JP7443677B2 - Bearings with sensors and synchronous measurement systems - Google Patents

Description

The present invention relates to a bearing with a sensor and a synchronous measurement system.

BACKGROUND ART Conventionally, for the purpose of detecting abnormalities in equipment, there have been an increasing number of situations in which information indicating whether the state of rotating equipment is normal or abnormal is being collected. Abnormalities in rotating equipment mainly appear in temperature and vibration.
As a state monitoring device that monitors the state of equipment including a rotating body, there is a technique described in Patent Document 1, for example. This technology analyzes signals from sensors installed in equipment that detect vibration, sound, or acoustic emissions, and diagnoses equipment abnormalities.

Japanese Patent Application Publication No. 2018-36124

However, with the technology described in Patent Document 1, although it is possible to diagnose whether or not an abnormality has occurred in the rotating equipment, it is difficult to identify the location where the abnormality is occurring (the angle at which the abnormality occurs). I can't.
SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a synchronous measurement system that can acquire physical quantities related to a rotating device in association with the rotational position of the rotating device, and a sensor-equipped bearing using the same.

In order to solve the above problems, a bearing with a sensor according to one aspect of the present invention includes: a bearing; a first sensor that measures a physical quantity related to the bearing and updates and holds the measured value at a first update cycle; a second sensor that measures the rotation angle of the bearing and updates and holds the measured value at a second update cycle; a measured value held by the first sensor; and a measured value held by the second sensor. an acquisition unit that acquires the measurement value in synchronization with the update completion timing of the measured value in either the first sensor or the second sensor.
Thereby, the physical quantity related to the bearing can be acquired in association with the position (angle) of the bearing. Therefore, it is possible to appropriately grasp what physical quantity is occurring at which position (angle) of the bearing.

Further, in the above-described sensor-equipped bearing, the first sensor is an acceleration sensor that measures vibrations of the bearing, and the second sensor measures a relative rotation angle of the inner ring with respect to the outer ring of the bearing. It may also be an angle sensor.
In this case, the vibration of the bearing can be acquired in association with the position (angle) of the bearing.

Furthermore, in the above-mentioned sensor-equipped bearing, unlike the first update period and the second update period, the acquisition unit may store the measured value held by the first sensor and the measured value held by the second sensor. The measured value may be acquired in synchronization with the update completion timing of the one of the first sensor and the second sensor with a longer update cycle.
In this case, measurement values having close measurement timings can be obtained from the first sensor and the second sensor. Moreover, since the measured values obtained from each sensor can all be updated measured values, the accuracy of the obtained data can be improved.

Further, in the sensor-equipped bearing, the acquisition unit includes a control unit that transfers the measured value held by the first sensor and the measured value held by the second sensor by DMA (Direct Memory Access); The device may further include a recording unit that records the measured value of the first sensor and the measured value of the second sensor, which are DMA-transferred by the control unit, in association with each other.
In this case, since the measured value of the sensor can be written directly to the recording section without going through the CPU, the load on the CPU can be reduced.

Furthermore, in the sensor-equipped bearing, at least one of the first sensor and the second sensor is capable of outputting an update completion signal each time updating of the measured value is completed, and the control The unit may trigger the DMA transfer using the update completion signal output from any of the sensors capable of outputting the update completion signal.
In this way, the sensor update completion signal may be used as an interrupt signal for starting DMA. Thereby, the measured values of the first sensor and the second sensor can be acquired reliably in synchronization with the timing at which the updated measured value of one of the sensors is completed.

Furthermore, in the sensor-equipped bearing described above, the recording section may record the measured value without conversion. In this way, by recording unconverted data (raw sensor data) in the recording section, data conversion processing can be omitted, and power consumption can be reduced accordingly.
Furthermore, the sensor-equipped bearing described above may further include a transmitter that transmits the measured value acquired by the acquirer to an external device. In this case, by analyzing the measured values in an external device, it becomes possible to diagnose an abnormality in the bearing, for example. Furthermore, at this time, it is also possible to specify the location (angle) at which the abnormality occurs in the bearing.

The sensor-equipped bearing also includes a power generation unit that generates power based on relative rotation between the outer ring and the inner ring of the bearing and supplies power to the first sensor, the second sensor, and the acquisition unit. Further provision may be made. In this case, in a sensor-equipped bearing that has a self-power generation function that does not require an external power supply, it is possible to appropriately acquire correspondence data between physical quantities and rotational positions (angles) related to the bearing.
Furthermore, a synchronous measurement system according to one aspect of the present invention includes a first sensor that measures a physical quantity related to a rotating device, updates and holds the measured value in a first update cycle, and a first sensor that measures a rotation angle of the rotating device. , a second sensor that updates and holds a measured value at a second update cycle, and a measured value held by the first sensor and a measured value held by the second sensor, which are updated and held by the first sensor and and an acquisition unit that acquires the measurement value in synchronization with the update completion timing of the measurement value in any of the second sensors.
Thereby, it is possible to obtain the physical quantity related to the rotating device in association with the position (angle) of the rotating device. Therefore, it is possible to appropriately grasp what physical quantity is occurring at which position (angle) of the rotating device.

