Bearing device

Abstract

To provide a bearing device that improves the operational reliability of bearings and increases design flexibility. [Solution] The bearing device 1 comprises a bearing 2 and a sensing unit 7 and a power generation unit G capable of supplying power to the sensing unit 7, which are provided inside the bearing 2. The sensing unit 7 and the power generation unit G are built into the bearing 2. Along with this, the power generation unit G is provided with an annular fixing part RP that maintains the phase of the stator 13 and fixes the stator 13 and the sensing unit 7. One end of the outer ring 9 of the bearing 2 is provided with an annular stepped portion 9c that restricts the axial position of the fixing part RP and houses the sensing unit assembly 4, including the fixing part RP, the stator 13 and the sensing unit 7, inside the bearing.

Description

[Technical Field]

[0001] The present invention relates to a bearing device, and to a technology capable of improving the operational reliability of a bearing and also improving the degree of freedom in design. [Background Art]

[0002] In a conventional bearing device, as shown in Fig. 10, a stepped annular recess is formed on the inner peripheral surface of the outer ring of a bearing 100, and a sensor unit SU is provided in this annular recess (Patent Document 1). The sensor unit SU includes a stator 101 fitted and fixed in the annular recess, a substrate 103 fixed to the stator 101 with screws, and a sensor supported by the substrate 103, and the like. [Prior Art Literature] [Patent Literature]

[0003] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2023-141396 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] In the prior art, screws are used to fix the substrate 103. However, regarding the screwed fastening state, due to the screw pitch and the length of the fastening portion (the plate thickness of the stator 101), the screw must be used in a state where the tip end of the screw protrudes axially inward from the end face 101a of the stator. As a result, during operation of the bearing, the steel balls 104 approach the screw by the amount of the axial clearance of the bearing, which may obstruct the movement of the steel balls 104. Furthermore, since the tip end of the screw protrudes axially inward from the end face 101a of the stator, it compresses the internal design space of the bearing 100, and the degree of freedom in designing bearing specifications and the sensing unit is limited.

[0005] An object of the present invention is to provide a bearing device capable of improving the operational reliability of a bearing and also improving the degree of freedom in design. [Means for solving the problem]

[0006] The present invention is a bearing device comprising a bearing, a sensing unit and a power generation unit capable of supplying power to the sensing unit, provided inside the bearing, The bearing has a fixed-side raceway and a rotating-side raceway, and comprises an annular fixing part that maintains the phase of the stator in the power generation section and to which the stator and the sensing section are fixed, and a sensing section assembly including the stator and the sensing section. An annular stepped portion is provided at one end of the fixed-side raceway, which restricts the axial position of the fixed component and houses the sensing unit assembly within the bearing.

[0007] This configuration includes an annular fixing component that maintains the phase of the stator and secures the stator and sensing unit. Furthermore, the annular stepped portion of the bearing can accommodate the sensing unit assembly, including the fixing component, stator, and sensing unit. As a result, screws protruding axially inward from the stator end face can be omitted. This prevents the bearing's rolling elements from interfering with the screws, improving the bearing's operational reliability. In addition, compared to conventional structures with screws, this configuration provides more internal design space for the bearing, resulting in greater design flexibility for the bearing specifications and the sensing unit.

[0008] The stator may be provided with an engaged portion that engages with an engaging portion provided on the fixed component. In this case, by engaging the engaged portion of the fixed component with the engaged portion of the stator, the two components can be easily and reliably fixed together while aligning the phases of the stator and the fixed component.

[0009] The aforementioned fixing component may be a resin component insert-molded into the stator. In this case, the resin component can be easily fixed to the stator, which is supported by a mold, by pouring resin into the cavity. Therefore, it becomes possible to improve the mass production efficiency of the bearing device.

[0010] The sensing unit assembly includes a substrate on which the sensing unit is supported. The engaging portion of the fixed component has a configuration in which a large-diameter and a small-diameter protrusion are superimposed in the axial direction, and the large-diameter protrusion may be inserted through the through hole which is the engaged portion of the stator, while the small-diameter protrusion may be fitted into a hole provided in the substrate. In this case, the large-diameter protrusion of the fixing component can secure the fixing component to the stator while ensuring the phase between the fixing component and the stator. Furthermore, since the small-diameter protrusion of the fixing component fits into the hole in the substrate, the small-diameter protrusion of the fixing component can restrict the axial position of the substrate relative to the fixing component while ensuring the phase between the fixing component and the substrate.

[0011] The large-diameter protrusion may have an axial height greater than or equal to the thickness of the stator, and the small-diameter protrusion may have an axial height greater than or equal to the thickness of the substrate. In this case, the substrate can be raised from the stator, preventing metal-to-metal contact between the substrate and the stator. Therefore, leakage current caused by metal contact can be prevented without interposing insulating materials between the substrate and the stator. Furthermore, since insulating materials are not required, the number of parts can be reduced, thereby lowering manufacturing costs.

