JP7114992B2 - rotating device - Google Patents

Description

The present invention relates to rotating devices.

Patent Literature 1 and Patent Literature 2 describe a bearing equipped with a sensor that detects various physical quantities around the bearing with a sensor and wirelessly transmits the detected information to a receiving device.

Japanese Patent Application Laid-Open No. 2003-307435 JP 2016-130577 A

In the sensor-equipped bearing, electric power generated by the power generation unit is supplied to the sensor and communication circuit. If the power supplied to the sensor or communication circuit is insufficient, the sensor or communication circuit may operate abnormally or stop operating at an unintended timing.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a rotating device capable of preventing malfunction due to power shortage.

A rotating device of this aspect is a rotating device having a first part and a second part that relatively rotate about a rotation axis, and based on the relative rotation of the first part and the second part, A power generation unit that generates power, a rechargeable power storage unit that is charged with the power generated by the power generation unit, a sensor, power stored in the power storage unit, and data detected by the sensor are supplied. and a voltage monitoring unit that monitors the voltage of the power storage unit, the voltage monitoring unit having a voltage monitoring circuit that transmits a signal based on the voltage of the power storage unit to the control unit.

According to this, the control unit can shift from the normal mode to the sleep mode before power shortage occurs. As a result, the rotating device can prevent the controller from malfunctioning due to power shortage. Further, for example, if a reset IC is used in the voltage monitoring circuit, power consumption for voltage monitoring can be reduced.

As a desirable aspect, the control unit includes a communication circuit that transmits the data to the outside, and a control circuit that controls the communication circuit, and the voltage monitoring circuit controls the voltage of the power storage unit to be equal to or lower than a first threshold. Then, a first signal is transmitted to the control circuit, and when the control circuit receives the first signal, the communication circuit stops transmitting the data to the outside. According to this, the control circuit and the communication circuit can shift from the normal mode to the sleep mode before power shortage occurs.

Preferably, the voltage monitoring circuit transmits a second signal to the control circuit when the voltage of the power storage unit becomes equal to or higher than a second threshold higher than the first threshold, and the control circuit transmits the second signal. Upon receipt, the communication circuitry begins transmitting the data out. According to this, in the rotating device, the control circuit and the communication circuit can return from the sleep mode to the normal mode when the electric storage unit is charged to the predetermined voltage.

Desirably, the control unit further includes a memory circuit for storing the data, the control circuit controls the memory circuit, and when the control circuit receives the first signal, the control circuit controls the Stop writing data to the storage circuit. According to this, the rotating device can prevent power shortage while the control circuit is writing data to the storage circuit.

Preferably, the voltage monitoring circuit transmits a second signal to the control circuit when the voltage of the power storage unit becomes equal to or higher than a second threshold higher than the first threshold, and the control circuit transmits the second signal. Upon receipt, the control circuit initiates writing of the data to the storage circuit. According to this, the rotating device can prevent power shortage while the control circuit is writing data to the storage circuit.

As a desirable aspect, the voltage monitoring circuit has a first voltage monitoring circuit that transmits the first signal and a second voltage monitoring circuit that transmits the second signal. According to this, the control section can shift from the normal mode to the sleep mode based on the first signal output by the first voltage monitoring circuit. Also, based on the second signal output by the second voltage monitoring circuit, the control unit can return from the sleep mode to the normal mode.

As a desirable aspect, the output control circuit further comprises an output control circuit for controlling supply of electric power from the power storage unit to the control unit based on the voltage of the power storage unit, wherein the output control circuit controls the voltage of the power storage unit to be equal to the first voltage. When the voltage of the power storage unit is equal to or greater than a third threshold value lower than two thresholds, power supply from the power storage unit to the control unit is turned on, and when the voltage of the power storage unit is less than the third threshold value, the power storage unit controls the control unit. Turn off power to the unit. According to this, the rotating device can stop the supply of electric power to the control unit before the voltage of the power storage unit becomes zero.

As a desirable aspect, the sensor has a first sensor and a second sensor whose detection target is different from that of the first sensor. According to this, the rotating device can output more useful data.

ADVANTAGE OF THE INVENTION According to this invention, the rotation apparatus which can prevent the malfunction by power shortage can be provided.

FIG. 1 is a perspective view of a sensor-equipped bearing according to this embodiment. FIG. 2 is an exploded perspective view of the sensor-equipped bearing of this embodiment. FIG. 3 is a cross-sectional view of a portion of the sensor-equipped bearing according to the present embodiment, which includes a power generating portion and a convex portion. FIG. 4 is a cross-sectional view of a portion of the sensor-equipped bearing according to the present embodiment, which includes the power generating portion and the recess. FIG. 5 is a cross-sectional view of a portion of the sensor-equipped bearing of the present embodiment, including the sensor substrate. FIG. 6 is an explanatory diagram for explaining the relationship between the voltage of the electromotive force and time in the sensor-equipped bearing of this embodiment. FIG. 7 is a plan view of the sensor unit of this embodiment. FIG. 8 is a perspective view of the cover of this embodiment. FIG. 9 is a diagram showing an example of an output signal waveform of the angle sensor of this embodiment. FIG. 10 is a diagram showing a configuration example of a circuit mounted on the substrate of the sensor-equipped bearing according to this embodiment. FIG. 11 is a graph schematically showing an example of voltage change of the power storage unit of the present embodiment. FIG. 12 is a flow chart showing an example of the operation sequence of the circuit mounted on the substrate of the sensor-equipped bearing of this embodiment. FIG. 13 is a diagram schematically showing the relationship between the operating period of the circuit mounted on the substrate of the sensor-equipped bearing according to the present embodiment and the power consumption of the CPU. FIG. 14 is a graph showing an example of temporal changes in the number of rotations of the sensor-equipped bearing.

Modes (embodiments) for carrying out the invention will be described in detail with reference to the drawings. The present invention is not limited by the contents described in the following embodiments. In addition, the components described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the components described below can be combined as appropriate.

FIG. 1 is a perspective view of a sensor-equipped bearing according to this embodiment. FIG. 2 is an exploded perspective view of the sensor-equipped bearing of this embodiment. FIG. 3 is a cross-sectional view of a portion of the sensor-equipped bearing according to the present embodiment, which includes a power generating portion and a convex portion. FIG. 4 is a cross-sectional view of a portion of the sensor-equipped bearing according to the present embodiment, which includes the power generating portion and the recess. FIG. 5 is a cross-sectional view of a portion of the sensor-equipped bearing of the present embodiment, including the sensor substrate. The sensor-equipped bearing 1 shown in FIG. 1 has a sensor unit 5, a tone ring 30, and a bearing main body 20, as shown in FIG.