According to one aspect of the present invention, physical quantities related to a rotating device (for example, a bearing) can be acquired in association with the rotational position of the rotating device, so that, for example, it is possible to identify the location (angle) where an abnormality occurs in a bearing. Become.

FIG. 1 is a diagram showing an overview of a measurement system in this embodiment. FIG. 2 is a diagram showing the update cycle of each sensor in the first embodiment. FIG. 3 is a flowchart showing the measurement data acquisition processing procedure. FIG. 4 is a diagram showing an example of measurement data. FIG. 5 is a diagram schematically illustrating a case where abnormality detection is performed in the first embodiment. FIG. 6 is a diagram showing the update cycle of each sensor in the second embodiment. FIG. 7 is a diagram schematically illustrating a case where abnormality detection is performed in the second embodiment. FIG. 8 is an exploded perspective view showing the configuration of the sensor-equipped bearing. FIG. 9 is an exploded perspective view showing the configuration of the sensor-equipped bearing. FIG. 10 is a plan view showing an example of the structure of the cover and the coil board. FIG. 11 shows an example of the configuration of the circuit board. FIG. 12 is an application example of a bearing with a sensor.

Embodiments of the present invention will be described below with reference to the drawings.
Note that the scope of the present invention is not limited to the following embodiments, and can be arbitrarily modified within the scope of the technical idea of the present invention.

(First embodiment)
In this embodiment, a measurement system that acquires measurement data in which a physical quantity related to a rotating device is associated with a rotational position (rotation angle) of the rotating device will be described.
This measurement system can be applied to a sensor-equipped bearing, for example. The sensor-equipped bearing includes a bearing, a first sensor that detects a physical quantity related to the bearing, and a second sensor that detects a rotational position (rotation angle) of the bearing. In this case, the measurement system acquires measurement data in which physical quantities related to the bearing are associated with rotation angles of the bearing. Here, the physical quantity may be acceleration indicating vibration of the bearing. That is, the first sensor can be an acceleration sensor that detects vibrations of the bearing. Further, the second sensor is an angle sensor that detects the relative rotation angle of the inner ring with respect to the outer ring of the bearing.

First, an overview of the measurement system will be explained with reference to FIG.
Here, a case will be described in which the measurement system 200 acquires measurement data that associates vibration (acceleration) and position (rotation angle) of a bearing. This measurement system 200 includes a control section 210, a measurement section 220, and a recording section 230.
The control unit 210 can be configured by a microcomputer. The control unit 210 includes a CPU 211 and a DMA controller (Direct Memory Access Controller: DMAC) 212. The measurement unit 220 includes an acceleration sensor 221 and an angle sensor 222. The recording unit 230 includes a memory 231. Note that the recording unit 230 may be included in the control unit 210.

The CPU 211 initializes the memory 231 and the sensors 221 and 222, and initializes the DMAC 212. When the DMAC 212 receives a DMA trigger, it starts DMA transfer. Specifically, when a DMA trigger is input, the DMAC 212 outputs the latest measured values (sensor data) held by the acceleration sensor 221 and the angle sensor 222 as unconverted data (raw data) without going through the CPU 211. Transfer to memory 231.
The acceleration sensor 221 and the angle sensor 222 update and hold measured values at respective predetermined update cycles inside the sensors. The acceleration sensor 221 and the angle sensor 222 are configured to transmit the measured values held at that moment to the outside when there is a request for transmitting the measured values from the outside.

FIG. 2 is a diagram showing update cycles of the acceleration sensor 221 and the angle sensor 222. In this embodiment, it is assumed that the acceleration sensor 221 and the angle sensor 222 are set so that the update completion timings of measured values are synchronized. In other words, the update cycle of the acceleration sensor 221 (first update cycle) and the update cycle of the angle sensor 222 (second update cycle) are equal. Note that the update cycle of the sensor is determined in advance according to the performance of the sensor.

Further, in this embodiment, the acceleration sensor 222 is set to output an interrupt signal (INT signal) to the DMAC 212 every time the measured value (acceleration) held inside the sensor is updated. The DMAC 212 uses the INT signal output from the acceleration sensor 222 as a DMA trigger to perform the above-described DMA transfer.
In this embodiment, the update completion timings of the measurement values of the acceleration sensor 221 and the angle sensor 222 are equal. Therefore, at the timing when the measurement values of the acceleration sensor 221 and the angle sensor 222 are respectively updated, the DMAC 212 acquires the acceleration data and the angle data that are the updated measurement values of each sensor, and transfers them to the memory 231. .

The memory 231 can be configured with, for example, SRAM. Note that the memory 231 may be a NAND type or NOR type flash memory or the like. This memory 231 stores measurement values (angle data, acceleration data) transferred from the DMAC 212. At this time, the memory 231 stores the angle data and acceleration data in one-to-one correspondence as measurement data.
In this way, the measurement system 200 acquires the measurement value (acceleration data) of the acceleration sensor 221 and the measurement value (angle data) of the angle sensor 222 in synchronization with the update completion timing of the measurement value in the acceleration sensor 221, functions as a synchronous measurement system. In FIG. 1, the control section 210 and the recording section 230 correspond to the acquisition section.

