Bearing device

Abstract

To provide a bearing device that can improve the sealing performance of the bearing. [Solution] The bearing device 1 comprises a bearing 2 and a power generation unit G provided at one end of the bearing 2. The power generation unit G is built into the bearing 2, and a contact-type seal member 6 covering the power generation unit G is fixed to the outer ring 9. The power generation unit G has a stator 13 supported by the outer ring 9 and a magnetic ring 5 supported by the inner ring 8 of the bearing 2 and facing the stator 13 with a gap in between. The inner ring 8 is provided with a seal lip sliding member 38 that slides the first lip portion 28 of the seal member 6 and prevents magnetic leakage from the magnetic ring 5. The seal lip sliding member 38 is formed in an L-shape in cross-section with a cylindrical portion 38a fitted to the circumferential surface of the inner ring 8 and a vertical plate portion 38b extending radially from one axial end of the cylindrical portion 38a.

Description

Technical Field

[0001] The present invention relates to a bearing device, and to a technology capable of improving the sealing performance of a bearing. Background Art

[0002] In a conventional bearing device, as shown in Fig. 10, a bearing 100 with a built-in sensor adapted to a bearing size specified in ISO standards or JIS standards is disclosed (Patent Document 1). 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, a magnetic ring 102 facing a stator 101 with a radial gap δ is exposed to the outside, so it may adsorb, for example, magnetic contamination (abbreviated as "contamination"). Therefore, it is conceivable to provide a contact-type sealing member covering the sensor and the magnetic ring on the bearing. In the contact-type sealing member, for example, a sealing lip at the tip slides on an outer circumferential surface of an inner ring that is a race ring on the rotation side.

[0005] However, when the inner ring is displaced relative to the outer ring in the axial direction by an amount equal to the axial clearance of the bearing, the sealing lip may come into contact with the magnetic ring. The magnetic ring is a component formed by mixing rare earth or ferrite into a rubber material, so it is harder than the sealing lip and has a rough surface. For this reason, there is a concern that if the sealing lip comes into contact with the magnetic ring, the sealing lip will wear undesirably.

[0006] An object of the present invention is to provide a bearing device capable of improving the sealing performance of a bearing. [Means for solving the problem]

[0007] The present invention is a bearing device comprising a bearing and a power generation unit provided inside the bearing, A contact-type sealing member covering the power generation section is fixed to the fixed-side raceway of the bearing. The power generation unit includes a stator supported by the fixed-side raceway and a magnetic ring supported by the rotating-side raceway of the bearing and facing the stator with a gap in between. The rotating raceway is equipped with a seal lip sliding member that slides the seal lip of the seal member and prevents magnetic leakage from the magnetic ring.

[0008] In this configuration, the seal lip of the sealing member slides against the seal lip sliding member. Therefore, even if the rotating raceway shifts in a direction that brings the seal lip closer to the magnetic ring, unwanted wear of the seal lip can be prevented. This improves the sealing performance of the bearing compared to conventional structures. Furthermore, the seal lip sliding member prevents magnetic leakage from the magnetic ring, thus preventing a decrease in the magnetic flux density to the stator.

[0009] A sensing unit, powered by the power generation unit, is incorporated into one end of the bearing, and the sealing member may cover the sensing unit together with the power generation unit. In this case, foreign matter can be prevented from entering the sensing unit, and the operational reliability of the bearing device incorporating the sensing unit can be improved.

[0010] The seal lip sliding member is preferably made of a non-magnetic material. If the seal lip sliding member is made of a magnetic material, the magnetic flux generated from the magnetic ring is more likely to leak into the seal lip sliding member, which worsens the power generation efficiency. If the seal lip sliding member is non-magnetic, such magnetic leakage can be prevented, and the decrease in magnetic flux density can be prevented without adding any new parts to prevent magnetic leakage. Therefore, the structure can be simplified and manufacturing costs reduced compared to adding new parts to prevent magnetic leakage. The above-mentioned magnetic leakage prevention effect can be obtained if the relative permeability of the seal lip sliding member is lower than that of the stator, but this effect is best achieved by using a non-magnetic material for the seal lip sliding member.

[0011] The seal lip sliding member is formed in an L-shape in cross-section, comprising a cylindrical portion fitted to the circumferential surface of the rotating raceway ring and a vertical plate portion extending radially from one axial end of the cylindrical portion. The seal lip may have a radial lip that slides on the cylindrical portion and an axial lip that slides on the vertical plate portion. This configuration prevents grease from leaking out of the bearing through the radial and axial lips, and more reliably prevents foreign matter such as contaminants from entering the bearing.