As shown in FIGS. 3 to 5, the bearing body 20 is a rolling bearing having an outer ring 21, an inner ring 22, and rolling elements 23. As shown in FIGS. The outer ring 21 and the inner ring 22 relatively rotate around the rotation axis Ax (see FIG. 1). In the following description, the inner ring 22 is assumed to be a rotating ring.

The cover 10 has an annular top plate 12 and a cylindrical side plate 11 connected around the top plate 12 . The cover 10 is made of a magnetic material such as silicon steel plate, carbon steel (JIS SS400 or S45C), martensitic stainless (JIS SUS420) or ferritic stainless (JIS SUS430).

As shown in FIG. 2 , in the sensor unit 5 , a plurality of power generation units 3 and a substrate 40 are attached to one surface 12A of the top plate 12 . One surface 12A is a surface facing the bearing main body 20 . The board 40 has a power supply board 41 and a sensor board 42 .

For example, as shown in FIGS. 1 and 2 , the power generation unit 3 is fixed to the top plate 12 by fastening bolts 19</b>A made of a non-magnetic material such as brass to female screw holes drilled in the top plate 12 . Similarly, the power board 41 and the sensor board 42 are fixed to the top plate 12 by fastening bolts 19B made of a non-magnetic material such as brass to female screw holes drilled in the top plate 12 . As shown in FIG. 1 , the bolts 19A and 19B have lengths that do not protrude from the cover 10 when attached to the cover 10 .

The tone ring 30 is provided with convex portions 31 protruding radially outward and concave portions 32 concave radially inward from the convex portions 31 alternately arranged in the circumferential direction. The tone ring 30 has a cylindrical protrusion 33 protruding toward the bearing body 20 on its inner peripheral side. The tone ring 30 is made of a magnetic material such as silicon steel plate, carbon steel (JIS standard SS400 or S45C), martensitic stainless steel (JIS standard SUS420) or ferritic stainless steel (JIS standard SUS430). .

The power generation section 3 has a permanent magnet 13 , a yoke 14 and a coil 15 . A permanent magnet 13 is fixed so as to be in contact with the top plate 12 . Yoke 14 is fixed so as to be in contact with permanent magnet 13 . The yoke 14 may be magnetically connected to the permanent magnet 13, and may not be directly connected. The yoke 14 is made of a magnetic material such as a silicon steel plate or NiFe alloy. It is desirable that the yoke 14 be made of a material having a magnetic permeability equal to or higher than that of the cover 10 so that the amount of magnetic flux inside the yoke 14 increases. If the yoke 14 is made of a silicon steel plate, the magnetic permeability will be high and the magnetic flux will easily pass through the yoke 14 .

The coil 15 is a so-called magnet wire in which a conducting wire is wound around the yoke 14 . The coils 15 of adjacent power generation units 3 are connected in series, and wires drawn out from the coils 15 of the plurality of power generation units 3 connected in series are connected to the power supply substrate 41 .

As shown in FIG. 3, one end of the side plate 11 is fitted into a groove 21A provided on the outer periphery of the outer ring 21 and fixed. The tubular projection 33 is fitted and fixed in a groove 22A provided on the inner circumference of the inner ring 22 . As a result, as shown in FIGS. 3 and 4, the inner peripheral end face of the yoke 14 and the inner peripheral end face of the top plate 12 are arranged at positions facing the convex portion 31 or the concave portion 32 of the tone ring 30 . Also, the cover 10 and the tone ring 30 can be easily attached to the bearing body 20 .

The magnetic field of the permanent magnet 13 causes the magnetic flux Mf to pass through the yoke 14 , the convex portion 31 or concave portion 32 of the tone ring 30 , and the top plate 12 of the cover 10 . Therefore, the permanent magnet 13, the yoke 14, the convex portion 31 or concave portion 32 of the tone ring 30, and the top plate 12 of the cover 10 form a magnetic circuit.

Further, as shown in FIG. 5, a magnetic body 311 exhibiting stronger magnetism than the tone ring 30 is attached to a part of the outer peripheral side end face 31IF of the projection 31 . For example, a concave portion corresponding to the shape and size of the magnetic body is provided on the outer peripheral side end surface 31IF of the convex portion 31 . The magnetic body 311 is fitted in this recess. The magnetic body 311 and the outer peripheral side end face 31IF around the magnetic body 311 are flush or substantially flush. The magnetic body 311 is, for example, a hard magnetic permanent magnet. In the tone ring 30, the magnetic body 311 is attached to only one location. The magnetic body 311 comes closest to the angle sensor 443 each time the inner ring 22 makes one relative rotation (360° rotation) with respect to the outer ring 21 . Angle sensor 443 includes, for example, a Hall element.

FIG. 6 is an explanatory diagram for explaining the relationship between the voltage of the electromotive force and time in the sensor-equipped bearing of this embodiment. Here, the horizontal axis of FIG. 6 is the time T, and the vertical axis is the voltage Vi of the electromotive force. When the outer ring 21 is fixed and the inner ring 22 rotates, the tone ring 30 rotates together with the inner ring 22, and the tone ring 30 and the power generating section 3 rotate relative to each other. For the yoke 14, an air gap from the inner peripheral end surface to the outer peripheral end surface 31IF of the protrusion 31 shown in FIG. 3, an air gap from the inner peripheral end surface to the outer peripheral end surface 32IF of the recessed portion 32 shown in FIG. are alternately replaced.

In this manner, the distance between the yoke 14 of the power generating section 3 and the outer circumference of the tone ring 30 changes periodically due to the protrusions 31 and the recesses 32 on the outer circumference of the tone ring 30 . As a result, the density of the magnetic flux Mf generated in the power generation section 3 changes. When the yoke 14 with the permanent magnet 13 and the tone ring 30 are close to each other, the magnetic flux Mf passing through the permanent magnet 13, the yoke 14 and the tone ring 30 is large, and the yoke 14 and the tone ring 30 are separated. , the magnetic flux Mf passing through the permanent magnet 13, yoke 14, and tone ring 30 is reduced. A voltage change occurs in the coil 15 in which the magnet wire is wound around the yoke 14 according to the density change of the magnetic flux Mf.

That is, when the yoke 14 and the outer peripheral end surface 31IF of the protrusion 31 are closest to each other, the magnetic flux Mf shown in FIG. 3 increases, and the electromotive force voltage V1 shown in FIG. When the yoke 14 and the outer peripheral end surface 32IF of the recess 32 are farthest apart, the magnetic flux Mf shown in FIG.