FIG. 3 is a flowchart showing the procedure of measurement data acquisition processing.
The process shown in FIG. 3 is started at the timing when power is supplied to the control unit 210 and the measurement unit 220, for example, when the user turns on the power.
First, in step S1, the CPU 211 initializes the acceleration sensor 221 and the angle sensor 222 and performs initial settings. Further, the CPU 211 performs initial settings of the DMAC 212.
Next, in step S2, the sensors 221 and 222 determine whether a measurement start signal has been input. Then, if the measurement start signal is not input, the sensors 221 and 222 wait until the measurement start signal is input, and if it is determined that the measurement start signal is input, the process moves to step S3 and starts measuring the measurement value. do.

In step S4, the CPU 211 determines whether a predetermined measurement time has elapsed since the start of the measurement. Here, the measurement time can be, for example, 1 second. The measurement time is set to be longer than the time required for the rotating ring of the bearing to rotate at least once. Note that the measurement time can be set as appropriate depending on the capacity and power consumption of the recording section 230.
If the CPU 211 determines that the above measurement time has not elapsed since the start of the measurement, the process proceeds to step S5, and if it determines that the above measurement time has elapsed since the start of the measurement, the process proceeds to step S8. Transition.
Note that depending on the selection of the microcomputer, DMA may be performed with the CPU stopped (low power consumption mode). In that case, the elapse of the measurement time may be monitored by a timer within the microcomputer, and the operation of the CPU may be stopped during monitoring. By stopping the operation of the CPU, it is possible to construct a synchronous measurement system for angle and acceleration with lower power consumption.

In step S5, the DMAC 212 determines whether or not the INT signal has been received from the acceleration sensor 221. If the INT signal has not been received, it is determined that the DMA trigger has not been received, and the process returns to step S4. On the other hand, if the DMAC 212 determines that the INT signal has been received from the acceleration sensor 221, the DMAC 212 determines that a DMA trigger has been received and proceeds to step S6.
In step S6, the DMAC 212 reads acceleration data from the acceleration sensor 221 and angle data from the angle sensor 222, and proceeds to step S7.
In step S7, the DMAC 212 transfers the measured values (acceleration data, angle data) read from the sensors 221 and 222 to the memory 231, and returns to step S4.

FIG. 4 is a diagram showing an example of measurement data stored in the memory 231.
As shown in FIG. 4, the memory 231 stores correspondence data between a plurality of angle data and acceleration data measured from the start of measurement until a predetermined measurement time has elapsed.
In step S8, the CPU 211 transmits the measurement data stored in the memory 231 to the outside, and ends the process of FIG. 3.

The measurement data transmitted by the measurement system 200 is used, for example, in a destination external device to diagnose a bearing abnormality. Specifically, as schematically shown in the left diagram of Fig. 5, when measurement data for three revolutions has been acquired, by averaging the vibrations for each angle, as shown in the right diagram of Fig. 5, Get results. This makes it possible to specify that a peak of acceleration exists at angle D, and that vibrations different from those at other angles are occurring at the position of angle D. Note that in this embodiment, by shortening the measurement data acquisition cycle, almost continuous data can be obtained.
In this way, by averaging data measured multiple times, noise can be mechanically removed and feature amounts can be extracted. Therefore, there is no need for complicated processing for removing noise, and there is no need for tuning for each model or individual, so processing is easy.

Note that in this embodiment, a case has been described in which the INT signal output by the acceleration sensor 221 at the timing of completion of updating the measurement value is used as a DMA trigger. However, the INT signal outputted by the angle sensor 222 at the timing when the measurement value update is completed may be used as the DMA trigger. When the update completion timings of the acceleration sensor 221 and the angle sensor 222 are synchronized as in this embodiment, the obtained measurement data will be the same no matter which INT signal is used as the DMA trigger.

As described above, the measurement system 200 according to the present embodiment acquires the measurement value held by the acceleration sensor 221 and the measurement value held by the angle sensor 222 in synchronization with the update completion timing of the measurement value in the acceleration sensor 221. can do. Therefore, measurement data in which acceleration data and angle data correspond one-to-one can be obtained. As a result, it is possible to appropriately understand at what angle and what kind of vibration is occurring during rotation, and it is possible to appropriately identify the location (angle) at which the abnormality occurs.
Conventionally, when diagnosing abnormalities in rotating equipment by monitoring vibration, it is assumed that the rotation speed is constant, and features such as peak value, effective value, and crest factor value are detected from single acceleration data, and frequency analysis is performed. I used to go there. However, in reality, the rotation speed of rotating equipment is not constant or is affected by noise. Therefore, in order to improve the accuracy of vibration-based abnormality diagnosis, measures have been taken to reduce the influence of rotational speed fluctuations and to remove noise from rotational vibration data. However, these countermeasures require processing to determine threshold values based on data from actual devices. Furthermore, noise may remain if only numerical processing is performed. Furthermore, since it is a numerical process, there is a risk that errors will accumulate as the process is repeated.