[0012] An insulating member may be provided in the gap between the substrate and the stator, and the substrate may be fixed to the stator via the insulating member. In this case, the substrate can be firmly fixed to the stator using an insulating member such as a potting material. The insulating member can prevent the substrate from making metal-to-metal contact with the stator. [Effects of the Invention]

[0013] The bearing device of the present invention is a bearing device comprising a bearing, and a sensing unit and a power generation unit provided inside the bearing and capable of supplying electric power to the sensing unit, wherein the bearing has a fixed-side bearing ring and a rotating-side bearing ring, the bearing device comprising an annular fixing component that maintains the phase of a stator in the power generation unit and to which the stator and the sensing unit are fixed, and a sensing unit assembly including the stator and the sensing unit, wherein an annular stepped portion that restricts the axial position of the fixing component and accommodates the sensing unit assembly in the bearing is provided at one end of the fixed-side bearing ring. Therefore, the operational reliability of the bearing can be improved, and the degree of freedom in design can be improved. [BRIEF DESCRIPTION OF THE DRAWINGS]

[0014] [Figure 1] FIG. 1 is a longitudinal sectional view of the bearing device according to the first embodiment of the present invention. [Figure 2] FIG. 2 is a side view of the bearing device. [Figure 3] FIG. 3 is a sectional view taken along line III-III in FIG. 1. [Figure 4] FIG. 4 is a partially enlarged view partially enlarging a main part of FIG. 1. [Figure 5] FIG. 5 is an enlarged sectional view showing, in an enlarged manner, the sensing unit assembly and the like of the bearing device. [Figure 6] FIG. 6 is a partially enlarged view showing, in an enlarged manner, the VI part in FIG. 4. [Figure 7] FIG. 7 is an exploded perspective view of a stator body and a fixing component in the bearing device. [Figure 8] FIG. 8 is an enlarged sectional view of a main part of a bearing device according to a second embodiment of the present invention. [Figure 9] FIG. 9 is a longitudinal sectional view of a bearing device according to a third embodiment of the present invention. [Figure 10] FIG. 10 is a longitudinal sectional view of a conventional bearing device. [DESCRIPTION OF EMBODIMENTS]

[0015] [First Embodiment] A bearing device according to an embodiment of the present invention will be described with reference to FIGS. 1 to 7. The bearing device is applied to, for example, all general industrial machinery such as motors and blowers, wind power generators, vehicles such as automobiles, motorcycles and railway vehicles, medical equipment, and the like. However, the bearing device is not limited to these applications.

[0016] <Schematic Structure of Bearing Device> As shown in FIG. 1, a bearing device 1 according to a first embodiment includes a bearing 2, an O-ring 3 serving as an annular seal portion, a sensing unit assembly 4, a magnetic ring 5, and a seal member 6 which will be described later. In the bearing device 1, members other than the bearing are built into one end portion (the left end portion in FIG. 1) of the bearing 2. The state of the bearing 2 measured by the sensing unit 7 of the sensing unit assembly 4 is transmitted to the outside of the bearing device 1 and monitored constantly or at predetermined time intervals. Members other than the bearing in the bearing device 1 may be collectively referred to as "sensing unit assembly and the like" in some cases.

[0017] <Bearing> The bearing 2 in this example includes an inner ring 8, an outer ring 9, a plurality of rolling elements 10 interposed between the raceways of the inner ring 8 and the outer ring 9, a cage 11 retaining these rolling elements 10, and a seal 12 provided at the other end of the bearing 2, and is a grease-lubricated rolling bearing. This rolling bearing is a deep groove ball bearing in which balls as the rolling elements 10 are interposed between the opposing raceways 8a and 9a of the inner ring 8 and the outer ring 9.

[0018] The rolling elements 10 are made of steel balls or ceramic balls. The cage 11 is a resin crown-shaped cage. A corrugated cage made of iron plate may be applied as the cage 11. The seal 12 is a contact seal that is fitted and fixed in an outer ring seal groove 9b provided on the inner circumferential surface of the outer ring, and contacts an inner ring seal groove 8b provided on the outer circumferential surface of the inner ring. The outer ring seal groove 9b is provided on the inner circumferential surface of the outer ring on the other end side (the right end side in FIG. 4) of the bearing 2. The inner ring seal groove 8b faces the outer ring seal groove 9b in the radial direction. A non-contact seal may be applied as the seal 12. This deep groove ball bearing is used, for example, in an inner ring rotation mode with the outer ring fixed, but may also be used in an outer ring rotation mode with the inner ring fixed as described later.