FIG. 7 is a plan view of the sensor unit of this embodiment. As shown in FIG. 7 , a power supply section 43 is mounted on the power supply substrate 41 . The power supply unit 43 converts the single-phase AC power supplied from the power generation unit 3 into a DC voltage and supplies the DC voltage to the sensor substrate 42 . A sensor 44 , a control section 45 having a communication circuit, and an antenna 47 are mounted on the sensor substrate 42 . DC power from the power supply unit 43 is supplied to the sensor 44 and the control unit 45 . The sensor 44, the control unit 45, and the antenna 47 may be composed of separate IC (Integrated Circuit) chips, or part or all of them may be composed of one IC chip. Also, the sensor 44 has, for example, an acceleration sensor 441 , a temperature sensor 442 and an angle sensor 443 .

FIG. 8 is a perspective view of the cover of this embodiment. As shown in FIG. 8, the cover 10 has a through hole 12H. As shown in FIG. 1, the through hole 12H is sealed with a non-magnetic lid 17 made of a non-magnetic material such as resin. As described above, the cover 10 has the antenna 47 on the bearing body 20 side. Here, since the cover 10 has magnetism, it has a function of shielding electromagnetic waves from the antenna 47 . Therefore, as shown in FIG. 7, the antenna 47 is arranged so as to overlap the non-magnetic lid 17 in a plan view of the bearing main body 20 viewed from the rotation axis Zr direction. That is, a non-magnetic lid 17 is provided on the portion of the cover 10 facing the antenna 47 . Therefore, the electromagnetic wave WV of the antenna 47 can reach the communication section 151 through the non-magnetic lid 17 .

Further, as shown in FIG. 8, one surface 12A of the top plate 12 is provided with a plurality of recesses 18 for arranging the power generation unit 3. As shown in FIG. For example, each of the multiple recesses 18 has a first recess 18A for arranging the coil 15 and a second recess 18B for arranging the permanent magnet 13 . When the one surface 12A is used as a reference surface, the first recess 18A is deeper than the second recess 18B.

FIG. 9 is a diagram showing an example of an output signal waveform of the angle sensor of this embodiment. The horizontal axis of FIG. 9 is the rotation angle (deg) of the tone ring 30 with respect to the angle sensor 443, and the vertical axis is the detection voltage generated at the angle sensor 443. In FIG. When the outer ring 21 is fixed and the inner ring 22 rotates, the tone ring 30 rotates together with the inner ring 22 , and the tone ring 30 rotates with respect to the angle sensor 443 . The air gap between the angle sensor 443 and the outer end face 31IF of the projection 31 shown in FIG. 3 and the air gap between the angle sensor 443 and the outer end face 32IF of the recess 32 shown in FIG. 4 alternately.

Thus, the distance between angle sensor 443 and tone ring 30 changes periodically. As a result, the magnetic flux density (magnetic field) passing through the angle sensor 443 changes, and the detection voltage of the angle sensor 443 changes according to the change in the magnetic flux density passing through the angle sensor 443 . For example, when the angle sensor 443 and the outer peripheral end surface 31IF of the projection 31 of the tone ring 30 are close to each other, the magnetic flux passing through the angle sensor 443 increases. At this time, the angle sensor 443 outputs a voltage V11 shown in FIG. When the angle sensor 443 and the outer peripheral end surface 31IF of the convex portion 31 of the tone ring 30 are separated from each other, the magnetic flux passing through the angle sensor 443 becomes small. At this time, the angle sensor 443 outputs a voltage V12 shown in FIG. Voltage V11>Voltage V12.

Further, as shown in FIG. 5, a magnetic body 311 having a larger holding force than the tone ring 30 and exhibiting hard magnetism is attached to the outer peripheral side end surface 31IF of the convex portion 31 . When magnetic body 311 comes closest to angle sensor 443, angle sensor 443 outputs voltage V10 shown in FIG. Voltage V10>Voltage V11. In the tone ring 30, the magnetic body 311 is attached to only one location. Each time the tone ring 30 makes one relative rotation (360° rotation) with respect to the angle sensor 443, the magnetic body 311 comes closest to the angle sensor 443, and the angle sensor 443 outputs the voltage V10 once. Therefore, the voltage V10 can be used as the origin of the angle detected by the angle sensor 443. FIG. In this embodiment, a threshold value Vm is set to detect the origin. V11<Vm≦V10. When the voltage output from the angle sensor 443 exceeds the threshold Vm, the control circuit 451 can determine that the angle sensor 443 has detected the origin.

In addition, the angle sensor 443 outputs a voltage waveform for a period corresponding to the number of the protrusions 31 and the recesses 32 shown in FIG. 2 after detecting the origin and before outputting the next origin. For example, the angle sensor 443 outputs a voltage waveform for 7 periods after detecting the origin and before outputting the next origin. Outputting voltage waveforms for 7 cycles means alternately outputting 7 V10 or V11 (maximum value) and 7 V12 (minimum value). Therefore, the control circuit 451 calculates the approximate rotation angle of the tone ring 30 with respect to the angle sensor 443 by counting the number of detections of the origin and the number of detections of maximum and minimum values after the detection of the origin. be able to. In addition, the control circuit 451 counts the number of detections of the origin and the number of detections of the maximum value and the minimum value after the detection of the origin, and also detects the voltage value output by the angle sensor 443 to detect the angle sensor. The rotation angle of tone ring 30 with respect to 443 can also be calculated in more detail.

5, the angle sensor 443 is fixed to the outer ring 21 via the sensor substrate 42 and the cover 10. As shown in FIG. Also, the tone ring 30 is fixed to the inner ring 22 . Therefore, the rotation angle of tone ring 30 with respect to angle sensor 443 is equal to the rotation angle of inner ring 22 with respect to outer ring 21 .

FIG. 10 is a diagram showing a configuration example of a circuit mounted on the substrate of the sensor-equipped bearing according to this embodiment. As shown in FIG. 10, a circuit 40A mounted on the substrate 40 (see FIG. 2) of the sensor-equipped bearing 1 includes a power generation section 50, a power supply section 43, a sensor 44, a control section 45, a voltage monitoring section 46 and an antenna 47 . The power generation section 50 is composed of the plurality of power generation sections 3 shown in FIGS. 2 to 4 and the tone ring 30 . The power supply unit 43 also includes a rectifying circuit 431 , a smoothing circuit 432 , a power storage circuit 433 , a chargeable/dischargeable power storage unit 434 , an output control circuit 435 , and a constant voltage output circuit 436 .

The power generation unit 50 generates single-phase AC power and outputs it to the rectifier circuit 431 of the power supply unit 43 . The rectifier circuit 431 full-wave rectifies the single-phase AC power generated by the power generation unit 3 to convert it into DC power, and outputs the DC power to the smoothing circuit 432 . A diode bridge is exemplified as the rectifier circuit 431, but the present embodiment is not limited to this. The smoothing circuit 432 smoothes the DC power output from the rectifier circuit 431 to reduce the AC component from the DC power. Then, the smoothing circuit 432 outputs the DC power with the AC component reduced to the power storage circuit 433 . Power storage circuit 433 charges power storage unit 434 with the DC power output from smoothing circuit 432 .

