Motor bearing wear monitoring device, disconnection detection program, disconnection estimation program, and disconnection detection method

Abstract

The present invention safely confirms the presence / absence of the disconnection of detection coils without stopping a canned motor pump.　A motor bearing wear monitoring device 5 according to the present invention monitors the wear state of a bearing on the basis of detection signals of a plurality of detection coils C1-C8 which detect a magnetic flux change corresponding to a mechanical positional change of a rotor 36 with respect to a stator 37. The motor bearing wear monitoring device comprises: a threshold value storage unit 53b; an acquisition unit 532 for acquiring radial path signals flowing through radial signal paths L1, L2 and thrust path signals flowing through thrust signal paths L3, L4; and a disconnection detection unit 535 for detecting the presence / absence of disconnection between the detection coils and the corresponding radial signal paths and thrust signal paths. The disconnection detection unit detects the presence / absence of disconnection between the detection coils and corresponding radial signal paths and thrust signal paths on the basis of respective voltage values of the radial path signals and the thrust path signals, radial threshold values, and thrust threshold values.

Description

Motor bearing wear monitoring device, wire break detection program, wire break estimation program, and wire break detection method

[0001] The present invention relates to a motor bearing wear monitoring device, a wire break detection program, a wire break estimation program, and a wire break detection method.

[0002] A canned motor pump has a structure in which the pump and motor are integrated to prevent leakage of the pumped fluid. Generally, the rotating structural components of a canned motor pump (the rotor, rotating shaft, bearings, and impeller) are sealed in a can filled with the pumped fluid. Therefore, the internal structure of the canned motor pump cannot be visually monitored from the outside. Therefore, to efficiently operate a canned motor pump with this structure, a device for monitoring the wear state of the bearings (hereinafter referred to as a "monitoring device") is used (see, for example, Patent Document 1).

[0003] JP 2013-78170 A

[0004] The monitoring device disclosed in Patent Document 1 uses a detection coil to measure changes in magnetic flux during rotor rotation, thereby monitoring the radial and axial displacement of the rotor (rotating shaft) caused by bearing wear. The detection coils are embedded in both longitudinal ends of the stator. Therefore, the presence or absence of a disconnection in the detection coil cannot be visually confirmed from the outside of the canned motor pump, and must be confirmed electrically. Electrical confirmation requires access to the terminal block. However, from the perspective of worker safety, access to the terminal block of a canned motor pump while it is operating is difficult, and exposure of the terminal block is also limited in explosion-proof environments. Therefore, electrical confirmation requires the canned motor pump to be stopped, which is not easy because stopping the canned motor pump would result in the shutdown of the manufacturing equipment or plant.

[0005] The present invention aims to provide a motor bearing wear monitoring device, a wire break detection program, a wire break estimation program, and a wire break detection method that can safely check for the presence or absence of a wire break in a detection coil without stopping a canned motor pump.

[0006] In one embodiment of the present invention, a motor bearing wear monitoring device monitors the wear state of a bearing supporting a rotating shaft of a rotor of a canned motor pump based on detection signals from a plurality of detection coils that detect magnetic flux changes corresponding to mechanical position changes of the rotor relative to a stator, and the plurality of detection coils include at least one set of radial detection coils that detect the magnetic flux changes in the radial direction of the rotating shaft, and at least one set of thrust detection coils that detect the magnetic flux changes in the thrust direction of the rotating shaft, and in the thrust direction, the radial detection coil and the thrust detection coil are arranged at an end of one direction side or the other direction side of the stator, and the radial detection coil is electrically connected to a radial signal path through which a radial composite signal flows, the detection signals of each of the radial detection coils being combined, and the thrust detection coil is electrically connected to a thrust signal path through which a thrust composite signal flows, the radial composite signal being a combination of the detection signals of each of the thrust detection coils being combined, and the radial signal path signal flowing through the radial signal path and the thrust signal path signal flowing through the thrust signal path; and an open circuit detection unit that detects the presence or absence of an open circuit in the detection coil, the radial signal path, and each of the thrust signal paths, wherein when there is no open circuit in the detection coil, the radial signal path, and the thrust signal path, the radial composite signal flows through the radial signal path as the radial path signal, and the thrust composite signal flows through the thrust signal path as the thrust path signal, and the open circuit detection unit detects the presence or absence of an open circuit between the radial detection coil and the radial signal path based on the voltage value of the radial path signal and the radial threshold, and detects the presence or absence of an open circuit between the thrust detection coil and the thrust signal path based on the voltage value of the thrust path signal and the thrust threshold.

[0007] In one embodiment of the present invention, a motor bearing wear monitoring device monitors the wear state of a bearing supporting a rotating shaft of a rotor of a canned motor pump based on detection signals from a plurality of detection coils that detect magnetic flux changes corresponding to mechanical position changes of the rotor relative to a stator, the plurality of detection coils including a set of radial detection coils that detect the magnetic flux changes in the radial direction of the rotating shaft, and a set of thrust detection coils that detect the magnetic flux changes in the thrust direction of the rotating shaft, the radial detection coil and the thrust detection coil being disposed at an end of one side or the other side of the stator in the thrust direction, the radial detection coil being electrically connected to a radial signal path through which a radial composite signal flows, the detection signals from each of the radial detection coils being combined, the thrust detection coil being electrically connected to a thrust signal path through which a thrust composite signal flows, the radial maximum voltage value being the maximum value of the voltage values ​​of the radial composite signal, and the thrust composite voltage value being the maximum value of the radial maximum voltage value. a voltage value storage unit that updates and stores a maximum thrust voltage value, which is the maximum value among the voltage values ​​of the signal; an acquisition unit that acquires a radial path signal flowing through the radial signal path, a thrust path signal flowing through the thrust signal path, the radial maximum voltage value, and the thrust maximum voltage value; a trained radial learning model that has been machine-learned to estimate the presence or absence of a disconnection between the radial detection coil and the radial signal path when the voltage value of the radial path signal and the radial maximum voltage value are input; and a disconnection estimation unit that estimates the presence or absence of a disconnection in each of the detection coil, the radial signal path, and the thrust signal path, when a large voltage value is input.The radial path signal flows through the thrust signal path, and the disconnection estimation unit inputs the voltage value and the radial maximum voltage value of the radial path signal into the radial learning model to estimate the presence or absence of a disconnection in each of the radial detection coil and the radial signal path, and inputs the voltage value and the thrust maximum voltage value of the thrust path signal into the thrust learning model to estimate the presence or absence of a disconnection in each of the thrust detection coil and the thrust signal path.

[0008] A wire breakage detection program in one embodiment of the present invention causes a computer to function as the motor bearing wear monitoring device in the first embodiment.

[0009] A wire breakage estimation program according to one embodiment of the present invention causes a computer to function as the motor bearing wear monitoring device according to the second embodiment.

[0010] In one embodiment of the present invention, a wire break detection method is carried out by a motor bearing wear monitoring device that monitors the wear state of a bearing supporting a rotating shaft of a rotor of a canned motor pump based on detection signals from a plurality of detection coils that detect magnetic flux changes corresponding to mechanical position changes of the rotor relative to a stator, wherein the plurality of detection coils include a set of radial detection coils that detect the magnetic flux changes in the radial direction of the rotating shaft, and a set of thrust detection coils that detect the magnetic flux changes in the thrust direction of the rotating shaft, and in the thrust direction, the radial detection coil and the thrust detection coil are arranged at ends on one side or the other side of the stator, and the radial detection coil is electrically connected to a radial signal path through which a radial composite signal flows, the detection signals from each of the radial detection coils being combined, and the thrust detection coil is electrically connected to a thrust signal path through which a thrust composite signal flows, The monitoring device includes a threshold memory unit that stores a radial threshold that is set to be smaller than the voltage value of the radial composite signal and a thrust threshold that is set to be smaller than the voltage value of the thrust composite signal, and when there is no open circuit in the detection coil, the radial signal path, and the thrust signal path, the radial composite signal flows through the radial signal path as a radial path signal, and the thrust composite signal flows through the thrust signal path as a thrust path signal, and the open circuit detection method includes an acquisition step in which the motor bearing wear monitoring device acquires the radial path signal from the radial signal path and acquires the thrust path signal from the thrust signal path, and an open circuit detection step in which the motor bearing wear monitoring device detects the open circuit in each of the radial detection coil and the radial signal path based on the voltage value of the radial path signal and the radial threshold, and detects the open circuit in each of the thrust detection coil and the thrust signal path based on the voltage value of the thrust path signal and the thrust threshold.

[0011] The present invention makes it possible to safely check whether or not a detection coil is broken without stopping the canned motor pump.

[0012] 11 is a side view of a canned motor pump. FIG. 12 is a schematic cross-sectional view showing a longitudinal section of a motor section provided in the canned motor pump of FIG. 1. FIG. 13 is a schematic enlarged cross-sectional view of section A of the motor section of FIG. 2. FIG. 14 is a functional block diagram showing an embodiment of a motor bearing wear monitoring device according to the present invention. FIG. 15 is a schematic perspective view of a stator core showing the arrangement of detection coils provided in the motor bearing wear monitoring device of FIG. 4. FIG. 16 is an enlarged perspective view of section B of FIG. 5. FIG. 17 is a schematic view showing an example of a detection signal output by the detection coils of FIG. 5. FIG. 18 is a schematic view showing an example of information stored in a RAM provided in the motor bearing wear monitoring device of FIG. 4. FIG. 19 is a schematic view showing an example of the appearance of a display unit provided in the motor bearing wear monitoring device of FIG. 4. FIG. 19 is a functional block diagram of an offset processing unit provided in the motor bearing wear monitoring device of FIG. 4. FIG. 19 is a flowchart showing an example of the operation of the motor bearing wear monitoring device of FIG. 4. FIG. 11 is a flowchart showing an example of an update process included in the operation of FIG. 11. FIG. 19 is a flowchart showing an example of a radial side wire break detection process included in the operation of FIG. 11. FIG. 19 is a flowchart showing an example of a wear amount detection process included in the operation of FIG. 11. FIG. 19 is a functional block diagram showing another embodiment of a motor bearing wear monitoring device according to the present invention. Fig. 18 is a schematic diagram showing an example of information stored in a storage unit included in the motor bearing wear monitoring device of Fig. 16. Fig. 19 is a flowchart showing an example of the operation of the motor bearing wear monitoring device of Fig. 16. Fig. 19 is a flowchart showing an example of radial side wire break estimation processing included in the operation of Fig. 18. Fig. 20 is a flowchart showing an example of thrust side wire break estimation processing included in the operation of Fig. 18.

[0013] The present invention provides a motor bearing wear monitoring device for a canned motor pump with a function to automatically detect disconnections in the detection coil and its signal path, thereby enabling safe confirmation of the presence or absence of disconnections in the detection coil and its signal path without stopping the canned motor pump. Details of each term will be described later.

[0014] Embodiments of a motor bearing wear monitoring device according to the present invention (hereinafter referred to as "the device"), a wire break detection program according to the present invention (hereinafter referred to as "the detection program"), a wire break estimation program according to the present invention (hereinafter referred to as "the estimation program"), and a wire break detection method according to the present invention (hereinafter referred to as "the detection method") will be described below. In the following description, reference will be made to the drawings as appropriate. In the drawings, identical members and elements are designated by the same reference numerals, and redundant description will be omitted. Furthermore, the dimensional proportions of the elements may be exaggerated for the sake of convenience and are not limited to the proportions shown in the drawings.

[0015] ●Canned motor pump● ●Configuration of canned motor pump

[0016] 1 is a side view of a canned motor pump 1. For ease of explanation, the drawing shows a cross-sectional view of the upper half of the canned motor pump 1.

[0017] The canned motor pump 1 (hereinafter simply referred to as "pump 1") has a structure that prevents leakage of the handled liquid, and is used particularly for pumping high-temperature liquids or highly hazardous liquids (e.g., explosive, flammable, or toxic liquids). The pump 1 comprises a pump section 2, a motor section 3, an adapter 4, and the device 5.

[0018] The pump 1 includes a pump unit 2, a motor unit 3, and an adapter 4. These components are the same as those of a known canned motor pump. Therefore, in the following description, only an outline of the pump unit 2, the motor unit 3, and the adapter 4 will be provided, and detailed descriptions thereof will be omitted.

[0019] In the following description, the "front direction" refers to the direction in which the pump section 2 is located relative to the motor section 3 (forward), and the "rear direction" refers to the direction in which the motor section 3 is located relative to the pump section 2 (rearward).

[0020] The pump section 2 draws in and discharges the pumped liquid. The pump section 2 includes a housing 20, an impeller 21, a pump chamber 22, a suction pipe section 23, and a discharge pipe section 24. The housing 20 defines the pump chamber 22 that houses the impeller 21, the suction pipe section 23 that is a path for the pumped liquid drawn into the pump chamber 22, and the discharge pipe section 24 that is a path for the pumped liquid discharged from the pump chamber 22. The pump chamber 22 is in communication with the suction pipe section 23 and the discharge pipe section 24.

[0021] The motor unit 3 is driven under predetermined driving conditions (e.g., 200 V, 60 Hz) to rotate the impeller 21. The motor unit 3 includes a housing 30, a rotating shaft 31, two bearings 32 and 33, two thrust washers 34 and 35, a rotor 36, a stator 37, a can 38, and a terminal 39. The motor unit 3 is an example of the motor defined in the present invention.

[0022] Fig. 2 is a schematic cross-sectional view showing a vertical section of the motor section 3. Fig. 3 is a schematic enlarged cross-sectional view of part A of the motor section 3 in Fig. 2. In the following description, Fig. 1 will be referred to as appropriate.

[0023] The housing 30 accommodates the stator 37 and the can 38 in a liquid-tight manner.

[0024] The rotating shaft 31 rotates due to the rotation of the rotor 36 and transmits rotational power to the impeller 21. The rotating shaft 31 is cylindrical. The rotating shaft 31 is inserted through the rotor 36 and fixed to the rotor 36. The front end of the rotating shaft 31 protrudes into the pump chamber 22, and the impeller 21 is attached to the front end. The rotating shaft 31 is provided with cylindrical sleeves 31a, 31b that protect the front and rear portions of the rotating shaft 31.

[0025] In the following description, the "thrust direction" refers to the axial direction of the rotating shaft 31, the "radial direction" refers to the radial direction of the rotating shaft 31, and the "circumferential direction" refers to the circumferential direction of the rotating shaft 31.

[0026] The bearing 32 is disposed in the front direction of the rotor 36 and rotatably supports the rotating shaft 31. The bearing 33 is disposed in the rear direction of the rotor 36 and rotatably supports the rotating shaft 31. The bearings 32 and 33 are, for example, plain bearings. The thrust washer 34 is attached to the rotating shaft 31 between the bearing 32 and the rotor 36 and limits the movement of the rotating shaft 31 in the front direction. The thrust washer 35 is attached to the rotating shaft 31 between the bearing 33 and the rotor 36 and limits the movement of the rotating shaft 31 in the rear direction.

