Bearing device and abnormality detection system

Abstract

To provide a bearing device enabling an external device to adjust time of sensor signals with high accuracy.SOLUTION: A bearing device comprises: a bearing including an outer ring and an inner ring; a power generation part for generating electricity by relative rotations of the inner ring and the outer ring; a power storage part for storing the electricity generated by the power generation part; a sensor for detecting status values on the bearing and outputting sensor signals; a data storage part for storing data of the sensor signals output from the sensor; a data communication part for sending the data stored in the data storage part to the external device; and a control part for controlling storage and sending of the data. The control part starts counting at predetermined time intervals when a voltage of the power storage part is at or greater than a voltage threshold, stores the number of counts when the sensor outputs the sensor signals and the data of the sensor signals at the time in a corresponding manner in the data storage part, acquires time information from the external device, and associates the time information and the data on the number of counts and the sensor signals stored in a corresponding manner.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a bearing device including a sensor unit that performs data communication with a bearing such as a rolling bearing, and to an abnormality detection system that uses the same. [Background technology]

[0002] Conventionally, there has been known, for example, a bearing device (also called a bearing with a sensor) in which a sensor unit is formed by mounting electronic components that perform data communication and sensors for detecting the state of the bearing on a circuit board or the like, and the sensor unit is fixed to the inner ring or outer ring of the bearing.

[0003] In a sensor-equipped bearing, for example, a generator and circuit board are placed on one end of a bearing used for inner ring rotation. The generator's stator is fixed to the outer ring of the bearing, and a coil is held in the stator. A magnetic ring magnetized with alternating north and south poles is fixed to the inner ring of the bearing as the generator's rotor. As the inner and outer rings of the bearing rotate relative to each other, electromagnetic induction generates an AC voltage in the coil, causing the generator to generate electricity. The power generated by the power generation unit is consumed, for example, in various parts of the bearing device, and can also be stored in the power storage unit. The (electronic) circuit board carrying the various circuits, sensors, and wireless devices is fixed to the outer ring of the bearing, for example via the stator, and is further sealed with an electronic circuit protection material.

[0004] The AC voltage (electricity) generated by the generator is input into the power supply circuit. The power supply circuit rectifies the AC voltage to DC voltage, and then obtains the constant voltage necessary for the operation of sensors and electronic components. The sensors are acceleration sensors, temperature sensors, etc., and are driven at a constant voltage to obtain sensor signals of bearing status values ​​such as vibration acceleration and temperature, which are the state of the bearing. The rotational speed is obtained by processing the voltage fluctuations of the generator's output (typically the AC output). For example, rotational speed information can be obtained from the alternating frequency and peak voltage of the AC output.

[0005] The obtained sensor signal and rotational speed data are transmitted to an external device, for example, by electronic components that perform data communication on an (electronic) circuit board. In bearings with wireless sensors, the data is transmitted to the external device wirelessly according to standards such as Bluetooth Low Energy (2.4 GHz). The transmitted data is received by an external data collection device or the like.

[0006] Patent Document 1 discloses, as prior art, a rotating device equipped with a bearing that includes a power generation unit, a power storage unit, a sensor signal storage circuit serving as a data storage unit, a control unit, and a communication circuit serving as a data communication unit. In this prior art, power generated by the power generation unit through the rotation of the bearing is stored in the power storage unit, and depending on the voltage of the power storage unit, data detected by the sensor is written to the storage circuit and wirelessly transmitted to an external device by the communication circuit. This prevents malfunctions such as unintended shutdowns due to power shortages and keeps power consumption of the communication circuit low. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 7020250 Summary of the Invention [Problem to be solved by the invention]

[0008] In a sensor-equipped bearing, the rotation of the bearing generates electricity, which is stored in a power storage unit to operate the electronic circuit. If the bearing does not rotate, the stored voltage in the power storage unit drops and the circuit stops operating. As a result, time information such as the date and time when the sensor signal was acquired (date and time information of the sensor signal) cannot be retained.

[0009] One possible solution is to equip the control unit of the sensor-equipped bearing with a primary battery as a regular power source. However, bearing devices such as (wireless) sensor-equipped bearings are often used as support bearings for the rotating shafts of motors, gears, and other components of machinery to detect abnormalities in rotating components. Therefore, the use of primary batteries, which require periodic replacement, is likely to increase costs due to the need to disassemble the machinery, and is not suitable for downsizing the bearing if a large-capacity battery is desired. For this reason, it is difficult to install a primary battery in the control unit or other component to store date and time information.

[0010] The bearing with wireless sensor described in Patent Document 1 switches between enabling and disabling writing to the memory circuit and wireless communication of the communication circuit depending on the voltage of the storage unit. However, if the voltage of the storage unit is low after writing data detected by the sensor, wireless communication must wait until the voltage increases to a level where communication is possible, which can result in a discrepancy between the date and time when the data is detected by the sensor and the date and time when the data is transmitted to an external device via wireless communication.

[0011] Furthermore, if the amount of data to be transmitted is large or if the storage capacity of the power storage unit is insufficient, the data must be transmitted wirelessly in multiple batches, which may result in a discrepancy between the date and time when the data is detected by the sensor and the date and time when the data is transmitted wirelessly to an external device.

[0012] If the data detected by the sensor is written to the memory circuit multiple times with intervals such as data sampling in between, the boundaries between the data and the measurement times may become unclear, especially if the circuit operation stops midway due to a power drop or other reason.

[0013] Additionally, when monitoring the operating status of equipment incorporating a wireless sensor-equipped bearing, it is conceivable to use data from another sensor installed on the equipment in addition to the data from the sensor in the wireless sensor-equipped bearing. In such cases, multiple pieces of data may be acquired by an external device, and the data from the other sensor may be time-aligned (matched) with the data from the sensor in the wireless sensor-equipped bearing to perform processing such as determining abnormalities in the equipment or bearings. However, if the data from the sensor in the wireless sensor-equipped bearing does not contain date and time information, it is not possible to synchronize the timing (time alignment) with other data from other sensors, and therefore it is not possible to process the data as if it were acquired on the same date and time (time), which could reduce the temporal consistency of the data and reduce the accuracy of abnormality determination.

[0014] Therefore, in order to solve the above-mentioned conventional problems, an object of the present invention is to provide a bearing device that enables highly accurate time synchronization of sensor signals using an external device, and to provide an abnormality detection system that can improve the accuracy of abnormality detection in equipment, bearings, etc., in equipment that incorporates this bearing device. [Means for solving the problem]

[0015] For example, the bearing device of the present invention is a bearing with a wireless sensor, and in order to solve the above-mentioned conventional problems, time information at the time of acquisition can be added to the data acquired by the bearing sensor. This makes it easy to synchronize the time with other sensor signals acquired by external devices, and in equipment incorporating this bearing device, the accuracy of anomaly detection in the equipment, bearings, etc. can be improved.