The output control circuit 435 transmits a control signal to the constant voltage output circuit 436 to control the constant voltage output circuit 436 . Under the control of the output control circuit 435 , the constant voltage output circuit 436 adjusts the DC power output from the power storage unit 434 to a constant voltage and outputs it to the sensor 44 and the control unit 45 .

For example, the output control circuit 435 monitors the voltage of the power storage unit 434 . When the voltage of the power storage unit 434 is equal to or higher than a preset threshold value (for example, a fourth management value BV4 in FIG. 11 described later), the output control circuit 435 transmits a signal instructing the constant voltage output circuit 436 to supply power. Thereby, the constant voltage output circuit 436 adjusts the DC power output from the power storage unit 434 to a constant voltage, and outputs the voltage to the sensor 44 and the control unit 45 . On the other hand, when the voltage of the storage unit 434 is less than a preset threshold value (for example, a first management value BV1 in FIG. 11 to be described later), the output control circuit 435 sends a signal to the constant voltage output circuit 436 to stop supplying power. Send. As a result, the constant voltage output circuit 436 stops power supply to the sensor 44 and the controller 45 .

As shown in FIGS. 10 and 11, the sensor 44 uses the supplied DC power to detect various physical or chemical quantities. For example, the sensor 44 has an acceleration sensor 441 that detects vibration of the bearing body 20 (see FIGS. 3 to 5), a temperature sensor 442 that detects the ambient temperature of the bearing body 20, and the angle sensor 443 described above. Although not shown, the sensor 44 includes a humidity sensor that detects the ambient humidity of the bearing body 20, and a gas sensor that detects gaseous hydrocarbons, hydrogen sulfide, ammonia, etc., which are generated due to oxidation deterioration of the lubricating oil in the bearing body 20. , an ultrasonic sensor or the like for detecting frictional noise generated in the bearing body 20 may be provided.

The control unit 45 stores data detected by the sensor 44 and transmits the data to the outside via the antenna 47 . For example, the control section 45 has a control circuit 451 , a memory circuit 452 and a communication circuit 453 . The control circuit 451 is, for example, a CPU (Central Processing Unit). The memory circuit 452 is, for example, a NAND or NOR flash memory. The communication circuit 453 is included in the CPU that constitutes the control circuit 451 . Alternatively, the communication circuit 453 may be composed of an IC chip different from the CPU. The control circuit 451 , memory circuit 452 and communication circuit 453 operate using DC power supplied from the power supply section 43 .

The control circuit 451 controls the memory circuit 452 and the communication circuit 453 . For example, the control circuit 451 converts various data detected by the sensor 44 from analog data to digital data (that is, A/D converts). Also, the control circuit 451 transfers and writes the A/D converted digital data to the storage circuit 452 . The control circuit 451 may temporarily store the A/D-converted digital data in a cache memory, read the temporarily stored digital data at an arbitrary timing, and transfer it to the storage circuit 452 . Also, the control circuit 451 reads out digital data from the storage circuit 452 and outputs it to the communication circuit 453 .

Under the control of the control circuit 451 , the communication circuit 453 transmits digital data read from the memory circuit 452 to the outside via the antenna 47 . For example, as shown in FIG. 1, the communication circuit 453 transmits digital data to the outside by wireless communication of electromagnetic waves WV. The transmitted digital data is received by the communication unit 151 of the host device 150 . Digital data received by the communication unit 151 is processed by the computer 152 . Thus, since the sensor-equipped bearing 1 can wirelessly transmit digital data, it can be miniaturized. In this embodiment, transmission of digital data to the outside by the communication circuit 453 may be wired instead of wireless.

Voltage monitoring unit 46 monitors the voltage of power storage unit 434 . The voltage monitoring section 46 has a first reset IC 461 and a second reset IC 462 . The first reset IC 461 outputs a first signal RST<b>1 to the control circuit 451 of the control section 45 . For example, when the voltage of the power storage unit 434 is higher than the second management value BV2 (see FIG. 11, which will be described later), the first reset IC 461 outputs a Low signal with a low voltage as the first signal RST1. When the voltage of the power storage unit 434 is equal to or lower than the second management value BV2, the first reset IC 461 outputs a High signal with a high voltage as the first signal RST1. A High signal output as the first signal RST1 is a sleep signal, which will be described later.

The second reset IC 462 outputs a second signal RST<b>2 to the control circuit 451 of the control section 45 . For example, when the voltage of the power storage unit 434 is less than the third management value BV3 (see FIG. 11 described later), the second reset IC 462 outputs a Low signal with a low voltage as the second signal RST2. When the voltage of the power storage unit 434 is equal to or higher than the third management value BV3, the second reset IC 462 outputs a High signal with a high voltage as the second signal RST2. A High signal output as the second signal RST2 is a wakeup signal, which will be described later.

As the first reset IC 461 and the second reset IC 462, for example, "S-1009 series manufactured by SII Semiconductor Co., Ltd." can be used.

As described above, the power generating section 50 (see FIG. 10) of the present embodiment rotates the inner ring 22 (see FIG. 3) with respect to the outer ring 21 (see FIG. 3) of the bearing body 20 (see FIG. 3). Electric power is generated, and power storage unit 434 is charged with the generated power. Thus, the charging of power storage unit 434 depends on the rotation of inner ring 22 with respect to outer ring 21 . Charging of the electric storage unit 434 is performed as needed regardless of each operation of the sensor 44 (see FIG. 10) and the control unit 45 (see FIG. 10). Based on the above, the voltage change of power storage unit 434 will be described with reference to FIG. 11 .

FIG. 11 is a graph schematically showing an example of voltage change of the power storage unit of the present embodiment. In FIG. 11, the horizontal axis indicates time, and the vertical axis indicates the voltage of power storage unit 434 (see FIG. 10). Further, L1 in FIG. 11 indicates an example of voltage change in this embodiment. A dashed line L2 in FIG. 11 indicates a voltage change in the comparative example.

As shown in FIG. 11, in the present embodiment, a plurality of management values (for example, first set value BV1 to fifth set value BV5) are set in advance for the voltage of power storage unit 434 . First management value BV1 is a voltage value when power supply from power storage unit 434 to control unit 45 is switched from on to off. The second management value BV2 is the voltage value when the control unit 45 shifts from the normal mode to the sleep mode. The third management value BV3 is the voltage value when the control unit 45 returns from the sleep mode to the normal mode. The fourth management value BV4 is a voltage value when power supply from power storage unit 434 to control unit 45 is switched from off to on. Fifth management value BV5 is a voltage value when power storage unit 434 is determined to be overcharged.