[0019] Figure 1 is a cross-sectional view taken along line II of Figure 2. Figure 3 is a cross-sectional view taken along line III-III of Figure 1. As shown in Figures 1 to 3, a first stepped portion 9c is formed on the inner circumferential surface of the outer ring 9 at one end. The first stepped portion 9c is a stepped annular recess, also referred to as the "first notch." As shown in Figure 4, a second stepped portion 8c is formed on the outer circumferential surface of the inner ring 8 at one end. The second stepped portion 8c is a stepped annular recess, also referred to as the "second notch." The first stepped portion 9c faces the second stepped portion 8c in the radial direction. These first and second stepped portions 9c and 8c provide space for housing the sensing assembly and the like at one end of the bearing 2.

[0020] In the following explanation, as shown in Figure 1, the direction of the bearing center axis AX is referred to as the "axial direction," the direction perpendicular to the bearing center axis AX is referred to as the "radial direction," and the direction around the bearing center axis AX is referred to as the "circumferential direction." Furthermore, the side facing the bearing center axis AX is referred to as the "inner diameter side," and the side moving away from the bearing center axis AX is referred to as the "outer diameter side."

[0021] <Regarding the main dimensions and internal specifications of the bearings> Bearing 2 has been modified to have the specified bearing size shown in Figures 1 to 3 by changing the predetermined internal bearing specifications. The aforementioned specified bearing size is the bearing inner diameter, bearing outer diameter, and bearing width as defined in ISO 15 or JIS 1512-1, and is also referred to as the main dimensions of the bearing. Simply adding the seal member 6 to the conventional technology would result in exceeding the specified bearing size. Therefore, in this embodiment, the predetermined internal bearing specifications have been modified so that even with the addition of the seal member 6 shown in Figures 1 to 3, the bearing size remains within the specified range. The term "bearing interior" refers to the space between the outer ring 9 and the inner ring 8 in the range from one axial end face to the other end face of the outer ring 9.

[0022] Specifically, as shown in Figure 4, the bearing 2 of the embodiment has been modified from the internal specifications of a general bearing by, for example, reducing the diameter of the steel balls, increasing the pitch circle diameter (PCD) of the steel balls, increasing the number of steel balls, and moving the axial position P1 of the racing surfaces 8a and 9a on the inner and outer rings 8 and 9 to the side opposite the sealing member (right side in Figure 4). By moving the axial position P1 of the racing surfaces 8a and 9a, a sensing assembly or the like can be built into one end of the bearing 2. By reducing the diameter of the steel balls, increasing the pitch circle diameter (PCD) of the steel balls, and increasing the number of steel balls, the bearing 2 can achieve a desired load capacity. The axial position P1 of the racing surfaces 8a and 9a, the diameter of the steel balls, the pitch circle diameter (PCD) of the steel balls, and the number of steel balls can be appropriately determined, for example, by simulation and / or testing.

[0023] <Sensing Unit Assembly> As shown in Figure 5, the sensing unit assembly 4 includes an annular fixing component RP, a stator 13, a substrate 15, the sensing unit 7 shown in Figure 3, and an antenna unit 17a. As shown in Figure 4, the power generation unit G is formed by the stator 13 and a magnetic ring (described later) 5 that faces the stator 13 across a radial gap δ1, also known as a radial gap. That is, the bearing device 1 is provided at one end of the bearing 2 and includes a sensing unit 7 and a power generation unit G capable of supplying power to the sensing unit 7. The power generation unit G is built into the bearing 2. The power generated by the power generation unit G can be supplied to the substrate 15 and the sensing unit 7.

[0024] <Regarding fixing parts, etc.> As shown in Figure 7, the fixed component RP maintains the phase of the stator 13 in the power generation section G (Figure 4). Furthermore, as shown in Figure 5, the stator 13 and the sensing section 7 are fixed to the fixed component RP. As shown in Figure 7, the fixed component RP is a flat, annular resin component and is provided coaxially with the stator body 19 on its axial outer surface, which will be described later. As shown in Figure 4, the first stepped portion 9c restricts the axial position of the fixed component RP, and the sensing section assembly 4, including the fixed component RP, the stator 13, and the sensing section 7, is housed in the bearing by the first and second stepped portions 9c and 8c.

[0025] As shown in Figure 7, the fixed component RP has a disc-shaped fixed component body 34 and a plurality of engaging portions 35 provided on one surface of the fixed component body 34. The plurality of engaging portions 35 are provided at predetermined phases on the fixed component body 34. The fixed component body 34 and the plurality of engaging portions 35 are integrally formed from the same resin material, but it is also possible to form them separately and fix the plurality of engaging portions 35 to one surface of the fixed component body 34. The stator body 19 and the fixed component RP are fixed to each other by adhesive or joining, or the fixed component RP is insert-molded into the stator body 19.

