The second raceway 5 and the magnetic ring 13 are arranged coaxially by fitting the magnetic ring 13 to the outer periphery of the second raceway 5. The stepped end 31 of the second raceway 5 is a portion for securing an annular space capable of accommodating the sensor unit 2 and the magnetic ring 13 between the circumferential surface portion 19 of the first raceway 4 and the second raceway 5, and has a shape that radially expands the space between the circumferential surface portion 19 and the end of the second raceway 5 that faces the stepped end 31 in the radial direction.

[0063] 1 and 2 guides the magnetic flux emitted from the magnetic ring 13 with a yoke structure, and induces an AC voltage in the coil 32 within the yoke structure. The stator 14 is provided in the sensor unit 2.

[0064] The yoke structure of the stator 14 is made up of a holder 9 and a yoke member 33 combined with annular side portion 11 of the holder 9, as shown in FIGS.

[0065] The holder 9 and the yoke member 33 are each made of a magnetic material such as a steel plate. The yoke member 33 is formed from a single metal plate. The overall shape of the yoke member 33 is formed by press molding.

[0066] The holder 9 has a first claw pole portion 34 which is seamlessly and integrally formed and extends from the side of the annular side portion 11 opposite the mating portion 12 (the side farther from the mating portion 12, the lower side in Figure 2) to the same side as the mating portion 12 (the right side in Figure 2) in the axial direction at regular intervals in the circumferential direction.

[0067] The yoke member 33 has, integrally and seamlessly, an annular plate portion 35 radially opposed to the fitting portion 12, a side plate portion 36 extending radially from the anti-annular side portion 11 side of the annular plate portion 35 (the side farther from the annular side portion 11, the lower side in Figure 2) to the anti-fitting portion 12 side (the side farther from the annular side portion 11, the right side in Figures 2 and 5), and a second claw pole portion 37 extending axially from the side plate portion 36 at a regular interval in the circumferential direction toward the annular side portion 11 side (the left side in Figure 5).

[0068] The yoke structure of the stator 14 is formed by a first claw pole portion 34, an annular side portion 11, an annular plate portion 35, a side plate portion 36, and a second claw pole portion 37. The fitting portion 12 of the holder 9 forms the outer periphery of the sensor unit 2. The first claw pole portion 34 and the second claw pole portion 37 are located on the inner periphery of the sensor unit 2.

[0069] As shown in Figures 2 and 4, the first claw pole portion 34 and the second claw pole portion 37 face each other in the radial direction with an air gap between them and the magnet 29. The first claw pole portion 34 and the second claw pole portion 37 are arranged in opposite directions in the axial direction and are arranged alternately in the circumferential direction. A circumferential air gap is formed between the first claw pole portion 34 and the second claw pole portion 37 that are adjacent in the circumferential direction. The total number of the first claw pole portions 34 and the second claw pole portions 37 is equal to the number of poles of the magnet 29 (the total number of north poles and south poles).

[0070] As shown in Fig. 5, arc-shaped holes 38 that axially penetrate the annular side portion 11 are formed at multiple locations in the circumferential direction. Protrusions 39 that fit into the inner surfaces of the holes 38 protrude in the axial direction from the annular plate portion 35. As shown in Fig. 6, the annular plate portion 35 is abutted in the axial direction against the annular side portion 11 at substantially all portions except for the areas where these protrusions 39 are present.

[0071] 2 and 5, the coil 32 is wound around a bobbin 40. The coil 32 and the bobbin 40 are arranged all around the circumference in a space surrounded by the annular side portion 11, the side plate portion 36, the annular plate portion 35, the first claw pole portion 34, and the second claw pole portion 37.

[0072] At least a portion of the surface of the coil 32 and the bobbin 40 may be in contact with the claw pole portions 34, 37, the annular side portion 11, and the side plate portion 36. When protecting the magnet wire constituting the coil 32 for the purposes of insulation, heat resistance, dust resistance, moisture resistance, and chafing prevention, a varnish treatment may be adopted in which the coil 32 is coated by dipping the coil 32 in varnish or by dripping varnish onto the coil 32. Also, the bobbin 40 may be omitted.