[0016] Furthermore, for example, in the bearing device and anomaly detection system of the present invention, when the voltage of the power storage unit of the wireless sensor-equipped bearing exceeds a threshold, the control unit generally starts counting at predetermined time intervals, associates the count with the sensor signal data at that time, and when date and time information, an example of time information, is acquired from an external device via wireless communication, links the count, the date and time information, and the sensor signal data stored corresponding to the count. The sensor signal data detected by the sensor can be stored in the data storage unit along with the associated count and date and time information. Note that the date and time information may be stored in the data storage unit simultaneously with the associated count and sensor signal data. In this case, it does not matter which comes first: the associated date and time information, the corresponding stored count and sensor signal data, or the associated stored data. Alternatively, the associated date and time information may be stored in the data storage unit after the corresponding count and sensor signal data have been stored in the data storage unit.

[0017] The bearing device according to the present invention comprises: A bearing device comprising: a bearing including an outer ring and an inner ring; a power generation unit that generates electricity through relative rotation between the inner ring and the outer ring; a power storage unit that stores the electricity generated by the power generation unit; a sensor that detects a state value related to the bearing and outputs a sensor signal; a data storage unit that saves data of the sensor signal output from the sensor; a data communication unit that transmits the data saved in the data storage unit to an external device; and a control unit that controls the saving of the data and the transmission of the data, The control unit When the voltage of the power storage unit becomes equal to or greater than a threshold value, counting is started at predetermined time intervals; The count number when the sensor signal is output from the sensor is stored in the data storage unit in association with the data of the sensor signal at that time, Time information is acquired from the external device, and the time information is linked to the correspondingly stored count number and sensor signal data.

[0018] In the bearing device according to the present invention, the control unit starts the counting when the voltage of the power storage unit exceeds a threshold value, and stores the count number when the sensor signal is output from the sensor in association with the sensor signal data at that time in the data storage unit. Time information is also acquired from the external device, and the count number is used to link the time information, the count number, and the sensor signal data. This achieves a temporal correspondence between the time information and the sensor signal data output from the sensor, improving the accuracy and temporal consistency of the time information. This enables highly accurate time synchronization with other sensor signals acquired by external devices.

[0019] In the above-described bearing device, The threshold value at which the control unit starts the counting may be set based on a voltage reference value that enables data communication with the external device or a voltage reference value that enables acquisition of the sensor signal. where: the threshold value is set based on a voltage reference value that enables data communication with the external device; After obtaining the time information from the external device, a predetermined amount of the count number when the sensor signal is output from the sensor, the time information at the time of the count number, and the data of the sensor signal stored corresponding to the count number are stored in the data storage unit in association with each other; The data stored in the data storage unit may be transmitted from the data communication unit to an external device, Also, the threshold value is set based on a voltage reference value that enables acquisition of the sensor signal; The count number when the sensor signal is output from the sensor is stored in the data storage unit in association with the data of the sensor signal at that time, and then acquiring the time information from the external device; The data communication unit may link the count number when the sensor signal is output from the sensor, the time information at that count number, and the sensor signal data stored corresponding to the count number, and transmit them to an external device.

[0020] According to the above configuration, the threshold value when the control unit starts the counting may be set, for example, based on a voltage reference value that enables data communication with the external device, or based on a voltage reference value that enables acquisition of the sensor signal. The threshold value may be set based on a voltage reference value that enables data communication with the external device, for example, when the rotation speed of the bearing repeatedly increases and decreases significantly, causing a so-called unstable state of rotation, which causes the voltage of the power storage unit to fall below threshold V3, which is the minimum threshold value that allows wireless communication to be maintained, and communication with the external device OF is likely to be interrupted. In this way, in an unstable case where the voltage of the storage unit falls below a predetermined threshold V3 a predetermined number of times or more, it is preferable to first obtain time information when the voltage of the storage unit reaches or exceeds a threshold V1, which is a threshold at which wireless communication can be initiated, for example, that is set based on a voltage reference value at which data communication with an external device is possible, and then link the count number with the time information and sensor signal data at that count number and store them in the data storage unit, and then transmit the data stored in the data storage unit to the external device after a stable state of rotation is confirmed, or if an unstable state of rotation is confirmed, after the rotation returns from the unstable state to a stable state again.

[0021] Furthermore, the voltage reference value is set based on the voltage reference value that allows acquisition of the sensor signal when, for example, there is no fluctuation in the rotational speed of the bearing (or the fluctuation is smaller than a predetermined range) and the rotation is in a stable state. In this case, the voltage of the power storage unit does not (or rarely) fall below the threshold V3. Therefore, communication with the external device is not (or rarely) interrupted. In this stable case where the number of times the voltage of the power storage unit falls below the threshold V3 is equal to or less than a predetermined number of times, it is preferable to store a predetermined amount of counts when a sensor signal is output from the sensor and data of the sensor signal at that time in the data storage unit, associate the counts with the time information at the time of the counts, and transmit the data to the external device from the data communication unit.

[0022] The anomaly detection system according to the present invention comprises: In equipment incorporating any of the above bearing devices, The data transmitted by the data communication unit is time-correlated with data acquired by the external device that is a sensor signal other than the sensor signal output from the sensor, and an abnormality in the equipment or the bearing is determined.

[0023] The anomaly detection system according to the present invention incorporates the bearing device described above with improved time information accuracy, which enables highly accurate time synchronization of other sensor signals acquired by an external device, etc. Therefore, when detecting anomalies in equipment, bearings, etc., data with improved time information accuracy is used, allowing for a time-consistent response and improving the accuracy of anomaly detection. [Effects of the Invention]

[0024] The bearing device according to the present invention can achieve highly accurate time synchronization of sensor signals with an external device, and the abnormality detection system according to the present invention can improve the accuracy of abnormality detection of equipment, bearings, etc. in equipment incorporating the bearing device. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a front vertical cross-sectional view showing a main part of a bearing device according to an embodiment of the present invention. [Figure 2A] FIG. 2 is a perspective view showing the overall appearance of the bearing device of FIG. [Figure 2B] 2B is a side view showing the bearing device of FIG. 2A with the cover of the sensor unit partially cut away. FIG. [Figure 3] FIG. 2 is an exploded perspective view of the sensor unit of FIG. 1. [Figure 4] FIG. 2 is a block diagram of a bearing with a wireless sensor, which is an example of the bearing device. [Figure 5] FIG. 4 is a flowchart showing an example of the operation of the above-mentioned bearing with a wireless sensor. [Figure 6] FIG. 4 is a waveform diagram of rotational speed showing an example of operation of the above-mentioned bearing with wireless sensor. [Figure 7] FIG. 4 is a waveform diagram of a stored voltage showing an example of operation of the above-mentioned bearing with a wireless sensor. [Figure 8] FIG. 4 is a waveform diagram of the count number showing an example of the operation of the above-mentioned bearing with wireless sensor. [Figure 9] 10 is a diagram showing an example of a data format stored in a data storage unit of the above-mentioned wireless sensor-equipped bearing. FIG. [Figure 10] FIG. 10 is a flowchart showing another example of the operation of the wireless sensor-equipped bearing. [Figure 11] FIG. 10 is a waveform diagram of rotational speed showing another example of operation of the above-mentioned bearing with wireless sensor. [Figure 12] FIG. 10 is a waveform diagram of a stored voltage showing another example of operation of the above-mentioned bearing with wireless sensor. [Figure 13] FIG. 10 is a waveform diagram of the count number showing another example of the operation of the above-mentioned bearing with wireless sensor. DETAILED DESCRIPTION OF THE INVENTION

[0026] An embodiment will be described in detail below with reference to the drawings. In the embodiments described below, when numbers, quantities, etc. are mentioned, the scope of the present disclosure is not necessarily limited to those numbers, quantities, etc., unless otherwise specified. The same reference numerals are used for the same or equivalent parts, and redundant descriptions may not be repeated. It is intended from the beginning that the configurations in the embodiments may be used in appropriate combinations.

