Wheel bearing device

Abstract

To provide a wheel bearing device capable of early detecting signs of abnormality occurring in a wheel bearing.SOLUTION: A wheel bearing device 1a comprises a fixing member 120, a rotary member 121 rotatable relative to the fixing member 120, a rolling element 5 arranged between the fixing member 120 and the rotary member 121, a heat flux sensor 60, and a sensor case 70. The sensor case 70 is inserted into a through hole 13 provided in one of the fixing member 120 and the rotary member 121. The heat flux sensor 60 is attached to the sensor case 70.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] Japanese Patent Laid-Open Publication No. 2004-36863 (Patent Document 1) discloses a wheel support bearing device including a double row rolling bearing and a sensor unit. The sensor unit includes a temperature sensor. The temperature sensor detects the temperature of the double row rolling bearing. This wheel support bearing device detects an abnormality occurring in the wheel support bearing based on the temperature detected by the temperature sensor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-36863 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the wheel support bearing device described in Patent Document 1, a temperature sensor is used to detect abnormalities in the wheel support bearing, making it difficult to quickly detect signs of abnormalities occurring in the wheel support bearing. The present disclosure has been made in consideration of the above problems, and has an objective to provide a wheel support bearing device that can more quickly detect signs of abnormalities occurring in the wheel support bearing. [Means for solving the problem]

[0005] A wheel bearing device according to a first aspect of the present disclosure includes a fixed member, a rotating member rotatable relative to the fixed member, rolling elements disposed between the fixed member and the rotating member, at least one heat flux sensor, and a sensor case to which the at least one heat flux sensor is attached. The sensor case is inserted into a through hole provided in one of the fixed member and the rotating member.

[0006] A wheel bearing device according to a second aspect of the present disclosure includes a fixed member, a rotating member rotatable relative to the fixed member, rolling elements disposed between the fixed member and the rotating member, and at least one heat flux sensor. One of the fixed member and the rotating member includes at least one seal. The at least one heat flux sensor is attached to the at least one seal. Effect of the Invention

[0007] In the wheel support bearing device of the present disclosure, an abnormality in the wheel support bearing is detected using a heat flux sensor, and therefore, according to the wheel support bearing device of the present disclosure, a sign of an abnormality occurring in the wheel support bearing can be detected earlier. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic cross-sectional view of a wheel bearing device according to a first embodiment. [Diagram 2] 5 is a diagram showing an example of an output from a heat flux sensor of the wheel bearing device of the first embodiment. FIG. [Diagram 3] 1 is a block diagram showing a schematic configuration of a wheel bearing device according to a first embodiment. [Figure 4] 11 is a schematic cross-sectional view of a wheel bearing device according to a second embodiment. FIG. [Diagram 5] FIG. 11 is a schematic cross-sectional view of a wheel bearing device according to a third embodiment. [Figure 6] 13 is a diagram showing an example of an output from a heat flux sensor of the wheel bearing device of the embodiment 3. FIG. [Figure 7] FIG. 11 is a block diagram showing a schematic configuration of a wheel bearing device according to a third embodiment. [Figure 8] FIG. 11 is a schematic cross-sectional view of a wheel bearing device according to a fourth embodiment. [Figure 9] FIG. 11 is a schematic cross-sectional view of a wheel bearing device according to a fifth embodiment. [Figure 10] 10 is a schematic enlarged partial cross-sectional view of a region X shown in FIG. 9 in the wheel bearing device of the fifth embodiment. [Figure 11]10 is a schematic enlarged partial cross-sectional view of a region XI shown in FIG. 9 of the wheel bearing device of the fifth embodiment. FIG. [Figure 12] FIG. 13 is a schematic cross-sectional view of a wheel bearing device according to a sixth embodiment. [Figure 13] FIG. 13 is a schematic cross-sectional view of a wheel bearing device according to a seventh embodiment. [Figure 14] FIG. 13 is a schematic cross-sectional view of a wheel bearing device according to an eighth embodiment. [Figure 15] FIG. 13 is a schematic cross-sectional view of a wheel bearing device according to a ninth embodiment. [Figure 16] FIG. 23 is a schematic cross-sectional view of a wheel bearing device according to a tenth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0010] (Embodiment 1)

[0011] A wheel bearing device 1 according to a first embodiment will be described with reference to Fig. 1 to Fig. 3. The wheel bearing device 1 is, for example, a bearing device for an automobile wheel. Specifically, it is a bearing device for a driving wheel of an automobile. The driving wheel is mechanically connected to a main driving source (for example, an engine, a motor, etc.) of the automobile.

[0012] The wheel bearing device 1 mainly includes a fixed member 120, a rotating member 121, rolling elements 5, a retainer 35, and a heat flux sensor 60. In this embodiment, the fixed member 120 includes an outer member 3 and seals 40, 45. The rotating member 121 includes an inner member 4 and a slinger 55. The outer member 3, the inner member 4, the rolling elements 5, and the retainer 35 configure a wheel bearing 2.

[0013] The outer member 3 includes an outer ring 10. The outer ring 10 is a fixed ring. The outer ring 10 includes a flange 17. The flange 17 is attached to a knuckle 50 of a suspension device (not shown) of a vehicle body. Specifically, the flange 17 is provided with a plurality of screw holes 18 along the circumferential direction of the flange 17. The knuckle 50 is disposed on the inboard side of the flange 17. A knuckle bolt (not shown) is inserted into the bolt hole 51 from the inboard side and further screwed into the screw hole 18 of the flange 17. In this manner, the flange 17 is attached to the knuckle 50. In this specification, when the wheel bearing device 1 is attached to a vehicle, the side that is closer to the outside in the vehicle width direction of the vehicle is referred to as the outboard side, and the side that is closer to the center of the vehicle is referred to as the inboard side.

[0014] The fixed member 120 includes a double-row first annular roll surface. Specifically, the outer member 3 has a double-row outer annular roll surface 6 formed on an inner circumferential surface of the outer member 3. The double-row outer annular roll surface 6 includes, for example, a first outer annular roll surface 11 and a second outer annular roll surface 12. The first outer annular roll surface 11 and the second outer annular roll surface 12 are spaced apart from each other in the central axial direction of the outer member 3 (the rotational axis direction of the wheel bearing 2) and are adjacent to each other. The first outer annular roll surface 11 is provided on the outboard side with respect to the second outer annular roll surface 12.

[0015] The rotating member 121 includes a double-row second annular rolling surface facing the double-row first annular rolling surface of the fixed member 120. Specifically, the inner member 4 has a double-row inner annular rolling surface 7 formed on the outer circumferential surface of the inner member 4. The double-row inner annular rolling surface 7 includes, for example, a first inner annular rolling surface 26 and a second inner annular rolling surface 27. The first inner annular rolling surface 26 and the second inner annular rolling surface 27 are spaced apart from each other in the central axis direction of the inner member 4 (the rotational axis direction of the wheel bearing 2) and are adjacent to each other. The first inner annular rolling surface 26 is provided on the outboard side with respect to the second inner annular rolling surface 27. The double-row inner annular rolling surface 7 faces the double-row outer annular rolling surface 6. Specifically, the first inner annular rolling surface 26 faces the first outer annular rolling surface 11. The second inner annular raceway surface 27 faces the second outer annular raceway surface 12 .

[0016] The inner member 4 includes a hub ring 21 and an inner ring 25. In this embodiment, the hub ring 21 and the inner ring 25 are rotating rings. The first inner annular rolling surface 26 is formed on the outer circumferential surface of the hub ring 21. The second inner annular rolling surface 27 is formed on the outer circumferential surface of the inner ring 25.

[0017] A through hole 22 extending in the direction of the central axis of the hub wheel 21 (the direction of the rotational axis of the wheel bearing 2) is provided in the center of the hub wheel 21. A stem portion of an outer ring of a constant velocity joint (not shown) is inserted from the inboard side into the through hole 22, and the stem portion is spline-fitted into the hub wheel 21. The outer ring of the constant velocity joint is joined to the inner member 4 by screwing a nut (not shown) onto the tip of the stem portion. The outer ring of the constant velocity joint is pressed against the end face of the inner ring 25. The inner member 4 is clamped between the outer ring of the constant velocity joint and the nut, and a preload is applied to the wheel bearing 2.

[0018] The hub wheel 21 includes a small diameter portion 23, a hub flange 28, and a pilot portion 24. The small diameter portion 23 is formed at the inboard end of the hub wheel 21. The small diameter portion 23 of the hub wheel 21 fits into an inner ring 25. The inner ring 25 abuts against a shoulder portion 30 of the hub wheel 21 that is continuous with the small diameter portion 23. The inner ring 25 applies a preload to the wheel bearing 2.

[0019] The hub flange 28 is disposed on the outboard side relative to the outer ring 10. The hub flange 28 has a plurality of bolt holes 29 formed in the circumferential direction of the hub flange 28. The wheel (not shown) and braking parts (not shown) such as a brake rotor are disposed on the outboard side relative to the hub flange 28. The wheel (not shown) and braking parts (not shown) such as a brake rotor are attached to the hub flange 28 by press-fitting hub bolts (not shown) into the plurality of bolt holes 29. The pilot portion 24 is provided at the outboard end of the hub wheel 21. The pilot portion 24 has a cylindrical shape and guides the wheel and braking parts.

[0020] The rolling elements 5 are disposed between a fixed member 120 (e.g., the outer member 3) and a rotating member 121 (e.g., the inner member 4). The rolling elements 5 are, for example, double-row rolling elements 5. The double-row rolling elements 5 are in contact with the double-row outer annular rolling surface 6 and the double-row inner annular rolling surface 7. Specifically, the double-row rolling elements 5 include, for example, a first row rolling element 31 and a second row rolling element 32. The first row rolling elements 31 and the second row rolling elements 32 are spaced apart from each other in the direction of the rotation axis of the wheel bearing 2 and are adjacent to each other. The first row rolling elements 31 are in contact with the first outer annular rolling surface 11 and the first inner annular rolling surface 26. The second row rolling elements 32 are in contact with the second outer annular rolling surface 12 and the second inner annular rolling surface 27. The first row rolling elements 31 are provided outboard of the second row rolling elements 32. The inner member 4 (hub ring 21 and inner ring 25) is rotatably supported relative to the outer member 3 (outer ring 10) via double row rolling elements 5. In this embodiment, the double row rolling elements 5 are each balls, and the wheel support bearing 2 is a double row angular contact ball bearing.

[0021] The cage 35 holds the double-row rolling elements 5. Specifically, the cage 35 holds the first row rolling elements 31 such that the interval between two adjacent rolling elements included in the first row rolling elements 31 in the circumferential direction of the cage 35 is within a certain range. The cage 35 holds the second row rolling elements 32 such that the interval between two adjacent rolling elements included in the second row rolling elements 32 in the circumferential direction of the cage 35 is within a certain range. The cage 35 separates the first row rolling elements 31 and the second row rolling elements 32 from each other in the central axial direction of the cage 35 (the rotational axis direction of the wheel bearing 2).

