Canned motor pump

Abstract

Disconnection of the lead wire due to expansion and contraction of the coil end can be prevented.SOLUTION: A canned motor pump 1 according to the present invention includes a motor bearing abrasion monitoring device 5 that monitors an abrasion state of a bearing, a rotor 24, a stator 25, a rotating shaft 31, a bearing 32, a can 36, a plurality of detection coils C that detect a magnetic flux change corresponding to a mechanical position change of the rotor with respect to the stator, a lead wire L wired between the detection coil and the motor bearing abrasion monitoring device, and a protection sheet S that protects the lead wire. The stator includes a stator core 351 and a plurality of conductive wires 352. In the axial direction of the rotating shaft, a part of each of the plurality of conductive wires protrudes from the stator core to form an annular coil end 353. A part of the lead wire is wired along the inner peripheral surface 354 of the coil end. The protective sheet is disposed between the inner peripheral surface and the lead wire.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a canned motor pump.

Background Art

[0002] There is known a canned motor pump in which a pump and a motor are integrated and there is no leakage of the handling liquid. The canned motor pump has a structure in which a rotating structure portion (rotor, rotating shaft, and bearing) is sealed in a can filled with the handling liquid. Therefore, the canned motor pump has a problem that "it is difficult to monitor the state of the rotating structure portion". Thus, in the canned motor pump, a device for monitoring the wear state of the bearing is used (for example, see Patent Document 1).

[0003] The device disclosed in Patent Document 1 includes four detection coils respectively arranged on both end sides of the stator in the longitudinal direction of the stator. This device measures a magnetic flux change corresponding to a position change of the rotor with respect to the stator based on detection signals output from each of the detection coils. The stator includes a cylindrical stator core and a plurality of conducting wires attached to the stator core. In the longitudinal direction of the stator, a part of each of the plurality of conducting wires protrudes from an end portion of the stator core. The plurality of protruding conducting wires form an annular coil end. On the other hand, in the longitudinal direction of the stator core, the detection coil is arranged at an end portion of the stator core. The detection coil is connected to a device for monitoring the wear state of the bearing via a lead wire. The lead wire is wired along the inner peripheral surface of the annular coil end.

[0004] In a canned motor pump, the coil ends become hot due to the heat generated when the stator produces a rotating magnetic field during operation. As a result, the coil ends expand. Conversely, when the canned motor pump stops operating or when its output is suppressed, the temperature of the coil ends decreases. As a result, the coil ends contract. In this way, the expansion and contraction of the coil ends are repeated in accordance with the operation of the canned motor pump. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 10-080103 [Overview of the project] [Problems that the invention aims to solve]

[0006] When a coil end expands, the overall volume of the coil end increases, and the inner surface of the coil end also stretches. As a result, the lead wire is pulled in the circumferential direction of the coil end due to the stretching of the inner surface of the coil end. In other words, tension is applied to the lead wire along its longitudinal direction. Consequently, the lead wire may break.

[0007] Furthermore, repeated expansion and contraction of the coil end can create gaps between the lead wires. If a portion of the lead wire becomes trapped in this gap, that portion will be pressed from both sides by the expansion of the coil end. In other words, tension is applied to the lead wire due to the pressure caused by the expansion of the coil end. As a result, the lead wire may break.

[0008] The present invention aims to prevent lead wire breakage due to expansion and contraction of the coil end. [Means for solving the problem]

[0009] A canned motor pump in one embodiment of the present invention comprises a rotor, a stator that rotates the rotor, a rotating shaft that rotates with the rotor, a bearing that supports the rotating shaft, a cylindrical can housing the rotor, the rotating shaft, and the bearing, a plurality of detection coils that detect changes in magnetic flux corresponding to changes in the mechanical position of the rotor relative to the stator, a motor bearing wear monitoring device that monitors the wear state of the bearing based on detection signals output from each of the plurality of detection coils, lead wires wired between the detection coils and the motor bearing wear monitoring device, and a protective sheet that protects the lead wires. The stator comprises a stator core and a plurality of conductors attached to the stator core, wherein in the axial direction of the rotating shaft, a portion of each of the plurality of conductors protrudes from the stator core to form an annular coil end, a portion of the lead wires is wired along the inner circumferential surface of the coil end, and the protective sheet is positioned between the inner circumferential surface and the lead wires. [Effects of the Invention]