[0027] A gap of length Lx1 is formed between the bearings 32, 33 and the thrust washers 34, 35. A gap of length Lx2 is formed between the bearings 32, 33 and the sleeves 31a, 31b.

[0028] The rotor 36 rotates due to a rotating magnetic field generated in the stator 37. The rotor 36 is cylindrical in shape and includes a plurality of (28 in this embodiment) rod-shaped rotor bars 36a embedded at equal intervals around the outer periphery of the rotor 36 in the circumferential direction.

[0029] The stator 37 generates a rotating magnetic field that rotates the rotor 36. The stator 37 has a substantially cylindrical shape and includes a stator core 37a and a plurality of motor windings 37b.

[0030] The stator core 37a holds the motor windings 37b and has a cylindrical shape. The stator core 37a has a plurality of teeth 37c (see FIG. 6 ; the same applies below).

[0031] The teeth 37c define slots 37d (see FIG. 6 ; the same applies below) through which the motor windings 37b are inserted. The teeth 37c are arranged at equal intervals in the circumferential direction on the inner circumferential surface of the stator core 37a. The motor windings 37b are inserted into the slots 37d and connected to a power supply device (not shown), such as an inverter, via terminals 39.

[0032] The can 38 liquid-tightly houses the rotary shaft 31, bearings 32 and 33, thrust washers 34 and 35, and rotor 36. The can 38 is cylindrical. A portion of the pumped fluid introduced from the suction pipe 23 is introduced into the can 38 and used to cool the bearings 32 and 33 and the motor unit 3, and is then discharged to the discharge pipe 24.

[0033] The adapter 4 is connected to the rear end of the pump unit 2 and the front end of the motor unit 3, and connects the pump unit 2 and the motor unit 3 together.

[0034] This device 5 monitors the wear state of the bearings 32, 33 that support the rotating shaft 31 by detecting a change in magnetic flux corresponding to a change in the mechanical position of the rotor 36 relative to the stator 37. The specific configuration of this device 5 will be described later.

[0035] Motor Bearing Wear Monitoring Device (1) Configuration of Motor Bearing Wear Monitoring Device (1) Next, the configuration of this device 5 will be described below. In the following description, reference will be made to Figures 1 to 3 as appropriate.

[0036] FIG. 4 is a functional block diagram showing an embodiment of the device 5. As shown in FIG.

[0037] The device 5 includes eight detection coils C1, C2, C3, C4, C5, C6, C7, and C8, a connection unit 50, two common paths Lc1 and Lc2, six signal paths L11, L12, L13, L14, L15, and L16, four signal processing circuits 51a, 51b, 51c, and 51d, an A / D converter 52, a control unit 53, a storage unit 54, a display unit 55, and an offset processing unit 56. The A / D converter 52 and the control unit 53 are realized by, for example, a microcomputer.

[0038] Fig. 5 is a schematic perspective view of the stator core 37a showing the arrangement of the detection coils C1 to C8, and Fig. 6 is an enlarged perspective view of part B in Fig. 5.

[0039] The detection coils C1 to C8 detect magnetic flux changes corresponding to changes in the position (displacement) of the rotor 36 relative to the stator 37 and generate and output detection signals (induced currents) indicating the magnetic flux changes. The rotor 36 displaces radially along with the rotating shaft 31 in accordance with the radial wear of the bearings 32 and 33, and displaces thrustly along with the rotating shaft 31 in accordance with the thrust wear of the bearings 32 and 33. In other words, the displacement of the rotor 36 can be considered the amount of wear of the bearings 32 and 33. Therefore, the device 5 can detect the amount of wear of the bearings 32 and 33 by detecting the displacement of the rotor 36 using the detection coils C1 to C8. The detection coils C1 to C8 are shaped like flat bobbins. The detection coils C1 to C8 are fitted into notches 37e formed in the teeth 37c at the front and rear ends of the stator 37.

[0040] In the circumferential direction, the detector coils C1 to C4 are attached at equal intervals (90° intervals) to the front end of the tooth portion 37c of the stator 37. In the circumferential direction, the detector coil C1 is arranged to face the detector coil C3 at a position "180°" opposite, and the detector coil C2 is arranged to face the detector coil C4 at a position "180°" opposite. Meanwhile, in the circumferential direction, the detector coils C5 to C8 are attached at equal intervals (90° intervals) to the rear end of the tooth portion 37c of the stator 37. In the circumferential direction, the detector coil C5 is arranged to face the detector coil C7 at a position "180°" opposite, and the detector coil C6 is arranged to face the detector coil C8 at a position "180°" opposite. That is, in the radial direction, the detector coils C1, C2, C5, and C6 are arranged to face the corresponding detector coils C3, C4, C7, and C8.

[0041] In the present invention, the detection coils C1, C2, C5, and C6 only need to be arranged to face the corresponding detection coils C3, C4, C7, and C8, and their positional relationship is not limited to an exact "180°" position. In other words, for example, due to manufacturing errors or the shape of the stator 37, their positional relationship in the circumferential direction may deviate from "180°" by several degrees (e.g., 1° to 5°).

[0042] Furthermore, in the present invention, the angle between the detector coil C1 (detector coil C3) and the detector coil C2 (detector coil C4) in the circumferential direction can be set appropriately between 0° and 180° and is not limited to 90°. That is, for example, the detector coil C2 can be disposed in the same position (0°) as the detector coil C1 in the circumferential direction. In this case, the detector coil C2 is disposed so as to be aligned rearward (or forward) from the detector coil C1 in the axial direction. This type of arrangement also applies to the detector coil C5 (detector coil C7) and the detector coil C6 (detector coil C8).

[0043] FIG. 7 is a schematic diagram showing an example of a detection signal.

[0044] The detection signals of the detection coils C1 to C8 include a waveform corresponding to changes in the main magnetic flux of the motor unit 3 (hereinafter referred to as the "fundamental wave component") and a waveform corresponding to changes in magnetic flux generated by induced current flowing through the rotor bars 36a of the rotor 36 (hereinafter referred to as the "harmonic component"). The fundamental wave component is generated by the drive voltage of the motor unit 3, and its frequency is the same as the drive frequency of the drive voltage. The harmonic components are generated by induced current flowing through the rotor bars 36a, and their frequency is determined by the rotation of the rotor 36 and the number of rotor bars 36a. For example, under the following conditions (drive frequency: 60 Hz, number of rotor bars 36a: 28), each of the detection coils C1 to C8 detects changes in magnetic flux generated by the rotor bars 36a 28 times during one rotation of the rotor 36. Therefore, the frequency of the harmonic components is 60 Hz x 28 = 1.68 kHz. In this way, the fundamental wave component is determined based on the drive frequency, and the harmonic components are determined based on the rotation of the rotor 36, the drive frequency, and the number of rotor bars 36a.

[0045] In the following description, reference will be made primarily to FIGS. 3 to 5. The detection coils C1, C3, C5, and C7 detect the radial displacement of the rotor 36 (i.e., the radial wear of the bearings 32 and 33) by detecting changes in magnetic flux corresponding to the radial displacement of the rotor 36 caused by an increase in the gap (L2) between the bearings 32 and 33 and the sleeves 31a and 31b. The detection coil C1 is electrically connected to the common path Lc1 and the detection coil C3. The detection coil C3 is electrically connected to the signal path L11 via a connection 50. The detection coils C1 and C3 form a pair of radial detection coils, connected in series so that their respective detection signals cancel each other out. The detection coil C5 is electrically connected to the common path Lc2 and the detection coil C7. The detection coil C7 is electrically connected to the signal path L12 via a connection 50. The detection coils C5 and C7 form another pair of radial detection coils, connected in series so that their respective detection signals cancel each other out. The detection coils C1, C3, C5, and C7 are examples of radial detection coils in the present invention. The detection coils C1 and C3 are examples of first radial detection coils in the present invention, and the detection coils C5 and C7 are examples of second radial detection coils in the present invention.

[0046] When the front side of the rotor 36 is displaced in the radial direction from its initial position, the signal level of the harmonic components increases on the side of the pair of detector coils C1 and C3 to which the rotor 36 is approaching (e.g., detector coil C1) and decreases on the side to which the rotor 36 is moving away (e.g., detector coil C3). Since the relative movement distance of the rotor 36 with respect to the detector coils C1 and C3 remains the same, the increase in signal level is the same as the decrease in signal level. Meanwhile, the signal level of the fundamental wave component does not increase or decrease. Therefore, when the detection signals of the detector coils C1 and C3 are combined to obtain (generate) their difference, the difference in the signal levels of the harmonic components in the combined signal (hereinafter referred to as the "combined signal (S13)") increases as the amount of displacement increases. This difference enables the amount of radial displacement of the front side of the rotor 36 to be detected. In other words, this difference indicates the amount of radial wear of the bearing 32, and the value of this difference is expressed as a voltage value. Similarly, in the composite signal (hereinafter referred to as the "composite signal (S57)") of the detection signals from the detection coils C5 and C7, the difference in the signal levels of the harmonic components increases as the amount of displacement increases. This difference makes it possible to detect the amount of radial displacement of the rear side of the rotor 36. In other words, this difference indicates the amount of radial wear of the bearing 33, and the value of this difference is expressed as a voltage value. Therefore, for example, when there is no radial displacement of the rotor 36, the fundamental wave component and the harmonic component cancel each other out in each composite signal (S13, S57), and theoretically the voltage value is "0". On the other hand, when there is radial displacement of the rotor 36, the difference in the harmonic components in each composite signal (S13, S57) increases as the amount of displacement increases, and the voltage value increases accordingly. Furthermore, since the detection coils C1 and C3 are independent of the detection coils C5 and C7, by comparing the values ​​of the composite signals (S13 and S57), it is possible to detect uneven wear (a state in which one is more worn than the other) of the bearings 32 and 33. The composite signal (S13) is an example of the radial composite signal and the first composite signal in the present invention, and the composite signal (S57) is an example of the radial composite signal and the second composite signal in the present invention.

[0047] The detection coils C2, C4, C6, and C8 detect a change in magnetic flux corresponding to the displacement of the rotor 36 in the thrust direction caused by an increase in the gap (L1) between the bearings 32 and 33 and the thrust washers 34 and 35, thereby detecting the amount of thrust displacement of the rotor 36 (i.e., the amount of thrust wear of the bearings 32 and 33). The detection coil C2 is electrically connected to the common path Lc2 and the detection coil C4. The detection coil C4 is electrically connected to the signal path L13 via a connection 50. The detection coils C2 and C4 form a pair of thrust detection coils, which are connected in series so that their detection signals overlap. Therefore, the detection signals from the detection coils C2 and C4 are combined to overlap each other, generating a combined signal (S24). The detection coil C6 is electrically connected to the common path Lc2 and the detection coil C8. The detection coil C8 is electrically connected to the signal path L14 via a connection 50. The detection coils C6 and C8 constitute another pair of thrust detection coils and are connected in series so that their detection signals are superimposed. Therefore, the detection signals from the detection coils C6 and C8 are superimposed and combined to generate a composite signal (S68). The detection coils C2, C4, C6, and C8 are examples of thrust detection coils in the present invention. The detection coils C2 and C4 are examples of first thrust detection coils in the present invention, and the detection coils C6 and C8 are examples of second thrust detection coils in the present invention. The composite signal (S24) is an example of a thrust composite signal and a third composite signal in the present invention, and the composite signal (S68) is an example of a thrust composite signal and a fourth composite signal in the present invention.

[0048] When the rotor 36 is displaced rearward from its initial position, the overlap between the detection coils C2 and C4 and the front end (end ring) of the rotor 36 in the thrust direction remains almost constant, while the overlap between the detection coils C6 and C8 and the rear end (end ring) of the rotor 36 decreases. As a result, the signal level of the fundamental component of the combined signal (S24) remains almost constant, while the signal level of the fundamental component of the combined signal (S68) decreases. Similarly, when the rotor 36 is displaced frontward from its initial position, the signal level of the fundamental component of the combined signal (S68) remains almost constant, while the signal level of the fundamental component of the combined signal (S24) decreases. Therefore, the thrust displacement of the rotor 36 can be detected from the difference between the combined signals (S24) and (S68). In other words, this difference indicates the thrust displacement of the rotor 36, i.e., the amount of wear of the bearings 32 and 33 in the thrust direction, and the value of this difference is expressed as a voltage value. Therefore, for example, when there is no displacement of the rotor 36 in the thrust direction, the fundamental wave component and the harmonic wave component cancel each other out in the difference, and theoretically, the voltage value is "0." On the other hand, when there is displacement of the rotor 36 in the thrust direction, the signal level of the fundamental wave component of one combined signal (e.g., combined signal (S24)) decreases in accordance with the amount of displacement, while the signal level of the fundamental wave component of the other combined signal (e.g., combined signal (S68)) barely changes. Therefore, in the signal indicating the difference, the difference value (voltage value) of the fundamental wave component increases in accordance with the amount of displacement. Furthermore, by comparing the magnitudes of the combined signals (S24, S68), the direction of displacement in the thrust direction can be detected.

[0049] The connection unit 50 is an interface to which the detection coils C1 to C8 are connected. The common paths Lc1 and Lc2, the detection coils C3, C7, C4, and C8, and the signal paths L11 to L14 are connected to the connection unit 50. The common paths Lc1 and Lc2 are connected to ground via the connection unit 50.

[0050] The signal processing circuits 51a to 51d are connected to corresponding sets of detection coils C1 to C8 and perform predetermined signal processing (rectification, AC-DC conversion) on the corresponding composite signals (S13, S57, S24, S68) to convert the composite signals (S13, S57, S24, S68) from AC to DC. The signal processing circuits 51a to 51d are configured, for example, with a filter circuit, a rectifier circuit, and an integrator circuit. The signal processing circuit 51a is connected to signal path L11 and converts the composite signal (S13) from AC to DC. The converted composite signal (S13) is input to the A / D converter 52 via signal path L11. The signal processing circuit 51b is connected to signal path L12 and converts the composite signal (S57) from AC to DC. The converted composite signal (S57) is input to the A / D converter 52 via signal path L12. The signal processing circuit 51c is connected to the signal path L13 and converts the composite signal (S24) from AC to DC. The converted composite signal (S24) is input to the A / D converter 52 via the signal path L13 and to the offset processing unit 56 via the signal path L15. The signal processing circuit 51d is connected to the signal path L14 and converts the composite signal (S68) from AC to DC. The converted composite signal (S68) is input to the A / D converter 52 via the signal path L14 and to the offset processing unit 56 via the signal path L16.