[0022] Grease is sealed in a gap formed between the fixed member 120 (e.g., the outer member 3) and the rotating member 121 (e.g., the inner member 4). The grease is a lubricant for the double-row rolling elements 5. The seal 40 is disposed at the outboard end of the gap formed between the fixed member 120 and the rotating member 121. The seal 45 is disposed at the inboard end of the gap formed between the fixed member 120 and the rotating member 121. The seals 40 and 45 prevent grease from leaking out of the gap formed between the outer member 3 and the inner member 4, and also prevent water, dust, and the like from entering this gap from outside the wheel bearing 2.

[0023] The seal 40 is fixed to a surface of the fixed member 120 that faces the rotating member 121 (for example, the inner circumferential surface of the outer member 3 (outer ring 10)). Specifically, the seal 40 includes a core metal 41 and a seal lip 42. The core metal 41 is fixed to the inner circumferential surface of the outer member 3 (outer ring 10). The seal lip 42 is attached to the core metal 41. The seal lip 42 is made of rubber. A tip of the seal lip 42 contacts a surface of the rotating member 121 that faces the fixed member 120 (for example, the outer circumferential surface of the inner member 4 (hub wheel 21)).

[0024] The seal 45 is fixed to a surface of the fixed member 120 facing the rotating member 121 (for example, the inner circumferential surface of the outer member 3 (outer ring 10)). Specifically, the seal 45 includes a core metal 46 and a seal lip 47. The core metal 46 is fixed to the inner circumferential surface of the outer member 3 (outer ring 10). The seal lip 47 is attached to the core metal 46. The seal lip 47 is formed of rubber. A tip of the seal lip 47 contacts the rotating member 121 (for example, a slinger 55). The slinger 55 is fixed to a surface of the rotating member 121 facing the fixed member 120 (for example, the outer circumferential surface of the inner member 4 (inner ring 25)).

[0025] The heat flux sensor 60 detects a change in heat flux between the fixed member 120 and the rotating member 121 due to a temperature difference between the fixed member 120 and the rotating member 121. The heat flux sensor 60 outputs a voltage (electrical signal) due to a temperature difference between the front surface and the back surface of the heat flux sensor 60. As the heat flux sensor 60, for example, a heat flux sensor using the Seebeck effect, such as the heat flux sensor disclosed in JP 2016-166832 A, can be used. The heat flux sensor 60 is not limited to a heat flux sensor using the Seebeck effect, and may be a heat flux sensor using any other principle, such as a heat flux sensor using a thermocouple or a heat flux sensor using a change in the electrical resistance of a conductor due to temperature.

[0026] The heat flux sensor 60 is attached to the fixing member 120. Specifically, the back surface of the heat flux sensor 60 is attached to the inner peripheral surface of the outer member 3 (outer ring 10) using an adhesive. The heat flux sensor 60 is disposed between one row (for example, the first row rolling element 31) of the double row rolling elements 5 and another row (the second row rolling element 32) of the double row rolling elements 5. The heat flux sensor 60 is disposed between the first outer annular rolling surface 11 and the second outer annular rolling surface 12. The heat flux sensor 60 is disposed between the first inner annular rolling surface 26 and the second inner annular rolling surface 27.

[0027] When an abnormality occurs in the wheel support bearing 2, the temperature of the wheel support bearing 2 changes. For example, the temperature of the double row inner annular rolling surface 7 of the rotating member 121 rises. The heat flux sensor 60 can detect a change in heat flux between the fixed member 120 and the rotating member 121 caused by a temperature difference between the fixed member 120 and the rotating member 121 without coming into contact with the double row inner annular rolling surface 7. The rate of change of heat flux is generally greater than the rate of change of temperature. Therefore, the heat flux sensor 60 can detect a sign of an abnormality in the wheel support bearing 2 (for example, a sign of a temperature rise on the double row inner annular rolling surface 7) earlier than a temperature sensor.

[0028] 2, when the wheel support bearing 2 is rotating normally at a constant speed, the output of the heat flux sensor 60 is stable. However, when an abnormality occurs in the wheel support bearing 2 at time t1, the output of the heat flux sensor 60 rises sharply. By monitoring the output of the heat flux sensor 60, signs of an abnormality in the wheel support bearing 2 can be detected earlier.

[0029] The wiring 64 is connected to the heat flux sensor 60. The wiring 64 passes through a through hole 13 provided in the fixed member 120 (e.g., the outer member 3, the outer ring 10), and is drawn out to the outside of the wheel bearing 2. The through hole 13 extends in the radial direction of the fixed member 120.

[0030] As shown in FIG. 3, the wheel support bearing device 1 further includes a control unit 66 and a storage unit 68. The control unit 66 includes a determination unit 67. The control unit 66 (determination unit 67) is electrically connected to the heat flux sensor 60 via the wiring 64. The output of the heat flux sensor 60 is input to the control unit 66 (determination unit 67) through the wiring 64. The determination unit 67 determines an abnormality in the wheel support bearing 2 including the fixed member 120, the rotating member 121, and the double row rolling elements 5 based on the output of the heat flux sensor 60. The determination unit 67 outputs a signal to notify of an abnormality in the wheel support bearing 2. The control unit 66 is, for example, a computing device such as a CPU. The storage unit 68 is, for example, a hard disk or a semiconductor memory.

[0031] In a first example, the determination unit 67 determines whether or not the output of the heat flux sensor 60 has exceeded a first threshold value stored in the storage unit 68. If the output of the heat flux sensor 60 has exceeded the first threshold value, the determination unit 67 outputs a signal notifying an abnormality in the wheel bearing 2. In a second example, the determination unit 67 determines whether or not a rate of change per unit time of the output of the heat flux sensor 60 has exceeded a second threshold value stored in the storage unit 68. If the rate of change per unit time of the output of the heat flux sensor 60 has exceeded the second threshold value, the determination unit 67 outputs a signal notifying an abnormality in the wheel bearing 2.

[0032] The wheel bearing device 1 may be a bearing device for a driven wheel of an automobile. The driven wheel is mechanically uncoupled from the main driving source (e.g., engine, motor, etc.) of the automobile. In a modified example of this embodiment, the heat flux sensor 60 may be attached to the rotating member 121. In this case, a generator (power source) (not shown) and a wireless communication means (not shown) are installed on the rotating member 121 side, and wiring on the rotating member 121 side is eliminated. The generator may be configured, for example, by arranging a magnetic ring magnetized with alternating N and S poles on the fixed member 120 side and arranging a stator with a built-in coil on the rotating member 121 side. In addition, the heat flux sensor 60 is connected to a circuit board (not shown) equipped with a wireless communication function, and this circuit board is connected to a power source. When this power source is a generator equipped with the above-mentioned stator and magnetic ring, wiring from the stator is connected to the circuit board to supply power from the generator to the circuit board. In addition to the above-mentioned wireless communication function, the circuit board may further include a rectifier circuit that converts AC voltage from the power source into DC voltage and an amplifier circuit that amplifies a signal from the sensor.

[0033] The effects of the wheel bearing device 1 of this embodiment will be described.

[0034] The wheel bearing device 1 of this embodiment includes a fixed member 120, a rotating member 121 that is rotatable relative to the fixed member 120, a rolling element 5 that is arranged between the fixed member 120 and the rotating member 121, and a heat flux sensor 60. The heat flux sensor 60 is attached to one of the fixed member 120 and the rotating member 121.

[0035] The rate of change of heat flux is generally greater than the rate of change of temperature, so by using the heat flux sensor 60, signs of an abnormality occurring in the wheel support bearing 2 can be detected earlier.

[0036] In the wheel bearing device 1 of this embodiment, the fixed member 120 includes a double-row first annular rolling surface (for example, the double-row outer annular rolling surface 6). The rotating member 121 includes a double-row second annular rolling surface (for example, the double-row inner annular rolling surface 7) facing the double-row first annular rolling surface. The rolling elements 5 are double-row rolling elements 5 that contact the double-row first annular rolling surface and the double-row second annular rolling surface. The heat flux sensor 60 is disposed between one row of the double-row rolling elements 5 (for example, the first row rolling elements 31) and another row of the double-row rolling elements 5 (for example, the second row rolling elements 32).

[0037] Therefore, signs of an abnormality in the wheel bearing 2 that occurs in at least one row of the double row rolling elements 5 (e.g., first row rolling elements 31) and another row of the double row rolling elements 5 (e.g., second row rolling elements 32) can be detected more quickly.

[0038] The wheel support bearing device 1 of the present embodiment further includes a determination unit 67 that determines an abnormality in the wheel support bearing 2 including the fixed member 120, the rotating member 121, and the rolling elements 5, based on the output of the heat flux sensor 60. Therefore, a sign of an abnormality occurring in the wheel support bearing 2 can be detected earlier.

[0039] (Embodiment 2)

[0040] A wheel support bearing device 1a according to the second embodiment will be described with reference to Fig. 4. The wheel support bearing device 1a according to the present embodiment has a similar configuration to the wheel support bearing device 1 according to the first embodiment, but differs mainly in the following respects.

[0041] The wheel bearing device 1a further includes a sensor case 70. The heat flux sensor 60 is attached to the sensor case 70 using an adhesive or the like. The sensor case 70 is inserted into a through hole 13 provided in a fixing member 120 (outer member 3, outer ring 10). The through hole 13 extends in the radial direction of the fixing member 120. Therefore, after the wheel bearing 2 is assembled, the heat flux sensor 60 can be easily incorporated into the wheel bearing 2 by inserting the sensor case 70 into the through hole 13.

[0042] The heat flux sensor 60 is attached to a tip 71 of the sensor case 70 proximate to the rotating member 121 (the inner member 4, the hub wheel 21). The heat flux sensor 60 is disposed in a portion of the sensor case 70 that protrudes from a surface (the inner peripheral surface of the outer member 3 (the outer ring 10)) of the fixed member 120 that faces the rotating member 121 (for example, the inner member 4 (the hub wheel 21)). Therefore, the distance between the heat flux sensor 60 and the rotating member 121 (the inner member 4, the hub wheel 21) is reduced. The heat flux sensor 60 can detect a change in the temperature of the wheel support bearing 2 more quickly and with higher accuracy. The heat flux sensor 60 can detect a sign of an abnormality in the wheel support bearing 2 more quickly and with higher accuracy.

[0043] The sensor case 70 includes a flange 72. A flat surface 14 is formed on a surface (for example, the outer peripheral surface of the outer member 3 (outer ring 10)) opposite to a surface (inner peripheral surface) of the fixed member 120 facing the rotating member 121. The flange 72 of the sensor case 70 is in contact with the flat surface 14. An elastic member (not shown) such as an O-ring may be sandwiched between the flange 72 of the sensor case 70 and the flat surface 14. The elastic member prevents water or dust from the outside of the wheel support bearing 2 from entering the gap formed between the fixed member 120 and the rotating member 121. The flange 72 of the sensor case 70 positions the heat flux sensor 60 in the radial direction of the fixed member 120 or the radial direction of the rotating member 121. Therefore, the heat flux sensor 60 can detect a change in the temperature of the wheel support bearing 2 with higher accuracy. The heat flux sensor 60 can detect a sign of an abnormality in the wheel support bearing 2 with higher accuracy.