In contrast, in the present embodiment, measurement data in which acceleration data and angle data correspond one-to-one can be obtained, so there is no need to worry about variations in rotational speed. Moreover, if measurement data obtained by measuring a plurality of times can be obtained, noise can be easily removed by mechanically averaging the data. Therefore, there is no need to determine a threshold value for signal processing as described above.
Furthermore, it is possible to easily identify the location (angle) at which an abnormality occurs, which could not be determined using acceleration data alone. Therefore, it becomes easier to utilize the abnormality diagnosis results for equipment maintenance and design improvement. Furthermore, by continuing measurement, it is also possible to monitor the degree of progress of the abnormality.

Furthermore, the measurement system 200 contributes to miniaturization of the entire configuration by connecting sensors to a microcomputer. Therefore, even if the device housing is small, the measurement system 200 can be housed within the same housing.
Furthermore, the measured values obtained from each sensor can be recorded in the memory 231 as unconverted data. Therefore, when recording data, there is no need for data processing such as conversion from hexadecimal notation to decimal notation, and high-speed data storage is possible. Further, the load due to data processing can be reduced, and power consumption can be reduced.
The measurement system 200 can also include a DMAC 212 that DMA-transfers measurement values held by each sensor, and a memory 231 that records the measurement values DMA-transferred by the DMAC 212. Since data acquisition and data storage can be performed by DMA transfer in this manner, the load on the CPU 211 can be reduced.
In other words, the measurement system 200 in this embodiment can be configured using an inexpensive MEMS sensor or a microcomputer with low power consumption.

Furthermore, if at least one of the acceleration sensor 221 and the angle sensor 222 is capable of outputting an update completion signal each time the measurement value update is completed, the update completion signal is output from either of the sensors capable of outputting the update completion signal. The signal can trigger a DMA transfer. For example, when the update completion signal of the acceleration sensor 221 is used as a trigger for DMA transfer, the DMA transfer of the measurement values of the acceleration sensor 221 and the angle sensor 222 can be executed in synchronization with the update completion timing of the measurement value of the acceleration sensor 221. I can do it. In this way, it is possible to reliably acquire the measured values of each sensor in synchronization with the timing at which the updated measurement values of any of the sensors are completed.

(Second embodiment)
Next, a second embodiment of the present invention will be described.
In the first embodiment described above, a case has been described in which the acceleration sensor 221 and the angle sensor 222 are set so that the update completion timings of measured values are synchronized. In this embodiment, a case will be described in which the update period of the acceleration sensor 221 and the update period of the angle sensor 222 are different, and the update completion timings of measured values are set to be different.

FIG. 6 is a diagram showing update cycles of the acceleration sensor 221 and the angle sensor 222 in this embodiment. In this embodiment, it is assumed that the update cycle of the acceleration sensor 221 is set to be longer than the update cycle of the angle sensor 222. Further, it is assumed that both the acceleration sensor 221 and the angle sensor 222 can output an INT signal to the DMAC 212 at the timing when the measurement value is updated.
In this way, when the update cycle of the acceleration sensor 221 and the update cycle of the angle sensor 222 are different, the INT signal output at the timing when the measurement value of the sensor with the longer update cycle is completed is used as the DMA trigger. do. That is, in this embodiment, the INT signal output from the acceleration sensor 221 with a long update cycle is used as a DMA trigger.

In this way, by using the INT signal output from the sensor with the longer update cycle as the DMA trigger, results close to synchronous measurement can be obtained. This point will be explained in detail below.
When the INT signal of the acceleration sensor 221 is used as a DMA trigger, the DMAC 212 acquires the measured values of the acceleration sensor 221 and the angle sensor 222 at time t1 and time t3 in FIG. Here, the measurement value of the acceleration sensor 221 that the DMAC 212 acquires at time t3 is the measurement value updated by the acceleration sensor 221 at time t3. Further, the measurement value of the angle sensor 222 that the DMAC 212 acquires at time t3 is the measurement value updated by the angle sensor 222 at time t2. In other words, there is a measurement timing error of the temporal width Δt1 between the acceleration data and the angle data acquired at time t3.

On the other hand, when the INT signal of the angle sensor 222 is used as a DMA trigger, the DMAC 212 acquires the measured values of the acceleration sensor 221 and the angle sensor 222 every time the measured value of the angle sensor 222 is updated. However, the measured value of the acceleration sensor 221 is not updated from time t1 to time t3. Therefore, when the INT signal of the angle sensor 222 is used as a DMA trigger, the measured value of the acceleration data 221 acquired by the DMAC 212 at time t1 and the measured value of the acceleration data 221 acquired by the DMAC 212 at time t2 before time t3. have the same value. In other words, a large measurement timing error such as a temporal width Δt2 occurs between the acceleration data and the angle data acquired at time t2.