[0027] This bearing device WB (FIG. 4) is a sensor-equipped bearing that includes a bearing 1 such as a rolling bearing, a sensor unit 2, and a generator 3, as shown in FIG.

[0028] Here, the circumferential direction centered on the central axis (central axis of rotation) of the rolling bearing 1 (not shown) is referred to as the "circumferential direction," the direction along the central axis of the bearing is referred to as the "axial direction," and the direction perpendicular to the central axis of the bearing is referred to as the "radial direction." In Figure 1, the axial direction corresponds to the left-right direction, and the radial direction corresponds to the up-down direction.

[0029] The structure of the sensor-equipped bearing will now be described. As shown in Figure 1, the rolling bearing 1 has a first raceway 4 which serves as the outer ring, a second raceway 5 which serves as the inner ring, and a plurality of rolling elements 6 arranged between the first raceway 4 and the second raceway 5. These rolling elements 6 are held at equal intervals in the circumferential direction by a cage 7.

[0030] The sensor unit 2 is a unit that integrates a circuit board 8 and a holder 9 that holds the circuit board 8. The circuit board 8 includes electronic components (described below) of a data communication unit that performs data communication, a temperature sensor 10, and the like. The holder 9 has a substantially annular side portion 11 that extends radially and has a substantially circular ring shape, and a fitting portion 12 that protrudes axially from the annular side portion 11. The sensor unit 2 of this embodiment is fixed to the first bearing ring 4.

[0031] The generator 3 comprises a magnetic ring 13, also called a rotor, which is arranged so as to be rotatable integrally with the second bearing ring 5, and a stator 14 which faces the magnetic ring 13 and is fixed to the first bearing ring 4. The generator 3 generates electricity by electromagnetically converting the relative rotational motion between the first bearing ring 4 and the second bearing ring 5 into alternating current by the magnetic ring 13 and the stator 14.

[0032] The rolling bearing 1 of this embodiment is a radial bearing, such as a bearing with an inner ring that rotates. The rolling bearing 1 is also a standard bearing that complies with a specific standard. Here, a standard bearing refers to a bearing that satisfies the dimensions specified in an ISO or JIS standard. For example, the dimensions of radial bearings other than tapered roller bearings are specified in ISO 15 or JIS B 1512-1. Note that while FIG. 1 illustrates an example in which the rolling bearing 1 is configured as a deep groove ball bearing, the rolling bearing 1 is not limited to a deep groove ball bearing.

[0033] The first bearing ring 4 is usually arranged as a stationary ring. The second bearing ring 5 is usually arranged as a rotating ring. The first bearing ring 4 is an outer ring having an inner circumference 16 including a first raceway surface portion 15. The second bearing ring 5 is an inner ring having an outer circumference including a second raceway surface portion 17. Each rolling element 6 is a ball that rolls between the raceway surface portions 15, 17. The raceway surface portions 15, 17 are the surfaces of the bearing rings 4, 5 that form the rolling paths of the rolling elements 6. In the illustrated example, they are continuous around the entire circumferential direction with a cross-sectional shape that forms a raceway groove corresponding to the diameter of the rolling elements 6.

[0034] A predetermined distance is maintained between the rolling elements 6, cage 7, and sensor unit 2. This distance is set so that the sensor unit 2 will not come into contact with the rolling elements 6 or cage 7 even if there is axial displacement due to the clearance inside the rolling bearing 1. The cage 7 is a crown-shaped cage that has a ring portion only on the side opposite the sensor unit 2 (the side facing away from the sensor unit 2, the left side in Figure 1) relative to each rolling element 6. To avoid interference between the sensor unit 2 and cage 7, the cage 7 does not have any part that is closer to the sensor unit 2 than the rolling elements 6. The sensor unit 2 does not have any part that protrudes axially from the rolling bearing 1.

[0035] The inner periphery 16 of the first bearing ring 4 includes a step portion 18 that axially receives the annular side portion 11 of the holder 9, and a peripheral surface portion 19 that fits into the fitting portion 12 of the holder 9. The step portion 18 extends radially and completely around the circumference. The peripheral surface portion 19 is a cylindrical surface that extends axially and completely around the circumference.

[0036] As shown in Fig. 1, the first raceway ring 4 has an end surface portion 20 located at one end of the axial width of the first raceway ring 4 (the right end in Fig. 1). The end surface portion 20 is along the radial direction. The step portion 18 and the circumferential surface portion 19 are formed at a position closer to the first raceway surface portion 15 in the axial direction than the end surface portion 20. The circumferential surface portion 19 intersects with the step portion 18 at the other axial end of the circumferential surface portion 19 (the left end in Fig. 1).

[0037] The holder 9 is an annular body that, when attached to the first bearing ring 4, positions the circuit board 8 relative to the first bearing ring 4. The entire holder 9 is formed from a single metal plate, seamlessly integrating the annular side portion 11 and the fitting portion 12. The annular side portion 11 is an annular plate with both radially extending side surfaces along the entire circumferential direction. The fitting portion 12 extends axially from the end of the annular side portion 11 closest to the first bearing ring 4. For example, the entire holder 9 is press-formed. The metal plate forming the holder 9 is thick enough to stably hold the position of the circuit board 8 relative to the first bearing ring 4. The fitting portion 12 is fitted to a peripheral surface portion 19 of the first bearing ring 4. This positions the holder 9 with a predetermined degree of coaxiality with the first bearing ring 4. The peripheral surface portion 19 of the first bearing ring 4 is formed by machining.

[0038] Depending on the required specifications for the arrangement of the temperature sensor 10 and other components held by the holder 9, it may be necessary to prevent the holder 9 from rotating in the circumferential direction relative to the first bearing ring 4. To meet these requirements, welds 22 are provided to join the holder 9 and the first bearing ring 4. Small welds 22 can be provided by laser welding. Although an example in which the welds 22 are provided around the entire circumferential circumference is shown (see FIGS. 2A and 2B), they can also be provided as spot welds at multiple locations evenly spaced around the circumferential direction.