[0051] The common path Lc1, the connection unit 50, the signal path L11, and the signal processing circuit 51a are electrically connected to the detection coils C1 and C3, forming a first path L1 through which the composite signal (S13) flows. The common path Lc1, the connection unit 50, the signal path L12, and the signal processing circuit 51b are electrically connected to the detection coils C5 and C7, forming a second path L2 through which the composite signal (S57) flows. The common path Lc2, the connection unit 50, the signal path L13, and the signal processing circuit 51c are electrically connected to the detection coils C2 and C4, forming a third path L3 through which the composite signal (S24) flows. The common path Lc2, the connection unit 50, the signal path L14, and the signal processing circuit 51d are connected to the detection coils C6 and C8, forming a fourth path L4 through which the composite signal (S68) flows. The first path L1 and the second path L2 are examples of radial signal paths in the present invention, and the third path L3 and the fourth path L4 are examples of thrust signal paths in the present invention. That is, the radial signal path includes the first path L1 and the second path L2, and the thrust signal path includes the third path L3 and the fourth path L4.

[0052] The A / D converter 52 converts analog signals input from the signal processing circuits 51 a to 51 d, the calculation circuit 56 c and the absolute difference conversion circuit 56 d (to be described later) into digital signals and outputs them to the control unit 53 .

[0053] The control unit 53 controls the overall operation of the device 5. The control unit 53 includes, for example, a processor such as a central processing unit (CPU) 53a, a volatile memory such as a random access memory (RAM) 53b that functions as a work area for the CPU 53a, and a nonvolatile memory such as a read-only memory (ROM) 53c that stores various information, such as the detection program and other control programs (e.g., a wear amount detection program). The control unit 53 includes a first acquisition unit 530, a wear amount detection unit 531, a second acquisition unit 532, an update unit 533, a threshold setting unit 534, a disconnection detection unit 535, and a display control unit 536. The RAM 53b is an example of a threshold storage unit and a voltage value storage unit in the present invention. The wear amount detection program is a program required to execute the wear amount detection process (ST4: see FIG. 15), which will be described later.

[0054] The detection program runs in the control unit 53, and cooperates with the hardware resources of the device 5 to implement the detection method described below. By causing a processor (CPU 53a) constituting the control unit 53 to execute the detection program, the detection program causes the processor to function as a second acquisition unit 532, an update unit 533, a threshold setting unit 534, a disconnection detection unit 535, and a display control unit 536, thereby causing the processor to execute the detection method. By causing a computer to execute the detection program and the wear amount detection program, the detection program and the wear amount detection program cause the computer to function as the device 5.

[0055] In the present invention, the detection program may be stored in the storage unit 54. Alternatively, the detection program may be stored in an installable file format or an executable file format on a non-transitory storage medium (e.g., a CD (Compact Disc), a DVD (Digital Versatile Disc), a USB (Universal Serial Bus) memory, etc.) and provided to the device 5 via a dedicated read-out medium.

[0056] The first acquisition unit 530 acquires the composite signal (S13), the composite signal (S57), and a signal indicating the difference between the composite signal (S24) and the composite signal (S68) (a difference signal (Sd) described later). Specific operations of the first acquisition unit 530 will be described later.

[0057] The wear amount detection unit 531 detects the amount of radial wear of the bearings 32, 33 by detecting the amount of radial displacement of the front and rear sides of the rotor 36 based on the voltage values ​​of the composite signals (S13, S57) acquired by the first acquisition unit 530. The wear amount detection unit 531 also detects the amount of thrust wear of the bearings 32, 33 by detecting the amount of thrust displacement of the rotor 36 based on the voltage value of the difference signal (Sd). The specific operation of the wear amount detection unit 531 will be described later.

[0058] The second acquisition unit 532 acquires the first maximum voltage value to the fourth maximum voltage value, the first signal (S1), the second signal (S2), the third signal (S3), and the fourth signal (S4), which will be described later. The second acquisition unit 532 is an example of the acquisition unit defined in the present invention. Specific operations of the second acquisition unit 532 will be described later.

[0059] In the present invention, the second acquisition unit 532 may function as the first acquisition unit 530 , and the first acquisition unit 530 may function as the second acquisition unit 532 .

[0060] The "first signal (S1)" is a signal flowing through the first path L1. When the detection coils C1, C3 and the first path L1 are not disconnected, the first signal (S1) may include not only the composite signal (S13) but also noise components. In other words, when the detection coils C1, C3 and the first path L1 are not disconnected, the composite signal (S13) flows through the first path L1 as the first signal (S1). On the other hand, when the detection coils C1, C3 or the first path L1 are disconnected, the first signal (S1) may not include the composite signal (S13) but may mainly include noise components. In other words, when the detection coils C1, C3 and the first path L1 are disconnected, the noise components may flow through the first path L1 as the first signal (S1).

[0061] The "noise components" are signal components (waveforms) that represent noise that originates from electromagnetic noise from a noise source (for example, the motor unit 3, the power supply supplied to the motor unit 3, etc.) and is included in the first signal (S1) to the fourth signal (S4) that flow through the detection coils C1 to C8 and the first path L1 to the fourth path L4. There are multiple causes of the noise components, and the signal level (i.e., voltage value) of the noise components differs depending on the cause and the noise entry path.

[0062] The "second signal (S2)" is a signal that flows through the second path L2. Similar to the first signal (S1), when the detection coils C5 and C7 and the second path L2 are not disconnected, the composite signal (S57) flows through the second path L2 as the second signal (S2). On the other hand, when the detection coils C5 and C7 or the second path L2 are disconnected, noise components may flow through the second path L2 as the second signal (S2).

[0063] The "third signal (S3)" is a signal that flows through the third path L3. Similar to the first signal (S1), when the detection coils C2 and C4 and the third path L3 are not disconnected, the composite signal (S24) flows through the third path L3 as the third signal (S3). On the other hand, when the detection coils C2 and C4 or the third path L3 are disconnected, the noise component flows through the third path L3 as the third signal (S3).

[0064] The "fourth signal (S4)" is a signal that flows through the fourth path L4. Similar to the first signal (S1), when the detection coils C6 and C8 and the fourth path L4 are not disconnected, the composite signal (S68) flows through the fourth path L4 as the fourth signal (S4). On the other hand, when the detection coils C6 and C8 or the fourth path L4 are disconnected, noise components may flow through the fourth path L4 as the fourth signal (S4).

[0065] The first signal (S1) and the second signal (S2) are examples of radial path signals in the present invention, and the third signal (S3) and the fourth signal (S4) are examples of thrust path signals in the present invention. That is, the radial path signals include the first signal (S1) and the second signal (S2), and the thrust path signals include the third signal (S3) and the fourth signal (S4).

[0066] The update unit 533 updates the first maximum voltage value, the second maximum voltage value, the third maximum voltage value, and the fourth maximum voltage value stored in the RAM 53b. Specific operations of the update unit 533 will be described later.

[0067] The "first maximum voltage value" is the maximum voltage value among the voltage values ​​of the composite signal (S13) acquired from the first path L1.

[0068] The "second maximum voltage value" is the maximum voltage value among the voltage values ​​of the composite signal (S57) acquired from the second path L2.

[0069] The "third maximum voltage value" is the maximum voltage value among the voltage values ​​of the composite signal (S24) acquired from the third path L3.

[0070] The "fourth maximum voltage value" is the maximum voltage value among the voltage values ​​of the composite signal (S68) acquired from the fourth path L4.

[0071] The first and second maximum voltage values ​​are examples of radial maximum voltage values ​​in the present invention, and the third and fourth maximum voltage values ​​are examples of thrust maximum voltage values ​​in the present invention. That is, the radial maximum voltage values ​​include the first and second maximum voltage values, and the thrust maximum voltage values ​​include the third and fourth maximum voltage values.

[0072] The threshold setting unit 534 sets the first, second, third, and fourth thresholds based on the first to fourth maximum voltage values. The set first to fourth thresholds are stored in the RAM 53b. Details of the first to fourth thresholds and the specific operation of the threshold setting unit 534 will be described later.

[0073] 8 is a schematic diagram showing an example of information stored in the RAM 53b. ｍａｘ " and the second maximum voltage value is "V2 ｍａｘ " and the third maximum voltage value is "V3 ｍａｘ " and the fourth maximum voltage value is "V4 ｍａｘ " and the first threshold is "V ｔ１ " and the second threshold is "V ｔ２ " and the third threshold is "V ｔ３" and the fourth threshold is "V ｔ４ The figure also shows that the first to fourth maximum voltage values ​​and the first to fourth threshold values ​​are stored in the RAM 53b.

[0074] In the following description, reference will be made mainly to Fig. 4. The disconnection detection unit 535 detects the presence or absence of a disconnection in the detection coils C1 to C8 and the first path L1 to the fourth path L4 based on the first signal (S1) to the fourth signal (S4) and the first threshold value to the fourth threshold value. The specific operation of the disconnection detection unit 535 will be described later.

[0075] The display control unit 536 controls the display on the display unit 55 based on the amount of wear detected by the wear amount detection unit 531 and the presence or absence of a break detected by the break detection unit 535. The specific operation of the display control unit 536 will be described later.

[0076] The storage unit 54 stores information (e.g., offset information, first correspondence information, second correspondence information, etc.) necessary for the operation of the device 5. The storage unit 54 is, for example, a non-volatile memory such as an EEPROM (Electrically Erasable Programmable Read-Only Memory) or a flash memory.

[0077] The "offset information" is information (e.g., a voltage value) indicating an offset voltage to be added to or subtracted from the composite signal (S24) in the offset processing described below. The offset information is measured or set in advance before shipping the pump 1 under predetermined reference driving conditions (e.g., driving frequency: 60 Hz, driving voltage: 200 V), and is stored in the storage unit 54.

[0078] "Offset processing" refers to processing for adding or subtracting an offset voltage to the composite signal (S24) so ​​that the difference between the composite signal (S24) and the composite signal (S68) correctly indicates the thrust direction displacement of the rotor 36 (the amount of thrust direction wear of the bearings 32 and 33) under the reference driving conditions. By the offset processing, the magnetic center position of the rotor 36 relative to the stator 37 in the thrust direction is virtually aligned with the mechanical center position of the rotor 36 relative to the stator 37 in the thrust direction (the two center positions coincide).

[0079] Whether the offset voltage is a signal to be added to the composite signal (S24) (addition signal) or subtracted from it (subtraction signal) is determined by the magnitude of the composite signals (S24, S68). That is, for example, when the composite signal (S24) is larger than the composite signal (S68), the offset voltage is a subtraction signal, and when the opposite is true, the offset voltage is an addition signal. In this embodiment, the offset voltage is an addition signal. This magnitude relationship is determined based on signals that have not been subjected to offset processing, i.e., the composite signals (S24, S68) input to the A / D converter 52 from the third path L3 and the fourth path L4.

[0080] The "first correspondence information" is information that indicates the correspondence between the position (displacement amount) in the thrust direction of the rotor 36 relative to the stator 37 and the difference value between the combined signal (S24) and the combined signal (S68) under predetermined driving conditions. In other words, the first correspondence information indicates the correspondence between the amount of wear in the thrust direction of the bearings 32, 33 and the voltage value under predetermined driving conditions.

[0081] The "second correspondence information" is information that indicates the correspondence between the radial position (displacement amount) of the rotor 36 relative to the stator 37 and the voltage value of the composite signal (S13, S57) under predetermined driving conditions. In other words, the second correspondence information indicates the correspondence between the radial wear amount of the bearings 32, 33 and the voltage value under predetermined driving conditions.

[0082] FIG. 9 is a schematic diagram showing an example of the appearance of the display unit 55. As shown in FIG.

[0083] The display unit 55 displays the wear state of the bearings 32 and 33, the rotation direction of the rotating shaft 31, and the presence or absence of breaks in the detection coils C1 to C8 and the first path L1 to the fourth path L4. The display unit 55 includes, for example, a plurality of light-emitting diodes (LEDs) that display the wear state in the radial and thrust directions, the rotation direction, and the presence or absence of breaks. The display unit 55 displays the wear state in the radial and thrust directions in three levels: "green," "yellow," and "red," and indicates the rotation direction by turning on (forward rotation) or off (reverse rotation). The display unit 55 also indicates the presence or absence of breaks by turning on (break present) or off (no break present).

[0084] FIG. 10 is a functional block diagram of the offset processing unit 56.

[0085] The offset processing section 56 performs offset processing based on the offset information and includes a D / A converter 56a, an offset voltage generating circuit 56b, an arithmetic circuit 56c, and a difference absolute value conversion circuit 56d.

[0086] The D / A converter 56a converts the offset information from a digital signal to an analog signal.

[0087] The offset voltage generating circuit 56b generates an offset voltage to be added to or subtracted from the composite signal (S24) of the detection coils C2 and C4 based on the offset information converted into an analog signal.

[0088] The arithmetic circuit 56c performs offset processing on the composite signal (S24) by adding or subtracting an offset voltage to the composite signal (S24), and calculates a difference between the offset-processed composite signal (S24) and the composite signal (S68). The signal path L13 is connected to the arithmetic circuit 56c via a signal path L15 between the signal processing circuit 51c and the A / D converter 52. The signal path L14 is connected to the arithmetic circuit 56c via a signal path L16 between the signal processing circuit 51d and the A / D converter 52.

[0089] The differential absolute value conversion circuit 56d converts the differential value calculated by the arithmetic circuit 56c into an absolute value. A signal indicating this absolute value (hereinafter referred to as the "difference signal (Sd)") is converted into a digital signal by the A / D converter 52 and input to the control unit 53.

[0090] Setting of the First to Fourth Thresholds Next, the setting of the first to fourth thresholds will be described below.

[0091] The "first threshold" is a threshold used to determine whether or not there is a disconnection in the detection coils C1 and C3 or the first path L1. The first threshold is set based on the first maximum voltage value and the signal level of the noise component flowing through the detection coils C1 and C3 and the first path L1. The first threshold is smaller than the third and fourth thresholds.

[0092] The "second threshold" is a threshold used to determine whether or not there is a disconnection in the detection coils C5, C7 or the second path L2. The second threshold is set based on the second maximum voltage value and the signal level of the noise component flowing through the detection coils C5, C7 and the second path L2. The second threshold is smaller than the third and fourth thresholds.

[0093] The "third threshold" is a threshold used to determine whether or not the detection coils C2 and C4 or the third path L3 are disconnected. The third threshold is set based on the third maximum voltage value and the signal level of the noise component flowing through the detection coils C2 and C4 and the third path L3.

[0094] The "fourth threshold" is a threshold used to determine whether or not there is a disconnection in the detection coils C6 and C8 or the fourth path L4. The fourth threshold is set based on the fourth maximum voltage value and the signal level of the noise component flowing through the detection coils C6 and C8 and the fourth path L4.

[0095] The first threshold value and the second threshold value are examples of the radial threshold value in the present invention, and the third threshold value and the fourth threshold value are examples of the thrust threshold value in the present invention. That is, the radial threshold value includes the first threshold value and the second threshold value, and the thrust threshold value includes the third threshold value and the fourth threshold value.