In this way, when the INT signal output from the sensor with the shorter update cycle is used as a DMA trigger, depending on the measurement value acquisition timing, the measured value before update may be obtained from the sensor with the longer update cycle. This will increase the measurement error.
As in this embodiment, by using the INT signal output from the sensor with the longer update cycle as the DMA trigger, data with less measurement timing error can be acquired. In other words, results close to synchronous measurement can be obtained, and measurement data accuracy can be improved. Further, since measurement data with low accuracy can be prevented from being acquired, power consumption can be reduced accordingly, and power saving can be achieved.

The measurement data acquired in this manner can be used, for example, in an external device to diagnose abnormalities in the bearing, as in the first embodiment described above. Specifically, as schematically shown in the left diagram of Fig. 7, when measurement data for three revolutions has been acquired, by averaging the vibrations for each angle, as shown in the right diagram of Fig. 7, Get results. This makes it possible to specify that a peak of acceleration exists at angle D, and that vibrations different from those at other angles are occurring at the position of angle D. Note that in this embodiment, since the measurement data acquisition cycle is slightly longer, discrete data is obtained compared to the first embodiment.

Note that here, a case has been described in which the acceleration sensor 221 with the longer update cycle can output the INT signal, but if only the angle sensor 222 with the shorter update cycle can output the INT signal, The INT signal of the angle sensor 222 may be used as a DMA trigger. In this case, the measurement timing error becomes larger than when the INT signal of the acceleration sensor 221 is used as a DMA trigger, but it is possible to obtain data corresponding to acceleration data and angle data.

(Example)
Examples of the present invention will be described below.
8 and 9 are exploded perspective views showing the configuration of the sensor-equipped bearing 1 including the measurement system 200 described above. FIG. 8 is a diagram of the sensor-equipped bearing 1 viewed from the cover 10 side, and FIG. 9 is a diagram of the sensor-equipped bearing 1 viewed from the bearing 120 side.
The sensor-equipped bearing 1 includes a sensor-equipped power generation unit 100 and a bearing 120. The sensor-equipped power generation unit 100 is attached to one side of the bearing 120. The sensor-equipped power generation unit 100 includes a cover 10, a coil board 20, a rotating section 30, a circuit board 40, and a back cover 60. Here, the back cover 60 is installed for the purpose of protecting the electronic circuit on the board. Note that the back cover 60 may not be installed, and the substrate may be protected with a potting agent or the like.

The cover 10 is a ring-shaped flat plate member, and is made of 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). It is made of a material that has
As shown in FIG. 9, a circuit board 40 is attached to the surface of the cover 10 facing the bearing 120. As shown in FIG. The circuit board 40 includes a power supply board 41 and a sensor board 42. The power supply board 41 and the sensor board 42 are fixed to the cover 10 by, for example, fastening bolts made of a non-magnetic material such as brass into female screw holes drilled in the cover 10. In this case, the bolt has a length that does not protrude from the cover 10 when it is attached to the cover 10. Note that the power supply board 41 and the sensor board 42 can be arbitrarily divided or integrated as necessary.

Further, a through hole is formed in the cover 10, and this through hole is sealed with a nonmagnetic lid 17 made of a nonmagnetic material such as resin. As will be described later, an antenna 47 (see FIG. 10, which will be described later) is mounted on the sensor board 42. Since the cover 10 is magnetic, it has the effect of shielding electromagnetic waves from the antenna 47. However, the antenna 47 is disposed at a position facing the non-magnetic lid 17, so that the electromagnetic waves from the antenna 47 can reach the external communication section via the non-magnetic lid 17.

The coil substrate 20 is attached to the surface of the cover 10 on the side facing the bearing 120. The coil substrate 20 is fixed to the cover 10 with, for example, an adhesive.
FIG. 10 is a plan view showing an example of the structure of the cover 10 and the coil substrate 20. The coil substrate 20 includes a flexible substrate 21, a coil pattern 23 provided on the flexible substrate 21, and a plurality of yokes 25 provided on the flexible substrate 21. Note that the installation of the yoke 25 is optional. The shape of the flexible substrate 21 in plan view is a perfect ring shape centered on the rotation axis Ax. The coil pattern 23 includes a plurality of planar coils stacked in the thickness direction of the flexible substrate 21. A planar coil is a pattern of conductors that is patterned and provided on a predetermined surface of an insulator. In this embodiment, conductor patterns are formed on multiple surfaces of an insulator. The present invention is not limited to this, and the conductor pattern may be formed on one surface of the insulator. The number of turns of the coil pattern 23 is proportional to the number of stacked planar coils. In this embodiment, the amount of power generation may be adjusted by changing the number of laminated planar coils depending on the use of the sensor-equipped power generation unit 100.
In addition, the coil pattern 23 extends so that concavities and convexities are alternately lined up along the circumferential direction of a circle centered on the rotation axis Ax in plan view. One yoke 25 is arranged in each of the concave and concave portions of the unevenness. The coil pattern 23 may have a shape in which a portion of the circle is missing because an angle sensor is disposed at a position where it can detect magnetic changes of an encoder magnet, which will be described later.

Moreover, the power supply board 41 and the sensor board 42 are attached to the outer peripheral side of the coil board 20 in plan view. A power supply unit 43 is mounted on the power supply board 41. The power supply section 43 converts the single-phase AC power supplied from the power generation section 50 (see FIG. 11 described later) into a DC voltage, and supplies the DC voltage to the sensor board 42 .