[0039] The circuit board 8 is a printed circuit board including the substrate 23 shown in FIGS. 2B and 3, the temperature sensor 10 mounted on the substrate 23, a wireless communication circuit 24 serving as a data communication unit mounted on the substrate 23, a power supply circuit 25 mounted on the substrate 23, and one or more other sensors 26 mounted on the substrate 23. The circuit board 8 may further include a power storage unit for storing power generated by the power generation unit (described below), a data storage unit for storing data of sensor signals output from the sensors, and a control unit for controlling data storage and transmission. The substrate 23 is an arc-shaped plate that is short in the radial direction and long in the circumferential direction. The temperature sensor 10, the wireless communication circuit 24, the power supply circuit 25, and one or more other sensors 26 are mounted on the surface of the substrate 23 facing the reversing body 6 (the right side in FIG. 1). As shown in FIGS. 2B and 3, the substrate 23 is fixed to the annular side portion 11 with a plurality of screws 27.

[0040] Temperature sensor 10 consists of a circuit that converts temperature into an electrical signal. Temperature sensor 10 is positioned axially opposite first raceway surface portion 15. As rolling bearing 1 rotates, it generates heat. One of the main causes of this heat generation is heat generated at the contact point between rolling elements 6 and first raceway ring 4. To enable this heat to reach temperature sensor 10 quickly and accurately, it is advisable to provide a heat conduction path consisting of a solid portion that continues axially from first raceway surface portion 15 to circuit board 8, preferably to temperature sensor 10, as shown in the figure.

[0041] The one or more other sensors 26 shown in Figures 2B and 3 are composed of circuits that convert physical or chemical quantities other than temperature into electrical signals. The type of other sensor 26 is not particularly limited. For example, at least one selected from the group consisting of an acceleration sensor and an AE (Acoustic Emission) sensor is included among the one or more other sensors 26. If an acceleration sensor is used, it is possible to detect radial or axial acceleration to monitor vibrations of the rolling bearing 1. If an AE sensor is used, it is possible to detect elastic waves (AE waves) emitted when sound generated when a part of an object, such as a component of the rolling bearing 1, is deformed or damaged, or when an impact is applied. Note that electronic components including a temperature sensor and an acceleration sensor may also be used.

[0042] The wireless communication circuit 24 is a communication circuit that converts predetermined information, such as the results of detection by the temperature sensor 10 and one or more other sensors 26, into radio waves and radiates them from an antenna 24a (FIG. 2B). The wireless communication circuit 24 conforms to a predetermined communication protocol and is generally modular. To avoid a decrease in wireless communication performance, the antenna 24a of the wireless communication circuit 24 is not in contact with other members, such as a sealant.

[0043] The power supply circuit 25 is a circuit that converts AC power generated by the stator 14 of the generator 3 into DC power used on the circuit board 8 .

[0044] To protect the circuit board 8 from exposure to the outside, the sensor unit 2 is provided with a cover 28 shown in FIG. 2A that covers the opening for inserting the circuit board 8 onto the annular side portion 11.

[0045] The magnetic ring 13 shown in FIG. 1 has a magnet 29 magnetized with alternating north and south poles in the circumferential direction as shown in FIG. 2B, and the core 30 of FIG. 1. The magnet 29 is formed of magnetic rubber extending in the circumferential direction. The magnet 29 is bonded to the core 30 around the entire circumferential direction. Vulcanization bonding can be used as the bonding method. The core 30 has a flange portion to increase its rigidity. Although the magnet 29 is exemplified as a magnetic material magnetized with multiple poles, it may also be composed of multiple permanent magnets.

[0046] The magnetic ring 13 is fixed to the outer periphery of the second bearing ring 5 by utilizing the stepped end 31 of the second bearing ring 5 so as not to protrude axially from the second bearing ring 5. By fitting the magnetic ring 13 onto the outer periphery of the second bearing ring 5, the second bearing ring 5 and the magnetic ring 13 are arranged coaxially. The stepped end 31 of the second bearing ring 5 is a portion for securing an annular space between the circumferential surface portion 19 of the first bearing ring 4 and the second bearing ring 5 that can accommodate the sensor unit 2 and the magnetic ring 13, and has a shape that radially expands the space between the circumferential surface portion 19 and the end of the second bearing ring 5 that faces this in the radial direction.

[0047] Stator 14 guides the magnetic flux emitted from magnetic ring 13 through a yoke structure, inducing an AC voltage in coil 32 within the yoke structure. Stator 14 is provided in sensor unit 2. As shown in FIG. 3, the yoke structure of stator 14 is made up of holder 9 and yoke member 33 combined with annular side portion 11 of holder 9.

[0048] The holder 9 and the yoke member 33 are each made of a magnetic material such as a steel plate. The yoke member 33 is formed from a single metal plate. The overall shape of the yoke member 33 is press-formed. The holder 9 has a first claw pole portion 34 that extends seamlessly and integrally from the annular side portion 11 on the side opposite the mating portion 12 (the side farther from the mating portion 12, or the lower side in FIG. 1) to the same side as the mating portion 12 in the axial direction (the right side in FIG. 1) at regular intervals in the circumferential direction.

[0049] The yoke member 33 in Figure 3 has a seamless, integrated annular plate portion 35 that faces the mating portion 12 in the radial direction, a side plate portion 36 that extends radially from the anti-annular side portion 11 side of the annular plate portion 35 (the side farther from the annular side portion 11 in Figure 1, the lower side) to the anti-mating portion 12 side (the side farther from the annular side portion 11, the right side in Figures 1 and 3), and a second claw pole portion 37 that extends axially from the side plate portion 36 at a regular interval in the circumferential direction toward the annular side portion 11 side (the left side in Figure 3).

[0050] The yoke structure of the stator 14 (FIG. 1) is formed by a first claw pole portion 34, an annular side portion 11, an annular plate portion 35, a side plate portion 36, and a second claw pole portion 37. The fitting portion 12 of the holder 9 forms the outer periphery of the sensor unit 2. The first claw pole portion 34 and the second claw pole portion 37 are located on the inner periphery of the sensor unit 2. As shown in FIG. 2B, the first claw pole portion 34 and the second claw pole portion 37 face each other radially with an air gap between them and the magnet 29. The first claw pole portion 34 and the second claw pole portion 37 are arranged axially in opposite directions and alternately in the circumferential direction. A circumferential air gap is formed between adjacent first claw pole portions 34 and second claw pole portions 37. The total number of first claw pole portions 34 and second claw pole portions 37 is equal to the number of poles (total number of north and south poles) of the magnet 29.

[0051] 3, arc-shaped holes 38 that axially penetrate the annular side portion 11 are formed at multiple locations in the circumferential direction. Protrusions 39 that fit into the inner surfaces of the holes 38 protrude in the axial direction from the annular plate portion 35. The annular plate portion 35 is abutted against the annular side portion 11 in the axial direction at substantially all portions except for the areas where these protrusions 39 are present.

[0052] The coil 32 is wound around a bobbin 40. The coil 32 and the bobbin 40 are arranged all around the circumference in a space surrounded by the annular side portion 11, the side plate portion 36, the annular plate portion 35, the first claw pole portion 34, and the second claw pole portion 37.

[0053] At least a portion of the surface of the coil 32 and bobbin 40 may be in contact with the claw pole portions 34, 37, the annular side portion 11, and the side plate portion 36. To protect the magnet wire forming the coil 32 for the purposes of insulation, heat resistance, dust resistance, moisture resistance, and chafing prevention, a varnish treatment may be employed in which the coil 32 is coated by dipping it in varnish or by dripping varnish onto the coil 32. The bobbin 40 may also be omitted.