[0044] The sensor case 70 houses a signal processing circuit (not shown), such as an electrical amplifier, that processes the output signal of the heat flux sensor 60. The signal processing circuit may, for example, amplify the output signal of the heat flux sensor 60. The sensor case 70 may further house other sensors, such as, for example, a temperature sensor or a vibration sensor.

[0045] The sensor case 70 is made of metal or resin. The sensor case 70 may be made of a material having a thermal conductivity equivalent to that of the outer member 3. In this case, the heat flux sensor 60 detects a heat flux generated due to a temperature difference between the fixed member 120 and the rotating member 121, similarly to the first embodiment.

[0046] The sensor case 70 may be formed of an insulating resin (e.g., polyphenylene sulfide (PPS) resin, etc.) having a lower thermal conductivity than the fixed member 120 (e.g., the outer member 3). In this case, a signal processing circuit for processing the output signal of the heat flux sensor 60 can be easily incorporated into the sensor case 70. In addition, since the sensor case 70 has a lower thermal conductivity than the fixed member 120 (e.g., the outer member 3), even if an abnormality occurs in the wheel support bearing 2 and the temperature of the rotating member 121 (the inner member 4) rises, the heat generated in the rotating member 121 is not easily transmitted to the fixed member 120 through the sensor case 70, and the temperature difference between the fixed member 120 and the rotating member 121 becomes large. Therefore, the heat flux sensor 60 can detect the change in the temperature of the wheel support bearing 2 more quickly and with higher accuracy. The heat flux sensor 60 can detect the sign of an abnormality in the wheel support bearing 2 more quickly and with higher accuracy.

[0047] The wiring 64 is connected to a sensor case 70. An elastic member such as the O-ring already mentioned may be provided between the sensor case 70 and the surface of the through hole 13. The wheel support bearing device 1a of the present embodiment includes a control unit 66 (see FIG. 3) including a determination unit 67 (see FIG. 3), and a memory unit 68 (see FIG. 3), similar to the wheel support bearing device 1 of the first embodiment.

[0048] In a modification of this embodiment, the sensor case 70 may be inserted into a through hole (not shown) provided in the rotating member 121. In this case, a generator (power source) (not shown) and a wireless communication means (not shown) are installed on the rotating member 121 side, and wiring on the rotating member 121 side is eliminated. The generator may be configured, for example, by arranging a magnetic ring magnetized with alternating N and S poles on the fixed member 120 side and arranging a stator incorporating a coil on the rotating member 121 side. In addition, the heat flux sensor 60 is connected to a circuit board (not shown) equipped with a wireless communication function, and this circuit board is connected to a power source. When this power source is a generator equipped with the above-mentioned stator and magnetic ring, wiring from the stator is connected to the circuit board to supply power from the generator to the circuit board. In addition to the above-mentioned wireless communication function, the circuit board may further include a rectifier circuit that converts AC voltage from the power source into DC voltage and an amplifier circuit that amplifies a signal from the sensor.

[0049] The wheel support bearing device 1a of the present embodiment provides the following effects in addition to the effects of the wheel support bearing device 1 of the first embodiment.

[0050] The wheel bearing device 1a of this embodiment includes a fixed member 120, a rotating member 121 that is rotatable relative to the fixed member 120, a rolling element 5 arranged between the fixed member 120 and the rotating member 121, a heat flux sensor 60, and a sensor case 70 to which the heat flux sensor 60 is attached. The sensor case 70 is inserted into a through hole 13 provided in one of the fixed member 120 and the rotating member 121.

[0051] Therefore, it is possible to more quickly detect signs of an abnormality occurring in the wheel bearing 2. Also, the heat flux sensor 60 can be easily incorporated into one of the fixed member 120 and the rotating member 121. This improves the workability of installing the heat flux sensor 60 in one of the fixed member 120 and the rotating member 121. It also becomes easy to attach and detach the heat flux sensor 60 to one of the fixed member 120 and the rotating member 121.

[0052] In the wheel bearing device 1a of this embodiment, the heat flux sensor 60 is disposed in a portion of the sensor case 70 that protrudes from one surface of the fixed member 120 and the rotating member 121.

[0053] This reduces the distance between one of the fixed member 120 and the rotating member 121 and the heat flux sensor 60. This allows the heat flux sensor 60 to detect changes in the temperature of the wheel support bearing 2 more quickly and with higher accuracy. The heat flux sensor 60 can detect signs of abnormality in the wheel support bearing 2 more quickly and with higher accuracy.

[0054] (Embodiment 3)

[0055] A wheel support bearing device 1b according to the third embodiment will be described with reference to Fig. 5. The wheel support bearing device 1b according to the present embodiment has a similar configuration to the wheel support bearing device 1a according to the second embodiment, but differs mainly in the following respects.

[0056] In the wheel bearing device 1b, the sensor case 70 has a first inclined surface 73 and a second inclined surface 74. The first inclined surface 73 faces toward one row (e.g., the first inner annular roll surface 26) of the double row annular roll surfaces (e.g., the double row inner annular roll surfaces 7) of the rotating member 121 (e.g., the inner member 4). The second inclined surface 74 faces toward another row (e.g., the second inner annular roll surface 27) of the double row annular roll surfaces (e.g., the double row inner annular roll surfaces 7) of the rotating member 121 (e.g., the inner member 4).

[0057] The wheel bearing device 1b includes heat flux sensors 60a, 60b. The heat flux sensor 60a is closer to the first row rolling elements 31 than the heat flux sensor 60b. The heat flux sensor 60a detects changes in heat flux at the first inner annular rolling surface 26, the first outer annular rolling surface 11, and the first row rolling elements 31. The heat flux sensor 60b is closer to the second row rolling elements 32 than the heat flux sensor 60a. The heat flux sensor 60b detects changes in heat flux at the second inner annular rolling surface 27, the second outer annular rolling surface 12, and the second row rolling elements 32.

[0058] The heat flux sensor 60a is attached to a first inclined surface 73 of the sensor case 70. The front surface of the heat flux sensor 60a faces toward the first inner annular roll surface 26. The heat flux sensor 60a detects changes in heat flux at the first inner annular roll surface 26. The heat flux sensor 60b is attached to a second inclined surface 74 of the sensor case 70. The front surface of the heat flux sensor 60b faces toward the second inner annular roll surface 27. The heat flux sensor 60b detects changes in heat flux at the second inner annular roll surface 27.

[0059] For example, when an abnormality occurs in the first inner annular roll surface 26 at time t1 (see FIG. 6), the temperature of the first inner annular roll surface 26 rises. As shown in FIG. 6, the output of the heat flux sensor 60a increases rapidly from time t1. Due to thermal conduction between the first inner annular roll surface 26 and the second inner annular roll surface 27, the temperature of the second inner annular roll surface 27 rises at time t2, which is after time t1. As shown in FIG. 6, the output of the heat flux sensor 60b increases rapidly from time t2. By monitoring the outputs of the heat flux sensors 60a and 60b or the difference between the outputs of the heat flux sensors 60a and 60b, a sign of an abnormality in the wheel bearing 2 can be detected early.

[0060] 7, the control unit 66 (determination unit 67) is electrically connected to the heat flux sensors 60a, 60b via wiring 64. The outputs of the heat flux sensors 60a, 60b are input to the control unit 66 through the wiring 64. The determination unit 67 determines an abnormality in the wheel support bearing 2 including the fixed member 120, the rotating member 121, and the double row rolling elements 5 based on the outputs of the heat flux sensors 60a, 60b. The determination unit 67 outputs a signal to notify of an abnormality in the wheel support bearing 2.

[0061] In a first example, the determination unit 67 determines whether or not the output of the heat flux sensor 60a and the output of the heat flux sensor 60b exceed a first threshold value stored in the storage unit 68. If the output of the heat flux sensor 60a exceeds the first threshold value, the determination unit 67 outputs a signal notifying an abnormality in the wheel bearing 2 (first inner annular rolling surface 26). If the output of the heat flux sensor 60b exceeds the first threshold value, the determination unit 67 outputs a signal notifying an abnormality in the wheel bearing 2 (second inner annular rolling surface 27).

[0062] In a second example, the determination unit 67 determines whether or not the rate of change per unit time of the output of the heat flux sensor 60a and the rate of change per unit time of the output of the heat flux sensor 60b exceed a second threshold value stored in the storage unit 68. If the rate of change per unit time of the output of the heat flux sensor 60a exceeds the second threshold value, the determination unit 67 outputs a signal notifying an abnormality of the wheel bearing 2 (the first inner annular rolling surface 26). If the rate of change per unit time of the output of the heat flux sensor 60b exceeds the second threshold value, the determination unit 67 outputs a signal notifying an abnormality of the wheel bearing 2 (the second inner annular rolling surface 27).

[0063] In a third example, the determination unit 67 determines whether or not the difference between the output of the heat flux sensor 60a and the output of the heat flux sensor 60b exceeds a third threshold value stored in the memory unit 68. When the difference between the output of the heat flux sensor 60a and the output of the heat flux sensor 60b exceeds the third threshold value, the determination unit 67 outputs a signal to notify of an abnormality in the wheel bearing 2.

[0064] In a fourth example, the determination unit 67 determines whether or not the difference between the rate of change per unit time of the output of the heat flux sensor 60a and the rate of change per unit time of the output of the heat flux sensor 60b exceeds a fourth threshold value stored in the storage unit 68. When the difference between the rate of change per unit time of the output of the heat flux sensor 60a and the rate of change per unit time of the output of the heat flux sensor 60b exceeds the fourth threshold value, the determination unit 67 outputs a signal notifying an abnormality of the wheel support bearing 2. In the third and fourth examples, the determination unit 67 can distinguish between a temperature rise of the wheel support bearing 2 during normal driving and a temperature rise of the wheel support bearing 2 when an abnormality occurs, so that an abnormality of the wheel support bearing 2 can be detected more accurately.

[0065] In a modified example of this embodiment, the sensor case 70 is inserted into a through hole (not shown) provided in the rotating member 121, the first inclined surface 73 faces toward one row (e.g., the first outer annular roll surface 11) of the double-row annular roll surfaces (e.g., the double-row outer annular roll surface 6) of the fixed member 120 (e.g., the outer member 3), the second inclined surface 74 faces toward another row (e.g., the second outer annular roll surface 12) of the double-row annular roll surfaces (e.g., the double-row outer annular roll surface 6) of the fixed member 120 (e.g., the outer member 3), and the front surface of the heat flux sensor 60a attached to the first inclined surface 73 faces toward the first outer annular roll surface 11, and the front surface of the heat flux sensor 60b attached to the second inclined surface 74 may face toward the second outer annular roll surface 12. In this modification, the heat flux sensor 60a detects a change in the heat flux on the first outer annular rolling surface 11, and the heat flux sensor 60b detects a change in the heat flux on the second outer annular rolling surface 12. In this case, a generator (power source) (not shown) and a wireless communication means (not shown) are installed on the rotating member 121 side, and wiring on the rotating member 121 side is eliminated. The generator can be configured, for example, by arranging a magnetic ring magnetized with alternating N and S poles on the fixed member 120 side and arranging a stator with a built-in coil on the rotating member 121 side. In addition, the heat flux sensor 60 is connected to a circuit board (not shown) equipped with a wireless communication function, and this circuit board is connected to a power source. When this power source is a generator equipped with the above-mentioned stator and magnetic ring, wiring from the stator is connected to the circuit board to supply power from the generator to the circuit board. In addition to the above-mentioned wireless communication function, the circuit board may further include a rectifier circuit that converts AC voltage from the power source into DC voltage and an amplifier circuit that amplifies a signal from the sensor.