[0026] As shown in Figure 4, the stator 13 is supported by the outer ring 9, which is a fixed-side raceway. The stator 13 has a stator body 19 that holds fixed components RP and a substrate 15, and a stator component 21 that supports the coil assembly 20. The stator body 19 is made of an annular magnetic material. The stator body 19 is formed in a substantially U-shape in longitudinal cross-section with a disc-shaped portion 19a, an outer diameter cylindrical portion 19b connected to the outer peripheral edge of the disc-shaped portion 19a, and an inner diameter portion 19c connected to the inner peripheral edge of the disc-shaped portion 19a. The disc-shaped portion 19a, the outer diameter cylindrical portion 19b, and the inner diameter portion 19c are integrally formed from a single material, for example by machining.

[0027] As shown in Figure 7, the disc-shaped portion 19a of the stator body 19 is provided with engaged portions 36 that engage with each engaging portion 35 of the fixed component RP. Specifically, as shown in Figures 5 and 7, the engaging portion 35 of the fixed component RP has a configuration in which large-diameter and small-diameter protrusions 35a and 35b are superimposed in the axial direction. In each engaging portion 35, the large-diameter and small-diameter protrusions 35a and 35b are provided coaxially and are formed in a cylindrical shape extending in the axial direction. The small-diameter protrusion 35b is smaller in diameter than the large-diameter protrusion 35a. The axial base end of the large-diameter protrusion 35a is provided on one surface of the fixing component body 34, and the small-diameter protrusion 35b is provided so as to overlap the axial tip of the large-diameter protrusion 35a.

[0028] The large-diameter protrusion 35a is inserted through the through-hole, which is the engaged portion 36 of the stator body 19. At the same time, as shown in Figures 3 and 5, the small-diameter protrusion 35b is fitted into the hole 15a provided in the substrate 15. The substrate 15 and the fixing component RP are firmly fixed together by applying, for example, an adhesive, between the hole 15a of the substrate 15 and the small-diameter protrusion 35b of the fixing component RP. Note that the method of fixing the substrate 15 to the fixing component RP is not limited to the adhesive; for example, bonding with an insulating material such as potting material or heat welding are also possible. In the state in which the small-diameter protrusion 35b is fitted into the hole 15a of the substrate 15, the axial inner surface of the substrate 15 is supported by the stepped surface 35aa of the large-diameter protrusion 35a.

[0029] <Parameters> As shown in Figure 6, the large-diameter protrusion 35a of the fixed component RP has an axial height H1 that is greater than or equal to the thickness t1 of the stator body 19. The small-diameter protrusion 35b has an axial height H2 that is greater than or equal to the thickness t2 of the substrate 15. The thickness t1 of the stator body 19 refers to the thickness of the disc-shaped portion 19a of the stator body 19.

[0030] The stator body 19 is fitted onto the inner circumferential surface of the outer ring 9, which is the fixed-side raceway ring. Specifically, the outer diameter side cylindrical portion 19b of the stator body 19 is fitted and fixed to the first stepped portion 9c of the outer ring 9. Furthermore, the outer diameter side portion of the other surface of the fixed component body 34 abuts against the stepped portion 9ca of the first stepped portion 9c. As a result, the sensing unit assembly 4, including the fixed component RP and the stator body 19, is positioned axially with respect to the outer ring 9. With the outer diameter cylindrical portion 19b fitted into the first stepped portion 9c, and the outer diameter portion of the fixing component body 34 in contact with the stepped portion 9ca, the stator body 19 does not protrude from the end face of the outer ring 9. In other words, the stator body 19 is housed in one end of the bearing 2.

[0031] An O-ring 3 is provided at the fitting portion k1 between the stator body 19 and the inner circumferential surface of the outer ring 9. An annular seal groove 9d is provided in the first stepped portion 9c of the outer ring 9, and the O-ring 3 is fitted into the seal groove 9d. This O-ring 3 prevents grease from leaking from inside the bearing through the fitting portion k1 between the outer diameter cylindrical portion 19b of the stator body 19 and the inner circumferential surface of the outer ring 9. A liquid gasket may be used instead of the O-ring 3 as the annular seal. By filling the seal groove 9d with liquid gasket, grease leakage from the bearing 2 can be prevented in the same way as with the O-ring 3.

[0032] As shown in Figure 5, an annular stator component 21 is fixed to the stator body 19 coaxially with the stator body 19. The stator component 21 is made of an annular magnetic material. The stator component 21 is formed in a substantially U-shape in longitudinal cross-section, consisting of a disc-shaped portion 21a, an outer diameter cylindrical portion 21b connected to the outer peripheral edge of the disc-shaped portion 21a, and an inner diameter portion 21c connected to the inner peripheral edge of the disc-shaped portion 21a. The components of the stator component 21 are also integrally formed from a single material by machining or the like, similar to the stator body 19. The outer diameter cylindrical portion 21b of the stator component 21 is fixed to the inner diameter portion of the disc-shaped portion 19a of the stator body 19. The stator body 19 and the stator component 21 are positioned at a predetermined phase while being fixed to each other.