[0054] The magnetic flux emanating from the north pole of the magnet 29 shown in FIG. 2B enters the annular side portion 11 (or side plate portion 36) from the first claw pole portion 34 (or second claw pole portion 37) in FIG. 3, passes through the annular plate portion 35, circulates around the coil 32 to the side plate portion 36 (or annular side portion 11), and returns to the south pole of the magnet 29 via the adjacent second claw pole portion 37 (or first claw pole portion 34). When the north and south poles of the magnet 29 swap positions as the second bearing ring 5 rotates relative to the first bearing ring 4, the magnetic flux direction reverses. The alternating magnetic field thus generated generates an alternating voltage at both ends 41, 41 of the coil 32, at the beginning and end of the winding. The ends 41, 41 of the coil 32 in FIG. 3 are connected to terminals 42, 42 on the circuit board 23 through small wiring holes formed in the annular plate portion 35.

[0055] As shown in FIG. 3 , the sensor unit 2 is assembled by placing the bobbin 40, around which the coil 32 is wound, between the annular side portion 11 of the holder 9 and the side plate portion 36 of the yoke member 33, and then combining the holder 9 and the yoke member 33 in the axial direction, with each protrusion 39 of the yoke member 33 fitting into a corresponding hole 38 in the annular side portion 11. This fitting ensures that the holder 9 and the yoke member 33 are coaxial with each other, and also ensures that the first claw pole portions 34 and the second claw pole portions 37 are alternately arranged in a predetermined phase with gaps in the circumferential direction. This allows the holder 9 and the yoke member 33 to be properly combined without using a jig. Preferably, the holes 38 and the protrusions 39 are formed in three or more locations, respectively.

[0056] After this assembly, protrusion 39 is fixed to the inner surface of hole 38. This fixing means may be, for example, press-fitting, bonding, laser welding, or a combination of these. It is also possible to omit protrusion 39 and hole 38. In this case, after coaxial alignment and phase alignment between the holder and yoke member are achieved using a jig (not shown), the butting portions of the annular side portion and the annular plate portion may be bonded, or laser welded from the outer periphery of the annular plate portion, or a combination of these may be used to fix them.

[0057] When holder 9 and yoke member 33 are combined and fixed as described above, stator 14 is completed as shown in Fig. 1. Note that, although an example has been shown in which annular plate portion 35 of yoke member 33 serves as a partition between the accommodation space for circuit board 8 and stator 14, it is also possible to provide a partition wall separate from the annular plate portion that divides the annular side portion of the holder into two regions in the radial direction, and to place the stator radially inside the partition wall.

[0058] Fig. 4 is a block diagram of a bearing with a wireless sensor as an example of a bearing device of this embodiment. Figs. 5 to 8 show an example of the operation of the bearing with a wireless sensor, and Fig. 9 shows an example of the format of data stored in the data storage unit of the bearing with a wireless sensor.

[0059] 4 is a bearing device comprising a bearing 1 such as a rolling bearing, a sensor unit 2, and a generator or power generation unit 3. The bearing WB with a wireless sensor comprises, for example, the sensor unit 2, the power generation unit 3 that generates electricity through the relative rotation of the inner ring 5 and the outer ring 4, a power storage unit 100 that stores the electricity generated by the power generation unit 3 and outputs the electricity to various components, sensors SS (a general term) such as the sensors 26 and temperature sensor 10 (sensors A to D, etc.) that detect status values ​​related to the bearing 1 such as vibration acceleration and temperature and output sensor signals, a data storage unit 300 that stores data on the sensor signals output from the sensors SS, a data communication unit 24 (which may correspond to the above-mentioned wireless communication circuit including the antenna 24a) that transmits the data stored in the data storage unit 300 to an external device OF, for example by wireless, and a control unit 200 that controls the storage and transmission of the data. The bearing with wireless sensor WB may further include, in addition to the sensor SS, a rotation sensor rs that detects the rotation speed of the bearing 1, and an A / D converter 110 that performs analog-to-digital conversion of the stored voltage of the storage unit 100 and outputs it as a digital voltage value.

[0060] Next, the operation of the wireless sensor-equipped bearing WB will be described. An overview of the signal flow, etc., is as follows: The power (generated voltage) generated by the power generation unit 3 due to the rotation of the bearing 1 is stored in the power storage unit 100. The power supply voltage [stored voltage] of the power storage unit 100 is converted by the A / D converter 110 to a (power supply) voltage value [stored voltage value] V and output to the control unit 200. Output signals detected by the multiple sensors SS installed on the unit are output to the control unit 200 as sensor signals. Information about the rotational speed of the bearing 1 detected or calculated by the rotation sensor rs from voltage fluctuations of the power generation unit 3 may be included in this sensor signal.

[0061] The operation is outlined as follows. When the voltage (stored voltage value) V of the power storage unit 100 exceeds a certain threshold, the control unit 200 starts counting at a predetermined interval, acquires date and time information, an example of time information, from the external device OF via wireless communication using the data communication unit 24, and associates the count number C at the time the date and time information was acquired with the external date and time information and the sensor signal data at that time. This sensor signal data, count number C, and date and time information data are associated and stored in the data storage unit 300. FIG. 9 shows an example of the format of data stored in the data storage unit 300. Date and time information corresponding to each count number C other than the date and time information (time information) acquired initially from the external device OF after the data communication unit 24 starts wireless communication is calculated by the control unit 200 based on the initially acquired date and time information. When the voltage of the power storage unit 100 exceeds a threshold, the data stored in the data storage unit 300 is transmitted to the external device OF via wireless communication from the data communication unit 24.

[0062] This will be described in detail using the control flow diagram of FIG. 5 . In Step _s1 of the flow diagram, the voltage V of the power storage unit 100 is checked, and if it exceeds the threshold value V1, the process proceeds to Step _s2. In Step _s2, the control unit 100 starts counting at a fixed time interval. This time interval is, for example, the sampling interval of the sensor signal or the time period of the stored data determined by the sampling interval when storing data in the data storage unit 300, and is determined based on experimental results, simulation results, etc. In Step _s3, the data communication unit 24 starts wireless communication and acquires date and time information from the external device OF. The count number C when the sensor signal is output from the sensor SS and the sensor signal data at that time are handled in correspondence with each other. However, in this flow, the count number C when the date and time information is acquired and the date and time information are linked and handled together with the sensor signal data at that time. Here, the threshold value V1 is set based on a voltage reference value that enables data communication with the external device OF. In this embodiment, the threshold value V1 is set as the threshold at which wireless communication can be initiated. As a result, after counting starts in Step_s2, date and time information can be obtained from the external device OF via wireless communication immediately, eliminating the waiting time or wasted time from the start of counting until the date and time information is obtained. Note that although threshold value V1 is set to the same as the voltage threshold at which wireless communication can start, it may also be adjusted as appropriate, for example to a slightly larger value.