Note that the sleep mode is a standby state in which power consumption is kept low. The sleep mode consumes less power per unit time than the normal mode. For example, the power consumption per unit time in the sleep mode of the CPU that constitutes the control unit 45 is sufficiently smaller than the power consumption per unit time in the normal mode of the same CPU. In the sleep mode, the control unit 45 uses power for searching and authenticating (hereinafter referred to as pairing) a connection destination (for example, the host device 150 in FIG. 1) for pair communication, but for other uses it uses power as much as possible. Wait without consuming.

For example, in the sleep mode, the control unit 45 stops writing or reading data relating to the physical quantity or chemical quantity detected by the sensor 44 to the storage circuit 452, or stops transmitting the data to the outside. Therefore, the power consumption per unit time of the control unit 45 is kept lower in the sleep mode than in the normal mode. When the control circuit 451 and the communication circuit 453 of the control unit 45 are composed of a CPU, the power consumption per unit time of the control circuit 451 and the communication circuit 453 is substantially the same as the power consumption per unit time of the CPU.

FIG. 11 shows a case where the voltage of power storage unit 434 is initially about 0 (V) and power is stored from that state. When power generation unit 50 (see FIG. 10) generates power, the generated power is stored in power storage unit 434 . When the control unit 45 (see FIG. 10) is in sleep mode, the power consumption of the control unit 45 is kept low, so the voltage of the power storage unit 434 rises. When the voltage of the power storage unit 434 rises and becomes equal to or higher than the third management value BV3, the second reset IC 462 transmits a wakeup signal to the control circuit 451 . When the control circuit 451 receives the wakeup signal, the control section 45 shifts from sleep mode to standard mode. However, at this stage, the power supply to the sensor 44 and the control unit 45 is kept stopped by the output control circuit 435 (see FIG. 10). When the voltage of power storage unit 434 further increases and becomes equal to or greater than fourth management value BV4 (see BP1 in FIG. 11), output control circuit 435 (see FIG. 10) controls constant voltage output circuit 436 (see FIG. 10). to start supplying power to the sensor 44 and the control unit 45 .

When power is supplied to the control unit 45 in the standard mode, the control circuit 451 writes data to and reads data from the storage circuit 452, and the communication circuit 453 performs data transmission. Therefore, the power consumption of control unit 45 increases, and the voltage of power storage unit 434 drops.

Next, when the voltage value of power storage unit 434 becomes equal to or lower than second management value BV2 (see BP2 in FIG. 11), first reset IC 461 transmits a sleep signal to control circuit 451 . When the control circuit 451 receives the sleep signal, the control section 45 shifts from the standard mode to the sleep mode. As described above, the power consumption of the control unit 45 is kept low in the sleep mode, so the voltage of the power storage unit 434 rises again.

When the voltage of the power storage unit 434 rises and becomes equal to or higher than the third management value BV3 (see BP3 in FIG. 11), the second reset IC 462 transmits a wakeup signal to the control circuit 451 . When the control circuit 451 receives the wakeup signal, the control section 45 returns from the sleep mode to the standard mode. In the standard mode, the power consumption of control unit 45 increases, so the voltage of power storage unit 434 drops again.

Thus, in the present embodiment, it is easy to maintain the voltage of power storage unit 434 within the range VR of the second management value BV2 or more and the third management value BV3 or less. As a result, it is possible to prevent shortage of electric power supplied to the sensor 44 and the control unit 45 . Further, when the voltage of the power storage unit 434 is within the range VR, data is stably written to and read from the memory circuit 452, data is transmitted by the communication circuit 453, and the like. This can prevent the sensor 44 and the controller 45 from malfunctioning due to power shortage.

Note that when the voltage of the power storage unit 434 is less than the first management value BV1, even if power is supplied from the power storage unit 434 to the control unit 45, the sensor 44 and the control unit 45 do not operate due to insufficient power, or do not operate stably. It will likely not work. Therefore, when the voltage of the storage unit 434 is less than the first management value BV1, the output control circuit 435 (see FIG. 10) stops power supply from the constant voltage output circuit 436 (see FIG. 10) to the sensor 44 and the control unit 45. stop. Further, when the voltage of power storage unit 434 is equal to or higher than fifth management value BV5, power storage unit 434 is overcharged. In this case, power storage circuit 433 (see FIG. 10) stops charging power storage unit 434 .

As indicated by the dashed line L2 in FIG. 11, in the comparative example, the sleep signal is not supplied to the control circuit. For example, if the control circuit runs out of power and stops while writing data to the memory circuit, the data may be stored in the memory circuit in a corrupted state. In addition, the control circuit and the communication circuit need to be paired again with the connection destination when power is resupplied from the power storage unit. Therefore, the comparative example consumes more energy and time.

In this embodiment, a sleep signal is supplied from the reset IC to the control circuit 451 before the control circuit 451 and the communication circuit 453 run out of power and stop. Therefore, the sensor-equipped bearing 1 of the present embodiment can prevent data from being stored in the storage circuit 452 in a corrupted state due to power shortage. In addition, the sensor-equipped bearing 1 can reduce the number of times of re-pairing with a connection destination (for example, the host device 150 in FIG. 1). This allows the sensored bearing 1 to reduce the energy and time required for re-pairing.

Next, the operation sequence of circuit 40A shown in FIG. 10 will be described. FIG. 12 is a flow chart showing an example of the operation sequence of the circuit mounted on the substrate of the sensor-equipped bearing of this embodiment.

First, the output control circuit 435 (see FIG. 10) checks the voltage of the electric storage unit 434 (see FIG. 10) (step ST1). Next, output control circuit 435 determines whether or not the voltage of power storage unit 434 is equal to or higher than preset fourth management value BV4 (step ST2). When the voltage of the power storage unit 434 is equal to or higher than the fourth management value BV4 (step ST2; Yes), the output control circuit 435 transmits a control signal to the constant voltage output circuit 436 to control the sensor 44 (see FIG. 10) and the control unit 45 (see FIG. 10). As a result, the constant voltage output circuit 436 supplies constant voltage power to the sensor 44 and the control section 45 (step ST3). On the other hand, if the voltage of power storage unit 434 is less than fourth management value BV4 (step ST2; No), the operation sequence returns to step ST1.