[0066] The wheel support bearing device 1b of this embodiment provides the following effects in addition to the effects of the wheel support bearing device 1a of the second embodiment.

[0067] In the wheel bearing device 1b of this embodiment, the sensor case 70 has a first inclined surface 73 and a second inclined surface 74. The first inclined surface 73 faces toward one row of the other of the double row annular rolling surfaces of the fixed member 120 and the rotating member 121. The second inclined surface 74 faces toward another row of the other of the double row annular rolling surfaces of the fixed member 120 and the rotating member 121. The at least one heat flux sensor includes a first heat flux sensor (heat flux sensor 60a) attached to the first inclined surface 73 and a second heat flux sensor (heat flux sensor 60b) attached to the second inclined surface 74.

[0068] Since it is possible to detect changes in heat flux between one row of the annular rolling surfaces of the other double row of the fixed member 120 and the rotating member 121 and another row of the annular rolling surfaces of the other double row of the fixed member 120 and the rotating member 121, signs of abnormality in the wheel bearing 2 can be detected early.

[0069] The wheel bearing device 1b of this embodiment further includes a judgment unit 67 that judges an abnormality in the wheel bearing 2 including the fixed member 120, the rotating member 121 and the double row rolling elements 5 based on the difference between the output of the first heat flux sensor (heat flux sensor 60a) and the output of the second heat flux sensor (heat flux sensor 60b), or the difference between the rate of change per unit time of the output of the first heat flux sensor and the rate of change per unit time of the output of the second heat flux sensor.

[0070] Therefore, signs of abnormality in the wheel support bearing 2 can be detected early.

[0071] (Embodiment 4)

[0072] A wheel support bearing device 1c according to the fourth embodiment will be described with reference to Fig. 8. The wheel support bearing device 1c according to the present embodiment differs from the wheel support bearing device 1 according to the first embodiment mainly in the configuration of the wheel support bearing 2c.

[0073] The wheel bearing device 1c is, for example, a bearing device for a railway vehicle axle. The wheel bearing device 1c mainly includes a fixed member 120, a rotating member 121, a rolling element 5c, a retainer 35c, and a heat flux sensor 60. In this embodiment, the fixed member 120 includes an outer member 3c, seals 40, 45, and seal cases 96, 97. The rotating member 121 includes an inner member 4c, an annular member 88, a nut (front cover) 90, a rear cover 91, a rotation prevention ring 92, and a set screw 93. The outer member 3c, the inner member 4c, the rolling element 5c, and the retainer 35c configure a wheel bearing 2c.

[0074] The outer member 3c includes an outer ring 10c. The outer ring 10c is fixed to a vehicle frame (not shown) or an axle box (not shown). In this embodiment, the outer ring 10c is a fixed ring.

[0075] The fixed member 120 includes a double-row first annular rolling surface. Specifically, the outer member 3c has a double-row outer annular rolling surface 6c formed on the inner peripheral surface of the outer member 3c. The double-row outer annular rolling surface 6c includes, for example, a first outer annular rolling surface 11c and a second outer annular rolling surface 12c. The first outer annular rolling surface 11c and the second outer annular rolling surface 12c are spaced apart from each other in the central axis direction of the outer member 3c (the rotational axis direction of the wheel bearing 2c) and are adjacent to each other. The first outer annular rolling surface 11c is provided on the axial end side of the axle 100 (the left side in FIG. 8) with respect to the second outer annular rolling surface 12c.

[0076] The rotating member 121 includes a double-row second annular rolling surface facing the double-row first annular rolling surface of the fixed member 120. Specifically, the inner member 4c has a double-row inner annular rolling surface 7c formed on the outer circumferential surface of the inner member 4c. The double-row inner annular rolling surface 7c includes, for example, a first inner annular rolling surface 26c and a second inner annular rolling surface 27c. The first inner annular rolling surface 26c and the second inner annular rolling surface 27c are spaced apart from each other in the central axis direction of the inner member 4c (the rotational axis direction of the wheel bearing 2c) and are adjacent to each other. The first inner annular rolling surface 26c is provided on the axial end side of the axle 100 with respect to the second inner annular rolling surface 27c. The double-row inner annular rolling surface 7c faces the double-row outer annular rolling surface 6c. Specifically, the first inner annular raceway surface 26c faces the first outer annular raceway surface 11c, and the second inner annular raceway surface 27c faces the second outer annular raceway surface 12c.

[0077] Specifically, the inner member 4c includes a first inner ring 81, a second inner ring 82, and an inner ring spacer 83. The first inner ring 81, the second inner ring 82, and the inner ring spacer 83 are fitted to an axial end of an axle 100 serving as a rotating member. In the present embodiment, the first inner ring 81, the second inner ring 82, and the inner ring spacer 83 are rotating rings.

[0078] The first inner ring 81 is located closer to the axial end of the axle 100 than the second inner ring 82. The inner ring spacer 83 is disposed between the first inner ring 81 and the second inner ring 82, and is in contact with the first inner ring 81 and the second inner ring 82. A first inner annular rolling surface 26c is formed on the outer circumferential surface of the first inner ring 81. A second inner annular rolling surface 27c is formed on the outer circumferential surface of the second inner ring 82.

[0079] The rolling element 5c is disposed between the fixed member 120 (for example, the outer member 3c) and the rotating member 121 (for example, the inner member 4c). The rolling element 5c is, for example, a double-row rolling element 5c. The double-row rolling element 5c is in contact with the double-row outer annular rolling surface 6c and the double-row inner annular rolling surface 7c. Specifically, the double-row rolling element 5c includes, for example, a first row rolling element 31c and a second row rolling element 32c. The first row rolling element 31c and the second row rolling element 32c are spaced apart from each other in the rotational axis direction of the wheel bearing 2 and are adjacent to each other. The first row rolling element 31c is in contact with the first outer annular rolling surface 11c and the first inner annular rolling surface 26c. The second row rolling elements 32c are in contact with the second outer annular rolling surface 12c and the second inner annular rolling surface 27c. The first row rolling elements 31c are provided on the outboard side of the second row rolling elements 32c. The inner member 4c (first inner ring 81, second inner ring 82, inner ring spacer 83) is rotatably supported on the outer member 3c (outer ring 10c) via the double row rolling elements 5c. In this embodiment, the double row rolling elements 5c are each tapered rollers, and the wheel support bearing 2c is a double row tapered roller bearing. The double row rolling elements 5c may each be cylindrical rollers, and the wheel support bearing 2c may be a double row cylindrical roller bearing.

[0080] The cage 35c holds the double-row rolling elements 5c. Specifically, the cage 35c holds the first row rolling elements 31c such that the interval between two adjacent rolling elements included in the first row rolling elements 31c is within a certain range in the circumferential direction of the cage 35c. The cage 35c holds the second row rolling elements 32c such that the interval between two adjacent rolling elements included in the second row rolling elements 32c is within a certain range in the circumferential direction of the cage 35c. The cage 35c separates the first row rolling elements 31c and the second row rolling elements 32c from each other in the central axis direction of the cage 35c (the rotational axis direction of the wheel bearing 2c).

[0081] Grease is filled in the gap formed between the fixed member 120 (e.g., outer member 3c) and the rotating member 121 (e.g., inner member 4c). The grease is a lubricant for the double-row rolling elements 5c. The seal 40 is disposed at the end of the gap formed between the fixed member 120 and the rotating member 121 on the axial end side of the axle 100. The seal 45 is disposed at the end of the gap formed between the fixed member 120 and the rotating member 121 on the anti-axial end side of the axle 100 (the right side in FIG. 8). The seals 40 and 45 prevent the grease from leaking out of the gap formed between the fixed member 120 and the rotating member 121 and also prevent water, dust, and the like from entering this gap from the outside of the wheel bearing 2c.

[0082] The seal 40 is fixed to a surface of the fixed member 120 facing the rotating member 121 (for example, the inner circumferential surface of the outer member 3c (outer ring 10c)). Specifically, the seal 40 is fixed to the inner surface of a seal case 96. The seal case 96 is fixed to an end of the inner circumferential surface of the outer member 3c on the axial end side of the axle 100. The seal 40 includes a core metal 41 and a seal lip 42 (see FIG. 10). The core metal 41 is fixed to the inner surface of the seal case 96. The seal lip 42 is attached to the core metal 41. The seal lip 42 is made of rubber. A tip of the seal lip 42 contacts a surface of the rotating member 121 facing the fixed member 120 (for example, the outer circumferential surface of the annular member 88).

[0083] The seal 45 is fixed to the outer member 3c (outer ring 10c). Specifically, the seal 45 is fixed to the inner surface of a seal case 97. The seal case 97 is fixed to the inner circumferential surface of the outer member 3c, at the end opposite the axle end of the axle 100. The seal 45 includes a core metal 46 and a seal lip 47 (see FIG. 11). The core metal 46 is fixed to the inner surface of the seal case 97. The seal lip 47 is attached to the core metal 46. The seal lip 47 is made of rubber. A tip of the seal lip 47 contacts a surface of the rotating member 121 facing the fixed member 120 (for example, the outer circumferential surface of the rear cover 91).

[0084] An annular member 88 and a nut (front cover) 90 are disposed on the axial end side of the axle 100 relative to the inner member 4c (first inner ring 81). The annular member 88 is, for example, an oil thrower. A rear cover 91 is disposed on the opposite axial end side of the axle 100 relative to the inner member 4c (first inner ring 81).

[0085] The rear cover 91 is press-fitted into the axle 100 and abuts against a shoulder 102 of the axle 100. Then, the inner member 4c is press-fitted into the axle 100. Specifically, the second inner ring 82, the inner ring spacer 83, and the first inner ring 81 are press-fitted into the axle 100 in this order. Next, the annular member 88 is press-fitted into the axle 100. Finally, the nut (front cover) 90 is screwed into a male thread 101 formed on the shaft end of the axle 100, and the annular member 88 and the inner member 4c are pressed against the rear cover 91. The inner member 4c, the annular member 88, and the rear cover 91 are sandwiched between the nut (front cover) 90 and the shoulder 102 of the axle 100. The nut (front cover) 90 and the shoulder 102 of the axle 100 fix the annular member 88 and the rear cover 91 to the inner member 4c. The rear cover 91 and the annular member 88 position the inner ring 25 in the axial direction of the axle 100 .