[0063] In Step_s4, it is checked whether there is unsent data, for example, in the data storage unit 300. If there is unsent data, the process proceeds to Step_s5. The voltage of the power storage unit 100 is checked, and if it is equal to or greater than threshold V1, the process proceeds to Step_s6, where the data is transmitted via wireless communication. In transmitting the unsent data, if the voltage of the power storage unit 100 is equal to or greater than threshold V3, data transmission continues until there is no unsent data (Step_s6 to Step_s7). If the voltage of the power storage unit 100 is less than threshold V3 or there is no unsent data, the process proceeds to Step_s12. Here, threshold V3 is the minimum threshold at which wireless communication can be maintained.

[0064] If there is no unsent data in the data storage unit in Step_s4, the process proceeds to Step_s8. Also, if it is determined in Step_s5 that the voltage V of the power storage unit 100 is not equal to or greater than the threshold value V1, the process proceeds to Step_s8. Step_s8 to Step_s11 are processes for acquiring sensor signals such as vibration acceleration and temperature from the various sensors SS at predetermined time intervals and writing them to the data storage unit 300. Step_s8 checks whether the interval time / sampling time for acquiring sensor signals at predetermined time intervals has elapsed, and if the interval time has elapsed, the process proceeds to Step_s9. Note that, as an initial setting at startup, the interval time is set to have elapsed. In Step_s9, it is determined whether the voltage V of the power storage unit 100 is equal to or greater than the threshold value V2. If it is equal to or greater than the threshold value V2, the process proceeds to Step_s10, where the voltage V is measured by the sensor, followed by Step_s11, where the data is written. After this, the process proceeds to Step_s12. In measurements by the sensor at Step_s10 and data writing at Step_s11, a predetermined amount of measurement and a predetermined amount of data writing (accumulation, storage) are performed while taking into consideration the relationship between the voltage V of the power storage unit 100 and the threshold V2 (the same applies below). If the interval time has not elapsed at Step_s8, or if the voltage of the power storage unit is less than the threshold V2 at Step_s9, the process proceeds to Step_s12. Here, the threshold V2 is set based on a voltage reference value that allows acquisition of a sensor signal, and in this embodiment, it is the threshold at which data measurement can be started.

[0065] In Step_s12, the voltage V of the power storage unit 100 is checked, and if it is less than the threshold V4, the process is terminated (for example, the system is shut down), and if it is equal to or greater than the threshold V4, the process returns to Step_s4 to continue. Here, the threshold V4 is the minimum threshold that can maintain the process of the above flow.

[0066] Fig. 6 is a graph showing changes in rotation speed ω of bearing 1 of bearing device WB or a rotating shaft (not shown) on the equipment side incorporating bearing 1. Fig. 7 is a graph showing changes in voltage V of power storage unit 100 in this embodiment. Fig. 8 is a graph showing changes in count number C in control unit 200.

[0067] The rotation speed ω of the bearing 1 increases from a stopped state (rotation speed 0) to ω1 at time t1 as shown in Figure 6. The voltage (storage voltage value) V of the power storage unit 100 increases from time t1 as the power generation unit 3 generates power due to the rotation of the bearing 1 as shown in Figure 7. At time t2, the voltage V becomes equal to or greater than the threshold value V1 (Step_s1 in Figure 5), so the control unit 200 starts counting (Step_s2) and also acquires date and time information from the external device OF via wireless communication (Step_s3). The count number C increases until time t8 when the voltage V becomes less than the threshold value V4 and the process is temporarily terminated (Figure 8).

[0068] In FIG. 7, wireless communication for acquiring date and time information is performed between times t2 and t3. However, this wireless communication consumes power, causing the voltage V of the power storage unit 100 to drop (the same applies to wireless communication between times t5 and t7 and between times t11 and t12, which will be described later). At time t3, after acquiring date and time information via wireless communication, the voltage of the power storage unit 100 is equal to or greater than the threshold V2 (Step_s9), so a sensor signal is acquired (Step_s10), and the data is stored in the data storage unit 300. The data stored in the data storage unit 300 is stored, for example, as shown in FIG. 9, in association with the count number C and date and time information, along with the data of each sensor signal. Immediately after startup, there is no unsent data, so Step_s4 is determined as No, and the process proceeds to Step_s8. Also, immediately after startup, as described above, the interval is initially set to have elapsed, so Step_s8 is determined as Yes, and the process proceeds to Step_s9.

[0069] Between times t3 and t4 in FIG. 7, in this example, power is consumed, but the power consumption is smaller than that of the wireless communication, and the power generated by the power generation unit 3 is greater, so the voltage V of the power storage unit 100 increases. Furthermore, between times t4 and t5, there is no power consumption due to wireless communication or the like, so the voltage V of the power storage unit 100 increases quickly. At time t5, the voltage V of the power storage unit 100 increases to the threshold value V1, so it is possible to start transmitting data to an external device via wireless communication. Here, because untransmitted data has been stored in the data storage unit 300 by the above-described Steps _s8 to _s11 performed up to time t5, a Yes determination is made in Step _s4, and data transmission to the external device OF via wireless communication starts (Steps _s4 to _s7).

[0070] Because wireless communication consumes a large amount of power, a voltage drop occurs in the power storage unit (from time t5). As shown in FIG. 6, the rotational speed of the bearing becomes 0 at time t6, and as shown in FIG. 7, the generated power becomes 0, and the voltage drop accelerates. At time t7, the voltage V of the power storage unit 100 becomes the threshold value V3, and although there is unsent data, wireless communication is temporarily terminated (No in Step_s7). As shown in FIG. 6, the rotational speed of the bearing 1 is 0 until time t10, and as shown in FIG. 7, the voltage V of the power storage unit 100 continues to drop further, and at time t8 it becomes less than the threshold value V4, and processing is stopped. At this time t8, the count value C that has been counted up until that point cannot be maintained and is reset to 0 (FIG. 8). At the subsequent time t9, the voltage V of the power storage unit 100 becomes 0.

[0071] At time t10 in FIG. 6, the rotational speed of bearing 1 increases again to ω1. At time t11 in FIG. 7, the voltage V of power storage unit 100 exceeds threshold value V1. Therefore, as shown in FIG. 8, control unit 200 restarts counting up from 0 (Step_s1). Wireless communication is initiated to acquire date and time information (Step_s2). Since there is unsent data from when wireless communication was temporarily terminated (middle), data transmission is resumed (Yes in Step_s4) and the accumulated data is transmitted. Transmission of this accumulated data (Step_s4 to Step_s7) is assumed to be completed at time t12. According to this embodiment, as shown in FIG. 9, each sensor signal is associated with date and time information. Therefore, even if data transmission is interrupted as described above from time t7 to t11, the division of each data block and the measurement time are not unclear.

[0072] 7, at time t12, the voltage V of the power storage unit 100 is equal to or greater than the threshold V2 (Step_s9), so a sensor signal is acquired (Step_s10), and the data is stored in the data storage unit 300. After time t13, there is no power consumption due to wireless communication or the like, so the voltage V of the power storage unit 100 rises rapidly.