[0073] The magnetic flux emanating from the N pole of the magnet 29 shown in Fig. 4, for example, enters the annular side portion 11 (or side plate portion 36) from the first claw pole portion 34 (or the second claw pole portion 37), passes through the annular plate portion 35, goes around the coil 32 to the side plate portion 36 (or the annular side portion 11), and returns to the S pole of the magnet 29 via the adjacent second claw pole portion 37 (or the first claw pole portion 34). When the positions of the N pole and the S pole of the magnet 29 are interchanged with the rotation of the second race 5 relative to the first race 4, the direction of the magnetic flux is reversed. The alternating magnetic field thus generated generates an AC voltage at both ends 41, 41 of the start and end of the winding of the coil 32.

[0074] Both ends 41, 41 of the coil 32 are connected to terminals 42, 42 provided on the substrate 23 through wiring holes formed slightly in the annular plate portion 35.

[0075] In assembling the sensor unit 2, as shown in FIG. 5, the bobbin 40 around which the coil 32 is wound is placed between the annular side portion 11 of the holder 9 and the side plate portion 36 of the yoke member 33, and the holder 9 and the yoke member 33 are assembled in the axial direction, and at this time, each protrusion 39 of the yoke member 33 is fitted into the corresponding hole 38 of the annular side portion 11. This fitting ensures that the holder 9 and the yoke member 33 are coaxial with each other, and the first claw pole portion 34 and the second claw pole portion 37 are arranged alternately in a predetermined phase with a gap in the circumferential direction. Therefore, the holder 9 and the yoke member 33 can be assembled appropriately without using a jig. It is preferable that the holes 38 and the protrusions 39 are each formed in three or more places.

[0076] After this assembly, the protrusion 39 is fixed to the inner surface of the hole 38. This fixing may be performed by, for example, press fitting, bonding, laser welding, or a combination of these.

[0077] It is also possible to omit the protrusions 39 and the holes 38. In this case, after the holder and the yoke member are coaxially aligned and phase-aligned using a jig (not shown), the butting portions of the annular side portion and the annular plate portion may be bonded or laser-welded from the outer periphery of the annular plate portion, or these may be fixed using a combination of these methods.

[0078] When holder 9 and yoke member 33 are fixed in the assembled state as described above, stator 14 is completed as shown in Figures 1 and 6. Note that, although an example has been shown in which annular plate portion 35 of yoke member 33 serves as a partition between the storage space for circuit board 8 and stator 14, it is also possible to provide a partition wall separate from the annular plate portion that divides the annular side portion of the holder into two regions in the radial direction, and to place the stator on the radial inside of that partition wall.

[0079] Next, the circuit board 8 is inserted onto the annular side portion 11, and the board 23 is fixed to the annular side portion 11 using a plurality of screws 27. At this time, the board surface opposite to the mounting surface of the temperature sensor 10, the wireless communication circuit 24, etc. is made to face the annular side portion 11. In order to insulate the holder 9 from the circuit board 8, an insulating sheet such as a polyimide film may be interposed between the board 23 and the annular side portion 11. The board 23 and the annular side portion 11 can also be fixed by adhesion using an adhesive, an adhesive sheet, etc., or by a combination of adhesion and screw fastening. When the adhesive, adhesive sheet, or insulating sheet is a component of the heat conduction path, it is preferable to use one with as good thermal conductivity as possible.

[0080] After the circuit board 8 is fixed to the annular side portion 11, an assembly process is performed in which the cover 28 is fitted between the fitting portion 12 and the annular plate portion 35 as shown in Figures 2 and 4. As a result, the cover 28 closes the opening between the fitting portion 12 and the annular plate portion 35 without contacting the circuit board 8, and the gap between the cover 28 and the circuit board 8 becomes filled with air. Note that there is no particular limit to the means for fixing the cover 28, but in order to improve the airtightness of the fitting portions between the cover 28 and the fitting portion 12 and between the cover 28 and the annular plate portion 35, an adhesive or a resin filler may be applied to the fitting portions.

[0081] The cover 28 is made of resin that does not contain metal. Even if the holder 9 and the yoke member 33 are made of metal, the cover 28 has radio wave permeability, so wireless communication using the antenna 24a is possible. It is also possible to seal the circuit board 8 by filling the opening between the fitting portion 12 and the annular plate portion 35 with a sealant without using the cover 28. In this case, since the antenna 24a is covered with the sealant, it is advisable to use a sealant with a low relative dielectric constant, such as a resin, to suppress shortening of the wavelength of the radio waves due to the dielectric constant of the sealant.

