JP2020026861A - Rolling bearing device - Google Patents

Abstract

To provide a rolling bearing device for enabling a control part to function in a low-speed rotation area with quick supply of required electric power to the control part while actualizing less heat generation in a high-speed rotation area than usual one.SOLUTION: A rolling bearing device 10 includes a bearing part, a power generation part 45 having a plurality of coils 51, 52 different in power generation efficiency for generating an induction current with the rotation of a body of rotation, a control part 44 to be driven by electric power generated by the power generation part 45, and a switching part 53 for switching between the plurality of coils 51, 52 for supplying the electric power to the control part 44.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a rolling bearing device.

  The rolling bearing is supplied with a lubricant in order to prevent a problem such as seizure from occurring. In order to maintain the lubricity of the rolling bearing, a configuration in which an oil supply device is provided together with the rolling bearing has been proposed. Patent Literature 1 discloses a configuration in which a lubricating device is provided on a rolling bearing that supports a rotating shaft of a machine tool.

  In the case of Patent Document 1, an on-off valve and the like are provided as an oil supply device in addition to a tank and a pump, and a control unit controls the on-off valve. For this control, a power supply unit is required. In Patent Literature 1, a magnet is attached to a rotating spacer (rotating body), and a coil is provided corresponding to the magnet. When the magnet rotates together with the spacer, an induced current is generated in the coil, and power is generated. The generated power is used for controlling the on-off valve and the like.

JP 2013-92238 A

  FIG. 7 is an explanatory diagram showing the relationship between the power generated by the power generation unit having the magnet and the coil as described above and the rotation speed of the rotating body (the spacer in the case of Patent Document 1). The generated power increases as the rotation speed increases.

  In FIG. 7, when the rotation speed is low, it is not possible to obtain power Pn required for the operation of the control unit (hereinafter, referred to as “required power Pn”). However, when the rotation speed exceeds Q, the power generated by the coil exceeds the required power Pn. The control unit can operate as long as the necessary power Pn is supplied. When the number of revolutions further increases and the power generation unit generates power exceeding the required power Pn, the power (electric energy) corresponding to the difference (ΔPu) between the generated power Pm and the required power Pn becomes the control unit (control board) or the like. Is consumed by the heat generated by the electronic components included in the device. If the state where the rotation speed is high continues, there is a possibility that the risk of failure of the electronic component may increase due to heat generation of the control unit.

  Therefore, it is considered that if the power generation efficiency of the coil is reduced, power is not generated uselessly in the high-speed rotation range, and heat generation can be suppressed. However, when the power generation efficiency of the coil is set to be low, the generated power cannot exceed the required power Pn unless the rotation speed is increased to some extent in the low-speed rotation region, and there is a problem that the control unit does not function.

  Therefore, the present invention enables the control unit to function quickly by supplying the necessary power to the control unit even in the low-speed rotation range, and also makes it possible to suppress the generation of heat in the high-speed rotation range as compared with the related art. It is an object to provide a rolling bearing device.

  The rolling bearing device of the present invention is provided with a plurality of cylindrical fixed bodies, a cylindrical rotating body provided radially inward or outward of the fixed body, and a plurality of rolling bearings provided between the rotating body and the fixed body. A bearing unit having a rolling element, and a power generation unit having a plurality of coils provided between the fixed body and the rotating body and having different power generation efficiencies for generating an induced current by rotation of the rotating body with respect to the fixed body. A control unit that operates with the power generated by the power generation unit; and a switching unit that switches a coil that supplies power to the control unit between the plurality of coils.

  According to this rolling bearing device, in the low-speed rotation range, the coil that supplies power to the control unit is selected so as to be a coil having high power generation efficiency. On the other hand, in the high-speed rotation range, the coil that supplies power to the control unit is selected so as to be a coil with low power generation efficiency. This allows the control unit to function quickly by supplying the necessary power to the control unit even in the low-speed rotation range.In addition, since the power generation efficiency is low in the high-speed rotation range, it is possible to suppress heat generation more than before. It becomes possible.

  In addition, the rolling bearing device includes a sensor that detects a rotation speed of the rotating body, and the switching unit switches a coil that supplies power to the control unit between the plurality of coils based on a detection result of the sensor. Is preferred. According to this configuration, it is possible to switch the coils at the required number of rotations.

  Further, it is preferable that the power generation efficiency differs between the plurality of coils due to the difference in the number of coil turns. According to this configuration, it is easy to make the power generation efficiency different between the plurality of coils.