[0096] Generally, if a sensor fails, the receiving device can detect the sensor failure by detecting an abnormal value in the signal from the sensor. However, as described below, the present device 5 detects the amount of wear in the thrust direction based on the differential signal (Sd), which indicates the difference (absolute value) between the composite signal (S24) and the composite signal (S68). In this detection method, even if one signal path is broken, the other signal remains normal. The amount of wear in the thrust direction is detected based on the voltage value of the fundamental wave component of the differential signal (Sd). Therefore, if one signal remains, the voltage value of the fundamental wave component of that signal may falsely detect the amount of wear in the thrust direction (which, of course, is different from the true amount of wear). As a result, a method of detecting a break simply using the voltage value of the differential signal (Sd) may not detect the abnormal value and may not detect breaks in the detection coils C2, C4, C6, C8, the third path L3, and the fourth path L4. Therefore, in order to detect breaks in the detection coils C2, C4, C6, C8, the third path L3, and the fourth path L4, it is more appropriate to evaluate the voltage value of the composite signal (S24, S68) than to evaluate the voltage value of the differential signal (Sd).

[0097] Meanwhile, as described below, the device 5 detects the radial wear amount based on the voltage value of the composite signal (S13, S57). In this detection method, for example, if the first path L1 is disconnected, the first signal (S1) does not include the composite signal (S13), and theoretically, its signal level becomes "0." In this case, the device 5 recognizes that this value is an abnormal value and can detect a disconnection in the detection coils C1, C3 or the first path L1. In this case, if a threshold value is used to detect an abnormal value, the threshold value must be at least smaller than the voltage value of the composite signal (S13). Here, the radial wear amount is detected based on the voltage value of each harmonic component of the composite signal (S13, S57). The signal level (voltage value) of the harmonic component is small even under normal conditions (e.g., several tens of mV to 300 mV), and may even be comparable to the signal level (voltage value) of the noise component. Therefore, even if an open circuit occurs in the detection coils C1, C3, or the first path L1, the signal level of the first signal (S1), which contains noise components, will not be "0," and the noise components may be mistaken for the composite signal (S13). As a result, an open circuit detection method that simply uses the voltage value of the composite signal (S13, S57) may detect an abnormal value as a normal value. Therefore, this detection method makes it difficult to detect an open circuit in the detection coils C1, C3, C5, C7, the first path L1, and the second path L2. Thus, detecting an open circuit in the detection coils C1, C3, C5, C7, the first path L1, and the second path L2 presents technical challenges unique to the device 5. Therefore, threshold processing that takes noise components into account is required to detect an open circuit in the detection coils C1, C3, C5, C7, the first path L1, and the second path L2.

[0098] Generally, the rotational speed (number of rotations) of a motor is changed by varying the drive frequency through inverter control. Because lowering the drive frequency without lowering the drive voltage would result in burnout of the motor, the drive frequency and drive voltage are generally changed simultaneously. The increase or decrease in drive frequency is proportional to the increase or decrease in drive voltage. As described above, the fundamental component of the detection signal is generated by the drive voltage, so the signal level (voltage value) of the fundamental component increases or decreases in proportion to the increase or decrease in the drive frequency and drive voltage. Furthermore, as the motor rotational speed increases or decreases, the frequency and signal level of the harmonic components also increase or decrease. Furthermore, as bearings 32 and 33 wear, the voltage value of the composite signals (S13, S57) increases. Furthermore, the contact resistances in the detection coils C1 to C8 and the first to fourth paths L1 to L4 increase over time, and the voltage values ​​of the composite signals (S13, S57, S24, S68) increase accordingly. Therefore, in the present device 5, a fixed value is not suitable as a threshold value for detecting a disconnection.

[0099] Therefore, in the present device 5, the first to fourth threshold values ​​are set by multiplying the first to fourth maximum voltage values ​​by a predetermined coefficient so that the first to fourth threshold values ​​change according to the latest trend of the voltage value. In other words, the "coefficient" is a coefficient (%) by which the first to fourth maximum voltage values ​​are multiplied in order to set the first to fourth threshold values. Specifically, the first threshold value "V ｔ１ " is the first maximum voltage value "V1 ｍａｘ " is multiplied by a coefficient "A1", and the second threshold "V ｔ２ " is the second maximum voltage value "V2 ｍａｘ " is multiplied by a coefficient "A2", and the third threshold "V ｔ３ " is the third maximum voltage value "V3 ｍａｘ " is multiplied by a coefficient "A3", and the fourth threshold "V ｔ４ " is the fourth maximum voltage value "V4 ｍａｘ" by the threshold value "A4." In other words, the first to fourth threshold values ​​are variable values ​​that increase based on the voltage values ​​(first maximum voltage value to fourth maximum voltage value) of each composite signal (S13, S57, S24, S68). Each coefficient is preset by an operator or the like based on the signal level of an expected noise component when the pump 1 is shipped, and is incorporated into the detection program and stored in the ROM 53c.

[0100] Each coefficient is set based on the signal level of the noise component contained in the corresponding first signal (S1) to fourth signal (S4). Specifically, each coefficient is set so that the first to fourth thresholds are smaller than the voltage value of each composite signal (S13, S57, S24, S68) and larger than the signal level of the noise component.

[0101] For example, when the first threshold is set to a low value, as described above, the voltage value of the composite signal (S13) may be small and comparable to the voltage value of the noise component. Therefore, if the first threshold is set to a high value, even normal values ​​may be determined to be abnormal (disconnected). Here, the voltage value of the noise component is unstable and fluctuates greatly. Furthermore, there are various types of noise components. Therefore, even if the first threshold is set to a low value, the voltage value of the noise component rarely exceeds the first threshold. Even if the voltage value of the noise component exceeds the first threshold, there will be times when the voltage value falls below the first threshold. Furthermore, the fluctuation range of the voltage value of the composite signal (S13) is relatively narrow (e.g., approximately 0 V to 300 mV). Therefore, setting the first threshold to a value significantly different from the normal value reduces the likelihood of false detection. Therefore, the coefficient used to set the first threshold is set to a relatively small value (e.g., 30%). The same applies to the coefficient used to set the second threshold.

[0102] On the other hand, for example, when the third threshold is set, the voltage value of the composite signal (S24) is large (e.g., approximately 1 V to 1.5 V), sufficiently larger than the voltage value of the noise component. Therefore, the third threshold can be set larger than the voltage value of the noise component. Here, as described above, as the amount of wear of the bearings 32, 33 in the thrust direction increases, the voltage value of one of the composite signals (S24, S68) decreases. Therefore, the coefficient used to set the third threshold is set to a value (e.g., 50%) such that the normal value does not fall below the third threshold even when the bearings 32, 33 wear in the thrust direction, and the third threshold is larger than the voltage value of the noise component. The coefficient used to set the fourth threshold is also set in this manner.

[0103] In this way, each coefficient is set based on the signal level (voltage value) of the noise component. In other words, the first to fourth thresholds are set based on the signal level (voltage value) of the noise component.

[0104] In the present invention, it is preferable that each coefficient is greater than "0%" and equal to or less than "50%", and is not limited to this embodiment.

[0105] Operation of the canned motor pump (motor bearing wear monitoring device (1)) Next, the operation of the pump 1 will be explained below, focusing on the operation of the device 5. In the following explanation, reference will be made to Figures 1 to 10 as appropriate.

[0106] FIG. 11 is a flowchart showing an example of the operation of the device 5.

[0107] During operation of the pump 1, a driving power source is supplied to the motor unit 3, and the rotor 36, rotary shaft 31, and impeller 21 rotate at a predetermined rotation speed. During this operation, the device 5 constantly and repeatedly executes an update process (ST1), a radial side wire break detection process (ST2), a thrust side wire break detection process (ST3), and a wear amount detection process (ST4). The radial side wire break detection process (ST2) and the thrust side wire break detection process (ST3) are examples of the present detection method.

[0108] Update Processing FIG. 12 is a flowchart showing an example of the update processing (ST1).

[0109] The "update process (ST1)" periodically acquires the voltage values ​​of each composite signal (S13, S57, S24, S68) while the pump 1 is operating, and updates and stores the first maximum voltage value through the fourth maximum voltage value stored in the RAM 53b. When the device 5 is started, the update process (ST1) is executed first. The detection coils C1 to C8 constantly output detection signals while the rotor 36 is rotating.

[0110] First, the second acquisition unit 532 acquires the composite signal (S13) input to the A / D converter 52 from the first path L1 as the first signal (S1), acquires the composite signal (S57) input to the A / D converter 52 from the second path L2 as the second signal (S2), acquires the composite signal (S24) input to the A / D converter 52 from the third path L3 as the third signal (S3), and acquires the composite signal (S68) input to the A / D converter 52 from the fourth path L4 as the fourth signal (S4), thereby acquiring the voltage values ​​"V1" to "V4" of each composite signal (S13, S57, S24, S68) (ST11: update acquisition step). Acquisition of each composite signal (S13, S57, S24, S68) is performed every predetermined time (e.g., 10 ms).

[0111] Next, the update unit 533 compares the acquired voltage values ​​"V1" to "V4" with the first maximum voltage value "V1" stored in the RAM 53b. ｍａｘ " ~ Fourth maximum voltage value "V4 ｍａｘ " (ST12: update comparison step). Specifically, the update unit 533 compares the voltage value "V1" of the composite signal (S13) with the first maximum voltage value "V1 ｍａｘ ", and the voltage value "V2" of the composite signal (S57) is compared with the second maximum voltage value "V2 ｍａｘ ", and the voltage value "V3" of the composite signal (S24) is compared with the third maximum voltage value "V3 ｍａｘ ", and the voltage value "V4" of the composite signal (S68) is compared with the fourth maximum voltage value "V4 ｍａｘ "Compare with ".

[0112] When any of the voltage values ​​"V1" to "V4" of each composite signal (S13, S57, S24, S68) is equal to or greater than the corresponding first maximum voltage value "V1 ｍａｘ " ~ Fourth maximum voltage value "V4 ｍａｘ" stored in the RAM 53b ("Y" in ST12), the updating unit 533 updates the first maximum voltage value "V1 ｍａｘ " ~ Fourth maximum voltage value "V4 ｍａｘ ", the corresponding voltage value "V1 ｍａｘ " ~ "V4 ｍａｘ " with the corresponding voltage values ​​"V1" to "V4" (ST13: voltage value updating step). That is, the RAM 53b updates only the first maximum voltage value "V1 ｍａｘ " ~ Fourth maximum voltage value "V4 ｍａｘ " is updated and stored.

[0113] Next, the threshold setting unit 534 sets the updated first maximum voltage value “V1 ｍａｘ " ~ Fourth maximum voltage value "V4 ｍａｘ ” based on the corresponding first threshold “V ｔ１ " ~ 4th threshold "V ｔ４ " is set (ST14: threshold value update step). The process (ST14) is ｍａｘ " ~ Fourth maximum voltage value "V4 ｍａｘ The first threshold value "V ｔ１ " ~ 4th threshold "V ｔ４ ” is executed only when the corresponding first threshold “V ｔ１ " ~ 4th threshold "V ｔ４ After setting ", the control unit 53 ends the update process (ST1).

[0114] On the other hand, the voltage values ​​"V1" to "V4" of each composite signal (S13, S57, S24, S68) are all equal to or greater than the corresponding first maximum voltage value "V1 ｍａｘ " ~ Fourth maximum voltage value "V4 ｍａｘ " or less ("N" in ST12), the updating unit 533 updates the first maximum voltage value "V1 ｍａｘ " ~ Fourth maximum voltage value "V4 ｍａｘ The control unit 53 does not update ", and ends the update process (ST1).

[0115] In the present invention, the process (ST14) may be executed for all of the first to fourth threshold values.

[0116] In the present invention, when the device 5 is started, it is preferable that all of the first maximum voltage value to the fourth maximum voltage value are updated and all of the first threshold value to the fourth threshold value are set.

[0117] Radial Side Disconnection Detection Processing FIG. 13 is a flowchart showing an example of radial side disconnection detection processing (ST2).

[0118] The "radial side disconnection detection process (ST2)" is a process for detecting the presence or absence of a disconnection in the path of the signal (composite signal (S13, S57)) for detecting the radial wear amount of the bearings 32, 33. That is, the radial side disconnection detection process (ST2) is a process for automatically detecting the presence or absence of a disconnection in the detection coils C1, C3, C5, C7 and the first path L1 to second path L2.

[0119] First, the second acquisition unit 532 acquires the voltage value "V1" of the first signal (S1) input to the A / D converter 52 via the first path L1, and acquires the voltage value "V2" of the second signal (S2) input to the A / D converter 52 via the second path L2 (ST21: first acquisition step). The acquisition of the voltage values ​​"V1" and "V2" is performed at predetermined time intervals (e.g., every 10 ms). Here, when there is no disconnection in the detection coils C1, C3, C5, and C7 and the first path L1 to the second path L2, the second acquisition unit 532 acquires the composite signal (S13) as the first signal (S1) and the composite signal (S57) as the second signal (S2).

[0120] In the present invention, the process (ST21) may be substituted by the process (ST11) in the update process (ST1). That is, the second acquisition unit 532 may acquire the voltage values ​​“V1” and “V2” acquired in the process (ST11).

[0121] Next, the disconnection detection unit 535 compares the voltage value “V1” of the acquired composite signal (S13) with the first threshold value “V ｔ１ " (ST22: first comparison step).

[0122] The voltage value "V1" is equal to or exceeds the first threshold value "V ｔ１" ("Y" in ST22), the open circuit detection unit 535 determines that there is an open circuit (abnormality) in the detection coils C1, C3 and the first path L1 (ST23). That is, the open circuit detection unit 535 detects an open circuit in the detection coils C1, C3 and the first path L1. At this time, the first signal (S1) does not include the composite signal (S13) and may include a noise component. In other words, the noise component may flow through the first path L1 as the first signal (S1).

[0123] On the other hand, when the voltage value "V1" is equal to or lower than the first threshold value "V ｔ１ If the above-mentioned value is "N" in ST22, the disconnection detection unit 535 determines that there is no disconnection (normal) in the detection coils C1, C3 and the first path L1 (ST24). At this time, the composite signal (S13) flows through the first path L1 as the first signal (S1).

[0124] Next, the disconnection detection unit 535 compares the voltage value “V2” of the acquired composite signal (S57) with the second threshold value “V ｔ２ " (ST25: second comparison step).

[0125] The voltage value "V2" is equal to or exceeds the second threshold value "V ｔ２ " ("Y" in ST25), the open circuit detection unit 535 determines that there is an open circuit (abnormality) in the detection coils C5, C7 and the second path L2 (ST26). That is, the open circuit detection unit 535 detects an open circuit in the detection coils C5, C7 and the second path L2. At this time, the second signal (S2) does not include the composite signal (S57) and may include a noise component. In other words, the noise component may flow through the second path L2 as the second signal (S2).