[0086] The nut (front cover) 90 is connected by a set screw 93 to a rotation prevention ring 92 that engages with a recess formed in the outer circumferential surface of the shaft end of the axle 100. The rotation prevention ring 92 and the set screw 93 prevent the nut (front cover) 90 from loosening and falling off the axle 100.

[0087] In this embodiment, the heat flux sensor 60 is fixed to the fixing member 120, as in the first embodiment. Specifically, the back surface of the heat flux sensor 60 is attached to the inner peripheral surface of the outer member 3c (outer ring 10c) using an adhesive. The heat flux sensor 60 is disposed between one row (for example, the first row rolling element 31c) of the double row rolling elements 5c and another row (for example, the second row rolling element 32c) of the double row rolling elements 5c. The heat flux sensor 60 is disposed between the first outer annular rolling surface 11c and the second outer annular rolling surface 12c. The heat flux sensor 60 is disposed between the first inner annular rolling surface 26c and the second inner annular rolling surface 27c. The heat flux sensor 60 is disposed between the first inner annular rolling surface 26c and the second inner annular rolling surface 27c. Therefore, it is possible to quickly detect signs of an abnormality in the wheel bearing 2c that occurs in at least one row of the double row rolling bodies 5c (e.g., the first row rolling body 31c) and another row of the double row rolling bodies 5c (e.g., the second row rolling body 32c).

[0088] A wiring 64 is connected to the heat flux sensor 60. The wiring 64 is passed through a through hole 13 provided in a fixed member 120 (for example, an outer member 3c (outer ring 10c)) and is drawn to the outside of the wheel support bearing 2c. The through hole 13 extends in the radial direction of the fixed member 120. As with the wheel support bearing device 1 of the first embodiment, the wheel support bearing device 1c further includes a determination unit 67 (see FIG. 3) that determines an abnormality in the wheel support bearing 2c including the fixed member 120, the rotating member 121 and the double-row rolling elements 5c based on the output of the heat flux sensor 60.

[0089] In a modification of this embodiment, the heat flux sensor 60 may be attached to the rotating member 121 instead of the fixed member 120. In this case, a generator (power source) (not shown) and a wireless communication means (not shown) are installed on the rotating member 121 side, and wiring on the rotating member 121 side is eliminated. The generator may be configured, for example, by arranging a magnetic ring magnetized with alternating N and S poles on the fixed member 120 side and arranging a stator with a built-in coil on the rotating member 121 side. In addition, the heat flux sensor 60 is connected to a circuit board (not shown) equipped with a wireless communication function, and this circuit board is connected to a power source. When this power source is a generator equipped with the above-mentioned stator and magnetic ring, wiring from the stator is connected to the circuit board to supply power from the generator to the circuit board. In addition to the above-mentioned wireless communication function, the circuit board may further include a rectifier circuit that converts AC voltage from the power source into DC voltage and an amplifier circuit that amplifies a signal from the sensor.

[0090] The wheel support bearing device 1c of the present embodiment provides the same effects as the wheel support bearing device 1 of the first embodiment.

[0091] (Embodiment 5)

[0092] A wheel support bearing device 1d according to the fifth embodiment will be described with reference to Fig. 9 to Fig. 11. The wheel support bearing device 1d according to the present embodiment has a similar configuration to the wheel support bearing device 1c according to the fourth embodiment, but differs mainly in the following respects.

[0093] The wheel bearing device 1d includes heat flux sensors 60a and 60b. As shown in FIG. 9 and FIG. 10, the heat flux sensor 60a is fixed to the seal 40. Specifically, the heat flux sensor 60a is attached to the core metal 41. For example, when an abnormality occurs in the first inner annular rolling surface 26c, heat is generated in the first inner annular rolling surface 26c. Since the annular member 88 is fixed to the inner member 4c (first inner ring 81), the heat generated in the first inner annular rolling surface 26c is conducted to the annular member 88. The heat flux sensor 60a detects a heat flux caused by a temperature difference between the annular member 88 and the seal 40. The heat flux sensor 60a can detect a sign of an abnormality in the first inner annular rolling surface 26c early.

[0094] As shown in FIG. 9 and FIG. 11, the heat flux sensor 60b is fixed to the seal 45. Specifically, the heat flux sensor 60b is attached to the core metal 46. For example, when an abnormality occurs in the second inner annular rolling surface 27c, heat is generated in the second inner annular rolling surface 27c. Since the rear cover 91 is fixed to the inner member 4c (the second inner ring 82), the heat generated in the second inner annular rolling surface 27c is conducted to the rear cover 91. The heat flux sensor 60b detects a heat flux caused by a temperature difference between the rear cover 91 and the seal 45. The heat flux sensor 60b can quickly detect a sign of an abnormality in the second inner annular rolling surface 27c.

[0095] Like the wheel bearing device 1b of embodiment 3, the wheel bearing device 1d further includes a judgment unit 67 (see Figure 7) that judges an abnormality in the wheel bearing 2c including the fixed member 120, the rotating member 121 and the double row rolling elements 5c based on the output of the heat flux sensor 60a and the output of the heat flux sensor 60b.

[0096] In a modification of this embodiment, the wheel support bearing device 1d may include one of the heat flux sensor 60a and the heat flux sensor 60b. The wheel support bearing device 1d of this modification further includes a determination unit 67 (see FIG. 3) that determines an abnormality of the wheel support bearing 2c including the fixed member, the rotating member 121, and the double row rolling elements 5c based on the output of one of the heat flux sensors 60a and 60b, similar to the wheel support bearing device 1 of the first embodiment. In another modification of this embodiment, the heat flux sensors 60a and 60b may be attached to the rotating member 121. The rotating member 121 may include the seals 40 and 45 and the seal cases 96 and 97, and the fixed member 120 may include a slinger 55.

[0097] The wheel support bearing device 1d of the present embodiment has the following advantages similar to those of the wheel support bearing devices 1b, 1c of the third and fourth embodiments.

[0098] The wheel bearing device 1d of this embodiment includes a fixed member 120, a rotating member 121 rotatable relative to the fixed member 120, a rolling element 5c disposed between the fixed member 120 and the rotating member 121, and at least one heat flux sensor (e.g., heat flux sensors 60a, 60b). One of the fixed member 120 and the rotating member 121 includes at least one seal (e.g., seals 40, 45). The at least one heat flux sensor is attached to the at least one seal.

[0099] The rate of change of heat flux is generally greater than the rate of change of temperature. Therefore, by using at least one heat flux sensor (e.g., heat flux sensors 60a, 60b), it is possible to detect a sign of an abnormality occurring in the wheel support bearing 2c earlier. Furthermore, since the at least one heat flux sensor is attached to at least one seal (e.g., seals 40, 45), it is not necessary to provide additional space for installing the at least one heat flux sensor. The wheel support bearing device 1d can be made smaller.

[0100] In the wheel bearing device 1d of this embodiment, the fixed member 120 includes a double-row first annular rolling surface (for example, the double-row outer annular rolling surface 6). The rotating member 121 includes a double-row second annular rolling surface (for example, the double-row inner annular rolling surface 7) facing the double-row first annular rolling surface. The rolling elements 5c are double-row rolling elements 5c that contact the double-row first annular rolling surface and the double-row second annular rolling surface. The double-row rolling elements 5c include a first row rolling element 31c and a second row rolling element 32c. The at least one seal includes a first seal (seal 40) and a second seal (seal 45). The at least one heat flux sensor includes a first heat flux sensor (heat flux sensor 60a) attached to the first seal and a heat flux sensor (heat flux sensor 60b) attached to the second seal. The first heat flux sensor is closer to the first row rolling elements 31c than the second heat flux sensor. The second heat flux sensor is closer to the second row rolling elements 32c than the first heat flux sensor.

[0101] Therefore, signs of an abnormality in the wheel bearing 2c that occurs in at least one row of the double row rolling elements 5 (e.g., the first row rolling elements 31) and another row of the double row rolling elements 5 (e.g., the second row rolling elements 32) can be detected more quickly.

[0102] (Embodiment 6)

[0103] A wheel support bearing device 1e according to the sixth embodiment will be described with reference to Fig. 12. The wheel support bearing device 1e according to the present embodiment has a similar configuration to the wheel support bearing device 1c according to the fourth embodiment, but differs mainly in the following respects.

[0104] The wheel bearing device 1e further includes a sensor case 70, as in the second embodiment. The heat flux sensor 60 is attached to the sensor case 70 using an adhesive or the like. The sensor case 70 is inserted into a through hole 13 provided in a fixing member 120 (outer member 3c, outer ring 10c). The through hole 13 extends in the radial direction of the fixing member 120. Therefore, after assembling the wheel bearing 2c, the heat flux sensor 60 can be easily incorporated into the wheel bearing 2c by inserting the sensor case 70 into the through hole 13. Note that, when the wheel bearing 2c is used in an axle box (not shown), a hole penetrating the axle box and the outer ring 10c may be formed, and the sensor case 70 may be inserted into this hole.

[0105] The heat flux sensor 60 is attached to the tip 71 of the sensor case 70 proximate to the rotating member 121 (the inner member 4c, the first inner ring 81, the second inner ring 82, and the inner ring spacer 83). The heat flux sensor 60 is disposed in a portion of the sensor case 70 that protrudes from the surface (the inner peripheral surface of the outer member 3c (the outer ring 10c)) of the fixed member 120 that faces the rotating member 121 (the inner member 4c, the first inner ring 81, the inner ring spacer 83, and the second inner ring 82). Therefore, the distance between the heat flux sensor 60 and the inner member 4c is small. The heat flux sensor 60 can detect the change in temperature of the wheel support bearing 2c more quickly and with higher accuracy. The heat flux sensor 60 can detect the sign of an abnormality in the wheel support bearing 2c more quickly and with higher accuracy.

[0106] The sensor case 70 includes a flange 72. The flange 72 of the sensor case 70 is in contact with a surface (outer peripheral surface) of the fixed member 120 (outer member 3c, outer ring 10c) opposite to a surface (inner peripheral surface) facing the rotating member 121. An elastic member (not shown) such as an O-ring may be sandwiched between the flange 72 of the sensor case 70 and a surface of the fixed member 120 (for example, the outer peripheral surface of the outer member 3c (outer ring 10c)). The flange 72 of the sensor case 70 positions the heat flux sensor 60 in the radial direction of the rotating member 121 or the radial direction of the fixed member 120. Therefore, the heat flux sensor 60 can detect a change in the temperature of the wheel support bearing 2c with higher accuracy. The heat flux sensor 60 can detect a sign of an abnormality in the wheel support bearing 2c with higher accuracy.

[0107] The sensor case 70 houses a signal processing circuit (not shown), such as an electric amplifier, that processes the output signal of the heat flux sensor 60. The signal processing circuit may, for example, amplify the output signal of the heat flux sensor 60. The sensor case 70 may further house a sensor, such as, for example, a temperature sensor or a vibration sensor. The wiring 64 is connected to the sensor case 70. An elastic member, such as the O-ring already mentioned, may be provided between the sensor case 70 and the surface of the through hole 13.