A sensor 44, a control circuit section 45, and an antenna 47 are mounted on the sensor board 42. The sensor 44 includes, for example, an acceleration sensor 441, a temperature sensor 442, and an angle sensor 443. Note that the sensor 44, the control circuit section 45, and the antenna 47 may be configured with separate IC (Integrated Circuit) chips, or a part or all of them may be configured with one IC chip.

Although simplified in FIG. 10, both ends of the coil pattern 23 are connected to the power supply board 41 via the lead wires 16. In this embodiment, the coil pattern 23 and the power supply board 41 may be connected through an FPC (Flexible Printed Circuit) connector instead of the lead wire 16. Alternatively, the coil board 20 may be extended and directly connected to the power supply board 41. Connection using an FPC connector does not require soldering, so the productivity of the sensor-equipped power generation unit 100 can be further improved.

Returning to FIGS. 8 and 9, the rotating part 30 includes a ring-shaped magnetic track 31, a ring-shaped base material 33, and a ring-shaped attachment jig 35. The base material 33 and the mounting jig 35 are preferably made of magnetic metal materials. The magnetic track 31 is provided on one side of the base material 33. The mounting jig 35 is fixed to the other side of the base material 33. The attachment jig 35 protrudes from the other surface of the base material 33 to one surface of the base material 33 through a penetrating opening located at the center of the base material 33 . One surface side of the base material 33 is the surface side facing the cover 10. The other side of the base material 33 is the side facing the back cover 60.
Note that the magnetic track 31 may be configured to be attachable to and detachable from the base material 33. Furthermore, when the back cover 60 is not installed as described above, the magnetic track 31 may be provided on the bearing 120. In this case, for example, the magnetic track 31 may be press-fitted into a groove formed in the bearing 120.

In this embodiment, the magnetic track 31 and the base material 33 are collectively referred to as an encoder magnet. For example, an encoder magnet is formed by forming a plastic magnet on one surface of a metal base material, and alternately magnetizing N and S poles on the surface of the formed plastic magnet. The attachment jig 35 is used to attach the encoder magnet to a shaft portion that passes through the sensor-equipped power generation unit 100 and the bearing 120.

The magnetic track 31 has a plurality of magnetic pole pairs 311 consisting of a north pole 31N and a south pole 31S. The plurality of magnetic pole pairs 311 are arranged in the circumferential direction of the magnetic track 31. The north poles 31N and the south poles 31S are arranged alternately.
Further, the distance between the centers of adjacent north poles 31N and south poles 31S in the magnetic track 31 is the same as the distance between the centers of adjacent yokes 25 in the coil substrate 20.

In this embodiment, when the magnetic track 31 rotates relative to the coil substrate 20 around the rotation axis Ax (see FIG. 10), one of the adjacent yokes 25 faces the N pole. In this case, the other yoke 25 faces the S pole. Furthermore, when one yoke 25 faces the south pole, the other yoke 25 faces the north pole. That is, adjacent yokes 25 of the coil substrate 20 do not face the same magnetic pole of the magnetic track 31. As a result, the phase of change in magnetic flux density passing through one yoke 25 and the phase of change in magnetic flux density passing through the other yoke 25 are shifted by 180 degrees.

In this way, when the magnetic track 31 rotates relative to the coil substrate 20, the magnetic poles facing the yoke 25 alternate. As a result, the magnetic flux density passing through the yoke 25 changes periodically. In response to this periodic change in magnetic flux density, a voltage change (for example, a sinusoidal AC voltage) occurs in the coil pattern 23 located around the yoke 25.

FIG. 11 is a diagram showing a configuration example of a circuit board 40 included in the sensor-equipped bearing 1. As shown in FIG. As described above, the circuit board 40 includes the power supply board 41 and the sensor board 42. Here, the sensor board 42 includes an angle sensor board 42a and a control board 42b.
The power supply board 41 includes a rectifier circuit 43a. This rectifier circuit 431 is included in the power supply section 43 (see FIG. 10).

The power generation section 50 includes a magnetic track 31 (see FIG. 8) and a coil substrate 20 (see FIG. 9). The power generation unit 50 generates power based on the relative rotation between the outer ring and the inner ring of the bearing 120, and supplies power to the sensor board 42.
The power generation unit 50 generates single-phase AC power and outputs it to the rectifier circuit 431. The rectifier circuit 431 performs full-wave rectification on the single-phase AC power generated by the power generation unit 50 and converts it into DC power. Although a diode bridge is exemplified as the rectifier circuit 431, the present embodiment is not limited thereto. The DC power output from the rectifier circuit 431 is smoothed by a smoothing circuit (not shown) and becomes a stable power source. Thereafter, power is stored in a power storage circuit and a power storage device (not shown). The DC power stored in the capacitor is output to the sensor board 42 after being adjusted to a constant voltage by a constant voltage output circuit (not shown) at the timing of measurement.