[0126] On the other hand, the voltage value "V2" is equal to or lower than the second threshold value "V ｔ２ If the above-mentioned value is "N" in ST25, the disconnection detection unit 535 determines that there is no disconnection (normal) in the detection coils C5, C7 and the second path L2 (ST27). At this time, the composite signal (S57) flows through the second path L2 as the second signal (S2).

[0127] Next, the display control unit 536 changes the display mode of the display unit 55 based on the determination result of the disconnection detection unit 535 (ST28: first display step). Specifically, when the disconnection detection unit 535 determines that there is an "abnormality," the display control unit 536 turns on the LED on the radial side of the display unit 55. On the other hand, when the disconnection detection unit 535 determines that there is a "normality," the display control unit 536 turns off the LED on the radial side of the display unit 55. Next, the control unit 53 ends the radial-side disconnection detection process (ST2).

[0128] Thus, in the radial-side disconnection detection process (ST2), the first threshold value is used to determine whether or not the detection coils C1 and C3 and the first path L1 are disconnected. As described above, the first threshold value is not set to "0" but is set to a value corresponding to the noise component contained in the first signal (S1). Therefore, when the detection coils C1 and C3 or the first path L1 are disconnected, the disconnection detection unit 535 can detect the disconnection even if the first signal contains noise components (even if the voltage value is not "0"). Here, due to the setting of the coefficient of the first threshold value, if the first signal (S1) contains noise components with a signal level similar to that of the normal combined signal (S13), the disconnection detection unit 535 may not be able to detect the disconnection and may make an erroneous detection. However, the voltage value of the noise components is unstable and fluctuates greatly. Therefore, although false detection may occur momentarily, when the voltage value of the noise component falls below the first threshold, the open circuit detector 535 can detect the open circuit in the detection coils C1 and C3 and the first path L1. This effect is also achieved in determining whether or not there is an open circuit in the detection coils C5 and C7 and the second path L2.

[0129] Furthermore, in the radial side disconnection detection process (ST2), the disconnection detection unit 535 automatically determines whether or not there is a disconnection in the detection coils C1, C3, C5, and C7 and the first path L1 to the second path L2 using the composite signal (S13, S57) used to detect the amount of wear in the radial direction, thereby automatically detecting the disconnection. Therefore, the device 5 does not require dedicated wiring or circuitry to execute the radial side disconnection detection process (ST2). Furthermore, the device 5 does not require external access to the terminals (terminal blocks) connected to the first path L1 and the second path L2. In other words, the device 5 does not require external access to the terminal blocks to check for the presence or absence of disconnections in the detection coils C1, C3, C5, and C7. Therefore, the user of the pump 1 can safely check for the presence or absence of disconnections in the detection coils C1, C3, C5, and C7 and the first path L1 to the second path L2 without stopping the pump 1.

[0130] In the present invention, the disconnection detection unit 535 may detect a disconnection in the detection coils C1 and C3 and the first path L1 when the acquired voltage value falls below the first threshold value multiple times within a predetermined time period. This detection method is also used to detect a disconnection in the detection coils C5 and C7 and the second path L2.

[0131] Thrust Side Disconnection Detection Processing FIG. 14 is a flowchart showing an example of thrust side disconnection detection processing (ST3).

[0132] The "thrust-side wire break detection process (ST3)" is a process for detecting the presence or absence of a wire break in the path of the signal (composite signal (S24, S68)) for detecting the amount of wear in the thrust direction of the bearings 32, 33. That is, the thrust-side wire break detection process (ST3) is a process for automatically detecting the presence or absence of a wire break in the detection coils C2, C4, C6, C8 and the third path L3 to the fourth path L4.

[0133] First, the second acquisition unit 532 acquires the voltage value "V3" of the third signal (S3) input to the A / D converter 52 via the third path L3, and acquires the voltage value "V4" of the fourth signal (S4) input to the A / D converter 52 via the fourth path L4 (ST31: second acquisition step). The acquisition of the voltage values ​​"V3" and "V4" is performed at predetermined time intervals (e.g., every 10 ms). Here, when there is no disconnection in the detection coils C2, C4, C6, and C8 and the third path L3 to the fourth path L4, the second acquisition unit 532 acquires the composite signal (S24) as the third signal (S3) and the composite signal (S68) as the fourth signal (S4).

[0134] In the present invention, the process (ST31) may be substituted by the process (ST11) in the update process (ST1). That is, the second acquisition unit 532 may acquire the voltage values ​​“V3” and “V4” acquired in the process (ST11).

[0135] Next, the disconnection detection unit 535 compares the voltage value “V3” of the acquired composite signal (S24) with the third threshold value “V ｔ３ " (ST32: third comparison step).

[0136] The voltage value "V3" is equal to the third threshold value "V ｔ３ " ("Y" in ST32), the open circuit detection unit 535 determines that there is an open circuit (abnormality) in the detection coils C2, C4 and the third path L3 (ST33). That is, the open circuit detection unit 535 detects an open circuit in the detection coils C2, C4 and the third path L3. At this time, the third signal (S3) does not include the composite signal (S24) and may include noise components. In other words, the noise components may flow through the third path L3 as the third signal (S3).

[0137] On the other hand, the voltage value "V3" is equal to or lower than the third threshold value "V ｔ３ If the above-mentioned value is equal to or greater than the predetermined value ("N" in ST32), the disconnection detection unit 535 determines that there is no disconnection (normal) in the detection coils C2, C4 and the third path L3 (ST34). At this time, the composite signal (S24) flows through the third path L3 as the third signal (S3).

[0138] Next, the disconnection detection unit 535 compares the voltage value “V4” of the acquired composite signal (S68) with the fourth threshold “Vｔ４ " (ST35: fourth comparison step).

[0139] The voltage value "V4" is equal to the fourth threshold value "V ｔ４ " ("Y" in ST35), the open circuit detection unit 535 determines that there is an open circuit (abnormality) in the detection coils C6, C8 and the fourth path L4 (ST36). That is, the open circuit detection unit 535 detects an open circuit in the detection coils C6, C8 and the fourth path L4. At this time, the fourth signal (S4) does not include the composite signal (S68) and may include noise components. In other words, the noise components may flow through the fourth path L4 as the fourth signal (S4).

[0140] On the other hand, the voltage value "V4" is equal to or lower than the fourth threshold value "V ｔ４ If the above-mentioned value is equal to or greater than the above ("N" in ST35), the disconnection detection unit 535 determines that there is no disconnection (normal) in the detection coils C6, C8 and the fourth path L4 (ST37). At this time, the composite signal (S68) flows through the fourth path L4 as the fourth signal (S4).

[0141] Next, the display control unit 536 changes the display mode of the display unit 55 based on the determination result of the disconnection detection unit 535 (ST38: second display step). Specifically, when the disconnection detection unit 535 determines that there is an "abnormality," the display control unit 536 turns on the LED on the thrust side of the display unit 55. On the other hand, when the disconnection detection unit 535 determines that there is a "normality," the display control unit 536 turns off the LED on the thrust side of the display unit 55. Next, the control unit 53 ends the thrust-side disconnection detection process (ST3).

[0142] Thus, in the thrust-side disconnection detection process (ST3), the third threshold value is used to determine whether or not the detection coils C2 and C4 and the third path L3 are disconnected. As described above, the third threshold value is not set to "0" but is set to a value corresponding to the noise component contained in the third signal. Therefore, when the detection coils C2 and C4 or the third path L3 are disconnected, the disconnection detection unit 535 can reliably detect the disconnection even if the third signal contains noise components (even if the voltage value is not "0"). This effect is also achieved in determining whether or not the detection coils C6 and C8 and the fourth path L4 are disconnected.

[0143] In the thrust-side open-circuit detection process (ST3), the open-circuit detection unit 535 automatically detects open circuits by automatically determining the presence or absence of open circuits in the detection coils C2, C4, C6, and C8, the third path L3, and the fourth path L4 using the composite signal (S24, S68) used to determine whether to add or subtract the offset voltage. That is, the open-circuit detection unit 535 detects open circuits using the composite signal (S24, S68) required to generate the differential signal (Sd) used to detect the amount of wear in the thrust direction. Therefore, the present device 5 does not require dedicated wiring or circuitry to perform the thrust-side open-circuit detection process (ST3). In other words, this detection method can be performed by simply adding this detection program to a conventional motor bearing wear detection device, without modifying the wiring or circuit configuration. Furthermore, the present device 5 does not require external access to the terminals (terminal blocks) connected to the third path L3 and the fourth path L4. That is, device 5 does not require access to the terminal block from outside device 5 in order to check for disconnections in detection coils C2, C4, C6, C8, etc. Therefore, the user of pump 1 can safely check for disconnections in detection coils C2, C4, C6, C8 and third path L3 to fourth path L4 without stopping pump 1.

[0144] Wear Amount Detection Processing FIG. 15 is a flowchart showing an example of the wear amount detection processing (ST4).

[0145] The "wear amount detection process (ST4)" is a process for detecting the amount of wear of the bearings 32, 33 based on each composite signal (S13, S57, S24, S68). The wear amount detection process (ST4) is an example of a wear amount detection method executed by the present device 5.

[0146] The detection coils C1 to C8 constantly output detection signals while the rotor 36 is rotating. The composite signals (S13, S57) from the detection coils C1, C3, C5, and C7 flow through the first path L1 and the second path L2 and are input to the A / D converter 52.

[0147] The detection signals (composite signals (S24, S68)) from the detection coils C2, C4, C6, and C8 are input to the arithmetic circuit 56c via signal paths L15 and L16. The arithmetic circuit 56c performs offset processing to calculate a difference value. The difference value is converted to an absolute value by the difference absolute value conversion circuit 56d. The offset composite signal (S24), composite signal (68), and a signal indicating the absolute value (difference signal (Sd)) are input to the A / D converter 52.

[0148] In the wear amount detection process (ST4), the wear amount detection unit 531 separately executes a process for detecting the amount of wear in the radial direction (ST41) and a process for detecting the amount of wear in the thrust direction (ST42). The process for detecting the amount of wear in the radial direction (ST41) and the process for detecting the amount of wear in the thrust direction (ST42) are well-known processes, and therefore only an outline thereof will be described below.

[0149] In the radial wear amount detection process (ST41), the first acquisition unit 530 acquires the voltage values ​​"V1" and "V2" of the combined signal (S13, S57). Next, the wear amount detection unit 531 detects the wear amounts of the bearings 32 and 33 based on the second correspondence information and the voltage values ​​"V1" and "V2." Next, the wear amount detection unit 531 compares both wear amounts and selects the larger wear amount as the radial wear amount. The detected wear amount is stored as log information in, for example, the storage unit 54.

[0150] In the present invention, the first acquisition unit 530 may acquire the voltage values ​​"V1" and "V2" acquired in the process (ST11).

[0151] In the thrust direction wear amount detection process (ST42), the first acquisition unit 530 acquires the voltage value (absolute value) "Vd" of the differential signal (Sd). The wear amount detection unit 531 detects the thrust direction wear amount of the bearings 32, 33 based on the first correspondence relationship information and the voltage value "Vd." As described above, the differential signal (Sd) is generated from the combined signal (S24, S68). In other words, the wear amount detection unit 531 detects the thrust direction wear amount of the bearings 32, 33 based on the combined signal (S24, S68). The detected wear amount is stored as log information, for example, in the memory unit 54.

[0152] Next, the display control unit 536 determines the display mode of the display unit 55 based on the detected amount of wear, and causes the display unit 55 to display in the determined display mode (ST43).

[0153] Summary (1) According to the embodiment described above, the device 5 includes a wear amount detection unit 531, a second acquisition unit 532, and a disconnection detection unit 535. The wear amount detection unit 531 detects the radial wear amount of the bearings 32, 33 based on the voltage values ​​of the respective composite signals (S13, S57), and detects the thrust wear amount of the bearings 32, 33 based on the voltage values ​​of the respective composite signals (S24, S68). The second acquisition unit 532 acquires the first signal (S1) flowing through the first path L1, the second signal (S2) flowing through the second path L2, the third signal (S3) flowing through the third path L3, and the fourth signal (S4) flowing through the fourth path L4. The open circuit detection unit 535 detects whether or not there is an open circuit in the detection coils C1, C3 and the first path L1 based on the voltage value of the first signal (S1) acquired via the first path L1 and a first threshold value, detects whether or not there is an open circuit in the detection coils C5, C7 and the second path L2 based on the voltage value of the second signal (S2) acquired via the second path L2 and a second threshold value, detects whether or not there is an open circuit in the detection coils C2, C4 and the third path L3 based on the voltage value of the third signal (S3) acquired via the third path L3 and a third threshold value, and detects whether or not there is an open circuit in the detection coils C6, C8 and the fourth path L4 based on the voltage value of the fourth signal (S4) acquired via the fourth path L4 and a fourth threshold value. When the disconnection detection unit 535 does not detect a disconnection, the composite signal (S13) flows through the first path L1 as the first signal (S1), the composite signal (S57) flows through the second path L2 as the second signal (S2), the composite signal (S24) flows through the third path L3 as the third signal (S3), and the composite signal (S68) flows through the fourth path L4 as the fourth signal (S4). The first threshold is set to be smaller than the voltage value of the composite signal (S13), the second threshold is set to be smaller than the voltage value of the composite signal (S57), the third threshold is set to be smaller than the voltage value of the composite signal (S24), and the fourth threshold is set to be smaller than the voltage value of the composite signal (S68). With this configuration, the present device 5 does not require dedicated wiring or circuits to perform the present detection method. Furthermore, the device 5 can automatically detect whether or not there is a break in the detection coils C1 to C8 and the first to fourth paths L1 to L4.Therefore, the user of the pump 1 can safely check for disconnections in the detection coils C1 to C8 and the first to fourth paths L1 to L4 without having to stop the pump 1.

[0154] Furthermore, according to the embodiment described above, the RAM 53b updates and stores the first to fourth maximum voltage values. The first threshold is set based on the first maximum voltage value, the second threshold is set based on the second maximum voltage value, the third threshold is set based on the third maximum voltage value, and the fourth threshold is set based on the fourth maximum voltage value. With this configuration, the first to fourth thresholds are set to change according to the latest trend in voltage values. Therefore, the device 5 can appropriately detect the presence or absence of a wire break even if the voltage value of each composite signal (S13, S57, S24, S68) increases over time, and can appropriately detect the presence or absence of a wire break even if the drive frequency is increased.

[0155] Furthermore, according to the embodiment described above, the first threshold is set based on the signal level of the noise component contained in the first signal (S1), the second threshold is set based on the signal level of the noise component contained in the second signal (S2), the third threshold is set based on the signal level of the noise component contained in the third signal (S3), and the fourth threshold is set based on the signal level of the noise component contained in the fourth signal (S4). With this configuration, even if the first signal (S1) to the fourth signal (S4) contain noise components, the device 5 can automatically detect the presence or absence of disconnections in the detection coils C1 to C8 and the first path L1 to the fourth path L4.