[0033] As shown in Figures 5 and 7, the inner diameter portion 19c of the stator body 19 has a plurality of claw portions 19ca that protrude in one axial direction. The plurality of claw portions 19ca are provided at regular intervals in the circumferential direction. In addition, as shown in Figure 5, the inner diameter portion 21c of the stator component 21 has a plurality of claw portions 21ca that protrude in the other axial direction. The plurality of claw portions 21ca are provided at regular intervals in the circumferential direction. The plurality of claw portions 19ca in the stator body 19 and the plurality of claw portions 21ca in the stator component 21 are arranged alternately with a gap in the circumferential direction. The stator component 21 is positioned and fixed to the stator body 19 at a predetermined phase such that the claw portions 19ca and 21ca are arranged alternately with a predetermined gap in the circumferential direction.

[0034] The coil assembly 20 has an annular bobbin 22 with a U-shaped cross-section and a coil 23 wound around the circumferential groove of the bobbin 22. The coil assembly 20 is supported inside the disc-shaped portion 21a, the outer diameter cylindrical portion 21b, and the inner diameter portion 21c of the stator component 21. The stator component 21, on which the coil assembly 20 is supported, is fixed to the stator body 19 as described above.

[0035] <Substrate, sensing unit, etc.> The substrate (also referred to as the "circuit board") 15 is provided in an arc shape along the disc-shaped portion 19a of the stator body 19 in the plan view shown in Figure 3. The substrate 15 is provided, for example, over a circumferential range of approximately 270 degrees along the disc-shaped portion 19a, and the wireless communication circuit 17 is provided at the remaining circumferential position.

[0036] As shown in Figures 5 and 7, the substrate 15 is supported by the stepped surface 35aa of the large-diameter protrusion 35a of the fixing component RP and is fitted and fixed to the small-diameter protrusion 35b. As shown in Figure 7, one surface of the fixing component body 34 is provided with a plurality of (two in this example) protrusions 37 that project in the axial direction. These protrusions 37 are formed in a cylindrical shape that extends in the axial direction and are provided in a different phase from the plurality of engaging portions 35. The plurality of protrusions 37 are integrally formed on the fixing component body 34 from the same resin material as the fixing component body 34, similar to the plurality of engaging portions 35.

[0037] As shown in Figure 3, the multiple protrusions 37 (Figure 7) are fitted into the holes 15b provided in the substrate 15. Furthermore, the axial tip portions of the protrusions 37 protrude a predetermined short distance from the axial outer surface of the substrate 15. A wireless communication circuit 17 is fitted and fixed to the axial tip portions of the protrusions 37.

[0038] The circuit board 15 is equipped with a sensing unit 7 for monitoring the state of the bearing 2, and a power supply circuit (not shown). The sensing unit 7 is built into the bearing 2. The state of the bearing 2 is synonymous with predetermined operating information for the bearing 2. Examples of the sensing unit 7 include a temperature sensor for measuring the temperature of the bearing 2 and an acceleration sensor for detecting the acceleration acting on the bearing 2. However, the sensing unit 7 is not limited to these sensors.

[0039] <Wireless communication circuit> A wireless communication circuit 17 is built into one end of the bearing 2. The wireless communication circuit 17 includes an antenna unit 17a. The wireless communication circuit 17 transmits the output of a sensing unit 7, such as a temperature sensor or an acceleration sensor, wirelessly to the outside of the bearing 2 using the antenna unit 17a. A control device (not shown) controls the system to output a warning light, a warning sound, a warning display, etc., or to limit the rotation of the bearing 2, or to stop the operation of the bearing 2, etc., when the output of the transmitted sensing unit 7 exceeds a predetermined threshold. An operator who has confirmed the output of a warning light, etc., may stop the drive source of the bearing device.

[0040] <Magnetic rings, etc.> As shown in Figure 5, the inner ring 8, which is the rotating raceway, supports a magnetic ring 5. The magnetic ring 5 faces the stator 13 with a radial gap δ1 between them. The magnetic ring 5 is fitted and fixed to the second stepped portion 8c of the inner ring 8. The magnetic ring 5 includes a core metal 18 and a multipole magnet 25 fixed to this core metal 18.