[0010] According to the present invention, lead wire breakage due to expansion and contraction of the coil end can be prevented. [Brief explanation of the drawing]

[0011] [Figure 1] This is a side view of a canned motor pump, illustrating an embodiment of the canned motor pump according to the present invention. [Figure 2] Figure 1 shows a schematic cross-sectional view of the motor section of the canned motor pump, specifically the vertical cross-section of the motor section. [Figure 3] Figure 1 is a perspective view of the stator of the canned motor pump. [Figure 4] Figure 3 is an enlarged perspective view of the stator core, showing the teeth where the detection coil is located. [Figure 5] Figure 3 is a schematic perspective view of the stator core, showing the arrangement of the detection coils in the stator. [Figure 6]It is an enlarged cross-sectional view of a coil end obtained by enlarging a portion A in FIG. 2. [Figure 7] It is a partial development view of the coil end showing a state where a lead wire is wired on the inner peripheral surface of the coil end in the stator of FIG. 3. [Figure 8] It is a partial development view of the coil end showing a state where a protective sheet is arranged on the inner peripheral surface of the coil end in FIG. 7. [Figure 9] It is a schematic side view of the coil end showing a state where a protective sheet is arranged on the inner peripheral surface of the coil end in FIG. 8. [Figure 10] It is a partial development view of the coil end showing a state where a coating sheet is arranged on the inner peripheral surface of the coil end in FIG. 7. [Figure 11] It is a schematic side view of the coil end showing a state where a coating sheet is arranged on the inner peripheral surface of the coil end in FIG. 9. [Figure 12] It is a schematic side view of the coil end showing a state where the coil end in FIG. 11 is tied with a string. [Figure 13] It is an enlarged cross-sectional view of a coil end showing a modified example of a stator included in the canned motor pump according to the present invention. [Figure 14] It is a partial development view of a coil end showing another modified example of a stator included in the canned motor pump according to the present invention.

Mode for Carrying Out the Invention

[0012] An embodiment of the canned motor pump according to the present invention will be described below. In the following description, the drawings are referred to as appropriate. In each figure, the same members and elements are denoted by the same reference numerals, and redundant descriptions are omitted. Also, the dimensional ratios of the respective elements may be exaggerated for convenience of explanation and are not limited to the ratios shown in each drawing.

[0013] In the following description, "downward" is the direction of gravity, and "upward" is the opposite direction of downward.

[0014] ● Canned Motor Pump ● ● Configuration of canned motor pump First, the configuration of the canned motor pump will be described below.

[0015] Figure 1 is a side view of the canned motor pump. For the sake of convenience in explanation, this figure shows the upper half of the canned motor pump 1 as a cross-sectional view.

[0016] The canned motor pump 1 (hereinafter referred to as "this pump 1") is a pump in which the pump section 2 and the motor section 3 are integrated without leakage of the handled liquid. This pump 1 is a pump used for pumping high-temperature liquids or highly dangerous liquids (for example, liquids having explosiveness, flammability, or toxicity). This pump 1 includes a pump section 2, a motor section 3, an adapter 4, a motor bearing wear monitoring device 5, a detection coil C (see Fig. 3), a lead wire L (see Fig. 3), a protective sheet S (see Fig. 3), and a string R (see Fig. 3).

[0017] The configuration of this pump 1 is common to that of known canned motor pumps. Therefore, in the following description, only the outline of the configuration of this pump 1 will be described and the detailed description will be omitted.

[0018] In the following description, "front" is the direction in which the pump section 2 is located with respect to the motor section 3, and "rear" is the direction in which the motor section 3 is located with respect to the pump section 2.

[0019] The pump section 2 sucks and discharges the handled 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 forms a pump chamber 22 that houses the impeller 21, a suction pipe section 23 that is a path for the handled liquid sucked into the pump chamber 22, and a discharge pipe section 24 that is a path for the handled liquid discharged from the pump chamber 22. The impeller 21 sucks and discharges the handled liquid by the rotational power of the motor section 3. The pump chamber 22 communicates with the suction pipe section 23 and the discharge pipe section 24.

[0020] The motor unit 3 is driven under predetermined driving conditions to rotate the impeller 21 of the pump unit 2. The motor unit 3 comprises a housing 30, a rotating shaft 31, a bearing 32, a thrust washer 33, a rotor 34, a stator 35, a can 36, a sleeve 37, and terminal terminals 38.