[0156] Furthermore, according to the embodiment described above, the first and second thresholds are smaller than the third and fourth thresholds. This configuration allows the first to fourth thresholds to be set to values ​​corresponding to the signal levels of the respective composite signals (S13, S57, S24, S68). As a result, the open circuit detector 535 can reliably detect the presence or absence of open circuits in the detection coils C2, C4, C6, and C8 and the third to fourth paths L3 to L4, without being affected by noise components.

[0157] Furthermore, according to the embodiment described above, the device 5 includes a threshold setting unit 534 that sets the first to fourth thresholds. With this configuration, the device 5 can automatically set the first to fourth thresholds according to the signal level of the noise component and the latest trend of the voltage value.

[0158] In the embodiment described above, the detection method is executed by the control unit 53. Alternatively, the detection method may be executed by an external computing device (e.g., a computer) connected to the device 5.

[0159] In addition, in the embodiment described above, some or all of the information stored in RAM 53b (e.g., the first maximum voltage value to the fourth maximum voltage value, the first threshold value to the fourth threshold value, etc.) may be stored in memory unit 54.

[0160] Furthermore, in the embodiment described above, the device 5 may have a function of acquiring the signal level of the noise component from the voltage values ​​of each of the first signal (S1) to the fourth signal (S4) and setting a coefficient based on the acquired signal level of the noise component. The signal level of the noise component is acquired using, for example, known filtering and FFT.

[0161] Furthermore, in the embodiment described above, the device 5 may detect the presence or absence of an open circuit in the detection coils C2, C4, C6, and C8, the third path L3 to the fourth path L4, and the signal paths L15 and L16 based on the differential signal (Sd) and a threshold value (fifth threshold value) corresponding to the differential signal (Sd). As described above, the differential signal (Sd) can be normal if one of the composite signals is present. However, because one of the voltage values ​​used to calculate the differential value drops significantly, the voltage value (absolute value) of the differential signal (Sd) in an abnormal state is greater than the normal voltage value. Therefore, by setting the fifth threshold value to a value greater than the voltage value of the differential signal (Sd), unlike the first to fourth threshold values, the device 5 can detect the presence or absence of an open circuit based on the voltage value of the differential signal (Sd) and the fifth threshold value. In this case, the device 5 also stores the maximum voltage value of the differential signal (Sd) in the memory unit 54 as a fifth maximum voltage value. Since the voltage value during an abnormal state may deviate significantly from the latest trend of the voltage value during normal state, the device 5 may periodically acquire the amount of change in the voltage value of the differential signal (Sd) and, based on this amount of change, detect the presence or absence of a break in the detection coils C2, C4, C6, C8, the third path L3 to the fourth path L4, and the signal paths L15 and L16.

[0162] Furthermore, in the embodiment described above, the device 5 does not need to include the threshold setting unit 534. In this case, the first to fourth thresholds are fixed values, and therefore, the accuracy of detecting disconnection decreases.

[0163] Furthermore, in the embodiments described above, the first to fourth thresholds need only be set to be smaller than the voltage values ​​of the corresponding composite signals (S13, S57, S24, S68), and do not necessarily have to be set based on the maximum voltage values ​​or noise components.

[0164] Furthermore, in the embodiment described above, the detection program and each coefficient may be stored in the storage unit 54 .

[0165] Motor Bearing Wear Monitoring Device (2) Next, another embodiment of this device (hereinafter referred to as the "second embodiment") will be described below, focusing on the differences from the previously described embodiment (hereinafter referred to as the "first embodiment"). The second embodiment differs from the first embodiment in that it uses a learning model to estimate the presence or absence of a break. In the following description, elements common to the first embodiment are assigned the same reference numerals, and their description will be omitted.

[0166] Configuration of Motor Bearing Wear Monitoring Device (2) FIG. 16 is a functional block diagram showing another embodiment (second embodiment) of the device.

[0167] The device 5A includes eight detection coils C1 to C8, a connection unit 50, two common paths Lc1 and Lo2, six signal paths L11 to L16, four signal processing circuits 51a to 51d, an A / D converter 52, a control unit 53A, a storage unit 54A, a display unit 55, and an offset processing unit 56. The A / D converter 52 and the control unit 53A are configured by, for example, a microcomputer.

[0168] The configuration of the device 5A is the same as that of the device 5 of the first embodiment, except for the control unit 53A and the storage unit 54A. Furthermore, in the device 5A, instead of the detection program of the first embodiment, an estimation program estimates the presence or absence of a wire break using a learning model described below. That is, instead of the detection method, the device 5A executes a wire break estimation method for the detection coils C1 to C8 using a learning model (hereinafter simply referred to as the "estimation method"). Details of the learning model will be described later.

[0169] The control unit 53A controls the overall operation of the device 5A. The control unit 53A is configured, for example, with a processor such as a CPU 53a, a volatile memory such as a RAM 53b that functions as a work area for the CPU 53a, and a non-volatile memory such as a ROM 53c that stores various information such as the estimation program and other control programs (e.g., a wear amount detection program). The control unit 53A includes a first acquisition unit 530, a wear amount detection unit 531, a second acquisition unit 532, an update unit 533, a display control unit 536, and a disconnection estimation unit 537.

[0170] The control unit 53A runs the estimation program, which cooperates with the hardware resources of the device 5A to implement the estimation method described below. By causing a processor (CPU 53a) constituting the control unit 53A to execute the estimation program, the estimation program can cause the processor to function as a second acquisition unit 532, a display control unit 536, and a wire break estimation unit 537, thereby executing the estimation method. Furthermore, by causing a computer to execute the estimation program and the wear amount detection program, the estimation program and the wear amount detection program can cause the computer to function as the device 5A.

[0171] In the present invention, the estimation program may be stored in the storage unit 54 A. Alternatively, the estimation program may be stored in a non-transitory storage medium (e.g., a CD, a DVD, a USB memory, or the like) in an installable file format or an executable file format and provided to the device 5 A via a dedicated read-out medium.

[0172] The disconnection estimation unit 537 estimates the presence or absence of a disconnection in the detection coils C1 to C8 and the first path L1 to the fourth path L4 based on the first signal (S1) to the fourth signal (S4), the first maximum voltage value to the fourth maximum voltage value, and learning models (first learning model M1, second learning model M2, third learning model M3, and fourth learning model M4) described below. Specific operations of the disconnection estimation unit 537 will be described later.

[0173] The memory unit 54A stores information necessary for the operation of the device 5A (e.g., the first learning model M1 to the fourth learning model M4, offset information, first correspondence information, second correspondence information, etc.). The memory unit 54A is, for example, a non-volatile memory such as an EEPROM or a flash memory. The memory unit 54A is an example of a learning model memory unit of the present invention.

[0174] FIG. 17 is a schematic diagram showing an example of information (first learning model M1 to fourth learning model M4) stored in the memory unit 54A.

[0175] The "first learning model M1" is a model that calculates the voltage value "V1" and the first maximum voltage value "V1" of the first signal (S1).ｍａｘ " is input, the first learning model M1 is a trained machine learning algorithm (i.e., a learning model) that has been trained to output the presence or absence (normal / abnormal) of a disconnection in the detection coils C1, C3 and the first path L1. The first learning model M1 is generated in advance by, for example, a machine learning device and stored in the storage unit 54A.

[0176] The "second learning model M2" is a model that calculates the voltage value "V2" and the second maximum voltage value "V2" of the second signal (S2). ｍａｘ " is input, the second learning model M2 is a trained learning model that has been machine-learned to output the presence or absence (normal / abnormal) of a disconnection in the detection coils C5, C7 and the second path L2. The second learning model M2 is generated in advance by, for example, a machine learning device and stored in the storage unit 54A.

[0177] The "third learning model M3" is a model that calculates the voltage value "V3" and the third maximum voltage value "V3" of the third signal (S3). ｍａｘ " is input, the third learning model M3 is a trained learning model that has been machine-learned to output the presence or absence (normal / abnormal) of a disconnection in the detection coils C2, C4 and the third path L3. The third learning model M3 is generated in advance by, for example, a machine learning device and stored in the memory unit 54A.

[0178] The "fourth learning model M4" is a model that calculates the voltage value "V4" and the fourth maximum voltage value "V4" of the fourth signal (S4). ｍａｘ " is input, the fourth learning model M4 is a trained learning model that has been machine-learned to output the presence or absence (normal / abnormal) of a disconnection in the detection coils C6, C8 and the fourth path L4. The fourth learning model M4 is generated in advance by, for example, a machine learning device and stored in the storage unit 54A.

[0179] The first learning model M1 and the second learning model M2 are examples of radial learning models in the present invention, and the third learning model M3 and the fourth learning model M4 are examples of thrust learning models in the present invention. That is, the radial learning models include the first learning model M1 and the second learning model M2, and the thrust learning models include the third learning model M3 and the fourth learning model M4.

[0180] Here, machine learning by a machine learning device is performed by, for example, subjecting training data to a known machine learning algorithm (e.g., a neural network having an input layer, multiple intermediate layers, and an output layer). "Learning data" includes information that serves as input data for the machine learning algorithm (learning model) and information that serves as output data (teaching data) associated with the input data.

[0181] The "input data" refers to explanatory variables in machine learning. In this embodiment, the input data are the voltage values ​​of the first signal (S1) to the fourth signal (S4) under predetermined conditions (predetermined operating conditions, predetermined wear state, predetermined period, and presence or absence of a disconnection), as well as the first maximum voltage value to the fourth maximum voltage value. As described above, if the detection coils C1 and C3 and the first path L1 are not disconnected, the composite signal (S13) flows as the first signal (S1), and its voltage value is a normal value greater than the first threshold. On the other hand, if the detection coils C1 and C3 or the first path L1 are disconnected, the first signal (S1) does not contain the composite signal (S13), and its voltage value is an abnormal value less than the first threshold. Similarly, if the detection coils C2, C4 to C8 and the second path L2 to the fourth path L4 are not disconnected, the voltage values ​​of the second signal (S2) to the fourth signal (S4) are normal values ​​greater than the corresponding second threshold value to fourth threshold value. On the other hand, if the detection coils C2, C4 to C8 or the second path L2 to the fourth path L4 are disconnected, the voltage values ​​of the second signal (S2) to the fourth signal (S4) are abnormal values ​​smaller than the corresponding second to fourth threshold values. In the first embodiment, the first to fourth threshold values ​​used to determine whether or not a disconnection exists are set as percentages of the first to fourth maximum voltage values. Therefore, the first to fourth threshold values ​​are proportional to the first to fourth maximum voltage values. Therefore, there is a correlation between the voltage value and the first maximum voltage value of the first signal (S1) and the presence or absence of a disconnection in the detection coils C1, C3 and the first path L1. Similarly, there is a correlation between the voltage values ​​and the second to fourth maximum voltage values ​​of the second to fourth signals (S2) to (S4) and the presence or absence of open circuits in the detection coils C5, C7, C2, C4, C6, and C8 and the second to fourth paths L2 to L4. Thus, there is a correlation between input data and output data. The input data can be obtained, for example, by operating a test device simulating the pump 1 under predetermined conditions for a predetermined period of time. The presence or absence of open circuits can be reproduced, for example, by turning on and off switches installed in multiple locations in the test device (e.g., between the serially connected detection coils C1 and C3, between the detection coil C3 and the connection portion 50, etc.).

[0182] The input data may be, for example, pseudo signals (voltage values) generated by a signal generating device within a predetermined period based on actual data (e.g., log data) previously acquired from a pump of the same model as pump 1.

[0183] Here, the "predetermined driving conditions" are, for example, driving frequencies between 40 Hz and 60 Hz that correspond to the environment in which the pump 1 is installed. The "predetermined wear state" is, for example, a wear state in which each composite signal (S13, S57, S24, S68) has a normal value. The "predetermined period" is a time (for example, several seconds to several tens of seconds) during which signals that can be used as learning data are obtained under the predetermined driving conditions and predetermined wear state.

[0184] The "output data" is a target variable in machine learning, and in this embodiment, is information indicating the "presence" or "absence" of a break in the detection coils C1 to C8 and the first path L1 to the fourth path L4. Numeric values ​​such as "0" and "1" are assigned to the "presence" or "absence" of a break. One piece of output data is associated with one corresponding piece of input data to constitute one piece of learning data.

[0185] In the present invention, the output data is not limited to the two states of "presence" and "absence" of a break. For example, if there is a difference in the signal level of the noise component depending on the position of the break, the output data may include the "position of the break."

[0186] In the present invention, the machine learning algorithm used for machine learning is not limited to a neural network as long as the first learning model M1 to the fourth learning model M4 generated by machine learning using a plurality of learning data can estimate the presence or absence of a disconnection. That is, the machine learning algorithm may be, for example, a random forest, a decision tree, a support vector machine, or the like.

[0187] As shown in FIG. 17 , the first learning model M1 generated in this manner can output whether or not there is a disconnection in the detection coils C1, C3 or the first path L1 when the voltage value and the first maximum voltage value of the first signal (S1) are input. That is, the first learning model M1 is machine-trained to output whether or not there is a disconnection in the detection coils C1, C3 or the first path L1 when the voltage value and the first maximum voltage value of the first signal (S1) are input as input data. Similarly, the second learning model M2 to the fourth learning model M4 are machine-trained to output whether or not there is a disconnection in the corresponding detection coils C2, C4 to C8 or the second path L2 to the fourth path L4 when the voltage values ​​and the second maximum voltage value to the fourth maximum voltage value of the corresponding second signal (S2) to the fourth signal (S4) are input as input data.

[0188] Operation of the canned motor pump (motor bearing wear monitoring device (2)) Next, the operation of the pump 1 (i.e., the estimation method) will be explained below, focusing on the operation of the device 5A.

[0189] FIG. 18 is a flowchart showing an example of the operation of the device 5A.

[0190] The operation of the pump 1 in the second embodiment is the same as the operation of the pump 1 in the first embodiment, except that the device 5A executes a radial-side wire break estimation process (ST5) and a thrust-side wire break estimation process (ST6) instead of the radial-side wire break detection process (ST2) and the thrust-side wire break detection process (ST3). That is, the device 5A constantly and repeatedly executes the update process (ST1), the radial-side wire break estimation process (ST5), the thrust-side wire break estimation process (ST6), and the wear amount detection process (ST4). The radial-side wire break estimation process (ST5) and the thrust-side wire break estimation process (ST6) are examples of estimation methods. In the following description, reference will be made to FIG. 16 as appropriate.

[0191] Radial Side Wire Break Estimation Processing FIG. 19 is a flowchart showing an example of radial side wire break estimation processing (ST5).

[0192] The "radial side disconnection estimation process (ST5)" is a process for estimating the presence or absence of a disconnection in the path of the signal (composite signal (S13, S57)) for detecting the radial wear amount of the bearings 32, 33. That is, the radial side disconnection estimation process (ST5) is a process for automatically estimating the presence or absence of a disconnection in the detection coils C1, C3, C5, C7 and the first path L1 to second path L2.