[0041] The core metal 18 has a cylindrical portion 18a that fits into the second stepped portion 8c, and a flange portion 18b that extends radially outward from one axial end of the cylindrical portion 18a. The flange portion 18b can increase the overall rigidity of the core metal 18. The multipole magnet 25 is made, for example, by vulcanizing and bonding a magnetic material, which is a mixture of magnetic powder and rubber, to the core metal 18, and then alternately magnetizing the N pole and S pole in the circumferential direction of the bearing.

[0042] The inner surface of the multipole magnet 25 abuts against the stepped portion of the second stepped portion 8c. This positions the magnetic ring 5 axially relative to the inner ring 8. When the cylindrical portion 18a of the mandrel 18 is fitted into the second stepped portion 8c, and the inner surface of the multipole magnet 25 abuts against the stepped portion, the magnetic ring 5 does not protrude from the end face of the inner ring 8. In other words, the magnetic ring 5 is housed at one end of the bearing.

[0043] The claw portion 19ca of the stator body 19, the claw portion 21ca of the stator component 21, and the magnetic ring 5 constitute a claw-pole type power generation unit G. The total number of claw portions 19ca and 21ca is equal to the number of poles of the multi-pole magnet 25, that is, the total number of north poles and south poles. Each end of the coil 23 drawn from the stator 13 is electrically connected to terminals (not shown) provided on the circuit board 15. These terminals are electrically connected to the power supply circuit. As the inner ring 8 rotates, the AC power output from the power generation unit G is converted to DC power by the power supply circuit. The temperature sensor, acceleration sensor, and the wireless communication circuit 17 shown in Figure 3 use the DC power converted by the power supply circuit.

[0044] <Regarding sealing materials> The seal member 6 in Figure 2 covers the sensing unit 7 and the power generation unit G in Figure 4. When the seal member 6 is removed from the bearing device 1, the sensing unit 7 and the power generation unit G are exposed. As shown in Figure 5, the seal member 6 is fitted and fixed to the inner circumferential surface of the outer ring 9 via the outer diameter side cylindrical portion 19b of the stator body 19. The seal member 6 has an annular core metal portion 16 fitted to the inner circumferential surface of the outer ring 9 and an elastic body 26 fixed to the core metal portion 16. The elastic body 26 is made of rubber or the like and has a seal body 27, a first lip portion 28, and a second lip portion 29. These seal body 27 and the first and second lip portions 28 and 29 are integrally formed.

[0045] The seal body 27 has a main body portion 27a extending inward from the core metal portion 16, and a bulging portion 27b provided on the axial inner end of the core metal portion 16 and a part of the outer circumference of the core metal portion 16. The bulging portion 27b has a tightening allowance with respect to the outer diameter side cylindrical portion 19b of the stator body 19. In Figure 5, a part of the bulging portion 27b is shown as fitted into the outer diameter side cylindrical portion 19b, but the part of the bulging portion 27b is a tightening allowance. When the core metal portion 16 is fitted into the outer diameter side cylindrical portion 19b of the stator body 19, the bulging portion 27b is elastically deformed and contacts the outer diameter side cylindrical portion 19b in a sealed state.

[0046] The annular first lip portion 28 is provided at the inner diameter end of the seal body 27 and slides against the outer circumferential surface of the inner ring 8. Specifically, the first lip portion 28 has an inner lip 28a and an outer lip 28b that branch out in the axial direction inward and outward. The inner lip 28a and the outer lip 28b each have an overlap with the outer circumferential surface of the inner ring 8. In Figure 5, the respective tip portions of the inner and outer lips 28a and 28b are shown to be fitted into the outer circumferential surface of the inner ring 8, and these respective tip portions are overlaps. Grease is pre-held in the annular groove 30 between the inner lip 28a and the outer lip 28b. The grease held in the annular groove 30 can further reduce the sliding resistance of the first lip portion 28.

[0047] The annular second lip portion 29 branches off from near the radial midpoint of the seal body 27. The second lip portion 29 contacts the stator 13 with an overlap. The second lip portion 29 inclines axially inward as it moves from near the radial midpoint of the seal body 27 toward the inner diameter. The tip portion of this second lip portion 29 contacts the outer diameter side cylindrical portion 21b of the stator component 21 with an overlap. In Figure 5, the tip portion of the second lip portion 29 is shown as fitted into the outer diameter side cylindrical portion 21b, but this tip portion is an overlap.

[0048] <Effects and Effects> As described above, the bearing device 1 in Figure 4 includes an annular fixing part RP that maintains the phase of the stator 13 and fixes the stator 13 and the sensing part 7. Furthermore, the sensing part assembly 4, including the fixing part RP, the stator 13 and the sensing part 7, can be housed in the annular stepped portions 9c and 8c of the bearing 2. Therefore, the screw that protrudes axially inward from the stator end face can be omitted. As a result, the rolling elements 10 of the bearing 2 do not interfere with the screw, improving the operational reliability of the bearing 2. In addition, compared to conventional structures with screws, there is more internal design space in the bearing 2, which improves the design freedom of the bearing specifications and the sensing part 7.