When power is supplied from the power supply unit 43, the control unit 45 performs initial setting (step ST4). For example, the control circuit 451 (see FIG. 10) and the communication circuit 453 (see FIG. 10) search and authenticate (pairing) a connection destination for pair communication as an initial setting. Also, the control circuit 451 sets conditions for starting and ending data transfer processing to the storage circuit 452 (see FIG. 10). For example, the start condition is detection of the origin (see FIG. 9) output from the angle sensor 443 . The control circuit 451 writes information on the threshold value Vm (see FIG. 9) for detecting the origin to the register of the CPU that constitutes the control unit 45 . Also, the termination condition is the number of times the origin is detected. The control circuit 451 writes the number of origin detections, which is the end condition, in the register of the CPU that constitutes the control unit 45 .

When constant-voltage power is supplied to the sensor 44, the sensor 44 starts detecting a physical quantity or a chemical quantity (step ST5). For example, the acceleration sensor 441 detects vibration of the bearing body 20 (see FIGS. 3 to 5) and outputs analog data. A temperature sensor 442 detects the ambient temperature of the bearing body 20 and outputs analog data. The angle sensor 443 detects the rotation angle of the inner ring 22 with respect to the outer ring 21 and outputs analog data. Analog data is converted into digital data by the A/D conversion function of control circuit 451 .

When the control circuit 451 detects the origin, the control circuit 451 transfers digital data to the memory circuit 452 . For example, the control circuit 451 temporarily stores digital data in the cache memory of the control circuit 451 and outputs the digital data stored in the cache memory to the storage circuit 452 in a time division manner. The storage circuit 452 stores digital data output by the control circuit 451 .

Next, the control circuit 451 reads the digital data from the memory circuit 452 and outputs it to the communication circuit 453 . The communication circuit 453 transmits the digital data to the outside from the antenna 47 (step ST6).

After completing the transmission process by the communication circuit 453, the control circuit 451 determines whether or not to continue detecting physical quantities or chemical quantities (step ST7). When continuing the detection of the physical quantity or chemical quantity (step ST7; Yes), the operation sequence proceeds to step ST9. If the detection of the physical quantity or chemical quantity is not to be continued (step ST7; No), the operation sequence proceeds to step ST8. In step ST8, the output control circuit 435 sends a control signal to the constant voltage output circuit 436 to instruct the sensor 44 and the control section 45 to stop outputting. As a result, the constant voltage output circuit 436 stops supplying power to the sensor 44 and the controller 45 . Circuit 40A then terminates the operating sequence.

On the other hand, in step ST9, the output control circuit 435 confirms the voltage of the electric storage unit 434 again. Next, output control circuit 435 determines whether or not the voltage of power storage unit 434 is greater than or equal to first management value BV1 (step ST10). When the voltage of power storage unit 434 is less than first management value BV1 (step ST10; No), the operation sequence proceeds to step ST8. In this case, the constant voltage output circuit 436 stops supplying power to the sensor 44 and the controller 45 . When the voltage of the storage unit 434 is equal to or higher than the first management value BV1 (step ST10; Yes), the constant voltage output circuit 436 continues to supply power to the sensor 44 and the control unit 45.

Voltage monitoring unit 46 outputs first signal RST<b>1 based on the voltage of power storage unit 434 to control circuit 451 . Control circuit 451 determines whether or not the voltage of power storage unit 434 is equal to or lower than second management value BV2 based on first signal RST1 (step ST11). For example, the threshold voltage of the first reset IC 461 is set to the second management value BV2. When the voltage of the power storage unit 434 is equal to or lower than the second management value BV2, the first reset IC 461 outputs a High signal (sleep signal) as the first signal RST1. When the voltage of power storage unit 434 is higher than second management value BV2, first reset IC 461 outputs a Low signal as first signal RST1. Upon receiving a High signal (sleep signal) as the first signal RST1, the control circuit 451 determines that the voltage of the power storage unit 434 is equal to or lower than the second control value BV2 (step ST11: Yes). Further, when receiving a Low signal as the first signal RST1, the control circuit 451 determines that the voltage of the power storage unit 434 is higher than the second management value BV2 (step ST11: No).

If the voltage of power storage unit 434 is higher than second management value BV2 (step ST11; No), the operation sequence returns to step ST5. Further, when the voltage of the power storage unit 434 is equal to or lower than the second management value BV2 (step ST11; No), the control circuit 451 and the communication circuit 453 controlled by the control circuit 451 shift from the normal mode to the sleep mode (step ST12).

Voltage monitoring unit 46 outputs second signal RST<b>2 based on the voltage of power storage unit 434 to control circuit 451 . Control circuit 451 determines whether or not the voltage of power storage unit 434 is greater than or equal to third management value BV3 based on second signal RST2 (step ST13). For example, the threshold voltage of the second reset IC 462 is set to the third management value BV3. When the voltage of power storage unit 434 is equal to or higher than third management value BV3, second reset IC 462 outputs a High signal (wakeup signal) as second signal RST2. When the voltage of power storage unit 434 is less than second management value BV2, second reset IC 462 outputs a Low signal as second signal RST2. When the control circuit 451 receives a High signal (wakeup signal) as the second signal RST2, it determines that the voltage of the power storage unit 434 is equal to or higher than the third management value BV3 (step ST13: Yes). Further, when receiving a Low signal as the second signal RST2, the control circuit 451 determines that the voltage of the power storage unit 434 is less than the third management value BV3 (step ST13: No).

When the voltage of the storage unit 434 is equal to or higher than the third management value BV3 (step ST13; Yes), the control circuit 451 and the communication circuit 453 return from the sleep mode to the standard mode (step ST14). After the control circuit 451 and the communication circuit 453 return to the standard mode, the operation sequence returns to step ST5. If the voltage of power storage unit 434 is less than third management value BV3 (step ST13; No), the operation sequence returns to step ST12. In this case, the control circuit 451 and the communication circuit 453 maintain sleep mode.

FIG. 13 is a diagram schematically showing the relationship between the operating period of the circuit mounted on the substrate of the sensor-equipped bearing according to the present embodiment and the power consumption of the CPU. In FIG. 13, the horizontal axis indicates time (s), and the vertical axis indicates the power consumption (W) per unit time of the CPU constituting the control circuit 451 (see FIG. 10) and the communication circuit 453 (see FIG. 10). . As shown in FIG. 13, the operation period of the circuit 40A (see FIG. 10) is divided into periods tm1 to tm3. A period tm1 is a period during which step ST4 of the flowchart shown in FIG. 12 is executed. A period tm2 is a period during which step ST5 of the flowchart shown in FIG. 12 is executed. A period tm3 is a period during which step ST6 of the flowchart shown in FIG. 12 is executed. In FIG. 13, EP1 indicates the amount of power consumption (J) of the CPU during period tm1. EP2 indicates the power consumption (J) of the CPU in period tm2. EP3 indicates the power consumption (J) of the CPU in period tm3. In period tm1, an inrush current flows through the CPU. Therefore, immediately after the start of the period tm1, the power consumption per unit time of the CPU temporarily increases.