[0073] As described above, in the bearing device of the above example, the threshold value V1 is set based on a voltage reference value that enables data communication with the external device OF, and after obtaining time information from the external device OF, a predetermined amount of the count number C when a sensor signal is output from the sensor SS is linked to the date and time information (time information) at the time of that count number C and the sensor signal data and stored in the data storage unit 300, and the data stored in the data storage unit 300 is transmitted to the external device from the data communication unit 24.

[0074] In the above example, as shown in Fig. 6, large increases and decreases in the rotational speed of the bearing 1 are repeated, which can cause a so-called unstable state of rotation, and for example, as shown in Fig. 7, the storage voltage value V falls below the threshold value V3, which tends to interrupt communication with the external device OF. In this case (unstable case) where the storage voltage value V falls below the threshold value V3 a predetermined number of times or more, it is preferable to first obtain date and time information (time information) when the storage voltage value V becomes equal to or greater than the threshold value V1, calculate date and time information corresponding to each count number C, associate the count number C with the date and time information and sensor signal data at the time of the count number C, and store them in the data storage unit 300, and then transmit the data stored in the data storage unit 300 to the external device after a stable state of rotation is confirmed, or if an unstable state of rotation is confirmed, after the unstable state of rotation returns to a stable state.

[0075] In equipment FC incorporating the bearing device WB of this embodiment as described above, an anomaly detection system can be applied that time-aligns (corresponds to) the data transmitted by the data communication unit 24 with data acquired in the external device OF from a sensor signal other than the sensor signal output from the sensor SS to determine abnormalities in the equipment FC or the bearing 1 (such as noise or heat caused by abnormal vibration or abnormal friction). In equipment FC incorporating a bearing device WB that achieves the effects described in this specification, the anomaly detection system can improve the accuracy of time information when detecting abnormalities in the equipment FC, bearing 1, etc., thereby improving the accuracy of anomaly detection. Note that other configurations that are virtually identical to those described and that are conceivable to those skilled in the art can be applied to the equipment FC and the anomaly detection system.

[0076] Next, another operational example (second example) of the bearing with wireless sensor according to this embodiment, which is different from the above, will be described with reference to Figures 10 to 13. Here, the block diagram of the bearing with wireless sensor and an example of the format of data stored in the data storage unit of the bearing with wireless sensor are the same as those in Figures 4 and 9.

[0077] A specific description will be given using the control flow diagram of FIG. 10 and the like. In Step_u1 of the flow diagram, the voltage (storage voltage value) V of the power storage unit 100 is checked, and if it becomes equal to or greater than a threshold value V2, the process proceeds to Step_u2. In Step_u2, the control unit 100 starts counting at a certain time interval. The threshold value V2 in Step_u1 is the voltage threshold at which measurement by the sensor SS can begin, so that immediately after starting counting in Step_u2, it is possible to proceed to the process of acquiring a sensor signal, which will be described below, thereby eliminating the waiting time or wasted time from the start of counting until the acquisition of a sensor signal. Note that although threshold value V2 is set to the same value as the voltage threshold at which sensor signal acquisition becomes possible, it may be adjusted as appropriate, for example to a slightly larger value.

[0078] In Step_u3, it is checked whether the interval time has elapsed in order to acquire the sensor signal at a predetermined time interval. If the interval time has elapsed, the process proceeds to Step_u4, and if the interval time has not elapsed, the process proceeds to Step_u7. Note that the interval time is initially set to have elapsed at startup. Therefore, in this case, the process first proceeds from Step_u3 to Step_u4. In Step_u4, it is checked whether the voltage of the storage unit is equal to or greater than the threshold V2. If it is equal to or greater than the threshold V2, the process proceeds to measurement by the sensor in Step_u5 and data writing in Step_u6, and after completion, the process proceeds to Step_u10. If the voltage of the storage unit is less than the threshold V2 in Step_u4, measurement and data writing are not performed (No in Step_u4), and the process proceeds to Step_u10.

[0079] The following describes a case where, in Step_u3, it is determined that the interval time has not elapsed, and the process proceeds to Step_u7. In Step_u7, it is checked whether there is unsent data in the data storage unit 300. If there is unsent data, the process proceeds to Step_u8, where the voltage V of the power storage unit 100 is checked. If the voltage V is equal to or greater than the threshold V1, the process proceeds to Step_u9, where date and time information is acquired via wireless communication, and the count number C is linked to the date and time information and the data of each sensor signal stored in the data storage unit 300 is transmitted to the external device OF. Then, the process proceeds to Step_u10. Here, up until the acquisition of the date and time information via wireless communication in Step_u9, the data storage unit 300 simply stores the count number C and the data of each sensor signal corresponding to the count number C in association with each other. After the acquisition of the date and time information via wireless communication in Step_u9, the count number C is linked to the date and time information and transmitted to the external device OF together with the data of each sensor signal stored in the data storage unit 300, as described above, and the date and time information is then written to the corresponding area in the data storage unit 300. The count number C and the date and time information may be linked and stored in the data storage unit 300 together with the data of each sensor signal (corresponding to the count number C), and then these linked three pieces of information (count number C, date and time information, and sensor signal data) may be transmitted to the external device OF. If there is no unsent data in Step_u7, or if the voltage of the power storage unit is less than the threshold V1 in Step_u8, the process proceeds to Step_u10.

[0080] In Step_u10, the voltage V of the power storage unit 100 is checked, and if it is less than the threshold value V4, the process ends, and if it is equal to or greater than the threshold value V4, the process returns to Step_u3 and continues.

[0081] Fig. 11 is a graph showing changes in rotation speed ω of bearing 1 of bearing device WB or a rotating shaft (not shown) on the equipment side incorporating bearing 1. Fig. 12 is a graph showing changes in voltage V of power storage unit 100 in the case of this second example. Fig. 13 is a graph showing changes in count number C in control unit 200.

[0082] The rotational speed ω of bearing 1 increases from a stopped state (rotational speed 0) to ω1 at time t1 (FIG. 11). The voltage V of the power storage unit 100 increases from time t1 due to power generation by the power generation unit 3 caused by the rotation of bearing 1 (FIG. 12). At time t2, the voltage V exceeds the threshold V2 (Step_u1 in FIG. 10), so the control unit 200 starts counting (Step_u2). The sensor SS measures the sensor signal to acquire the predetermined amount (Step_u5). The sensor signal and the count number C are associated and stored in the data storage unit 300 for the predetermined amount (Step_u6). Immediately after startup, the interval is set to have elapsed, so the process moves from Step_u3 to Step_u4. Furthermore, because the voltage V is equal to or greater than the threshold V2, the process moves from Step_u4 to Step_u5.

[0083] 12, measurement is performed by the sensor SS from time t2 to t3, but this measurement consumes power, causing the voltage V of the power storage unit 100 to drop (the same applies to the time from t4 to t5 and the time from t8 to t9, which will be described later). The time from t3 to t4 is an interval period in the measurement, during which no power is consumed by measurement, wireless communication, etc., and the voltage V of the power storage unit 100 rises. After time t3, the voltage V becomes equal to or greater than the threshold value V2, so the sensor signal is acquired again (Step_u5), and the sensor signal and the count number C are stored in the data storage unit 300 in association with each other, with the date and time information left blank (Step_u6).