An angle sensor 443 is mounted on the angle sensor board 42a of the sensor board 42. Furthermore, an acceleration sensor 441, a microcomputer 451, an external memory 452, and a wireless module (transmission unit) 453 are mounted on the control board 42b of the sensor board 42. The microcomputer 451, external memory 452, and wireless module 453 are included in the control circuit section 45 (see FIG. 10).
Acceleration sensor 441 and angle sensor 443 use DC power supplied from power supply board 41 to detect acceleration and rotation angle.
For example, the angle sensor 443 is mounted on the angle sensor board 42a so as to be located on the side of the magnetic track 31. The rotating part 30 having the magnetic track 31 is fixed to the inner ring of the bearing 120, and the angle sensor 443 detects the magnetic flux density that changes as the magnetic track 31 rotates together with the inner ring of the bearing 120. Detects the rotation angle of the inner ring relative to the outer ring.
Note that the angle sensor 443 may be of an incremental type or an absolute type.

The microcomputer 451 includes a CPU 451a, a DMAC 451b, and an internal memory 451c. The microcomputer 451 writes the measured value obtained from the sensor 44 into the external memory 452.
Here, the microcomputer 451 corresponds to the control section 210 in FIG. That is, the CPU 451a corresponds to the CPU 211 in FIG. 1, and the DMAC 451b corresponds to the DMAC 212 in FIG. Further, the sensor 44 corresponds to the measuring section 220 in FIG. 1, and the external memory 452 corresponds to the recording section 230 in FIG.

The wireless module 453 transmits data stored in the internal memory 451c and the external memory 452 to the outside under the control of the CPU 451a. This wireless module 453 includes the antenna 47 shown in FIG. For example, the wireless module 453 transmits data to an external device via wireless communication. The transmitted data is received and processed by the communication unit of the external device.
In this embodiment, a case has been described in which the sensor-equipped bearing 1 and the external device perform wireless communication, but any communication standard may be used as long as the sensor-equipped bearing 1 and the external device can communicate with each other. do not have. That is, data transmission from the sensor-equipped bearing 1 to the external device may be performed by wired communication.

Although the case where the measured value obtained from the sensor 44 is written to the external memory 452 has been described here, the measured value obtained from the sensor 44 may be written to the internal memory 451c, or the measured value obtained from the sensor 44 may be written to the internal memory 451c and the external memory 452. 452 may be used in combination. Further, the internal memory 451c and the external memory 452 may be one memory.

As described above, the measurement system 200 according to the present embodiment can achieve miniaturization and power saving, and can also be stored in a small device housing. Therefore, this measurement system 200 can be stored in the narrow space between the inner ring and outer ring of the bearing in the sensor-equipped bearing 1 using a magnetic encoder as described above, and it is possible to construct a sensor device in the same housing. become. Further, the present invention can also be applied to a data wireless transmission type device having a self-power generation function without an external power supply.
In this way, the measurement system 200 applied to the sensor-equipped bearing 1 of the data wireless transmission type having the self-power generation function uses the minute electric power generated by the self-power generation function to measure the physical quantity related to the bearing by the rotational position (angle) of the bearing. ) can be acquired and wirelessly transmitted to an external device.
Note that although the case where the present invention is applied to the sensor-equipped bearing 1 having a self-power generation function has been described here, the power supply may be an external power supply.

Further, the above-described sensor-equipped bearing 1 can be applied to, for example, a bearing portion of a water turbine.
FIG. 12 is a diagram showing the configuration of a Pelton water turbine 300 including the sensor-equipped bearing 1. As shown in FIG.
The Pelton water turbine 300 includes an impeller (runner) 311. A large number of blades (buckets) 312 are provided on the outer periphery of the runner 311.
Further, the Pelton water turbine 300 includes a plurality of (two in FIG. 12) nozzles 321. A needle valve 322 is arranged within each nozzle 321 so as to be movable forward and backward. When the opening of the nozzle 321 is controlled by the needle valve 322 and water is injected from the tip of the nozzle 321, the blades 312 receive the water and the impeller 311 rotates. The Pelton water turbine 300 generates electricity through the rotation of the impeller 311.

While the impeller 311 is rotating, water hits each blade 312, causing vibrations in the bearing. At this time, if any abnormality has occurred in any of the plurality of blades 312 included in the Pelton turbine 300, the vibration level when water hits that blade 312 will be lower than the vibration level when water hits the other blades 312. The vibration level is different from that at the time.
Therefore, by installing the above-mentioned sensor-equipped bearing 1 in the bearing part of the Pelton water turbine 300, acquiring measurement data that associates the vibration of the bearing with the rotational position (angle), and analyzing the acquired measurement data, It is possible to specify which blade 311 has an abnormality. For example, if it is identified that an abnormality has occurred in the fourth blade 312, only the fourth blade 312 in which the abnormality has occurred can be repaired or replaced, thereby reducing maintenance costs. .