[0012] The outer diameter H of the vertical plate portion preferably satisfies the following relationship. Magnetic ring outer diameter ≤ H < (stator inner diameter - maximum radial clearance of bearing) In this case, even if the rotating raceway is axially misaligned with respect to the stationary raceway by the amount of the bearing's axial clearance, the magnetic ring will not interfere with the stator. Therefore, it is possible to prevent the rotation of the bearing from being hindered during the operation of the bearing device. [Effects of the Invention]

[0013] The bearing device of the present invention is a bearing device comprising a bearing and a power generation unit provided at one end of the bearing, wherein the power generation unit is built into the bearing, a contact-type seal member covering the power generation unit is fixed to a stationary race of the bearing, the power generation unit has a stator supported by the stationary race and a magnetic ring supported by a rotating race of the bearing and opposed to the stator with a gap therebetween, and the rotating race is provided with a seal lip sliding member that allows a seal lip of the seal member to slide thereon and prevents magnetic leakage from the magnetic ring. Accordingly, the sealing performance of the bearing can be improved. [Brief Description of the Drawings]

[0014] [Figure 1] It is an exploded perspective view of the bearing device according to the first embodiment of the present invention. [Figure 2] It is a longitudinal sectional view of the bearing device. [Figure 3] It is a side view of the bearing device. [Figure 4] It is a partially enlarged view in which a main portion of FIG. 2 is partially enlarged. [Figure 5] It is an enlarged sectional view showing an enlarged sensing unit assembly and the like of the bearing device. [Figure 6] It is a partially enlarged view showing an enlarged portion VI in FIG. 5. [Figure 7] It is an enlarged sectional view showing an enlarged seal lip sliding member and the like in the bearing device according to the second embodiment of the present invention. [Figure 8] It is a longitudinal sectional view of the bearing device according to the third embodiment of the present invention. [Figure 9] It is a longitudinal sectional view of the bearing device according to the fourth embodiment of the present invention. [Figure 10] It is a longitudinal sectional view of a conventional bearing device. [Mode for Carrying Out the Invention]

[0015] [First Embodiment] A bearing device according to an embodiment of the present invention will be described with reference to Figs. 1 to 6. The bearing device is applied to, for example, general industrial machinery such as motors and blowers, wind power generators, vehicles including automobiles, motorcycles, 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, the bearing device 1 according to the first embodiment includes a bearing 2, an O-ring 3 that is an annular seal portion, a sensing portion assembly 4, a magnetic ring 5, a contact-type seal member 6, and a seal lip sliding member 38 to be described later. As shown in Fig. 2, members other than the bearing in the bearing device 1 are built into one end portion (the left end portion in Fig. 2) of the bearing 2. The state of the bearing 2 measured by the sensing portion 7 of the sensing portion 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 portion assembly and the like".

[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 raceway surfaces of the inner ring 8 and the outer ring 9, a cage 11 that retains 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 raceway surfaces 8a and 9a of the inner ring 8 and the outer ring 9.

[0018] The rolling elements 10 are formed of steel balls or ceramic balls. The cage 11 is a resin-made crown-shaped cage. A corrugated cage made of an 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 peripheral surface of the outer ring, and contacts an inner ring seal groove 8b provided on the outer peripheral surface of the inner ring. The outer ring seal groove 9b is provided on the inner peripheral 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 outer ring fixed, inner ring rotation arrangement, but may also be used in an inner ring fixed, outer ring rotation arrangement as described later.

[0019] Figure 2 is a cross-sectional view taken along line II of Figure 3. As shown in Figures 2 and 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 2, 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 Figure 2 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 the bearing remains within the specified bearing size even with the addition of the seal member 6 shown in Figure 2.

[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 1, 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.> The fixed component RP maintains the phase of the stator 13 in the power generation section G. Furthermore, as shown in Figures 1 and 5, the stator 13 and the sensing section 7 are fixed to the fixed component RP. 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] The fixing component RP has a disc-shaped fixing component body 34 and a plurality of engaging portions 35 provided on one surface of the fixing component body 34. The plurality of engaging portions 35 are provided at predetermined phases on the fixing component body 34. The fixing 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 fixing component body 34. The stator body 19 and the fixing component RP are fixed to each other by adhesive or joining, or the fixing component RP is insert-molded into the stator body 19.

[0026] The stator 13 is supported by an 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 a 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, consisting of 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] 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 Figure 5, 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, 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] <Substrate, sensing unit, etc.> The substrate (also called a "circuit board") 15 is arranged in an arc shape along the disc-shaped portion 19a of the stator body 19 in a plan view of the substrate 15. As shown in Figure 1, the substrate 15 is provided 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.

[0030] As shown in Figure 5, 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 Figures 1 and 5, a plurality of projections 37 protruding in the axial direction are provided on one surface of the fixing component body 34. These projections 37 are formed in a cylindrical shape extending in the axial direction and are provided in a different phase from the plurality of engaging portions 35. The plurality of projections 37, like the plurality of engaging portions 35, are integrally formed on the fixing component body 34 from the same resin material as the fixing component body 34.