[0108] The wheel bearing device 1e of this embodiment, like the wheel bearing device 1 of embodiment 1, is equipped with a control unit 66 (see Figure 3) including a determination unit 67 (see Figure 3), and a memory unit 68 (see Figure 3).

[0109] In a modification of this embodiment, the sensor case 70 may be inserted into a through hole (not shown) provided in the rotating member 121. In this case, a generator (power source) (not shown) and a wireless communication means (not shown) are installed on the rotating member 121 side, and wiring on the rotating member 121 side is eliminated. The generator may be configured, for example, by arranging a magnetic ring magnetized with alternating N and S poles on the fixed member 120 side and arranging a stator incorporating a coil on the rotating member 121 side. In addition, the heat flux sensor 60 is connected to a circuit board (not shown) equipped with a wireless communication function, and this circuit board is connected to a power source. When this power source is a generator equipped with the above-mentioned stator and magnetic ring, wiring from the stator is connected to the circuit board to supply power from the generator to the circuit board. In addition to the above-mentioned wireless communication function, the circuit board may further include a rectifier circuit that converts AC voltage from the power source into DC voltage and an amplifier circuit that amplifies a signal from the sensor.

[0110] The wheel support bearing device 1e of the present embodiment provides the same effects as those of the wheel support bearing devices 1a, 1c of the second and fourth embodiments.

[0111] (Embodiment 7)

[0112] A wheel support bearing device 1f of the seventh embodiment will be described with reference to Fig. 13. The wheel support bearing device 1f of the present embodiment has a similar configuration to the wheel support bearing device 1c of the fourth embodiment, but differs mainly in the following respects.

[0113] In the wheel support bearing device 1f, similarly to the wheel support bearing device 1b of the third embodiment, the sensor case 70 has a first inclined surface 73 and a second inclined surface 74. The first inclined surface 73 faces toward one row (e.g., the first inner annular roll surface 26c) of the double row annular roll surfaces (e.g., the double row inner annular roll surfaces 7c) of the rotating member 121 (inner member 4c). The second inclined surface 74 faces toward another row (e.g., the second inner annular roll surface 27c) of the double row annular roll surfaces (e.g., the double row inner annular roll surfaces 7c) of the rotating member 121 (inner member 4c).

[0114] The wheel bearing device 1f includes heat flux sensors 60a and 60b, similar to the wheel bearing device 1b of the third embodiment. The heat flux sensor 60a is closer to the first row rolling elements 31c than the heat flux sensor 60b. The heat flux sensor 60a detects changes in heat flux at the first inner annular rolling surface 26c, the first outer annular rolling surface 11c, and the first row rolling elements 31c. The heat flux sensor 60b is closer to the second row rolling elements 32c than the heat flux sensor 60a. The heat flux sensor 60b detects changes in heat flux at the second inner annular rolling surface 27c, the second outer annular rolling surface 12c, and the second row rolling elements 32c.

[0115] The heat flux sensor 60a is attached to a first inclined surface 73 of the sensor case 70. The front surface of the heat flux sensor 60a faces toward the first inner annular raceway surface 26c. The heat flux sensor 60a detects changes in heat flux on the first inner annular raceway surface 26c. The heat flux sensor 60b is attached to a second inclined surface 74 of the sensor case 70. The front surface of the heat flux sensor 60b faces toward the second inner annular raceway surface 27c. The heat flux sensor 60b detects changes in heat flux on the second inner annular raceway surface 27c.

[0116] Like the wheel bearing device 1b of embodiment 3, the wheel bearing device 1f further includes a judgment unit 67 (see Figure 7) that judges an abnormality in the wheel bearing 2c including the fixed member 120, the rotating member 121 and the double row rolling elements 5c based on the output of the heat flux sensor 60a and the output of the heat flux sensor 60b.

[0117] In a modification of this embodiment, the sensor case 70 may be inserted into a through hole (not shown) provided in the rotating member 121. In this case, a generator (power source) (not shown) and a wireless communication means (not shown) are installed on the rotating member 121 side, and wiring on the rotating member 121 side is eliminated. The generator may be configured, for example, by arranging a magnetic ring magnetized with alternating N and S poles on the fixed member 120 side and arranging a stator incorporating a coil on the rotating member 121 side. In addition, the heat flux sensor 60 is connected to a circuit board (not shown) equipped with a wireless communication function, and this circuit board is connected to a power source. When this power source is a generator equipped with the above-mentioned stator and magnetic ring, wiring from the stator is connected to the circuit board to supply power from the generator to the circuit board. In addition to the above-mentioned wireless communication function, the circuit board may further include a rectifier circuit that converts AC voltage from the power source into DC voltage and an amplifier circuit that amplifies a signal from the sensor.

[0118] The wheel support bearing device 1f of the present embodiment provides the same effects as the wheel support bearing devices 1b, 1c of the third and fourth embodiments.

[0119] (Embodiment 8)

[0120] A wheel support bearing device 1g of the eighth embodiment will be described with reference to Fig. 14. The wheel support bearing device 1g of this embodiment differs from the wheel support bearing device 1 of the first embodiment mainly in the configuration of a wheel support bearing 2g.

[0121] The wheel bearing device 1g is, for example, a bearing device for an automobile wheel. Specifically, it is a bearing device for a driven wheel of an automobile. The wheel bearing device 1g mainly includes a fixed member 120, a rotating member 121, a rolling element 5, a retainer 35, a heat flux sensor 60, and a sensor case 70. In this embodiment, the rotating member 121 includes an outer member 3g, a seal 45, and a cap 105. The fixed member 120 includes an inner member 4g and a slinger 55. The outer member 3g, the inner member 4g, the rolling element 5, and the retainer 35 constitute a wheel bearing 2g.

[0122] The outer member 3g includes a hub-integrated outer ring 10g. The hub-integrated outer ring 10g is a rotating ring. The hub-integrated outer ring 10g includes a hub flange 28. A wheel (not shown) is attached to the hub flange 28. Specifically, the hub flange 28 is provided with a plurality of bolt holes 29 along the circumferential direction of the hub flange 28. The wheel is disposed on the outboard side of the hub flange 28. A bob bolt (not shown) is press-fitted into the bolt hole 29 to attach the wheel to the hub flange 28.

[0123] The rotating member 121 includes a double-row second annular rolling surface. Specifically, the outer member 3g has a double-row outer annular rolling surface 6 formed on an inner circumferential surface of the outer member 3g. The double-row outer annular rolling surface 6 includes, for example, a first outer annular rolling surface 11 and a second outer annular rolling surface 12. The first outer annular rolling surface 11 and the second outer annular rolling surface 12 are spaced apart from each other in the central axial direction of the outer member 3g (the rotational axis direction of the wheel bearing 2g) and are adjacent to each other. The first outer annular rolling surface 11 is provided on the outboard side with respect to the second outer annular rolling surface 12.

[0124] The fixed member 120 includes a double-row first annular rolling surface facing the double-row second annular rolling surface of the rotating member 121. Specifically, the inner member 4g has a double-row inner annular rolling surface 7 formed on the outer circumferential surface of the inner member 4g. The double-row inner annular rolling surface 7 includes, for example, a first inner annular rolling surface 26 and a second inner annular rolling surface 27. The first inner annular rolling surface 26 and the second inner annular rolling surface 27 are spaced apart from each other in the central axis direction of the inner member 4g (the rotational axis direction of the wheel bearing 2g) and are adjacent to each other. The first inner annular rolling surface 26 is provided on the outboard side with respect to the second inner annular rolling surface 27. The double-row inner annular rolling surface 7 faces the double-row outer annular rolling surface 6. Specifically, the first inner annular rolling surface 26 faces the first outer annular rolling surface 11. The second inner annular raceway surface 27 faces the second outer annular raceway surface 12 .

[0125] The inner member 4g includes a first inner ring 81g and a second inner ring 82g. The first inner ring 81g and the second inner ring 82g are fitted to an axial end of the axle 110. In this embodiment, the first inner ring 81g and the second inner ring 82g are fixed rings. The first inner ring 81g is located closer to the axial end (outboard side) of the axle 110 than the second inner ring 82g. A first inner annular rolling surface 26 is formed on an outer circumferential surface of the first inner ring 81g. A second inner annular rolling surface 27 is formed on an outer circumferential surface of the second inner ring 82g.

[0126] The rolling elements 5 are disposed between a rotating member 121 (for example, an outer member 3g) and a fixed member 120 (for example, an inner member 4g). The rolling elements 5 are double-row rolling elements 5. The double-row rolling elements 5 are in contact with the double-row outer annular rolling surface 6 and the double-row inner annular rolling surface 7. Specifically, the double-row rolling elements 5 include, for example, a first row rolling element 31 and a second row rolling element 32. The first row rolling elements 31 and the second row rolling elements 32 are spaced apart from each other in the direction of the rotation axis of the wheel bearing 2 and are adjacent to each other. The first row rolling elements 31 are in contact with the first outer annular rolling surface 11 and the first inner annular rolling surface 26. The second row rolling elements 32 are in contact with the second outer annular rolling surface 12 and the second inner annular rolling surface 27. The outer member 3g (hub-integrated outer ring 10g) is rotatably supported relative to the inner member 4g (first inner ring 81g and second inner ring 82g) via double row rolling elements 5. In this embodiment, the double row rolling elements 5 are balls, and the wheel support bearing 2g is a double row angular contact ball bearing.

[0127] The cage 35 holds the double-row rolling elements 5. Grease is sealed in a gap formed between a rotating member 121 (e.g., outer member 3g) and a fixed member 120 (e.g., inner member 4g). The grease is a lubricant for the double-row rolling elements 5.

[0128] The seal 45 is disposed at the end of the gap formed between the fixed member 120 and the rotating member 121 on the side opposite the axle end (inboard side) of the axle 110. The seal 45 prevents grease from leaking out of the gap formed between the fixed member 120 and the rotating member 121, and prevents water, dust, and the like from entering the gap from the outside of the wheel bearing 2g. The seal 45 is fixed to a surface of the rotating member 121 facing the fixed member 120 (for example, the inner circumferential surface of the outer member 3g (hub-integrated outer ring 10g)). Specifically, the seal 45 includes a core metal 46 and a seal lip 47. The core metal 46 is fixed to the inner circumferential surface of the outer member 3g (hub-integrated outer ring 10g). The seal lip 47 is attached to the core metal 46. The seal lip 47 is made of rubber. The tip of the seal lip 47 is in contact with the fixed member 120 (for example, the slinger 55). The slinger 55 is fixed to a surface of the fixed member 120 that faces the rotating member 121 (for example, the outer circumferential surface of the inner member 4 (the inner ring 25)).

[0129] The cap 105 is attached to the end of the outer member 3g (hub-integrated outer ring 10g) on ​​the axial end side (outboard side) of the axle 110. Specifically, the end of the cap 105 is press-fitted into the end of the inner circumferential surface of the outer member 3g (hub-integrated outer ring 10g) on ​​the axial end side (outboard side) of the axle 110. The cap 105 closes the opening of the outer member 3g (hub-integrated outer ring 10g) on ​​the axial end side (outboard side) of the axle 110. The cap 105 prevents grease, which is a lubricant, from leaking out and prevents water, dust, and the like from entering the wheel bearing 2g from the outside of the wheel bearing 2g. The cap 105 is formed, for example, by pressing a steel plate.