In this embodiment, the control circuit 451 and the communication circuit 453 shift to sleep mode to suppress power consumption before the power stored in the power storage unit 434 is exhausted and stopped. In the sleep mode, the control circuit 451 and the communication circuit 453 maintain pairing with the connection destination while keeping power consumption low. As a result, the sensor-equipped bearing 1 (see FIG. 1) can reduce the required number of times during the period tm1, and can repeat the periods tm2 and tm3. As a result, the sensor-equipped bearing 1 can reduce the ratio of the power consumption EP1 to the power consumption EP2 and EP3.

FIG. 14 is a graph showing an example of temporal changes in the number of rotations of the sensor-equipped bearing. The horizontal axis of FIG. 14 is time. The vertical axis in FIG. 14 is the rotational speed of the sensor-equipped bearing. Rsa on the vertical axis is, for example, the rotational speed of the sensor-equipped bearing 1 when the power generated by the power generation unit 50 exceeds the power that can be stored in the power storage unit 434 . Rsb on the vertical axis is the number of rotations of the sensor-equipped bearing 1 when the power generated by the power generation unit 50 is below the minimum power consumption of various circuits of the sensor-equipped bearing 1 . As shown in FIG. 14, the rotation of the sensor-equipped bearing 1 may be at a high speed of Rsa or higher, or at a low speed of Rsb or lower. As described above, since the rotation speed of the sensor-equipped bearing 1 often fluctuates from moment to moment, the electric power generated by the power generation unit 50 is often unstable.

However, the power storage circuit 433 of the sensor-equipped bearing 1 stores electric power generated by the power generation unit 50 in the power storage unit 434 if the power storage unit 434 can be charged regardless of whether the rotation is at a high speed or at a low speed. . For example, the power storage circuit 433 has a Zener diode. In the case of high-speed rotation, the power storage circuit 433 causes surplus power generated by the power generation unit 50 to flow to the Zener diode and is released to the outside, and the remaining power to flow to the power storage unit 434 to store. Further, in the case of low-speed rotation, the power storage circuit 433 allows all the power generated by the power generation unit 50 to flow to the power storage unit 434 for storage.

As described above, the sensor-equipped bearing 1 according to the present embodiment generates power based on the relative rotation between the bearing main body 20 having the outer ring 21 and the inner ring 22 that rotate relatively and the outer ring 21 and the inner ring 22. A power generation unit 50, a chargeable/dischargeable power storage unit 434 that is charged with the power generated by the power generation unit 50, a sensor 44 that detects a physical quantity or a chemical quantity of the bearing body 20, and power stored in the power storage unit 434. , a control unit 45 supplied with data relating to physical or chemical quantities detected by the sensor 44 , and a voltage monitoring unit 46 that monitors the voltage of the electric storage unit 434 . The voltage monitoring unit 46 includes a first reset IC 461 that transmits a first signal RST1 based on the voltage of the power storage unit 434 to the control unit 45, and a second reset IC 461 that transmits a second signal RST2 based on the voltage of the power storage unit 434 to the control unit 45. and a reset IC 462 .

According to this, in the sensor-equipped bearing 1, the controller 45 can shift from the normal mode to the sleep mode before the controller 45 runs out of power. As a result, the sensor-equipped bearing 1 can prevent the controller 45 from malfunctioning due to power shortage.

For example, if power is lost while the control circuit 451 is writing data to the memory circuit 452, the memory circuit 452 may be damaged. However, in this embodiment, the voltage monitoring unit 46 monitors the voltage of the power storage unit 434 . Then, the monitoring result is output to the control circuit 451 . Thus, the control circuit 451 can determine whether or not the power storage unit 434 has sufficient power to stably write data to the memory circuit 452 . That is, the control circuit 451 can determine whether data can be stably written to the memory circuit 452 or whether data cannot be stably written to the memory circuit 452 . In this embodiment, data is written to the storage circuit 452 by the control circuit 451 when the voltage of the power storage unit 434 is sufficiently high (for example, when it is equal to or higher than the second management value BV2). As a result, the control circuit 451 can stably write data to the memory circuit 452 and prevent damage to the memory circuit 452 due to loss of power.

Further, in the sensor-equipped bearing 1 according to the present embodiment, the voltage monitoring unit 46 monitors the voltage of the electric storage unit 434, so that the firmware can be updated more safely. More specifically, in most modules equipped with an IC chip capable of wireless communication (hereinafter referred to as wireless module), firmware update is supported by wireless update (OTA-DFU: Over the Air Device Firmware Update). This is because wireless modules are assumed to be used in a wireless environment, and it is often difficult to use a wired update tool. Since the OTA also eventually requires writing to the flash memory, loss of power during the OTA may corrupt the flash memory.

On the other hand, in the sensor-equipped bearing 1 according to the present embodiment, the voltage monitoring unit 46 having the first reset IC 461 and the second reset IC 462 detects the voltage of the storage unit 434 even during wireless firmware update (OTA). Monitor. Writing update data to the flash memory of the storage circuit 452 is performed while the voltage monitoring unit 46 monitors the voltage of the power storage unit 434 . When the voltage of the storage unit 434 becomes insufficient during OTA (for example, when it becomes equal to or lower than the second control value BV2), the control circuit 451 and the communication circuit 453 shift from normal mode to sleep mode, and writing to the flash memory is interrupted. After that, when the voltage of the power storage unit 434 recovers (for example, becomes equal to or higher than the third management value BV3), the control circuit 451 and the communication circuit 453 shift from sleep mode to normal mode, and writing to the flash memory is resumed. Even if the voltage of the storage unit 434 does not recover and the power is lost, writing to the flash memory is stopped by the sleep mode, so damage to the flash memory can be avoided. Since corruption of flash memory is avoided, OTA can be resumed or redone after power is restored.

In addition, in the flash memory included in the storage circuit 452, the area in which firmware is stored (hereinafter referred to as firmware area) is preferably less than half of the total capacity of the flash memory. Further, the remaining capacity of the flash memory is preferably an area for storing firmware update data and an area for storing data relating to physical or chemical quantities detected by the sensor 44 . As a result, it is possible to prevent the update data from being lost when the power is lost. Also, in the flash memory, it is preferable that the firmware area and the area provided for storing update data are switched for each OTA described above. As a result, data writes can be prevented from concentrating on a specific area of the flash memory, and deterioration of the flash memory can be suppressed.

Further, in the sensor-equipped bearing 1 , the reset ICs (the first reset IC 461 and the second reset IC 462 ) are used to monitor the voltage of the electric storage unit 434 . As a result, the sensor-equipped bearing 1 can keep the power consumption for voltage monitoring low.