[0082] After the cover 28 is fixed, the sensor unit 2 is fixed to the first raceway 4, as shown in Fig. 1 and Fig. 2. In addition, the magnetic ring 13 is fixed to the outer periphery of the second raceway 5. Since the first raceway 4 and the second raceway 5 are arranged coaxially, the sensor unit 2 and the magnetic ring 13 are also arranged coaxially.

[0083] The magnetic ring 13 can be fixed to the second race 5 by press-fitting or bonding, or by using both.

[0084] On the other hand, the sensor unit 2 is fixed to the first race 4 by performing a fitting process in which the fitting portion 12 of the holder 9 is fitted into the peripheral surface portion 19 of the first race 4 and the annular side portion 11 is abutted against the step portion 18, and then performing a welding process in which the chamfered portion 21 is joined to the outer periphery of the holder 9 to provide a welded portion 22. The assembly process of the cover 28 may be performed after the welding process to avoid adverse effects on the cover 28 due to welding heat.

[0085] Since the variation in the radial gap between the magnetic ring 13 fixed to the second raceway 5, which is a component of the radial bearing, and the stator 14 of the sensor unit 2 fixed to the first raceway 4, which is also a component of the radial bearing, is small, a stable amount of power can be generated by the generator 3 composed of the magnetic ring 13 and the stator 14, compared to the case where a magnetic ring is provided on the cage. Since the detection and wireless communication can be performed by the circuit board 8 using the generator 3 as a power source, the sensor unit 2 can be made wireless. Note that a storage battery may be mounted on the annular side portion 11 or the board 23 as an emergency power source. Also, the power source for making it wireless is not limited to a generator, and may be a storage battery that can be mounted on the sensor unit or a power receiving circuit of a wireless power supply device.

[0086] This bearing device (see Figures 1 and 2) is as described above and comprises a rolling bearing 1 having a first raceway 4, a second raceway 5, and a plurality of rolling elements 6 arranged between the first raceway 4 and the second raceway 5, a sensor unit 2 having a sensor (a temperature sensor 10 included in a circuit board 8, other sensors 26) and a holder 9 for holding the sensor (the temperature sensor 10, etc.), the holder 9 having an annular side portion 11 extending radially and an engagement portion 12 protruding axially from the annular side portion 11, and the first raceway 4 having an inner circumference 16 including a raceway surface portion (first raceway surface portion 15), a step portion 18 for receiving the holder 9 axially, and a peripheral surface portion 19 that engages with the engagement portion 12.

[0087] In this bearing device (see Figures 1 and 2), in particular, by providing a welded portion 22 joining the holder 9 and the first raceway 4, the holder 9 is prevented from being pulled out of the first raceway 4 by the welded portion 22, and since this makes it possible to set a looser fit between the peripheral portion 19 of the first raceway 4 and the mating portion 12 of the holder 9, deformation of both the first raceway 4 and the holder 9 due to their mating can be reduced.

[0088] Furthermore, in this bearing device, since the peripheral surface 19 of the first raceway 4 and the mating portion 12 of the holder 9 are fitted with a loose fit, there is no radial interference between the peripheral surface 19 and the mating portion 12, and therefore deformation of both the first raceway 4 and the holder 9 due to their fitting can be particularly reduced.

[0089] Furthermore, in this bearing device, the first race 4 has a chamfered portion 21 that continues from the peripheral surface portion 19 to one end of the width of the first race 4 (the same axial position as the end surface portion 20), and the welded portion 22 joins the chamfered portion 21 to the holder 9 and is provided so as not to protrude beyond the one end of the width (end surface portion 20) toward the one axial end side (the right side in Figs. 1 and 2), thereby preventing the welded portion 22 from interfering when the bearing device is accommodated between a housing (not shown) and a shaft. More specifically, even if the welded portion 22 is provided, the width of the bearing device is not increased, and the welded portion 22 does not get in the way when the end surface portion 20 of the first race 4 is butted against a housing shoulder, a shaft shoulder, a housing lid, a nut, or the like in the axial direction for positioning.

[0090] In this bearing device, an open space is provided on the side surface at one end of the bearing device to enable welding and accommodating the welded portion 22 by forming a chamfered portion 21 on the first race 4, but such an open space can be provided in other ways. As an example, a bearing device according to a second embodiment is shown in Fig. 7. Note that only the differences from the first embodiment will be described here, and the same reference numerals will be used to designate the same components as those in the first embodiment.