  Further, at the timing when the power generation voltage of the coil with low power generation efficiency can exceed the required voltage of the control unit, the switching unit switches from the coil with high power generation efficiency to the coil with low power generation efficiency. Is preferred. According to this configuration, it is possible to further enhance the function of suppressing heat generation in the high-speed rotation range as compared with the related art.

  ADVANTAGE OF THE INVENTION According to the rolling bearing device of this invention, it becomes possible to supply a required electric power to a control part quickly even in a low-speed rotation area, and to function a control part. It is possible to suppress heat generation more.

It is sectional drawing which shows an example of a rolling bearing device. It is sectional drawing which looked at the inner ring spacer, the lubrication unit, and the outer ring spacer from the axial direction. It is a perspective view of an inner ring spacer. It is a block diagram of a rolling bearing device. It is a flowchart explaining operation | movement which switches the coil which supplies electric power to a control part. FIG. 4 is an explanatory diagram illustrating a relationship between a voltage generated by a power generation unit and a rotation speed of a rotating body. FIG. 4 is an explanatory diagram illustrating a relationship between power generated by a power generation unit having a magnet and a coil, and a rotation speed of a rotating body.

[Overall rolling bearing device]
FIG. 1 is a sectional view showing an example of the rolling bearing device. Although not shown, a rolling bearing device 10 (hereinafter, also referred to as a “bearing device 10”) shown in FIG. 1 rotatably supports a shaft of a spindle device of a machine tool, and is provided inside a bearing housing of the spindle device. Is housed in Note that the rolling bearing device of the present invention is applicable to other than machine tools. In the following description, a direction parallel to the center line C of the bearing device 10 is referred to as an “axial direction”, and a direction orthogonal to the axial direction is referred to as a “radial direction”.

  The bearing device 10 illustrated in FIG. 1 includes a bearing unit 20 and a refueling unit 40. The bearing portion 20 has an inner ring 21, an outer ring 22, a plurality of balls (rolling elements) 23, and a retainer 24 for holding the plurality of balls 23, and constitutes a ball bearing (rolling bearing). Further, the bearing device 10 includes a cylindrical inner race spacer 17 and a cylindrical outer race spacer 18.

  The refueling unit 40 has a ring shape as a whole, and is provided adjacent to the bearing 20 in the axial direction. The refueling unit 40 of the present embodiment is provided radially inward of the outer race spacer 18 and is located axially adjacent to the annular space 11 formed between the inner race 21 and the outer race 22. 11 has a function of supplying lubricating oil. The configuration and function of the refueling unit 40 will be described later. Although not shown, the refueling unit 40 (a main body 41 to be described later) and the outer race spacer 18 may be integrated, and the refueling unit 40 may have a function as an outer race spacer.

  In the present embodiment, the outer race 22 and the outer race spacer 18 are attached to the bearing housing, and the inner race 21 and the inner race spacer 17 rotate together with the shaft. The inner race 21 is a cylindrical member that fits around the shaft, and has a track (hereinafter referred to as “inner race track 25”) formed on the outer periphery thereof. In the present embodiment, the inner race 21 and the inner race spacer 17 are separate bodies, but they are not shown, but they may be integrated (integrally inseparable). The inner ring 21 and the inner ring spacer 17 form a cylindrical rotating body 61. The outer ring 22 is a cylindrical member fixed to the inner peripheral surface of the bearing housing 8, and a track (hereinafter, referred to as “outer ring track 26”) is formed on the inner circumference thereof. In the present embodiment, the outer race 22 and the outer race spacer 18 are separate bodies, but they are not shown, but they may be integrated (integrally inseparable). The outer ring 22 and the outer ring spacer 18 constitute a cylindrical fixed body 62.

  The ball 23 is interposed between the inner race 21 and the outer race 22 and rolls on the inner raceway 25 and the outer raceway 26. The retainer 24 is annular, and a plurality of pockets 27 for accommodating the balls 23 are formed along the circumferential direction. The ball 23 and the retainer 24 are provided in the annular space 11.

  FIG. 2 is a cross-sectional view of the inner race spacer 17, the oil supply unit 40, and the outer race spacer 18 as viewed from the axial direction. The refueling unit 40 of the present embodiment includes a tank 42, a pump 43, a control unit 44, a power generation unit 45, and a sensor 39. These are provided on an annular main body 41 of the refueling unit 40. The main body 41 is attached to the inner peripheral side of the outer race spacer 18 and has a function as a frame for holding the pump 43 and the like. The main body 41 is an annular member, but has a hollow space formed therein, in which a tank 42, a pump 43, a control unit 44, a power generation unit 45, and a sensor 39 are provided.