[0021] Figure 2 is a schematic cross-sectional view of the motor unit 3, showing a longitudinal section of the motor unit 3.

[0022] The housing 30 contains the stator 35 and the can 36 in a liquid-tight manner.

[0023] The rotating shaft 31 rotates together with the rotor 34. The rotating shaft 31 rotates due to the rotation of the rotor 34 and transmits rotational power to the impeller 21. The rotating shaft 31 is cylindrical in shape. The rotating shaft 31 is inserted into the rotor 34 and fixed thereto. The front end of the rotating shaft 31 protrudes into the pump chamber 22, and the impeller 21 is attached to this front end. The rotating shaft 31 is equipped with cylindrical shaft sleeves 311 that protect both sides of the rotating shaft 31.

[0024] In the following explanation, "axial direction" refers to the direction along the axis of rotation of the rotation axis 31, "radial direction" refers to the direction along the diameter (radius) of the rotation axis 31 (stator 35), and "circumferential direction" refers to the circumferential direction of the rotation axis 31 (stator 35).

[0025] The bearing 32 rotatably supports the rotating shaft 31. In the axial direction, the bearing 32 is located at both ends of the rotor 34. The bearing 32 is, for example, a sliding bearing. The thrust washer 33 restricts the axial movement of the rotating shaft 31. The thrust washer 33 is installed between the bearing 32 and the rotor 34 on the rotating shaft 31.

[0026] The rotor 34 rotates due to the rotating magnetic field generated in the stator 35. The rotor 34 has a cylindrical shape.

[0027] Figure 3 is a perspective view of the stator 35 of this pump 1. Figure 4 is an enlarged perspective view of the stator core 351, showing a magnified view of the tooth portion 35a where the detection coil C is located. In the following explanation, Figures 1 and 2 will be referred to as appropriate, along with Figures 3 and 4.

[0028] The stator 35 generates a rotating magnetic field that rotates the rotor 34. The stator 35 has a roughly cylindrical shape. The stator 35 comprises a stator core 351 and a plurality of conductors 352.

[0029] The stator core 351 holds multiple conductors 352. The stator core 351 has a cylindrical shape. The stator core 351 is provided with multiple teeth 35a. The multiple teeth 35a are arranged on the inner circumferential surface of the stator core 351. The teeth 35a protrude radially inward from the stator core 351 and are members aligned axially. In the circumferential direction, the multiple teeth 35a are arranged at equal intervals. Slots 35b are formed between the teeth 35a through which the conductors 352 are inserted.

[0030] Of the multiple tooth portions 35a, the axial ends of four tooth portions 35a are cut out in a slit-like manner, forming notches 35c. That is, four notches 35c are formed at each of the openings at both ends of the stator core 351. In the circumferential direction, the four notches 35c are arranged at equal intervals (90° intervals) at each of the openings of the stator core 351. The detection coil C, which will be described later, is attached to the notches 35c.

[0031] The conductors 352 are inserted through slots 35b and attached to the stator core 351. In the axial direction, a portion of each of the multiple conductors 352 protrudes from both ends of the stator core 351. The multiple protruding conductors 352 are bundled together to form an annular coil end 353.

[0032] The coil end 353 releases the heat generated when the stator 35 generates a rotating magnetic field. The shape of the coil end 353 is annular, following the shape of the opening of the stator core 351. In the coil end 353, multiple conductors 352 are bent circumferentially to form bundles of conductors 352. These bundles of conductors 352 are bundled together with other bundles of conductors 352 to form the coil end 353. The coil end 353 has an inner circumferential surface 354. The shape of the inner circumferential surface 354 is substantially cylindrical.

[0033] In the following explanation, the primary referenced drawing will be Figure 1. The can 36 liquid-tightly houses the rotating shaft 31, bearing 32, thrust washer 33, and rotor 34. The can 36 is cylindrical in shape. A portion of the handling fluid introduced from the suction pipe section 23 is introduced into the can 36 and used to cool the bearing 32 and motor section 3. The handling fluid used for cooling is discharged into the discharge pipe section 24.

[0034] The sleeve 37 reinforces the can 36. The sleeve 37 covers the outer surface of the can 36 that is not covered by the stator core 351.

[0035] Multiple conductors 352 and lead wires L, held by the stator core 351, are connected to the terminal terminal 38. The conductors 352 are connected to a power supply device (not shown), such as an inverter, via the terminal terminal 38.