[0031] The multiple protrusions 37 are fitted into holes 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.

[0032] 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.

[0033] <Wireless communication circuit> As shown in Figure 1, 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.

[0034] <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.

[0035] 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.

[0036] 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.

[0037] 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 1 use the DC power converted by the power supply circuit.

[0038] <Regarding sealing materials> The sealing member 6 in Figure 2 covers the sensing unit 7 and the power generation unit G. When the sealing 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 sealing 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 sealing 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 that serve as seal lips. These seal body 27 and the first and second lip portions 28 and 29 are formed integrally.

[0039] 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 to be 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 It is elastically deformed and comes into contact with the outer diameter cylindrical portion 19b in a sealed state.

[0040] The annular first lip portion 28 is provided on the inner diameter side of the seal body 27 and slides against the seal lip sliding member 38, which will be described later. Specifically, the first lip portion 28 has a radial lip 28b that slides against the cylindrical portion 38a of the seal lip sliding member 38 and an axial lip 28a that slides against the vertical plate portion 38b of the seal lip sliding member 38. The radial lip 28b protrudes inward from the inner diameter side tip of the seal body 27. The axial lip 28a is inclined outward from the inner surface of the inner diameter side portion of the seal body 27 as it moves axially inward.

[0041] The axial lip 28a and radial lip 28b have an overlap with respect to the seal lip sliding member 38. In Figure 5, the respective tip portions of the axial lip 28a and radial lip 28b are shown to be fitted into the seal lip sliding member 38, and these respective tip portions are overlaps. Grease is pre-held in the annular groove 30 between the axial lip 28a and the radial lip 28b. The grease held in the annular groove 30 can further reduce the sliding resistance of the first lip portion 28.

[0042] 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.

[0043] <Regarding seal lip sliding members> The inner ring 8 supports a seal lip sliding member 38 adjacent to the magnetic ring 5. The seal lip sliding member 38 slides the first lip portion (seal lip) 28 of the seal member 6 and prevents magnetic leakage from the magnetic ring 5. The seal lip sliding member 38 is fitted and fixed to the second stepped portion 8c of the inner ring 8.

[0044] The seal lip sliding member 38 is made of a non-magnetic material such as an austenitic stainless steel plate or aluminum. Examples of the stainless steel plate include SUS304. The seal lip sliding member 38 is formed in an L-shape in cross-section with a cylindrical portion 38a and a vertical plate portion 38b.

[0045] The cylindrical portion 38a is fitted onto the second stepped portion 8c, which is the circumferential surface of the inner ring 8. The vertical plate portion 38b extends radially outward from one axial end of the cylindrical portion 38a and abuts against the outer surface of the magnetic ring 5. The cylindrical portion 38a and the vertical plate portion 38b are integrally formed from a single material, for example by machining. The outer circumferential surface of the cylindrical portion 38a in the seal lip sliding member 38 slides against the radial lip 28b. The outer surface of the vertical plate portion 38b in the seal lip sliding member 38 slides against the axial lip 28a.

[0046] <Parameters> As shown in Figure 6, the outer diameter H of the vertical plate portion 38b satisfies the following relationship. The outer diameter of magnetic ring 5, 5D ≤ H < (inner diameter of stator 13, 13d - maximum radial clearance of the bearing) By setting the relationship as described above, even if the inner ring 8 is axially misaligned with respect to the outer ring 9 by the axial clearance of the bearing 2 shown in Figure 4, the seal lip sliding member 38 will not interfere with the stator 13. Therefore, it is possible to prevent the rotation of the bearing 2 from being hindered during the operation of the bearing device 1.

[0047] <Effects and Effects> In the bearing device 1 described above, the first lip portion (seal lip) 28 of the seal member 6 slides against the seal lip sliding member 38. Therefore, even if the inner ring 8 shifts in a direction that brings the first lip portion 28 closer to the magnetic ring 5, it is possible to prevent the first lip portion 28 from wearing down undesirably. This improves the sealing performance of the bearing 2 compared to conventional structures. In addition, the seal lip sliding member 38 prevents magnetic leakage from the magnetic ring 5, thus preventing a decrease in the magnetic flux density to the stator 13.

[0048] Since the sealing member 6 covers the sensing unit 7 together with the power generation unit G, it prevents foreign matter from entering the sensing unit 7 and improves the operational reliability of the bearing device 1 which houses the sensing unit and the like. Since the seal lip sliding member 38 is made of a non-magnetic material, it can prevent magnetic leakage from the magnetic ring 5 on its own, and the decrease in magnetic flux density can be prevented without adding any new parts to prevent magnetic leakage. Therefore, the structure can be simplified and manufacturing costs reduced compared to when new parts are added to prevent magnetic leakage.