  The tank 42 is for storing lubricating oil (oil), and is connected to the pump 43 through a pipe 46 for flowing the lubricating oil to the pump 43. 1, the pump 43 has a function of supplying lubricating oil to the annular space 11 of the bearing unit 20. In order to exhibit this function, the pump 43 has an ejection port (nozzle) 50 for discharging lubricating oil. The pump 43 has an oil chamber (internal space) 43b that is connected to the ejection port 50 and stores lubricating oil, and a piezoelectric element 43a. When a voltage is applied to the piezoelectric element 43a and the piezoelectric element 43a operates, the volume of the oil chamber 43b changes. As a result, the pump 43 sends the lubricating oil in the oil chamber 43b from the ejection port 50 to the annular space of the bearing portion 20. 11 can be discharged. In particular, when the piezoelectric element 43a operates, the lubricating oil is discharged from the ejection port 50 as an oil droplet at an initial velocity. That is, the oil droplet flies from the ejection port 50. The spout 50 is open toward the inner raceway 25 of the bearing 20, and even if the oil droplets discharged from the spout 50 hit the ball 23 or pass between adjacent balls 23, 23. The inner raceway 25 can be hit.

  2, the control section 44 has a function of controlling the operation of the pump 43. The power generation unit 45 is provided between the inner race spacer 17 and the outer race spacer 18. The power generation unit 45 generates an induced current when the inner ring 21 and the inner ring spacer 17 rotate to generate power. For this purpose, as will be described later, the power generation unit 45 has coils 51 and 52. The power generation unit 45 supplies the generated power to the control unit 44 and the sensor 39 as power for the operation.

  The voltage applied to the pump 43 is output from the control unit 44. That is, the power required to operate the control unit 44 includes the power required to operate the pump 43. The electric power required to operate the control unit 44 is referred to as “required voltage”. The required voltage is a voltage at which the control unit 44 can operate, and thus is also referred to as a driving start voltage. The power generation unit 45 generates power by rotation of the bearing unit 20 as will be described later. The generated power is supplied to the control unit 44 and the like, and the control unit 44 operates using the power generated by the power generation unit 45. The control unit 44 is configured by a circuit having a microcomputer and the like, and also includes a rectifier circuit for rectifying the generated current of the power generation unit 45 and the like.

  As described above, the pump 43 is configured to eject (fly) the lubricating oil in the tank 42 (the oil chamber 43b) from the ejection port 50 as an oil droplet toward the target of the bearing unit 20. From the viewpoint of efficient use of the lubricating oil, the pump 43 ejects a predetermined amount of oil droplets in one discharge operation, and the oil droplets reach the target of the bearing unit 20. By one operation of the pump 43, several picoliters to several nanoliters of lubricating oil is ejected from the ejection port 50 as an oil droplet P. The targets in the present embodiment are the ball 23 and the inner raceway 25.

[Description of Configuration of Power Generation Unit 45 and the Like]
FIG. 3 is a perspective view of the inner ring spacer 17. The inner ring spacer 17 is provided with a plurality of magnets 55 at intervals along the circumferential direction. In FIG. 2, a first coil 51 and a second coil 52 are provided on the outer race spacer 18. The first coil 51 and the second coil 52 are arranged so as to radially oppose a magnet 55 provided side by side at intervals in the circumferential direction. As the inner race spacer 17 rotates in one direction, each of the first coil 51 and the second coil 52 approaches and separates from each of the plurality of magnets 55, and this approach and separation are repeated. Thereby, an induced current is generated in each of the first coil 51 and the second coil 52 (power generation is performed).

  FIG. 4 is a block diagram of the bearing device 10. The power generation unit 45 including the first coil 51 and the second coil 52 is electrically connected to the control unit 44 via the switching unit 53. The power generated by the power generation unit 45 is supplied to the control unit 44 through the switching unit 53. The switching unit 53 is configured by a circuit including a switch unit (SW1, SW2). The switching unit 53 has a function of switching a coil that supplies power to the control unit 44 between the two coils 51 and 52. That is, the switching unit 53 selects one of the coils for supplying the generated voltage to the control unit 44 from the first coil 51 and the second coil 52. The operation of switching the coil that supplies power to the control unit 44 is referred to as a “switching operation”. The switching operation in the switching unit 53 is based on a command signal from the control unit 44. The first switch unit SW1 is connected in series with the first coil 51, the second switch unit SW2 is connected in series with the second coil 52, and these are connected in parallel to the control unit 44. .