[0130] The inner member 4g is press-fitted into the axle 110. Specifically, the second inner ring 82g and the first inner ring 81g are press-fitted into the axle 110 in this order. An end face of the inner member 4g (second inner ring 82g) on ​​the opposite end side (inboard side) of the axle 110 abuts against a shoulder portion 112 of the axle 110. A bolt 111 is formed at an end of the axle 110. A washer 117 is interposed between a nut 116 and the inner member 4g (first inner ring 81g). The nut 116 is fastened to the bolt 111. The inner member 4g is sandwiched between the shoulder portion 112 of the axle 110 and the washer 117. The inner member 4g is positioned in the axial direction of the axle 110 (the rotational axis direction of the wheel support bearing 2g), and a preload is applied to the wheel support bearing 2g.

[0131] In this embodiment, the heat flux sensor 60 is disposed between one row (for example, the first row rolling element 31) of the double row rolling elements 5 and another row (for example, the second row rolling element 32) of the double row rolling elements 5, as in the second embodiment. The heat flux sensor 60 is disposed between the first outer annular rolling surface 11 and the second outer annular rolling surface 12. The heat flux sensor 60 is disposed between the first inner annular rolling surface 26 and the second inner annular rolling surface 27. Therefore, a sign of an abnormality in the wheel bearing 2g that occurs in at least one of the row (for example, the first row rolling element 31) of the double row rolling elements 5 and the other row (for example, the second row rolling element 32) of the double row rolling elements 5 can be detected early.

[0132] In this embodiment, the heat flux sensor 60 is attached to the sensor case 70 using an adhesive or the like, as in the second embodiment. The sensor case 70 is inserted into a through hole 13g provided in the fixing member 120 (the inner member 4g). The through hole 13g extends in the radial direction of the fixing member 120. The through hole 13g is formed by combining a recess of the first inner ring 81g and a recess of the second inner ring 82g. Therefore, after assembling the wheel support bearing 2g, the heat flux sensor 60 can be easily incorporated into the wheel support bearing 2g by inserting the sensor case 70 into the through hole 13g.

[0133] The heat flux sensor 60 is attached to a tip 71 of the sensor case 70 proximate to the rotating member 121 (outer member 3g, hub-integrated outer ring 10g). The heat flux sensor 60 is disposed in a portion of the sensor case 70 that protrudes from the surface (for example, the outer circumferential surface of the inner member 4g (inner ring 25)) of the fixed member 120 that faces the rotating member 121 (outer member 3g, hub-integrated outer ring 10g). Therefore, the distance between the heat flux sensor 60 and the rotating member 121 (outer member 3g) is reduced. The heat flux sensor 60 can detect a change in the temperature of the wheel support bearing 2g more quickly and with higher accuracy. The heat flux sensor 60 can detect a sign of an abnormality in the wheel support bearing 2g more quickly and with higher accuracy.

[0134] The sensor case 70 includes a flange 72. The flange 72 of the sensor case 70 is disposed in a groove 114 provided in the axle 110. The flange 72 of the sensor case 70 is in contact with the inner circumferential surface of the fixed member 120 (the inner member 4g (the first inner ring 81g and the second inner ring 82g)). An elastic member (not shown) such as an O-ring may be sandwiched between the flange 72 of the sensor case 70 and the inner circumferential surface of the inner member 4g. The flange 72 of the sensor case 70 positions the heat flux sensor 60 in the radial direction of the fixed member 120 or the radial direction of the rotating member 121. Therefore, the heat flux sensor 60 can detect a change in the temperature of the wheel support bearing 2g with higher accuracy. The heat flux sensor 60 can detect a sign of an abnormality in the wheel support bearing 2g with higher accuracy.

[0135] The sensor case 70 houses a signal processing circuit (not shown) such as an electric amplifier that processes the output signal of the heat flux sensor 60. The signal processing circuit may, for example, amplify the output signal of the heat flux sensor 60. The sensor case 70 may further house a sensor such as a temperature sensor or a vibration sensor. A wiring 64 is connected to the sensor case 70. The wiring 64 passes through a groove 114 provided in the axle 110 and is drawn out to the outside of the wheel bearing 2g. An elastic member such as the O-ring already mentioned may be provided between the sensor case 70 and the surface of the through hole 13g.

[0136] Like the wheel bearing device 1a of embodiment 2, the wheel bearing device 1g further includes a judgment unit 67 (see Figure 3) that judges an abnormality in the wheel bearing 2g including the fixed member 120, the rotating member 121 and the double row rolling elements 5 based on the output of the heat flux sensor 60.

[0137] In a modification of this embodiment, the sensor case 70 may be inserted into a through hole (not shown) provided in the rotating member 121. In this case, a generator (power source) (not shown) and a wireless communication means (not shown) are installed on the rotating member 121 side, and wiring on the rotating member 121 side is eliminated. The generator may be configured, for example, by arranging a magnetic ring magnetized with alternating N and S poles on the fixed member 120 side and arranging a stator incorporating a coil on the rotating member 121 side. In addition, the heat flux sensor 60 is connected to a circuit board (not shown) equipped with a wireless communication function, and this circuit board is connected to a power source. When this power source is a generator equipped with the above-mentioned stator and magnetic ring, wiring from the stator is connected to the circuit board to supply power from the generator to the circuit board. In addition to the above-mentioned wireless communication function, the circuit board may further include a rectifier circuit that converts AC voltage from the power source into DC voltage and an amplifier circuit that amplifies a signal from the sensor.

[0138] The wheel support bearing device 1g of the present embodiment provides the same effects as the wheel support bearing device 1a of the second embodiment.

[0139] (Embodiment 9)

[0140] A wheel support bearing device 1h according to the ninth embodiment will be described with reference to Fig. 15. The wheel support bearing device 1h according to the present embodiment has a similar configuration to the wheel support bearing device 1g according to the eighth embodiment, but differs mainly in the following respects.

[0141] In the wheel support bearing device 1h, the sensor case 70 has a first inclined surface 73 and a second inclined surface 74, similar to the wheel support bearing device 1b of the third embodiment. The first inclined surface 73 faces toward one row (e.g., the first outer annular roll surface 11) of the double row annular roll surfaces (e.g., the double row outer annular roll surface 6) of the rotating member 121 (e.g., the outer member 3g). The second inclined surface 74 faces toward another row (e.g., the second outer annular roll surface 12) of the double row annular roll surfaces (e.g., the double row outer annular roll surface 6) of the rotating member 121 (e.g., the outer member 3g).

[0142] The wheel bearing device 1h includes heat flux sensors 60a and 60b, similar to the wheel bearing device 1b of the third embodiment. The heat flux sensor 60a is closer to the first row rolling elements 31 than the heat flux sensor 60b. The heat flux sensor 60a detects changes in heat flux at the first inner annular rolling surface 26, the first outer annular rolling surface 11, and the first row rolling elements 31. The heat flux sensor 60b is closer to the second row rolling elements 32 than the heat flux sensor 60a. The heat flux sensor 60b detects changes in heat flux at the second inner annular rolling surface 27, the second outer annular rolling surface 12, and the second row rolling elements 32.

[0143] The heat flux sensor 60a is attached to a first inclined surface 73 of the sensor case 70. The front surface of the heat flux sensor 60a faces toward the first outer annular raceway surface 11. The heat flux sensor 60 detects changes in heat flux on the first outer annular raceway surface 11. The heat flux sensor 60b is attached to a second inclined surface 74 of the sensor case 70. The front surface of the heat flux sensor 60b faces toward the second outer annular raceway surface 12. The heat flux sensor 60b detects changes in heat flux on the second outer annular raceway surface 12.

[0144] Like the wheel bearing device 1b of embodiment 3, the wheel bearing device 1h further includes a judgment unit 67 (see Figure 7) that judges an abnormality in the wheel bearing 2g including the fixed member 120, the rotating member 121 and the double row rolling elements 5 based on the output of the heat flux sensor 60a and the output of the heat flux sensor 60b.

[0145] In a modification of this embodiment, the sensor case 70 may be inserted into a through hole (not shown) provided in the rotating member 121. In this case, a generator (power source) (not shown) and a wireless communication means (not shown) are installed on the rotating member 121 side, and wiring on the rotating member 121 side is eliminated. The generator may be configured, for example, by arranging a magnetic ring magnetized with alternating N and S poles on the fixed member 120 side and arranging a stator incorporating a coil on the rotating member 121 side. In addition, the heat flux sensor 60 is connected to a circuit board (not shown) equipped with a wireless communication function, and this circuit board is connected to a power source. When this power source is a generator equipped with the above-mentioned stator and magnetic ring, wiring from the stator is connected to the circuit board to supply power from the generator to the circuit board. In addition to the above-mentioned wireless communication function, the circuit board may further include a rectifier circuit that converts AC voltage from the power source into DC voltage and an amplifier circuit that amplifies a signal from the sensor.

[0146] The wheel support bearing device 1h of the present embodiment has the same effects as those of the wheel support bearing devices 1b, 1g of the third and eighth embodiments.

[0147] (Embodiment 10)

[0148] A wheel support bearing device 1i according to a tenth embodiment will be described with reference to Fig. 16. The wheel support bearing device 1i according to this embodiment has a similar configuration to the wheel support bearing device 1h according to the ninth embodiment, but differs mainly in the following respects.

[0149] The wheel bearing device 1i does not include a sensor case 70. The heat flux sensor 60a is fixed to a surface of the fixed member 120 facing the rotating member 121 (for example, the outer circumferential surface of the inner member 4g (first inner ring 81g)). Specifically, the heat flux sensor 60a is provided between the first row rolling element 31 and the end of the inner member 4g (first inner ring 81g) on ​​the axial end side (outboard side) of the axle 110. The heat flux sensor 60a is provided on the outer circumferential surface of the inner member 4g (first inner ring 81g) in a portion between the first inner annular rolling surface 26c and the end of the inner member 4g (first inner ring 81g) on ​​the axial end side (outboard side) of the axle 110.

[0150] For example, when an abnormality occurs in the first outer annular roll surface 11, the first inner annular roll surface 26, or the first row rolling elements 31, heat is generated in the first outer annular roll surface 11, the first inner annular roll surface 26, or the first row rolling elements 31. For example, the temperature of the rotating member 121 rises, and a temperature difference occurs between the rotating member 121 and the fixed member 120. The heat flux sensor 60a detects the heat flux caused by the temperature difference between the fixed member 120 and the rotating member 121. The heat flux sensor 60a can quickly detect a sign of an abnormality in the first outer annular roll surface 11, the first inner annular roll surface 26, or the first row rolling elements 31.