[0193] First, the second acquisition unit 532 acquires the voltage value "V1" of the first signal (S1) input to the A / D converter 52 from the first path L1, acquires the voltage value "V2" of the second signal (S2) input to the A / D converter 52 from the second path L2, and acquires the first maximum voltage value "V1" from the RAM 53b. ｍａｘ " and the second maximum voltage value "V2 ｍａｘ " is acquired (ST51: first acquisition step). The acquisition of each voltage value is executed at predetermined time intervals (for example, every 10 ms).

[0194] Next, the disconnection estimation unit 537 calculates the voltage value “V1” and the first maximum voltage value “V1 ｍａｘ " into the first learning model M1, and based on the output of the first learning model M1, estimates the "presence" or "absence" of a disconnection in the detection coils C1, C3 and the first path L1. Similarly, the disconnection estimation unit 537 estimates the "presence" or "absence" of a disconnection in the detection coils C1, C3 and the first path L1 based on the output of the first learning model M1. ｍａｘ " is input into the second learning model M2, and based on the output of the second learning model M2, it is estimated whether or not there is a break in the detection coils C5, C7 and the second path L2 (ST52: first estimation step).

[0195] Next, the display control unit 536 determines the display mode of the display unit 55 based on the estimated "presence" or "absence" of the break, and causes the display unit 55 to display in the determined display mode (ST53: first display step). That is, for example, when it is estimated that there is a break, the display control unit 536 turns on the LED on the radial side of the display unit 55. Next, the control unit 53A ends the radial-side break estimation process (ST5).

[0196] Thrust Side Breakage Estimation Processing FIG. 20 is a flowchart showing an example of thrust side breakage estimation processing (ST6).

[0197] The "thrust-side wire break estimation process (ST6)" is a process for estimating the presence or absence of a wire break in the path of the signal (composite signal (S24, S68)) for detecting the amount of wear in the thrust direction of the bearings 32, 33. That is, the thrust-side wire break estimation process (ST6) is a process for automatically estimating the presence or absence of a wire break in the detection coils C2, C4, C6, C8 and the third path L3 to the fourth path L4.

[0198] First, the second acquisition unit 532 acquires the voltage value "V3" of the third signal (S3) input to the A / D converter 52 from the third path L3, acquires the voltage value "V4" of the fourth signal (S4) input to the A / D converter 52 from the fourth path L4, and acquires the third maximum voltage value "V3" from the RAM 53b. ｍａｘ " and the fourth maximum voltage value "V4 ｍａｘ " is acquired (ST61: second acquisition step). The acquisition of each voltage value is executed at predetermined time intervals (for example, every 10 ms).

[0199] Next, the disconnection estimation unit 537 detects the voltage value “V3” and the third maximum voltage value “V3 ｍａｘ " into the third learning model M3, and based on the output of the third learning model M3, the disconnection estimation unit 537 estimates the "presence" or "absence" of a disconnection in the detection coils C2, C4 and the third path L3. Similarly, the disconnection estimation unit 537 estimates the "presence" or "absence" of a disconnection in the detection coils C2, C4 and the third path L3 based on the output of the third learning model M3. ｍａｘ " is input into the fourth learning model M4, and based on the output of the fourth learning model M4, it is estimated whether or not there is a break in the detection coils C6, C8 and the fourth path L4 (ST62: second estimation step).

[0200] Next, the display control unit 536 determines the display mode of the display unit 55 based on the estimated "presence" or "absence" of the wire break, and causes the display unit 55 to display in the determined display mode (ST63: second display step). That is, for example, when it is estimated that there is a wire break, the display control unit 536 turns on the LED on the thrust side of the display unit 55. Next, the control unit 53A ends the thrust-side wire break estimation process (ST6).

[0201] Summary (2) According to the embodiment described above, the device 5A includes a RAM 53b, a wear amount detection unit 531, a second acquisition unit 532, a disconnection estimation unit 537, and a memory unit 54A. The RAM 53b updates and stores the first to fourth maximum voltage values. The second acquisition unit 532 acquires the first to fourth maximum voltage values ​​and the voltage values ​​of the first to fourth signals (S1) to (S4). The memory unit 54A stores the first to fourth learning models M1 to M4. The disconnection estimation unit 537 inputs the voltage values ​​of the first to fourth signals (S1) to (S4) and the first to fourth maximum voltage values ​​to the corresponding first to fourth learning models M1 to M4, and estimates the presence or absence of a disconnection in the detection coils C1 to C8 or the first to fourth paths L1 to L4. With this configuration, the device 5A does not require dedicated wiring or circuitry to execute the estimation method. Furthermore, the device 5A can automatically estimate the presence or absence of a disconnection in the detection coils C1 to C8 and the first path L1 to the fourth path L4 without undergoing threshold processing as in the device 5 of the first embodiment. Therefore, the user of the pump 1 can safely check the presence or absence of a disconnection in the detection coils C1 to C8 and the first path L1 to the fourth path L4 without having to stop the pump 1.

[0202] Other Embodiments In the above-described embodiments, the number of detection coils C1 to C8 is not limited to "8" as long as the present invention can be implemented.

[0203] In addition, in each of the embodiments described above, the control units 53 and 53A may be configured with a processor such as a DSP (Digital Signal Processor) or a (GP) GPU (General Purpose Graphics Processing Unit) instead of the CPU 53a.

[0204] Furthermore, in the second embodiment described above, the estimation method is executed by the control unit 53A. Alternatively, the estimation method may be executed by an external computing device (e.g., a computer) connected to the device 5A.

[0205] Furthermore, in the second embodiment described above, some of the information stored in the storage unit 54A (e.g., the first learning model M1 to the fourth learning model M4) may be incorporated into the present estimation program and stored in the ROM 53c, in which case the ROM 53c may function as a learning model storage unit in the present invention.

[0206] Furthermore, in each of the embodiments described above, the pump 1 does not necessarily have to include the device 5, 5A. That is, for example, the detection coils C1 to C8 may be provided in the motor unit 3, and the device 5, 5A may be located away from the pump unit 2, the motor unit 3, and the adapter 4. In this case, the device 5, 5A may be connected to the detection coils C1 to C8 via a cable, or the device 5, 5A and the motor unit 3 may have a communication function, and the device 5, 5A may be connected to the motor unit 3 via a wireless communication line so as to be able to receive detection signals.

[0207] Furthermore, in the second embodiment described above, the estimation program may be stored in the storage unit 54A.

[0208] Furthermore, in each of the embodiments described above, the pump 1, rather than the device 5, 5A, may be provided with the detection coils C1 to C8.

[0209] Embodiments of the Present Invention Next, embodiments of the present invention that can be understood from the above-described embodiments will be described below, using the terms and symbols described in the respective embodiments.

[0210] A first embodiment of the present invention is a motor bearing wear monitoring device (e.g., motor bearing wear monitoring device 5) that monitors the wear state of bearings (e.g., bearings 32, 33) supporting a rotating shaft (e.g., rotating shaft 31) of a canned motor pump (e.g., canned motor pump 1) based on detection signals from a plurality of detection coils (e.g., detection coils C1 to C8) that detect magnetic flux changes corresponding to mechanical position changes of a rotor (e.g., rotor 36) relative to a stator (e.g., stator 37) of the motor (e.g., motor unit 3). The plurality of detection coils include a set of radial detection coils (e.g., detection coils C1, C3, detection coils C5, C7) that detect the magnetic flux changes in the radial direction of the rotating shaft, and a set of thrust detection coils (e.g., detection coils C2, C4, detection coils C6,C8), in which the radial detection coil and the thrust detection coil are disposed at an end of one direction side or the other direction side of the stator in the thrust direction, the radial detection coil is electrically connected to a radial signal path (e.g., a first path L1, a second path L2) through which a radial composite signal (e.g., a composite signal (S13), a composite signal (S57)) flows, in which the detection signals of the radial detection coils are composited, and the thrust detection coil is a threshold value storage unit (e.g., RAM 53b) electrically connected to a thrust signal path (e.g., third path L3, fourth path L4) through which a combined thrust resultant signal (e.g., combined signal (S24), combined signal (S68)) flows, the threshold value storage unit storing radial threshold values ​​(e.g., first threshold value, second threshold value) set to be smaller than the voltage value of the radial resultant signal, and thrust threshold values ​​(e.g., third threshold value, fourth threshold value) set to be smaller than the voltage value of the thrust resultant signal; and a radial path through which the combined thrust signal flows. and a disconnection detection unit (e.g., a disconnection detection unit 535) that detects the presence or absence of a disconnection in the detection coil, the radial signal path, and the thrust signal path, and when there is no disconnection in the detection coil, the radial signal path, and the thrust signal path, the radial composite signal is detected. flows through the radial signal path as the radial path signal, the thrust resultant signal flows through the thrust signal path as the thrust path signal, and the disconnection detection unit detects the presence or absence of the disconnection between the radial detection coil and the radial signal path based on the voltage value of the radial path signal and the radial threshold value, and detects the presence or absence of the disconnection between the thrust detection coil and the thrust signal path based on the voltage value of the thrust path signal and the thrust threshold value.This configuration allows the pump user to safely check the presence or absence of disconnections in the detection coil and the first to fourth paths without stopping the pump.

[0211] A second embodiment of the present invention is the motor bearing wear monitoring device of the first embodiment, further comprising a voltage value storage unit (e.g., RAM 53b) that updates and stores a radial maximum voltage value that is the maximum value of the voltage values ​​of the radial composite signal and a thrust maximum voltage value that is the maximum value of the voltage values ​​of the thrust composite signal, the radial threshold value being set based on the radial maximum voltage value, and the thrust threshold value being set based on the thrust maximum voltage value. With this configuration, the device can appropriately detect the presence or absence of a wire break even if the voltage values ​​of the composite signals increase over time.

[0212] A third aspect of the present invention is the motor bearing wear monitoring device of the second aspect, wherein the radial threshold is set based on the signal level of a noise component included in the radial path signal, and the thrust threshold is set based on the signal level of a noise component included in the thrust path signal. With this configuration, even if the first to fourth signals contain noise components, the device can automatically detect whether or not there is a break in the detection coil and the first to fourth paths.

[0213] A fourth aspect of the present invention is the motor bearing wear monitoring device of the third aspect, wherein the radial threshold value is smaller than the thrust threshold value. With this configuration, the first to fourth threshold values ​​can be set to values ​​corresponding to the signal level of the composite signal.

[0214] A fifth aspect of the present invention is a motor bearing wear monitoring device according to any one of the first to fourth aspects, further comprising a threshold setting unit (e.g., threshold setting unit 534) that sets the radial threshold and the thrust threshold. With this configuration, the device can automatically set the first to fourth thresholds according to the signal level of the noise component and the latest trend of the voltage value.

[0215] A sixth aspect of the present invention is the first aspect, wherein the plurality of detector coils include a set of first radial detector coils (e.g., detector coils C1 and C3) and a set of second radial detector coils (e.g., detector coils C5 and C7) that function as a set of the radial detector coils, and a set of first thrust detector coils (e.g., detector coils C2 and C4) and a set of second thrust detector coils (e.g., detector coils C6 and C8) that function as a set of the thrust detector coils, and the first radial detector coils and the first thrust detector coils are The radial signal path is electrically connected to the first radial detection coil, and a first composite signal (e.g., composite signal (S13)) obtained by combining the detection signals of the first radial detection coils flows as the radial composite signal. The radial signal path is electrically connected to the second radial detection coil, and the detection signals of the second radial detection coils flow as the radial composite signal. and a second path (e.g., second path L2) through which the synthesized second synthesized signal (e.g., synthesized signal (S57)) flows as the radial synthesized signal, and the thrust signal path is electrically connected to the first thrust detection coil and includes a third path (e.g., third path L3) through which a third synthesized signal (e.g., synthesized signal (S24)) obtained by synthesizing the detection signals of the first thrust detection coils flows as the thrust synthesized signal, and a fourth synthesized signal (e.g., fourth path L4) through which a fourth synthesized signal (e.g., fourth path L5) obtained by synthesizing the detection signals of the second thrust detection coils flows as the thrust synthesized signal. and a fourth path (e.g., fourth path (L4)) through which a first signal (e.g., a composite signal (S68)) flows as the thrust composite signal, the radial threshold value includes a first threshold value set to be smaller than a voltage value of the first composite signal and a second threshold value set to be smaller than a voltage value of the second composite signal, the thrust threshold value includes a third threshold value set to be smaller than a voltage value of the third composite signal and a fourth threshold value set to be smaller than a voltage value of the fourth composite signal, and the acquisition unit acquires a first signal (e.g.,a first signal (S1)) flowing through the second path and a second signal (for example, a second signal (S2)) flowing through the second path are acquired as the radial path signals, a third signal (for example, a third signal (S3)) flowing through the third path and a fourth signal (for example, a fourth signal (S4)) flowing through the fourth path are acquired as the thrust path signals, and when there is no break in the detection coil, the first path, the second path, the third path, and the fourth path, the first composite signal flows through the first path as the first signal, the second composite signal flows through the second path as the second signal, and the third composite signal flows through the third path as the third signal, The fourth composite signal flows through the fourth path as the fourth signal, and the open circuit detection unit detects the presence or absence of the open circuit between the first radial detection coil and the first path based on the voltage value of the first signal and the first threshold value, detects the presence or absence of the open circuit between the second radial detection coil and the second path based on the voltage value of the second signal and the second threshold value, detects the presence or absence of the open circuit between the first thrust detection coil and the third path based on the voltage value of the third signal and the third threshold value, and detects the presence or absence of the open circuit between the second thrust detection coil and the fourth path based on the voltage value of the fourth signal and the fourth threshold value. With this configuration, the device can appropriately detect the presence or absence of open circuits in the first to fourth paths even if the voltage values ​​of each composite signal increase over time.