  The first coil 51 and the second coil 52 have different power generation efficiencies. More specifically, the first coil 51 has a larger number of coil turns than the second coil 52. For this reason, the first coil 51 has higher power generation efficiency (power generation performance) than the second coil 52. That is, even when the rotating body 61 rotates at the same rotation speed, the generated voltage of the first coil 51 becomes higher than the generated voltage of the second coil 52. In the embodiment shown in FIG. 2, the first coil 51 and the second coil 52 are arranged side by side in the circumferential direction. However, the arrangement of these coils 51 and 52 may be an arrangement other than that shown in the drawing. A magnetic force is generated between each of the coils 51 and 52 and the inner race spacer 17 having the magnet 55, and this magnetic force tends to displace the inner race spacer 17 (the shaft on which the inner race spacer 17 is fitted) in the radial direction. . Therefore, in order to suppress the eccentricity due to the displacement of the inner race spacer 17 (the shaft) due to the magnetic force, although not shown, the first coil 51 and the second coil 52 are 180 ° with respect to the center line C. Preferably, they are provided separately.

  As described above, the coil for supplying power to the control unit 44 is switched between the two coils 51 and 52 by the switching unit 53. For this purpose, in the present embodiment, the bearing device 10 includes a sensor 39 that detects the rotation speed of the rotating body 61 (the inner ring spacer 17). The sensor 39 is a non-contact type sensor, for example, has a configuration including a semiconductor MR element, and detects the inner race spacer 17 having the magnet 55 as a detection target. While the rotation speed detected by the sensor 39 is equal to or lower than a required value (threshold), as shown in FIG. 4, the first switch SW1 of the switching unit 53 is in the ON state, and the second switch SW2 is OFF. State. Therefore, the coil that supplies power to the control unit 44 is the first coil 51. When the rotation speed detected by the sensor 39 exceeds a required value (threshold), the first switch unit SW1 of the switching unit 53 switches to the off state, and the second switch unit SW2 switches to the on state. Thereby, the coil that supplies power to the control unit 44 is switched from the first coil 51 to the second coil 52. As described above, the switching unit 53 switches the coil that supplies power to the control unit 44 between the two coils 51 and 52 based on the detection result of the sensor 39.

  The operation of the bearing device 10 having the above configuration will be described. FIG. 5 is a flowchart illustrating an operation of switching a coil that supplies power to the control unit 44. FIG. 6 is an explanatory diagram showing the relationship between the voltage generated by the power generation unit 45 and the number of rotations of the rotating body 61.

  When the rotating body 61 starts rotating, in the switching unit 53, the first switch unit SW1 is on and the second switch unit SW2 is off (see FIG. 4). When the rotating body 61 starts rotating, the induced current generated in the first coil 51 is supplied to the control unit 44. However, as shown in FIG. 6, the control unit 44 cannot operate until the voltage generated by the first coil 51 exceeds the required voltage Vn of the control unit 44. When the rotation speed of the rotating body 61 exceeds Q1, the voltage generated by the first coil 51 exceeds the required voltage Vn of the control unit 44. Then, the control unit 44 becomes operable.

  The rotation speed of the rotating body 61 is detected by the sensor 39 (Step S1 in FIG. 5). If the rotation speed of the rotating body 61 is lower than Q2 (threshold value Q2) even if it becomes higher than Q1 ("Yes" in step S2 of FIG. 5), the first switch SW1 is turned on and the second switch SW2 is turned off. Is maintained (step S3 in FIG. 5).