[0151] The heat flux sensor 60b is fixed to a surface of the fixed member 120 facing the rotating member 121 (for example, the outer circumferential surface of the inner member 4g (second inner ring 82g)). Specifically, the heat flux sensor 60b is provided between the second row rolling elements 32 and the end of the inner member 4g (second inner ring 82g) on ​​the opposite axial end side (inboard side) of the axle 110. The heat flux sensor 60b is provided on the outer circumferential surface of the inner member 4g (second inner ring 82g) in a portion between the second inner annular rolling surface 27c and the end of the inner member 4g (second inner ring 82g) on ​​the opposite axial end side (inboard side) of the axle 110.

[0152] For example, when an abnormality occurs in the second outer annular rolling surface 12, the second inner annular rolling surface 27, or the second row rolling elements 32, heat is generated in the second outer annular rolling surface 12, the second inner annular rolling surface 27, or the second row rolling elements 32. For example, the temperature of the rotating member 121 rises, and a temperature difference occurs between the fixed member 120 and the rotating member 121. The heat flux sensor 60b detects the heat flux caused by the temperature difference between the fixed member 120 and the rotating member 121. The heat flux sensor 60b can quickly detect a sign of an abnormality in the second outer annular rolling surface 12, the second inner annular rolling surface 27, or the second row rolling elements 32.

[0153] The wheel support bearing device 1i, like the wheel support bearing device 1b of the third embodiment, further includes a determination unit 67 (see FIG. 7) that determines an abnormality in the wheel support bearing 2g including the fixed member 120, the rotating member 121, and the double-row rolling elements 5 based on the output of the heat flux sensor 60a and the output of the heat flux sensor 60b. The wheel support bearing device 1i includes wiring (not shown) connected to the heat flux sensors 60a and 60b. The heat flux sensors 60a and 60b may be wirelessly connected to the determination unit 67 so as to be able to communicate with each other.

[0154] A modification of this embodiment will now be described.

[0155] The wheel support bearing device 1i may include one of the heat flux sensor 60a and the heat flux sensor 60b. In this case, the wheel support bearing device 1i includes a determination unit 67 (see FIG. 3) that determines an abnormality in the wheel support bearing 2g including the fixed member 120, the rotating member 121, and the double row rolling elements 5 based on the output of one of the heat flux sensors 60a and 60b, similarly to the wheel support bearing device 1 of the first embodiment.

[0156] The heat flux sensors 60a, 60b may be provided on the inner circumferential surface of the fixed member 120 (the inner member 4g (the first inner ring 81g and the second inner ring 82g)) between the first row rolling element 31 and the second row rolling element 32. The heat flux sensors 60a, 60b may be fixed to the surface of the rotating member 121 facing the fixed member 120 (for example, the inner circumferential surface of the outer member 3g). In this case, a generator (power source) (not shown) and wireless communication means (not shown) are installed on the rotating member 121 side, and wiring on the rotating member 121 side is eliminated. The generator can be configured, for example, by arranging a magnetic ring magnetized with alternating N and S poles on the fixed member 120 side and arranging a stator with a built-in coil on the rotating member 121 side. The heat flux sensor 60 is connected to a circuit board (not shown) equipped with a wireless communication function, and this circuit board is connected to a power source. When the power source is a generator equipped with the above-mentioned stator and magnetic ring, the wiring from the stator is connected to a circuit board to supply power from the generator to the circuit board. In addition to the above-mentioned wireless communication function, the circuit board may further include a rectifier circuit that converts AC voltage from the power source into DC voltage, and an amplifier circuit that amplifies signals from the sensor.

[0157] The wheel support bearing device 1i of this embodiment has the same effects as those of the wheel support bearing device 1h of the ninth embodiment.

[0158] Various aspects of the present disclosure are summarized below as appendices. (Appendix 1) A fixing member; a rotating member rotatable relative to the fixed member; A rolling element disposed between the fixed member and the rotating member; at least one heat flux sensor; a sensor case in which the at least one heat flux sensor is mounted; The sensor case is inserted into a through hole provided in one of the fixed member and the rotating member. (Appendix 2) 2. The wheel bearing device according to claim 1, wherein the at least one heat flux sensor is disposed in a portion of the sensor case that protrudes from the one surface of the fixed member and the rotating member. (Appendix 3) the fixed member includes a double-row first annular rolling surface, the rotating member includes a double row second annular rolling surface opposing the double row first annular rolling surface, the rolling elements are double-row rolling elements in contact with the double-row first annular rolling surface and the double-row second annular rolling surface, 3. The wheel bearing device according to claim 1, wherein the at least one heat flux sensor is disposed between one row of the double row of rolling elements and another row of the double row of rolling elements. (Appendix 4) The sensor case has a first inclined surface and a second inclined surface, the first inclined surface faces toward one row of the double row annular rolling surfaces of the other of the fixed member and the rotating member, the second inclined surface faces toward another row of the double row annular rolling surfaces of the other of the fixed member and the rotating member, 4. The wheel bearing device of claim 3, wherein the at least one heat flux sensor includes a first heat flux sensor attached to the first inclined surface and a second heat flux sensor attached to the second inclined surface. (Appendix 5) A fixing member; a rotating member rotatable relative to the fixed member; A rolling element disposed between the fixed member and the rotating member; at least one heat flux sensor; one of the stationary member and the rotating member includes at least one seal; The at least one heat flux sensor is attached to the at least one seal. (Appendix 6) the fixed member includes a double-row first annular rolling surface, the rotating member includes a double row second annular rolling surface opposing the double row first annular rolling surface, the rolling elements are double-row rolling elements in contact with the double-row first annular rolling surface and the double-row second annular rolling surface, The double row rolling elements include a first row rolling element and a second row rolling element, the at least one seal includes a first seal and a second seal; the at least one heat flux sensor includes a first heat flux sensor attached to the first seal and a second heat flux sensor attached to the second seal; the first heat flux sensor is closer to the first row rolling elements than the second heat flux sensor is, The wheel bearing device according to claim 5, wherein the second heat flux sensor is closer to the second row rolling elements than the first heat flux sensor. (Appendix 7) 7. The wheel bearing device according to claim 1, further comprising a determination unit that determines an abnormality in the wheel bearing including the fixed member, the rotating member, and the rolling elements based on an output of the at least one heat flux sensor. (Appendix 8) The wheel bearing device according to claim 4 or 6, further comprising a judgment unit that judges an abnormality in the wheel bearing including the fixed member, the rotating member, and the double row rolling elements, based on a difference between an output of the first heat flux sensor and an output of the second heat flux sensor, or a difference between a rate of change per unit time of the output of the first heat flux sensor and a rate of change per unit time of the output of the second heat flux sensor.

[0159] The embodiments 1 to 10 disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present disclosure is indicated 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]

[0160] 1, 1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h, 1i wheel bearing device, 2, 2c, 2g wheel bearing, 3, 3c, 3g outer member, 4, 4c, 4g inner member, 5, 5c rolling element, 6, 6c double row outer annular rolling surface, 7, 7c double row inner annular rolling surface, 10, 10c outer ring, 10g hub integral outer ring, 11, 11c first outer annular rolling surface, 12, 12c second outer annular rolling surface, 13, 13g, 22 through hole, 14 flat surface, 17, 72 flange, 18 screw hole, 21 hub ring, 23 small diameter portion, 24 pilot portion, 25 inner ring, 26, 26c first inner annular rolling surface, 27, 27c second inner annular rolling surface, 28 Hub flange, 29, 51 Bolt hole, 30, 102, 112 Shoulder, 31, 31c First row rolling element, 32, 32c Second row rolling element, 35, 35c Cage, 40, 45 Seal, 41, 46 Core, 42, 47 Seal lip, 50 Knuckle, 55 Slinger, 60 Heat flux sensor, 60a, 60b Heat flux sensor, 64 Wiring, 66 Control unit, 67 Judgment unit, 68 Memory unit, 70 Sensor case, 71 Tip, 73 First inclined surface, 74 Second inclined surface, 81, 81g First inner ring, 82, 82g Second inner ring, 83 Inner ring spacer, 88 Annular member, 91 Rear cover, 92 Anti-rotation ring, 93 Set screw, 96, 97 Seal case, 100, 110 Axle, 101 male thread, 105 cap, 111 bolt, 114 groove, 116 nut, 117 washer, 120 fixed member, 121 rotating member.

Claims

1. A fixing member; a rotating member rotatable relative to the fixed member; A rolling element disposed between the fixed member and the rotating member; at least one heat flux sensor; a sensor case in which the at least one heat flux sensor is mounted; The sensor case is inserted into a through hole provided in one of the fixed member and the rotating member.

2. 2 . The wheel bearing device according to claim 1 , wherein the at least one heat flux sensor is disposed in a portion of the sensor case that protrudes from the one surface of the fixed member and the rotating member.

3. the fixed member includes a double-row first annular rolling surface, the rotating member includes a double row second annular roll surface opposing the double row first annular roll surface, the rolling elements are double-row rolling elements in contact with the double-row first annular rolling surface and the double-row second annular rolling surface, 2. The wheel bearing device according to claim 1, wherein the at least one heat flux sensor is disposed between one row of the double rows of rolling elements and another row of the double rows of rolling elements.

4. The sensor case has a first inclined surface and a second inclined surface, the first inclined surface faces toward one row of the double row annular rolling surfaces of the other of the fixed member and the rotating member, the second inclined surface faces toward another row of the double row annular rolling surfaces of the other of the fixed member and the rotating member, 4. The wheel bearing device according to claim 3, wherein the at least one heat flux sensor includes a first heat flux sensor attached to the first inclined surface and a second heat flux sensor attached to the second inclined surface.

5. A fixing member; a rotating member rotatable relative to the fixed member; A rolling element disposed between the fixed member and the rotating member; at least one heat flux sensor; one of the stationary member and the rotating member includes at least one seal; The at least one heat flux sensor is attached to the at least one seal.

6. the fixed member includes a double-row first annular rolling surface, the rotating member includes a double row second annular roll surface opposing the double row first annular roll surface, the rolling elements are double-row rolling elements in contact with the double-row first annular rolling surface and the double-row second annular rolling surface, The double row rolling elements include a first row rolling element and a second row rolling element, the at least one seal includes a first seal and a second seal; the at least one heat flux sensor includes a first heat flux sensor attached to the first seal and a second heat flux sensor attached to the second seal; the first heat flux sensor is closer to the first row rolling elements than the second heat flux sensor; The wheel bearing device according to claim 5 , wherein the second heat flux sensor is closer to the second row of rolling elements than the first heat flux sensor.

7. 7. The wheel bearing device according to claim 1, further comprising a determination unit that determines an abnormality in the wheel bearing including the fixed member, the rotating member, and the rolling elements based on an output of the at least one heat flux sensor.

8. 7. The wheel bearing device according to claim 4, further comprising a determination unit that determines an abnormality in the wheel bearing including the fixed member, the rotating member, and the double row rolling elements, based on a difference between an output of the first heat flux sensor and an output of the second heat flux sensor, or a difference between a rate of change per unit time of the output of the first heat flux sensor and a rate of change per unit time of the output of the second heat flux sensor.

Images