[0091] The fitting portion 51 of the holder 50 according to the second embodiment has a plate end 51a disposed at a position closer to the rolling body side (left side in FIG. 7, see FIG. 2) than the end face portion 20. The welded portion 52 joins the plate end 51a to the inner peripheral end portion between the circumferential surface portion 19 and the end face portion 20 of the first raceway ring 53 (the side of the circumferential surface portion 19 closer to the end face portion 20). The first raceway ring 53 is one in which the chamfered portion between the circumferential surface portion 19 and the end face portion 20 is omitted, and the inner peripheral end portion between the circumferential surface portion 19 and the end face portion 20 is formed in the same plane as the circumferential surface portion 19. The welded portion 52 is provided so as not to protrude beyond the end face portion 20 toward one end side in the axial direction (right side in FIG. 7). The arrangement of the plate end 51a may be determined in accordance with the arrangement of the welded portion 52, and the plate end 51a may be provided continuously around the entire circumference, or may be provided only at a plurality of locations evenly spaced in the circumferential direction. If the cover 28 interferes with the welding process, the assembly process of the cover 28 may be performed after the welding process.

[0092] In the bearing device of the second embodiment, by utilizing the open space between the plate end 51a of the fitting portion 51 of the holder 50 and one end of the width (end face portion 20) of the first raceway 53, the welded portion 52 is arranged so that it does not extend beyond the one end of the width (end face portion 20) of the first raceway toward the one axial end side (the right side in Figure 7), thereby preventing the welded portion 52 from interfering when the bearing device of the second embodiment is accommodated between a housing not shown and a shaft.

[0093] In the above-described embodiments, the welded portion is provided in close proximity to the fitting portion, but the welded portion can also be provided at a position distant from the fitting portion. As an example, a third embodiment is shown in Figures 8 and 9. Note that the third embodiment is a further modification of the second embodiment, so only the differences from the second embodiment will be described here, and the same components as those in the second embodiment will be denoted by the same reference numerals.

[0094] The first raceway ring 60 according to the third embodiment has a notch 62 which is recessed axially from the end face portion 20 and intersects with the circumferential surface portion 61. The notch 62 is arranged at four locations equally spaced in the circumferential direction. The width between the intersection of the notch 62 and the step portion 18 on the circumferential surface portion 61 is shorter than the width between the step portion 18 and a portion of the circumferential surface portion 61 other than the intersection. The notch 62 is formed in a groove shape which penetrates between the inner and outer periphery of the first raceway ring 60 in a straight line in the radial direction.

[0095] The holder 63 has a protruding portion 64 that extends radially from the fitting portion 51 and fits into the notch portion 62. The welded portion 65 joins the protruding portion 64 and the notch portion 62 and is provided so as not to protrude beyond the end face portion 20 toward one end in the axial direction.

[0096] The protruding portion 64 is provided in the same phase as the notch portion 62. The protruding portion 64 protrudes in the same direction as the groove length direction of the notch portion 62. The protruding length of the protruding portion 64 from the fitting portion 51 is set shorter than the groove length of the notch portion 62 from the peripheral surface portion 61. The plate thickness of the protruding portion 64 is set to be equal to or less than the groove depth of the notch portion 62 from the end face portion 20. The protruding portion 64 and the groove bottom surface of the notch portion 62 overlap in the axial direction. With these settings, the notch portion 62 has an open space sufficient to accommodate the protruding portion 64 and the welded portion 65 and also to allow the welded portion 65 to be cut away with a router or the like.

[0097] In the bearing device according to the third embodiment, the projection 64 and the welded portion 65 of the holder 63 are provided so as not to protrude beyond the one axial end of the first bearing ring 60 by utilizing the space of the notched portion 62 recessed in the axial direction from the end face portion 20 at one end of the width of the first bearing ring 60, so that the projection 64 and the welded portion 65 do not interfere with each other when the bearing device according to the third embodiment is accommodated between a housing (not shown) and a shaft. Also, the notched portion 62 recessed in the axial direction from the end face portion 20 at one end of the width of the first bearing ring 60 can be provided with a margin so that the welded portion 65 can be cut off with a router or the like, so that by cutting off the welded portion 65, the sensor unit 66 can be pulled out of the first bearing ring 60 without any significant damage, and the removed sensor unit 66 can be reused.