  When the sensor 39 detects that the rotation speed of the rotating body 61 has exceeded the threshold value Q2 (“No” in step S2 of FIG. 5), the switching unit 53 switches off the first switch unit SW1 and turns off the second switch unit SW1. The switch SW2 is turned on (step S4 in FIG. 5). In FIG. 6, when the rotation speed of the rotating body 61 is the threshold value Q2, the voltage generated by the first coil 51 is V1, but the voltage generated by the second coil 52 is V2 lower than V1. (V1> V2). This is because the second coil 52 is configured to have lower power generation efficiency than the first coil 51. However, the generated voltage V2 by the second coil 52 immediately after the switching is higher than the required voltage Vn. For example, when the rotation speed of the rotating body 61 is the threshold value Q2, the generated voltage V2 of the second coil 52 is higher than the required voltage Vn and less than 110% of the required voltage Vn (Vn <V2 <Vn × 1). .1). Thus, in the present embodiment, at the timing when the power generation voltage of the second coil 52 having low power generation efficiency is estimated to exceed the required voltage Vn, that is, at the timing when the rotation speed exceeds Q2, the power generation efficiency is high. The switching unit 53 switches from one coil 51 to a second coil 52 with low power generation efficiency.

  In the high rotation region where the rotation speed of the rotating body 61 is higher than the threshold value Q2, the state where the first switch unit SW1 is off and the second switch unit SW2 is on is continued. Then, when the rotation speed of the rotating body 61 is in a low rotation region equal to or less than the threshold value Q2, the switching unit 53 turns on the first switch unit SW1 and turns off the second switch unit SW2.

  Here, if the power generation efficiency of the first coil 51 is the same as the power generation efficiency of the second coil 52, the relationship between the voltage generated by the first coil 51 and the rotation speed is one point in FIG. It is as shown by the straight line indicated by the chain line. In this case, the voltage generated by the first coil 51 cannot exceed the required voltage Vn until the rotation speed becomes higher than Q1 (instead of Q1 in the above embodiment). However, in the present embodiment, the first coil 51 has higher power generation efficiency than the second coil 52. Therefore, when the rotation speed reaches Q1, as shown by the solid line in FIG. 6, the voltage generated by the first coil 51 can exceed the required voltage Vn. That is, even in the low-speed rotation range, it becomes possible to quickly supply the necessary power to the control unit 44 and make the control unit 44 function.

  Further, a case where the switching operation is not performed in the switching unit 53 will be described. That is, this is a case where the generated voltage of the first coil 51 is continuously supplied to the control unit 44. In this case, the relationship between the voltage generated by the first coil 51 and the number of rotations is as shown by the two-dot chain line in FIG. In this case, the difference between the voltage V3 'generated by the power generation unit 45 (first coil 51) at the rotation speed Q3 included in the high-speed rotation region and the required voltage Vn is ΔVu. On the other hand, as in the present embodiment, when the switching operation is performed in the switching unit 53 and the generated voltage of the second coil 52 is supplied to the control unit 44 in the high-speed rotation range, the switching speed at the rotation speed Q3 is reduced. The difference between the voltage V3 generated by the power generation unit 45 (second coil 52) and the required voltage Vn is ΔVw smaller than ΔVu (ΔVu> ΔVw). Electric energy corresponding to the difference between the voltage generated by the power generation unit 45 and the required voltage Vn is consumed when the electronic components included in the control unit 44 generate heat. In the present embodiment, since the difference ΔVw is small, heat generation is suppressed even in a high-speed rotation range.

  As described above, the bearing device 10 of the present embodiment includes the power generation unit 45 that generates and generates an induced current by the rotation of the rotating body 61 with respect to the fixed body 62, the control unit 44 that operates with the generated power of the power generation unit 45, A switching unit 53. The power generation unit 45 includes a first coil 51 and a second coil 52 having different power generation efficiencies. The switching unit 53 switches a coil that supplies power to the control unit 44 between the two coils 51 and 52. According to the bearing device 10, in the low-speed rotation range, the coil that supplies power to the control unit 44 is selected to be the first coil 51 with high power generation efficiency. On the other hand, in the high-speed rotation range, the coil that supplies power to the control unit 44 is selected to be the second coil 52 with low power generation efficiency. Thus, as described with reference to FIG. 6, it is possible to quickly supply the necessary power to the control unit 44 in the low-speed rotation range (the rotation speed Q1) and make the control unit 44 function. Then, in the high-speed rotation region, the switching to the second coil 52 having low power generation efficiency is performed, so that heat generation can be suppressed as compared with the related art.

  In the present embodiment, a sensor 39 for detecting the number of rotations of the rotating body 61 is provided. Therefore, the switching unit 53 switches the coil that supplies power to the control unit 44 between the two coils 51 and 52 based on the detection result of the sensor 39. With this configuration, it is possible to switch between the coils 51 and 52 at a required rotation speed (threshold value Q2). The switching between the coils 51 and 52 may be performed by means other than the means based on the rotation speed. For example, when the voltage at which the second coil 52 can generate power exceeds the required voltage Vn, the coil that supplies power to the control unit 44 may be switched from the first coil 51 to the second coil 52. In this case, a sensor that detects the voltage generated by the power generation unit 45 (second coil 52) is provided instead of the sensor 39 that detects rotation.