[0084] From time t5, there is again a measurement interval period, and until time t6, there is no power consumption due to measurement, wireless communication, etc., so the voltage V of the power storage unit 100 rises. At time t6, although it is a measurement interval state, there is unsent data (Step_u7), and the voltage of the power storage unit becomes equal to or greater than the threshold value V1 (Step_u8). Therefore, between times t6 and t7, date and time information is acquired and data is transmitted via wireless communication with the external device OF (Step_u9). After the date and time information is acquired via this wireless communication, the date and time information is transmitted in association with the accumulated count number C and the sensor signal data corresponding to this count number C. In this example, the date and time information is then stored in the data storage unit 300 in association with the accumulated count number C and the sensor signal. As a result, the date and time information is stored in the corresponding blank space in the data storage unit 300. For example, as shown in Figure 9, the count number C and date and time information may be linked to the data of each sensor signal and stored, or to reduce the amount of data to be stored and transmitted, the count number C corresponding to a specific sensor signal, for example the first sensor signal of each measurement, may be linked to date and time information and transmitted, and the acquisition date and time of each sensor signal (data) may be calculated by an external device or the like from the count number C and the time interval between counts C. After linking the count number C, date information, and sensor signal data in this way, these data are transmitted to the external device OF via wireless communication. Because date and time information is linked to the sensor signal of each measurement, the division of each data item and the measurement time are not unclear even when data from multiple measurements is transmitted at once.

[0085] The period from time t7 to t8 is a measurement standby time, during which the voltage in the power storage unit rises because there is no power consumption due to measurement, wireless communication, etc. At time t8, the voltage V becomes equal to or greater than the threshold value V2, so the sensor signal is acquired again (Step_u4, Step_u5) until time t9, and the sensor signal and count number are stored in the data storage unit (Step_u6). After time t9, the system enters a measurement standby time again. In this second example, the process continues uninterrupted after time t2, so the count number C continues to increase (Figure 13).

[0086] In the second example, the voltage V of the power storage unit 100 does not fall below the threshold V3, and therefore the case where the voltage V falls below the threshold V3 is not described. However, even in the second example, when the voltage V falls below the threshold V3, wireless communication is temporarily terminated even if there is untransmitted data, as seen in the operation of the wireless sensor-equipped bearing WB described using FIGS. 5 to 8. When the voltage V falls below the threshold V4, processing is stopped and the count value C is reset to 0. Then, when the voltage V of the power storage unit 100 becomes equal to or greater than the threshold V1, wireless communication is started to acquire date and time information, and if there is untransmitted data when the wireless communication is temporarily terminated (middle stage), data transmission is resumed. If the count value C has been reset, when the voltage V of the power storage unit 100 becomes equal to or greater than the threshold V2, the control unit 200 resumes counting up from 0.

[0087] As described above, in the bearing device of the second example, the threshold value V2 is set based on the voltage reference value that enables acquisition of the sensor signal, and a predetermined amount of the count number C when the sensor signal is output from the sensor SS is stored in the data storage unit 300 in association with the sensor signal data at that time. Date and time information (time information) is then acquired from the external device OF, and the count number C when the sensor signal is output from the sensor SS is linked to the time information and sensor signal data at that count number and transmitted to the external device OF from the data communication unit 24.

[0088] In the above example, as shown in FIG. 11, there is no fluctuation in the rotational speed of the bearing 1 (or it is smaller than a predetermined range), and the rotation is in a stable state. At this time, for example, as shown in FIG. 12, the storage voltage value V does not (or rarely) fall below the threshold V3. Therefore, communication with the external device OF is not (or rarely) interrupted. In this case (stable case) where the storage voltage value V falls below the threshold V3 a predetermined number of times or less (less than a predetermined number of times), it is preferable to store a predetermined amount of count numbers C when a sensor signal is output from the sensor SS and the sensor signal data at that time in the data storage unit 300, and then obtain date and time information (time information) from the external device OF and transmit the count numbers C, the time information at the time of the count numbers, and the sensor signal data linked to each other from the data communication unit 24 to the external device OF.

[0089] According to the above embodiment, the sensor signal data acquired by the sensor SS of the bearing with wireless sensor 1 is always accompanied by the date and time information at the time of data acquisition. This improves the time consistency in time alignment between the sensor signal data acquired by the sensor SS received by the external device OF and other sensor signal data other than this data, and also improves the accuracy of abnormality detection / determination of equipment, bearings, etc.

[0090] Although the embodiments of the present invention have been described above, the disclosed embodiments are illustrative in all respects and are not limiting. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0091] 1. Bearings 3 Generator (power generating section) 4 outer ring 5. Inner Circle 24 Data Communications Department 100 Power storage unit 200 control section 300 Data Storage Unit FC equipment OF external device SS Sensor WB (Wireless) Sensor-Equipped Bearing (Bearing Unit)

Claims

1. A bearing device comprising: a bearing including an outer ring and an inner ring; a power generation unit that generates electricity through relative rotation between the inner ring and the outer ring; a power storage unit that stores the electricity generated by the power generation unit; a sensor that detects a state value related to the bearing and outputs a sensor signal; a data storage unit that saves data of the sensor signal output from the sensor; a data communication unit that transmits the data saved in the data storage unit to an external device; and a control unit that controls the saving of the data and the transmission of the data, The control unit When the voltage of the power storage unit becomes equal to or greater than a threshold value, counting is started at predetermined time intervals; the count number when the sensor signal is output from the sensor is stored in the data storage unit in association with the data of the sensor signal at that time; acquiring time information from the external device and associating the time information with the correspondingly stored data of the count number and the sensor signal; Bearing device.

2. 2. The bearing device of claim 1, A bearing device, wherein the threshold value when the control unit starts the counting is set based on a voltage reference value that enables data communication with the external device or a voltage reference value that enables acquisition of the sensor signal.

3. The bearing device of claim 2, the threshold value is set based on a voltage reference value that enables data communication with the external device; After obtaining the time information from the external device, a predetermined amount of the count number when the sensor signal is output from the sensor, the time information at the time of the count number, and the data of the sensor signal stored corresponding to the count number are stored in the data storage unit in association with each other; transmitting the data stored in the data storage unit from the data communication unit to an external device; Bearing device.

4. The bearing device of claim 2, the threshold value is set based on a voltage reference value that enables acquisition of the sensor signal; The count number when the sensor signal is output from the sensor is stored in the data storage unit in association with the data of the sensor signal at that time, and then acquiring the time information from the external device; the count number when the sensor signal is output from the sensor, the time information at the time of the count number, and the data of the sensor signal stored corresponding to the count number are linked together and transmitted from the data communication unit to an external device; Bearing device.

5. In equipment incorporating the bearing device according to any one of claims 1 to 4, The data transmitted by the data communication unit is time-correlated with data of a sensor signal other than the sensor signal output from the sensor, and an abnormality in the equipment or the bearing is determined. Anomaly detection system.

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