[0098] In each of the above-mentioned embodiments, the holder and the first raceway are welded, but it is also possible to weld a separate member different from the holder to the first raceway and use this separate member to pull out the holder from the first raceway and to prevent it from rotating. As an example, a fourth embodiment is shown in Figures 10 and 11. Note that the fourth embodiment is a further modification of the third embodiment, so here, only the differences from the third embodiment will be described, and the same components as those in the third embodiment will be given the same reference numerals.

[0099] The holder 70 according to the fourth embodiment is one in which the protruding plate portion of the third embodiment is omitted, and accordingly, the fitting portion 71 has a concave plate edge 71a recessed in the axial direction in the same phase as the notch portion 62. As a separate member replacing the protruding plate portion of the third embodiment, a pressing plate 72 overlapping the concave plate edge 71a and the notch portion 62 in the axial direction, and a welding portion 73 joining the pressing plate 72 and the notch portion 62 are provided. The pressing plate 72 and the welding portion 73 are in the same relationship with respect to the notch portion 62 as the protruding plate portion and the welding portion of the third embodiment, and are provided so as not to protrude from the end face portion 20 of the first race 60 toward one end side in the axial direction. The pressing plate 72 fixed to the first race 60 and the concave plate edge 71a recessed in the axial direction of the fitting portion 71 of the holder 70 can be engaged in the circumferential direction at their respective circumferential ends. Therefore, even if a force acts on the first raceway 60 or the holder 70 in a direction that causes the first raceway 60 and the holder 70 to rotate relative to each other in the circumferential direction, the engagement between the pressure plate 72 and the concave plate edge 71a achieves a rotation prevention effect in which the holder 70 is locked relative to the first raceway 60 in the circumferential direction.

[0100] In the bearing device according to the fourth embodiment, in particular, the first race 60 has an end surface portion 20 extending in the radial direction at one end of the width of the first race 60, and a notch portion 62 that is recessed in the axial direction from the end surface portion 20 and intersects with the inner circumference including the peripheral surface portion 61, the fitting portion 71 of the holder 70 has a concave plate edge 71a recessed in the axial direction in the same phase as the notch portion 62, and a welding portion 73 is provided to join a pressing plate 72 that overlaps with the concave plate edge 71a and the notch portion 62 in the axial direction to the notch portion 62, and the pressing plate 72 and the welding portion 73 are disposed axially further from the end surface portion 20. Since the holder 70 is provided so as not to protrude toward the one end, the holder 70 is prevented from being pulled out of the first race 60 by the pressing plate 72 welded to the first race 60, and the fit between the peripheral surface 61 and the fitting portion 71 of the holder 70 can be set loosely, so that the deformation of the first race 60 and the holder 70 due to the fitting between them can be reduced, and the pressing plate 72 and the welded portion 73 can be prevented from interfering with each other when the bearing device according to the fourth embodiment is accommodated between a housing (not shown) and a shaft. Also, the notch 62 recessed in the axial direction from the end surface 20 at one end of the width of the first race 60 can be provided with a margin so that the welded portion 73 can be cut off with a router or the like, so that if the welded portion 73 is cut off and the pressing plate 72 is removed, the sensor unit 74 can be pulled out of the first race 60 without any particular damage, and the removed sensor unit 74 can be reused.

[0101] In addition, in the bearing device of the fourth embodiment, the peripheral surface 61 of the first raceway 60 and the mating portion 71 of the holder 70 are fitted together with a clearance, and the holder 70 is prevented from rotating by circumferential engagement between the pressure plate 72 and the concave plate edge 71a. As a result, there is no radial interference between the peripheral surface 61 and the mating portion 71, and therefore deformation of the first raceway 60 and the holder 70 due to their engagement can be particularly reduced. Furthermore, the pressure plate 72 fixed to the first raceway 60 by welding can be used to prevent the holder 70 from rotating, thereby enabling the sensor unit 74 to be fixed to the first raceway 60.