[0049] As shown in Figure 6, the seal lip sliding member 38 is formed in an L-shape in cross-section by a cylindrical portion 38a and a vertical plate portion 38b extending radially from one axial end of the cylindrical portion 38a. The first lip portion 28 has a radial lip 28b that slides on the cylindrical portion 38a and an axial lip 28a that slides on the vertical plate portion 38b. With this configuration, the radial lip 28b and the axial lip 28a can prevent grease inside the bearing from leaking to the outside of the bearing, and can more reliably prevent foreign matter such as contaminants from entering the bearing.

[0050] Therefore, the rotation of the bearing 2 shown in Figure 4 will not lock undesirably, and abnormalities in the power generation unit G and sensing unit 7 due to contamination, etc., can be prevented. As a result, predetermined operating information of the bearing 2 can be reliably detected. The second lip portion 29 can prevent grease inside the bearing from entering the sensing unit 7. Therefore, the operational reliability of the bearing device 1, which incorporates the sensing unit, etc., can be further improved.

[0051] Furthermore, as shown in Figure 5, 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.

[0052] <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.

[0053] [Second embodiment: Figure 7, with insulating material] As shown in Figure 7, the seal lip sliding member 38 has a magnetic material 38A made of, for example, a steel plate such as SPCC, and an insulating sheet material 39. The sheet material 39 is an annular thin plate sandwiched between the magnetic material 38A and the magnetic ring 5. The sheet material 39 may be fixed to the inner surface of the vertical plate portion 38b of the magnetic material 38A.

[0054] [Third embodiment: Figure 8, without sensing unit, etc.] As shown in Figure 8, it is also possible to remove the sensing unit from the bearing device 1 and configure it so that the power generated by the power generation unit G is supplied to the load outside the bearing.

[0055] [Fourth embodiment: Figure 9, configuration in which a sealing member is fitted to the outer circumference of the inner ring] Contrary to the first to third 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 first lip portion 28 of the sealing member 6 slides against the sealing lip sliding member 38 fitted to the stepped portion 9c of the outer ring 9.

[0056] 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.

[0057] A bearing device comprising a bearing 2 having an inner ring 8 and an outer ring 9, and a power generation unit G provided at one end of the bearing 2, The power generation unit G is housed in the bearing 2, and a contact-type sealing member 6 covering the power generation unit G is fixed to the outer ring 9 or the inner ring 8. The power generation unit includes a stator 13 supported by either the outer ring 9 or the inner ring 8, and a magnetic ring 5 supported by the other raceway of either the outer ring 9 or the inner ring 8 and facing the stator 13 with a gap between them. The other raceway is equipped with a bearing device having a seal lip sliding member 38 that slides the seal lip 28 of the seal member 6 and prevents magnetic leakage from the magnetic ring 5.

[0058] 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.

[0059] 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.

[0060] 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]

[0061] 1...Bearing device, 2...Bearing, 5...Magnetic ring, 6...Seal member, 7...Sensing part, 8...Inner ring (rotating side raceway, stationary side raceway), 9...Outer ring (stationary side raceway, rotating side raceway), 13...Stator, 28...First lip part (seal lip), 28b...Radial lip, 28a...Axial lip, 38...Seal lip sliding member, 38a...Cylindrical part, 38b...Vertical plate part, G...Power generation part

Claims

1. A bearing device comprising a bearing and a power generation unit provided inside the bearing, A contact-type sealing member covering the power generation section is fixed to the fixed-side raceway of the bearing. The power generation unit includes a stator supported by the fixed-side raceway and a magnetic ring supported by the rotating-side raceway of the bearing and facing the stator with a gap in between. The bearing device is provided with a sealing lip sliding member on the rotating raceway that slides the sealing lip of the sealing member and prevents magnetic leakage from the magnetic ring.

2. A bearing device according to claim 1, wherein a sensing unit supplied with power by the power generation unit is built into one end of the bearing, and the sealing member covers the sensing unit together with the power generation unit.

3. A bearing device according to claim 1 or claim 2, wherein the seal lip sliding member is made of a non-magnetic material.

4. In the bearing device according to claim 1 or claim 2, the seal lip sliding member is formed in an L-shape in cross-section by a cylindrical portion fitted to the circumferential surface of the rotating raceway ring and a vertical plate portion extending radially from one axial end of the cylindrical portion. The seal lip is a bearing device having a radial lip that slides on the cylindrical portion and an axial lip that slides on the vertical plate portion.

5. The bearing device according to claim 4, wherein the outer diameter H of the vertical plate portion satisfies the following relationship. Magnetic ring outer diameter ≤ H < (stator inner diameter - maximum radial clearance of bearing)

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