For example, as a method of monitoring the voltage of the electric storage unit 434, a method of using the A/D conversion function of the control circuit 451 instead of using the reset IC is also conceivable. By using the A/D conversion function of the control circuit 451, voltage information can be obtained with a high resolution. However, A/D conversion consumes a large amount of current. If the voltage measurement of the power storage unit 434 is performed using the A/D conversion function of the control circuit 451, the power stored in the power storage unit 434 is greatly reduced. In consideration of this point, the present embodiment uses a low power consumption reset IC for monitoring the voltage of the power storage unit 434 . As a result, the sensor-equipped bearing 1 can keep the power consumption for voltage monitoring low.

Further, by using the reset IC for monitoring the voltage of the electric storage unit 434, the sensor-equipped bearing 1 can return the control circuit 451 and the communication circuit 453 from the sleep mode to the normal mode at a suitable timing.

More specifically, when voltage monitoring is performed by the A/D conversion function of the control circuit 451, it is possible to shift from the normal mode to the sleep mode. stand by. Therefore, the control circuit 451 does not know when to return from the sleep mode to the regular mode. Wake-up by a timer is also conceivable, but since the sensor-equipped bearing 1 rotates passively to obtain power, there is no guarantee that the power will be restored after a certain period of time. Therefore, in the voltage monitoring by the A/D conversion function of the control circuit 451, it is difficult to return from the sleep mode to the normal mode at suitable timing. In consideration of this point, the present embodiment uses a reset IC for monitoring the voltage of the power storage unit 434 .

Since the sensor-equipped bearing 1 is rotated, it cannot control the amount of power generation, but it stores electricity no matter how low the rotation speed is. This embodiment is a countermeasure for preventing malfunction and saving power in an unstable electric power situation in which the rotational speed of the sensor-equipped bearing 1 fluctuates from moment to moment. According to this embodiment, it is possible to provide the sensor-equipped bearing 1 that can prevent malfunction even in an unstable power situation and that can save power.

The above-described second control value BV2 corresponds to the "first threshold" of the present disclosure, the above-described third control value BV3 corresponds to the "second threshold" of the present disclosure, and the above-described first control value corresponds to the present disclosure. It corresponds to the "third threshold". Also, the sleep signal (the High signal of the first signal RST1) described above corresponds to the "first signal" of the present disclosure. Also, the above-described wakeup signal (the High signal of the second signal RST2) corresponds to the "second signal" of the present disclosure. Two sensors arbitrarily selected from the acceleration sensor 441, the temperature sensor 442, and the angle sensor 443 described above correspond to the "first sensor" and the "second sensor" of the present disclosure.

In this embodiment, the set value of the threshold voltage when the reset IC outputs a High signal or a Low signal may be rewritable by the computer 152 of the host device 150 or the like. For example, the first reset IC 461 and the second reset IC 462 may each contain a register. The computer 152 of the host device 150 may be able to rewrite the second management value BV2 stored in the register of the first reset IC 461 via the communication section 151 of the host device 150 . Similarly, the computer 152 may be able to rewrite the third management value BV3 stored in the register of the second reset IC 462 via the communication section 151 . According to this, the user can change the voltage value when the first reset IC 461 outputs the sleep signal and the voltage value when the second reset IC 462 outputs the wakeup signal without exchanging the reset ICs. It can be changed arbitrarily.

Also, in the above embodiments, the reset IC is described as the voltage monitoring circuit of the present disclosure, but the reset IC is merely an example. The voltage monitoring circuit of the present disclosure may be, for example, a voltage detector or voltage detector that operates with low power consumption. Alternatively, a comparator circuit composed of an operational amplifier with low power consumption may be used.

Further, in the above embodiment, the sensor-equipped bearing 1 was exemplified as the rotating device of the present disclosure, but the rotating device of the present disclosure is not limited to the sensor-equipped bearing. The rotating device of the present disclosure may, for example, be a sensored rotating device mounted coaxially with a bearing rather than a sensored bearing.

1 Bearing with sensor (an example of a rotating device)
10 cover 20 bearing body (an example of a rotating device body)
21 outer ring (an example of the first part)
22 inner ring (an example of the second part)
40 substrate 40A circuit 41 power supply substrate 42 sensor substrate 43 power supply unit 44 sensor 45 control unit 46 voltage monitoring unit 47 antenna 50 power generation unit 150 host device 151 communication unit 152 computer 434 power storage unit 435 output control circuit 436 constant voltage output circuit 441 acceleration sensor 442 temperature sensor 443 angle sensor 451 control circuit 452 memory circuit 453 communication circuit 461 first reset IC (an example of a first voltage monitoring circuit)
462 Second reset IC (an example of a second voltage monitoring circuit)
BV1 First management value BV2 Second management value BV3 Third management value BV4 Fourth management value BV5 Fifth management value RST1 First signal RST2 Second signal

Claims (5)

A rotating device having a first part and a second part that rotate relative to each other about a rotation axis,
a power generation unit that generates power based on the relative rotation of the first part and the second part;
a chargeable/dischargeable power storage unit that is charged with power generated by the power generation unit;
a sensor;
a control unit supplied with power stored in the power storage unit and data detected by the sensor;
a voltage monitoring unit that monitors the voltage of the power storage unit,
The control unit
a storage circuit that stores the data;
a communication circuit for transmitting the data to an external device;
stopping the writing of the data to the storage circuit and the transmission of the data to the external device by the communication circuit when the voltage of the power storage unit becomes equal to or lower than a first threshold;
The rotating device , wherein when the voltage of the power storage unit becomes equal to or higher than a second threshold higher than the first threshold, writing of the data to the storage circuit and transmission of the data to the external device by the communication circuit are started . an output control circuit that controls the supply of electric power from the power storage unit to the control unit based on the voltage of the power storage unit;
The output control circuit is
turning on power supply from the power storage unit to the control unit when the voltage of the power storage unit is equal to or higher than a third threshold higher than the second threshold;
2. The rotating device according to claim 1 , wherein when the voltage of said power storage unit is less than a fourth threshold lower than said first threshold , power supply from said power storage unit to said control unit is turned off. the communication circuit is paired with the external device;
The rotating device according to claim 2, wherein the control unit maintains the pairing when the voltage of the power storage unit is equal to or higher than the fourth threshold. The sensor is
4. The rotating device according to any one of claims 1 to 3 , comprising a first sensor and a second sensor whose detection target is different from that of the first sensor. 5. The rotating device according to any one of claims 1 to 4, wherein said first part and said second part are respectively an outer ring and an inner ring of a bearing.

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