[0102] In each of the above-mentioned embodiments, the first raceway ring is an outer ring, and the fitting portion of the holder is fitted to the circumferential surface of the inner circumference thereof, but it is also possible to use the first raceway ring as an inner ring, and to fit the fitting portion of the holder to the circumferential surface of the outer circumference thereof. In this case, the first raceway ring has an outer circumference including a raceway surface portion, a step portion that axially receives the rolling element side of the holder, and a circumferential surface portion that fits with the fitting portion. Therefore, when the first raceway ring is an inner ring in each of the above-mentioned embodiments, the inside and outside in the radial direction only need to be understood in reverse, and therefore illustrations and detailed explanations of these cases are omitted. That is, in each of the above-mentioned embodiments, if the cross-sectional structures depicted in the longitudinal front views of Figures 1, 2, 7, 8 and 10 are rotated 180 degrees counterclockwise to form an upside-down view, and the upper side of the cross section of the first raceway in the upside-down view is the outer periphery side of the inner ring and the left side of the first raceway in the upside-down view is the axial end side, then this will show how to provide welds, notches, protruding portions, pressure plates, etc. when the first raceway is used as the inner ring.

[0103] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0104] 1. Rolling bearings 2, 66, 74 Sensor Unit 4, 53, 60 First race 5 Second bearing ring 6 Rolling elements 9, 50, 63, 70 Holder 10 Temperature sensor (sensor) 11 Circular side 12, 51, 71 Fitting part 15 Raceway surface section 16 Inner Circumference 18 Step section 19, 61 Peripheral part 21 Chamfered part 22, 52, 65, 73 Welded parts 26 Other sensors (sensors) 51a Board edge 62 Notch 64 Veneer section 71a Concave plate edge 72 Presser plate

Claims

1. a rolling bearing having a first raceway, a second raceway, and a plurality of rolling elements disposed between the first raceway and the second raceway; a sensor unit having a sensor and a holder for holding the sensor; The holder has an annular side portion extending in a radial direction and a fitting portion protruding in an axial direction from the annular side portion, The holder is formed of a metal plate, In a bearing device, the first raceway has an inner periphery or an outer periphery including a raceway surface portion, a step portion that axially receives the rolling element side of the holder, and a peripheral surface portion that fits with the fitting portion, A bearing device comprising: a welded portion for joining the holder and the first race;

2. 2. The bearing device according to claim 1, wherein the peripheral surface of the first race and the fitting portion of the holder are fitted with a clearance.

3. the first raceway has a chamfered portion that is continuous from the circumferential surface portion to one end of the width of the first raceway, 3. The bearing device according to claim 1, wherein the welded portion joins the chamfered portion and the holder and is provided so as not to protrude beyond the one end of the width toward the one axial end.

4. the fitting portion of the holder has a plate end that is disposed at a position closer to the rolling element side than one end of the width of the first raceway, 3. The bearing device according to claim 1, wherein the welded portion joins the plate end and the first race and is provided so as not to protrude beyond the one end of the width toward the one end in the axial direction.

5. the first raceway has an end surface portion extending in a radial direction at one end of the width of the first raceway, and a notch portion recessed in an axial direction from the end surface portion and intersecting an inner circumference or an outer circumference including the peripheral surface portion, the holder has a protruding plate portion that extends radially from the fitting portion and is fitted into the notch portion, 3. The bearing device according to claim 1, wherein the welded portion joins the protruding plate portion and the cutout portion and is provided so as not to protrude beyond the end face portion toward the one end in the axial direction.

6. a rolling bearing having a first raceway, a second raceway, and a plurality of rolling elements disposed between the first raceway and the second raceway; a sensor unit having a sensor and a holder for holding the sensor; The holder has an annular side portion extending in a radial direction and a fitting portion protruding in an axial direction from the annular side portion, The holder is formed of a metal plate, In a bearing device, the first raceway has an inner periphery or an outer periphery including a raceway surface portion, a step portion that axially receives the rolling element side of the holder, and a peripheral surface portion that fits into the fitting portion, the first raceway has an end surface portion extending in a radial direction at one end of the width of the first raceway, and a notch portion recessed in an axial direction from the end surface portion and intersecting an inner circumference or an outer circumference including the peripheral surface portion, The fitting portion has a concave plate edge recessed in the axial direction in the same phase as the cutout portion, A weld is provided to join a pressing plate overlapping the concave plate edge and the cutout portion in the axial direction to the cutout portion, A bearing device, characterized in that the pressure plate and the welded portion are arranged so as not to protrude beyond the end face portion toward one end in the axial direction.

7. the circumferential surface portion of the first raceway and the fitting portion of the holder are fitted with a clearance, 7. The bearing device according to claim 6, wherein said holder is prevented from rotating by circumferential engagement between said pressing plate and said concave plate edge.

Images