  In the present embodiment, the first coil 51 and the second coil 52 have different power generation efficiencies due to different numbers of coil turns. According to this configuration, it is easy to make the power generation efficiency different between the first coil 51 and the second coil 52. In order to make the power generation efficiency different between the two coils 51 and 52, means other than the means for making the number of coil turns different may be used.

  As described with reference to FIG. 6, in the present embodiment, at the timing when the power generation voltage of the second coil 52 having a low power generation efficiency can exceed the required voltage of the control unit 44, the first power generation efficiency having a high power generation efficiency is obtained. The switching unit 53 switches from the coil 51 to the second coil 52 with low power generation efficiency. That is, the first coil 51 is used until the generated voltage of the second coil 52 exceeds the required voltage Vn. For this reason, in the high-speed rotation region, it is possible to suppress the unnecessary generation of the power greatly exceeding the required voltage Vn, and it is possible to further enhance the function of suppressing heat generation as compared with the related art.

[Modifications]
In the bearing device 10 of the embodiment (see FIG. 1), the inner race 21 and the inner race spacer 17 are a rotating body 61, and the outer race 22 and the outer race spacer 18 are a fixed body 62. Alternatively, the inner ring 21 and the inner ring spacer 17 may be the fixed body 62, and the outer ring 22 and the outer ring spacer 18 may be the rotating body 61 (not shown). Further, the rolling element may be a cylindrical roller, a tapered roller, or the like other than the ball 23. Further, for example, the arrangement of the magnet 55, the inner ring spacer 17 and the like may be in a form other than that illustrated, and the power generation unit 45 may have a configuration other than that illustrated.

  In the embodiment, the first coil 51 functions as a low-speed coil, and the second coil 52 functions as a high-speed coil. The power generation unit 45 may include three or more coils. For example, when the power generation unit 45 has three coils, the first coil functions as a low-speed coil, the second coil functions as a high-speed coil, and the third coil functions as a medium-speed coil. The second coil (high-speed coil) has lower power generation efficiency than the first coil (low-speed coil). The third coil (medium-speed coil) has lower power generation efficiency than the first coil (low-speed coil), but has higher power generation efficiency than the second coil (high-speed coil). Then, at the first switching speed (first threshold), the coil that supplies power to the control unit 44 is switched from the first coil to the third coil, and the second switching speed is higher than the first switching speed. At the switching speed (second threshold value), the coil that supplies power to the control unit 44 can be switched from the third coil to the second coil. As described above, the number of coils included in the power generation unit 45 may be two or more, and may be four instead of three.

  The embodiments disclosed above are illustrative in all aspects and not restrictive. That is, the rolling bearing device of the present invention is not limited to the illustrated embodiment, but may be another embodiment within the scope of the present invention.

10: Rolling bearing device 20: Bearing part 23: Ball (rolling element)
39: sensor 44: control unit 45: power generation unit 51: first coil 52: second coil 53: switching unit 61: rotating body 62: fixed body Vn: required voltage

Claims (4)

A bearing having a cylindrical fixed body, a cylindrical rotating body provided radially inward or outward of the fixed body, and a plurality of rolling elements provided between the rotating body and the fixed body. When,
A power generation unit having a plurality of coils provided between the fixed body and the rotating body and having different power generation efficiencies for generating an induced current by rotation of the rotating body with respect to the fixed body;
A control unit that operates on the power generated by the power generation unit;
A switching unit that switches a coil that supplies power to the control unit between the plurality of coils,
A rolling bearing device comprising: A sensor for detecting a rotation speed of the rotating body,
The rolling bearing device according to claim 1, wherein the switching unit switches a coil that supplies power to the control unit between the plurality of coils based on a detection result of the sensor. The rolling bearing device according to claim 1, wherein the power generation efficiency is different among the plurality of coils due to a difference in the number of coil turns.
Receiving device.   The power generation voltage of the coil with low power generation efficiency is switched by the switching unit from the coil with high power generation efficiency to the coil with low power generation efficiency at a timing when it is possible to exceed the required voltage of the control unit. The rolling bearing device according to any one of Items 1 to 3.

Images