(Modified example)
In the above embodiment, a case has been described in which the rotating device is a bearing, but the rotating device may be a gear, for example. In this case as well, by connecting the acceleration sensor that measures the vibration of the gear and the angle sensor that measures the rotation angle of the gear to the microcontroller, measurement data that associates the vibration of the gear with the rotational position (angle) is obtained. It is possible to configure a measurement system that In this case, based on the acquired measurement data, it is possible to diagnose which tooth of the gear has an abnormality.
Further, in the above embodiment, a case has been described in which an acceleration sensor that detects acceleration indicating vibration of the bearing is used as a physical quantity related to the bearing, but the physical quantity is not limited to vibration (acceleration). For example, it is also possible to use an ultrasonic sensor that detects friction noise generated in bearings. In this case as well, it becomes possible to specify at which position (angle) of the bearing the abnormal noise is occurring.

Furthermore, in the above embodiment, a case has been described in which measurement data in which acceleration data and angle data are associated is acquired, but measurement data in which three or more types of measurement values including acceleration data and angle data are associated is acquired. You can also. In this case, each measurement value of three or more types of sensors is acquired in synchronization with the timing at which the update of the measurement value in any one of the sensors is completed. For example, each measurement value is acquired in synchronization with the update completion timing of the longer update cycle of at least two sensors among three or more types of sensors.

Furthermore, in the above embodiment, the case where the measurement data is used for abnormality diagnosis of the bearing has been described, but the method of using the measurement data is not limited. In other words, the measurement data can be used for purposes other than abnormality diagnosis.
For example, when the above-described sensor-equipped bearing 1 is applied to a joint of a robot arm, it is possible to specify the angle of the robot arm at which vibration occurs. Therefore, in this case, teaching may be performed so that the arm tip moves along a trajectory that does not generate vibrations.

Note that the configuration of the synchronous measurement system described above is not only applicable to rotating equipment, but also applicable to, for example, linear motion mechanisms. When applied to a linear motion mechanism, the horizontal position and physical quantities related to the device can be measured in synchronization.
Furthermore, the above-described synchronous measurement system is applicable not only to a system that synchronously measures an angle (position) and other physical quantities, but also to a system that synchronously measures a plurality of physical quantities each measured by a plurality of different sensors. For example, it can be applied to a system that synchronously measures pressure changes and vibrations of fluid in pipes in a factory. In this case, it is possible to detect and predict failures such as pipe damage.

DESCRIPTION OF SYMBOLS 1...Bearing with a sensor, 100...Power generation unit with a sensor, 120...Bearing, 200...Measurement system, 210...Control unit, 211...CPU, 212...DMA controller (DMAC), 220...Measurement unit, 221...Acceleration sensor, 222 ...Angle sensor, 230...Recording section, 231...Memory

Claims (6)

bearing and
a first sensor that measures a physical quantity related to the bearing that is different from a rotation angle of the bearing, and updates and holds the measured value at a first update cycle;
a second sensor that measures the rotation angle of the bearing and updates and holds the measured value at a second update cycle different from the first update cycle;
Acquisition of a measured value held by the first sensor and a measured value held by the second sensor at the timing of completion of update of the measured value in either the first sensor or the second sensor. and,
At least the sensor with a longer update cycle among the first sensor and the second sensor is capable of outputting an update completion signal each time the update of the measurement value is completed,
The acquisition unit includes:
Using the update completion signal output from the sensor with the longer update cycle as a trigger, the measured value held by the first sensor and the measured value held by the second sensor are transferred via DMA (Direct Memory Access). a control unit to transfer;
A bearing with a sensor, comprising: a recording unit that records the measured value of the first sensor and the measured value of the second sensor, which have been DMA-transferred by the control unit, in association with each other. The first sensor includes an acceleration sensor that measures vibrations of the bearing,
The sensor-equipped bearing according to claim 1, wherein the second sensor is an angle sensor that measures a relative rotation angle of the inner ring with respect to the outer ring of the bearing. The sensor-equipped bearing according to claim 1 or 2, further comprising a transmitter that transmits the measured value acquired by the acquirer to an external device. Claim further comprising: a power generation unit that generates power based on relative rotation between the outer ring and the inner ring of the bearing and supplies power to the first sensor, the second sensor, and the acquisition unit. 4. The sensor-equipped bearing according to any one of 1 to 3 . The sensor-equipped bearing according to any one of claims 1 to 4 , characterized in that it has a self-power generation function without an external power supply. a first sensor that measures a physical quantity related to the rotating device that is different from a rotation angle of the rotating device, and updates and holds the measured value at a first update cycle;
a second sensor that measures the rotation angle of the rotating device and updates and holds the measured value at a second update cycle different from the first update cycle;
Acquisition of a measured value held by the first sensor and a measured value held by the second sensor at the timing of completion of update of the measured value in either the first sensor or the second sensor. and,
At least the sensor with a longer update cycle among the first sensor and the second sensor is capable of outputting an update completion signal each time the update of the measurement value is completed,
The acquisition unit includes:
Using the update completion signal output from the sensor with the longer update cycle as a trigger, the measurement value held by the first sensor and the measurement value held by the second sensor are transferred via DMA (Direct Memory Access). a control unit to transfer;
A synchronous measurement system comprising: a recording unit that records the measured value of the first sensor and the measured value of the second sensor, which are DMA-transferred by the control unit, in association with each other.

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