[0049] The stator 13 is provided with an engaged portion 36 that engages with an engaging portion 35 provided on the fixed component RP. Therefore, by engaging the engaged portion 35 of the fixed component RP with the engaged portion 36 of the stator 13, the phases of the stator 13 and the fixed component RP can be easily and reliably aligned, and both components can be easily fixed together. If the fixed component RP is a resin part insert-molded into the stator body 19, the resin part can be easily fixed to the stator body 19, which is supported by a mold, by pouring resin into the cavity. Therefore, it is possible to improve the mass production efficiency of the bearing device 1.

[0050] The engaging portion 35 of the fixed component RP has a configuration in which large-diameter and small-diameter protrusions 35a and 35b are superimposed in the axial direction. The large-diameter protrusion 35a is inserted through the through hole, which is the engaged portion 36 of the stator 13, and the small-diameter protrusion 35b is fitted into the hole 15a provided in the substrate 15. In this case, the large-diameter protrusion 35a of the fixed component RP can fix the fixed component RP to the stator 13 while ensuring the phase between the fixed component RP and the stator 13. Furthermore, since the small-diameter protrusion 35b of the fixed component RP is fitted into the hole 15a of the substrate 15, the small-diameter protrusion 35b of the fixed component RP can regulate the axial position of the substrate 15 relative to the fixed component RP while ensuring the phase between the fixed component RP and the substrate 15.

[0051] As shown in Figure 6, the large-diameter protrusion 35a has an axial height H1 greater than or equal to the thickness t1 of the stator body 19, and the small-diameter protrusion 35b has an axial height H2 greater than or equal to the thickness t2 of the substrate 15. In this case, the substrate 15 can be raised from the stator 13, preventing the substrate 15 from making metal-to-metal contact with the stator 13. Therefore, leakage current caused by metal contact can be prevented without interposing insulating material between the substrate 15 and the stator 13. Furthermore, since insulating material is not required, the number of parts can be reduced, thereby lowering manufacturing costs.

[0052] As shown in Figure 4, the bearing device 1 is provided with a sealing member 6 covering the sensing unit 7 and the power generation unit G, thereby preventing grease leakage from the bearing and preventing foreign matter from entering the bearing 2. This improves the operational reliability of the bearing device 1, which incorporates the sensing unit and other components. In particular, since the magnetic ring 5 and the stator 13 are covered in a sealed state by the sealing member 6, it is possible to prevent the magnetic ring and other components from attracting contaminants. Therefore, the rotation of the bearing 2 will not lock as desired, and it is possible to prevent abnormalities from occurring in the power generation unit G and the sensing unit 7 due to contaminants. As a result, predetermined operating information of the bearing 2 can be reliably detected.

[0053] As shown in Figure 5, the sealing member 6 has first and second lip portions 28 and 29. The first lip portion 28 prevents grease inside the bearing from leaking to the outside of the bearing 2 and more reliably prevents foreign matter such as contaminants from entering the bearing. The second lip portion 29 prevents grease inside the bearing from entering the sensing portion 7. Therefore, the operational reliability of the bearing device 1, which incorporates the sensing portion, can be further improved.

[0054] Furthermore, an O-ring 3 is provided at the fitting portion k1 between the stator body 19 and the inner circumferential surface of the outer ring 9. This prevents grease from leaking from the fitting portion k1. As shown in Figure 4, the internal specifications of the bearing were changed to specify the bearing size. Therefore, compared to the conventional structure with a sealing member at the end of the bearing device, the overall size of the bearing device can be reduced, and the versatility of incorporating the bearing device 1 into various devices can be increased.

[0055] <Regarding other embodiments> In the following description, parts corresponding to matters previously described in each embodiment will be denoted by the same reference numerals, and redundant explanations will be omitted. When only a part of the configuration is described, the other parts of the configuration will be the same as those in the previously described embodiment unless otherwise specified. Identical configurations will produce the same effects. Not only are combinations of the parts specifically described in each embodiment possible, but partial combinations of embodiments are also possible, provided that there are no particular problems with the combination.

[0056] [Second embodiment: Figure 8, with insulating material] As shown in Figure 8, an insulating member 14 may be provided in the gap between the substrate 15 and the stator 13. An insulating member 14, such as potting material, is provided in the gap between the axial outer surface of the substrate 15 and the disc-shaped portion 19a of the stator body 19. Thus, the substrate 15 is fixed to the stator 13 via the insulating member 14. In addition, similar to the first embodiment, a large-diameter protrusion 35a is inserted through the through hole 36 of the stator 13, and a small-diameter protrusion 35b is fitted into the hole 15a provided in the substrate 15. According to the second embodiment, the substrate 15 can be firmly fixed to the stator 13 using an insulating member 14 such as a potting material. Furthermore, the insulating member 14 can prevent the substrate 15 from making metal-to-metal contact with the stator 13.