[0216] A seventh embodiment of the present invention is a motor bearing wear monitoring device (for example, motor bearing wear monitoring device 5A) that monitors the wear state of a bearing that supports a rotating shaft of a rotor based on detection signals from each of a plurality of detection coils that detect magnetic flux changes corresponding to a mechanical position change of the rotor relative to a stator of a motor of a canned motor pump, wherein the plurality of detection coils include a set of radial detection coils that detect the magnetic flux changes in the radial direction of the rotating shaft, and a set of thrust detection coils that detect the magnetic flux changes in the thrust direction of the rotating shaft, and in the thrust direction, the radial detection coil and the thrust detection coil are arranged at an end of one direction side or the other direction side of the stator, and the radial detection coil is electrically connected to a radial signal path through which a radial composite signal flows, the detection signals from each of the radial detection coils being combined, and the thrust detection coil is electrically connected to a thrust signal path through which a thrust composite signal flows, and a radial maximum voltage value that is the maximum value of the voltage values ​​of the radial composite signal and a thrust voltage value of the thrust detection coil are detected. a voltage value storage unit that updates and stores a maximum thrust voltage value, which is the maximum value among the voltage values ​​of the thrust combined signal; an acquisition unit that acquires a radial path signal flowing through the radial signal path, a thrust path signal flowing through the thrust path, the radial maximum voltage value, and the thrust maximum voltage value; and a trained radial learning model (e.g., a first learning model M1, a second learning model M2, etc.) that has been machine-learned to estimate the presence or absence of a disconnection between the radial detection coil and the radial signal path when the voltage value of the radial path signal and the radial maximum voltage value are input. 2), a learned thrust learning model storage unit (e.g., storage unit 54A) that stores a trained thrust learning model (e.g., a third learning model M3, a fourth learning model M4) that has been machine-learned to estimate the presence or absence of a disconnection between the thrust detection coil and the thrust signal path when the voltage value of the thrust path signal and the maximum thrust voltage value are input, and a disconnection estimation unit (e.g., disconnection estimation unit 537) that estimates the presence or absence of a disconnection in the detection coil, the radial signal path, and each of the thrust signal paths,When there is no break in each of the thrust signal paths, the radial composite signal flows through the radial signal path as the radial path signal, and the thrust composite signal flows through the thrust signal path as the thrust path signal, and the break estimation unit inputs the voltage value of the radial path signal and the radial maximum voltage value into the radial learning model to estimate the presence or absence of a break in each of the radial detection coil and the radial signal path, and inputs the voltage value of the thrust path signal and the thrust maximum voltage value into the thrust learning model to estimate the presence or absence of a break in each of the thrust detection coil and the thrust signal path.With this configuration, the device can automatically estimate the presence or absence of a break in the detection coil and the first to fourth paths without undergoing threshold processing.

[0217] An eighth embodiment of the present invention is a wire breakage detection program that causes a computer to function as the motor bearing wear monitoring device in the first embodiment. With this configuration, a pump user can safely check for wire breakage in the detection coil and the first to fourth paths without stopping the pump.

[0218] A ninth embodiment of the present invention is a wire break estimation program that causes a computer to function as the motor bearing wear monitoring device of the seventh embodiment. With this configuration, the device can automatically estimate the presence or absence of a wire break in the detection coil and the first to fourth paths without undergoing threshold processing.

[0219] A tenth embodiment of the present invention is a wire break detection method (e.g., radial side wire break detection process (ST2), thrust side wire break detection process (ST3)) executed by a motor bearing wear monitoring device (e.g., motor bearing wear monitoring device 5) that monitors the wear state of a bearing supporting a rotating shaft of a rotor based on detection signals of each of a plurality of detection coils that detect magnetic flux changes corresponding to a mechanical position change of the rotor with respect to a stator of the motor of a canned motor pump, wherein the plurality of detection coils include a set of radial detection coils that detect the magnetic flux changes in the radial direction of the rotating shaft, and a set of thrust detection coils that detect the magnetic flux changes in the thrust direction of the rotating shaft, and in the thrust direction, the radial detection coil and the thrust detection coil are arranged at an end of one direction side or the other direction side of the stator, and the radial detection coil is electrically connected to a radial signal path through which a radial composite signal flows, the detection signals of each of the radial detection coils being combined, and the thrust detection coil outputs a thrust composite signal The motor bearing wear monitoring device is electrically connected to a thrust signal path through which the radial composite signal flows, and the motor bearing wear monitoring device includes a threshold memory unit that stores a radial threshold value that is set to be smaller than the voltage value of the radial composite signal, and a thrust threshold value that is set to be smaller than the voltage value of the thrust composite signal, and when the detection coil, the radial signal path, and the thrust signal path are not broken, the radial composite signal flows through the radial signal path as a radial path signal, and the thrust composite signal flows through the thrust signal path as a thrust path signal. The disconnection detection method includes an acquisition step (e.g., a first acquisition step (ST21), a second acquisition step (ST31)) in which the motor bearing wear monitoring device acquires the radial path signal from the radial signal path and acquires the thrust path signal from the thrust signal path, and the motor bearing wear monitoring device detects the disconnection in each of the radial detection coil and the radial signal path based on the voltage value of the radial path signal and the radial threshold value, and determines whether or not the disconnection has occurred based on the voltage value of the thrust path signal and the thrust threshold value.The disconnection detection method includes a disconnection detection step (e.g., a first comparison step (ST22), a second comparison step (ST25), a third comparison step (ST32), and a fourth comparison step (ST35)) for detecting the disconnection in each of the thrust detection coil and the thrust signal path. With this configuration, the user of the pump can safely check for the presence or absence of a disconnection in the detection coil and the first to fourth paths without stopping the pump.

[0220] REFERENCE SIGNS LIST 1 Canned motor pump 3 Motor unit 31 Rotating shaft 32 Bearing 33 Bearing 36 Rotor 37 Stator 5 Motor bearing wear monitoring device 53a CPU (processor) 53b RAM (threshold value storage unit, voltage value storage unit) 531 Wear amount detection unit 532 Second acquisition unit (acquisition unit) 534 Threshold value setting unit 535 Disconnection detection unit 5A Motor bearing wear monitoring device 537 Disconnection estimation unit 54A Storage unit (learning model storage unit) C1 Detection coil (radial detection coil, first radial detection coil) C2 Detection coil (thrust detection coil, first thrust detection coil) C3 Detection coil (radial detection coil, first radial detection coil) C4 Detection coil (thrust detection coil, first thrust detection coil) C5 Detection coil (radial detection coil, second radial detection coil) C6 Detection coil (thrust detection coil, second thrust detection coil) C7 Detection coil (radial detection coil, second radial detection coil) C8 Detection coil (thrust detection coil, second thrust detection coil) L1 First path (radial signal path) L2 Second path (radial signal path) L3 Third path (thrust signal path) L4 Fourth path (thrust signal path) M1 First learning model (radial learning model) M2 Second learning model (radial learning model) M3 Third learning model (thrust learning model) M4 Fourth learning model (thrust learning model)

Claims

1. A motor bearing wear monitoring device for a canned motor pump, which monitors the wear state of a bearing supporting a rotating shaft of a rotor based on detection signals from a plurality of detection coils that detect magnetic flux changes corresponding to mechanical position changes of the rotor relative to the stator of the motor, wherein the plurality of detection coils include: a set of radial detection coils that detect the magnetic flux changes in the radial direction of the rotating shaft; and a set of thrust detection coils that detect the magnetic flux changes in the thrust direction of the rotating shaft, wherein in the thrust direction, the radial detection coil and the thrust detection coil are arranged at one end of the stator or the other end, and the radial detection coil is electrically connected to a radial signal path through which a radial composite signal flows, the detection signals of the radial detection coils being combined, and the thrust detection coil is electrically connected to a thrust signal path through which a thrust composite signal flows, the detection signals of the thrust detection coils being combined, the radial signal path signal flowing through the radial signal path and the thrust signal path signal flowing through the thrust signal path; an acquisition unit that acquires the radial signal path signal flowing through the radial signal path and the thrust signal path signal flowing through the thrust signal path; and an open circuit detection unit that detects the presence or absence of an open circuit in the detection coil, the radial signal path, and the thrust signal path, respectively; wherein, when there is no open circuit in the detection coil, the radial signal path, and the thrust signal path, the radial combined signal flows through the radial signal path as the radial path signal, and the thrust combined signal flows through the thrust signal path as the thrust path signal, and the open circuit detection unit detects the presence or absence of an open circuit between the radial detection coil and the radial signal path based on the voltage value of the radial path signal and the radial threshold, and detecting whether or not the disconnection between the thrust detection coil and the thrust signal path occurs based on the voltage value of the thrust path signal and the thrust threshold value.

2. A motor bearing wear monitoring device as described in claim 1, comprising: a voltage value memory unit that updates and stores: a radial maximum voltage value that is the maximum value among the voltage values ​​of the radial composite signal; and a thrust maximum voltage value that is the maximum value among the voltage values ​​of the thrust composite signal; wherein the radial threshold value is set based on the radial maximum voltage value, and the thrust threshold value is set based on the thrust maximum voltage value.

3. The motor bearing wear monitoring device according to claim 2, wherein the radial threshold is set based on the signal level of a noise component contained in the radial path signal, and the thrust threshold is set based on the signal level of a noise component contained in the thrust path signal.

4. The motor bearing wear monitoring device according to claim 3, wherein the radial threshold value is smaller than the thrust threshold value.

5. The motor bearing wear monitoring device according to any one of claims 1 to 4, further comprising: a threshold setting unit that sets the radial threshold value and the thrust threshold value.

6. The plurality of detector coils include a set of first radial detector coils and a set of second radial detector coils that function as a set of radial detector coils, and a set of first thrust detector coils and a set of second thrust detector coils that function as a set of thrust detector coils, wherein the first radial detector coil and the first thrust detector coil are arranged at an end of the stator on the one side, and the second radial detector coil and the second thrust detector coil are arranged at an end of the stator on the other side, and the radial signal path comprises: a first path electrically connected to the first radial detector coils, through which a first composite signal formed by combining the detection signals of the first radial detector coils flows as the radial composite signal; and a second path electrically connected to the second radial detector coils, through which a second composite signal formed by combining the detection signals of the second radial detector coils flows as the radial composite signal, and the thrust signal path is the radial threshold comprises: a third path electrically connected to the first thrust detection coil, through which a third composite signal obtained by combining the detection signals of the first thrust detection coils flows as the thrust composite signal; and a fourth path electrically connected to the second thrust detection coil, through which a fourth composite signal obtained by combining the detection signals of the second thrust detection coils flows as the thrust composite signal, wherein the radial threshold comprises: a first threshold set to be smaller than a voltage value of the first composite signal; and a second threshold set to be smaller than a voltage value of the second composite signal, and the thrust threshold comprises: a third threshold set to be smaller than a voltage value of the third composite signal; and a fourth threshold set to be smaller than a voltage value of the fourth composite signal, wherein the acquisition unit acquires the first signal flowing through the first path and the second signal flowing through the second path as the radial path signals, and acquires the third signal flowing through the third path and the fourth signal flowing through the fourth path as the thrust path signals, When the detection coil, the first path, the second path, the third path, and the fourth path are not disconnected,2. The motor bearing wear monitoring device of claim 1, wherein the first combined signal flows through the first path as the first signal, the second combined signal flows through the second path as the second signal, the third combined signal flows through the third path as the third signal, and the fourth combined signal flows through the fourth path as the fourth signal, and the open circuit detection unit: detects the presence or absence of the open circuit between the first radial detection coil and the first path based on a voltage value of the first signal and the first threshold value, detects the presence or absence of the open circuit between the second radial detection coil and the second path based on a voltage value of the second signal and the second threshold value, detects the presence or absence of the open circuit between the first thrust detection coil and the third path based on a voltage value of the third signal and the third threshold value, and detects the presence or absence of the open circuit between the second thrust detection coil and the fourth path based on a voltage value of the fourth signal and the fourth threshold value.

7. A motor bearing wear monitoring device for a canned motor pump, which monitors the wear state of a bearing supporting a rotating shaft of a rotor based on detection signals from a plurality of detection coils that detect magnetic flux changes corresponding to mechanical position changes of the rotor relative to the stator of the motor, wherein the plurality of detection coils include: a set of radial detection coils that detect the magnetic flux changes in the radial direction of the rotating shaft; and a set of thrust detection coils that detect the magnetic flux changes in the thrust direction of the rotating shaft, wherein in the thrust direction, the radial detection coil and the thrust detection coil are arranged at an end of one side or the other side of the stator, the radial detection coil is electrically connected to a radial signal path through which a radial composite signal flows, the detection signals from each of the radial detection coils being combined, and the thrust detection coil is electrically connected to a thrust signal path through which a thrust composite signal flows, the radial maximum voltage value being the maximum value of the voltage values ​​of the radial composite signal, and the thrust maximum voltage value being the maximum value of the voltage values ​​of the thrust composite signal. an acquisition unit that acquires the radial path signal flowing through the radial signal path, the thrust path signal flowing through the thrust signal path, the radial maximum voltage value, and the thrust maximum voltage value; a trained radial learning model that has been machine-learned to estimate the presence or absence of a disconnection between the radial detection coil and the radial signal path when the voltage value of the radial path signal and the radial maximum voltage value are input; and a trained thrust learning model that has been machine-learned to estimate the presence or absence of a disconnection between the thrust detection coil and the thrust signal path when the voltage value of the thrust path signal and the thrust maximum voltage value are input; and a disconnection estimation unit that estimates the presence or absence of a disconnection in the detection coil, the radial signal path, and the thrust signal path,the thrust composite signal flows through the thrust signal path as the thrust path signal, and the open circuit estimation unit inputs the voltage value and the radial maximum voltage value of the radial path signal into the radial learning model to estimate the presence or absence of an open circuit in each of the radial detection coil and the radial signal path, and inputs the voltage value and the thrust maximum voltage value of the thrust path signal into the thrust learning model to estimate the presence or absence of an open circuit in each of the thrust detection coil and the thrust signal path.

8. A wire breakage detection program that causes a computer to function as the motor bearing wear monitoring device described in claim 1.

9. A wire breakage estimation program that causes a computer to function as the motor bearing wear monitoring device according to claim 7.

10. A wire break detection method executed by a motor bearing wear monitoring device that monitors the wear state of a bearing supporting a rotating shaft of a rotor of a canned motor pump based on detection signals from a plurality of detection coils that detect magnetic flux changes corresponding to mechanical position changes of the rotor relative to the stator, wherein the plurality of detection coils include: a set of radial detection coils that detect the magnetic flux changes in the radial direction of the rotating shaft; and a set of thrust detection coils that detect the magnetic flux changes in the thrust direction of the rotating shaft, wherein in the thrust direction, the radial detection coil and the thrust detection coil are arranged at an end of one side or the other side of the stator, the radial detection coil is electrically connected to a radial signal path through which a radial composite signal flows, the detection signals of each of the radial detection coils being combined, and the thrust detection coil is electrically connected to a thrust signal path through which a thrust composite signal flows, the detection signals of each of the thrust detection coils being combined, and the motor bearing wear monitoring device: and a threshold memory unit that stores a radial threshold that is set to be smaller than the voltage value of the radial composite signal and a thrust threshold that is set to be smaller than the voltage value of the thrust composite signal, wherein when there is no open circuit in the detection coil, the radial signal path, and the thrust signal path, the radial composite signal flows through the radial signal path as a radial path signal, and the thrust composite signal flows through the thrust signal path as a thrust path signal, and the open circuit detection method includes: an acquisition step in which the motor bearing wear monitoring device acquires the radial path signal from the radial signal path and acquires the thrust path signal from the thrust signal path; and an open circuit detection step in which the motor bearing wear monitoring device detects the open circuit in each of the radial detection coil and the radial signal path based on the voltage value of the radial path signal and the radial threshold, and detects the open circuit in each of the thrust detection coil and the thrust signal path based on the voltage value of the thrust path signal and the thrust threshold.

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