[0057] [Third embodiment: Figure 9, configuration in which a sealing member is fitted to the outer circumference of the inner ring] Contrary to the first and second embodiments, as shown in Figure 9, the inner ring 8 may be used as the fixed-side raceway, and the sealing member 6 may be fitted to the outer circumferential surface of the inner ring 8. In this case, the outer ring 9 becomes the rotating-side raceway, and the inner lip 28a and outer lip 28b of the sealing member 6 slide against the inner circumferential surface of the outer ring 9.

[0058] The bearing device can also be configured as shown in Figures 4 and 8, for example, with the inner ring 8 as the fixed-side raceway and the outer ring 9 as the rotating-side raceway. Alternatively, the bearing device can be configured as shown in Figure 9, for example, with the outer ring 9 as the fixed-side raceway and the inner ring 8 as the rotating-side raceway. These bearing devices are described below as examples of proposed designs.

[0059] A bearing device comprising a bearing 2 having an inner ring 8 and an outer ring 9, and a sensing unit 7 and a power generation unit G capable of supplying power to the sensing unit 7, provided at one end of the bearing 2, The sensing unit 7 and the power generation unit G are built into the bearing 2, and an annular fixing part RP is provided that maintains the phase of the stator 13 in the power generation unit G and fixes the stator 13 and the sensing unit 7. A bearing device is provided with an annular stepped portion 9c (8c) at one end of the inner ring 8 or the outer ring 9, which restricts the axial position of the fixed component RP and houses the sensing component assembly 4, including the fixed component RP, the stator 13, and the sensing component 7, within the bearing.

[0060] Of the first and second lip portions 28 and 29 in the sealing member, the second lip portion 29 may be omitted. The magnetic ring 5 may also be a so-called axial gap type power generation unit, facing the stator 13 across an axial gap.

[0061] The bearing 2 is not limited to the deep groove ball bearing described above, but may also be a rolling bearing such as an angular contact ball bearing or a tapered roller bearing. The rolling bearing may be an all-ball type ball bearing without a cage. The bearing 2 may be an open-type rolling bearing without a bearing seal 12, and the grease inside the bearing may be sealed by a cover member on the device side. Bearing 2 can also be fitted with main dimensions other than the specified bearing size. Bearing 2 is not limited to rolling bearings; a sliding bearing may also be used.

[0062] While embodiments for carrying out the present invention have been described above based on the embodiments, the embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present invention is indicated by the claims rather than the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0063] 1...Bearing device, 2...Bearing, 4...Sensing unit assembly, 7...Sensing unit, 8...Inner ring (rotating side raceway, stationary side raceway), 9...Outer ring (stationary side raceway, rotating side raceway), 9c...First stepped portion, 13...Stator, 14...Insulating member, 15...Substrate, 15a...Hole, 35...Engaging portion, 35a...Large diameter protrusion, 35b...Small diameter protrusion, 36...Engaged portion, G...Power generation unit, RP...Fixed part

Claims

1. A bearing device comprising a bearing, a sensing unit and a power generation unit capable of supplying power to the sensing unit, provided inside the bearing, The bearing has a fixed-side raceway and a rotating-side raceway. The power generation unit comprises an annular fixing part that maintains the phase of the stator and to which the stator and the sensing unit are fixed, and a sensing unit assembly including the stator and the sensing unit. A bearing device wherein one end of the fixed-side raceway is provided with an annular stepped portion that restricts the axial position of the fixed component and houses the sensing unit assembly within the bearing.

2. A bearing device according to claim 1, wherein the stator is provided with an engaged portion that engages with an engaging portion provided on the fixed component.

3. A bearing device according to claim 1 or claim 2, wherein the fixed part is a resin part insert-molded into the stator.

4. In the bearing device according to claim 2, the sensing unit assembly includes a substrate on which the sensing unit is supported, The engagement portion of the fixed component has a configuration in which a large-diameter and a small-diameter protrusion are superimposed in the axial direction, and the large-diameter protrusion is inserted through a through hole which is the engaged portion of the stator, while the small-diameter protrusion is fitted into a hole provided in the substrate.

5. The bearing device according to claim 4, wherein the large-diameter protrusion has an axial height greater than or equal to the thickness of the stator, and the small-diameter protrusion has an axial height greater than or equal to the thickness of the substrate.

6. A bearing device according to claim 5, wherein an insulating member is provided in the gap between the substrate and the stator, and the substrate is fixed to the stator via the insulating member.

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