[0036] The adapter 4 is connected to the rear end of the pump unit 2 and the front end of the motor unit 3, thus connecting the pump unit 2 and the motor unit 3.

[0037] The motor bearing wear monitoring device 5 monitors the wear state of the bearing 32 based on detection signals output from each of the multiple detection coils C. In other words, the motor bearing wear monitoring device 5 monitors the wear state of the bearing 32 supporting the rotating shaft 31 by detecting changes in magnetic flux corresponding to changes in the position of the rotor 34 relative to the stator 35.

[0038] Figure 5 is a schematic perspective view of the stator core 351, showing the arrangement of detection coils C1 to C8. In the following explanation, Figures 1 to 4 will be referred to as appropriate, along with Figure 5.

[0039] The motor bearing wear monitoring device 5 is connected to eight detection coils C (C1, C2, C3, C4, C5, C6, C7, C8) via lead wires L. The motor bearing wear monitoring device 5 includes a control unit (not shown), a storage unit (not shown), and a display unit (not shown).

[0040] The detection coils C (C1 to C8) detect changes in magnetic flux corresponding to changes in the position (displacement) of the rotor 34 relative to the stator 35. The detection coils C generate and output detection signals indicating changes in magnetic flux. The rotor 34 is displaced axially with the rotating shaft 31 according to the amount of axial wear of the bearing 32, and is displaced radially with the rotating shaft 31 according to the amount of radial wear of the bearing 32. In other words, the amount of displacement of the rotor 34 can be considered as the amount of wear of the bearing 32. Therefore, the motor bearing wear monitoring device 5 can detect the amount of wear of the bearing 32 by detecting the amount of displacement of the rotor 34 using the eight detection coils C (C1 to C8).

[0041] The detection coils C (C1-C8) are flattened bobbin-shaped. Each detection coil C has a connecting end E to which a lead wire L is connected. The detection coils C (C1-C8) are fitted into the notches 35c of the stator 35.

[0042] In the circumferential direction, detection coils C1 to C4 are mounted at equal intervals (90° intervals) in the notches 35c located at the front end of the tooth portion 35a. Detection coil C1 is positioned to face detection coil C3 at a 180° position, and detection coil C2 is positioned to face detection coil C4 at a 180° position. On the other hand, in the circumferential direction, detection coils C5 to C8 are mounted at equal intervals (90° intervals) in the notches 35c located at the rear end of the tooth portion 35a. Detection coil C5 is positioned to face detection coil C7 at a 180° position, and detection coil C6 is positioned to face detection coil C8 at a 180° position.

[0043] The amount of wear on the axial bearing 32 is detected, for example, by detection coils C2, C4, C6, and C8. The detection coils C2, C4, C6, and C8 detect changes in magnetic flux corresponding to the axial displacement of the rotor 34 due to the widening of the gap between the bearing 32 and the thrust washer 33. By detecting such changes in magnetic flux, the amount of axial displacement of the rotor 34 (i.e., the amount of axial wear on the bearing 32) is detected.

[0044] The amount of radial wear on the bearing 32 is detected, for example, by detection coils C1, C3, C5, and C7. The detection coils C1, C3, C5, and C7 detect changes in magnetic flux corresponding to the radial displacement of the rotor 34 due to the widening of the gap between the bearing 32 and the shaft sleeve 311. By detecting such changes in magnetic flux, the amount of radial displacement of the rotor 34 (i.e., the amount of radial wear on the bearing 32) is detected.

[0045] The lead wire L transmits the detection signal detected by the detection coil C. The lead wire L is a known lead wire covered with an insulator. The lead wire L is connected to the connection end E of the detection coil C. That is, two lead wires L are wired from the detection coil C. A portion of the lead wire L is wired along the inner circumferential surface 354 of the coil end 353. The lead wire L is connected to the terminal terminal 38 which is connected to the motor bearing wear monitoring device 5.

[0046] The control unit controls the operation of the entire motor bearing wear monitoring device 5. The control unit is composed of, for example, a processor such as a CPU (Central Processing Unit), volatile memory such as RAM (Random Access Memory) which functions as the CPU's workspace, and non-volatile memory such as ROM (Read Only Memory) which stores various information such as programs and other control programs. The control unit is connected, for example, to a storage unit and a display unit.

[0047] Figure 6 is an enlarged cross-sectional view of the coil end 353, which is an enlarged view of section A in Figure 2. In the following explanation, Figures 2 and 3 will be referred to as appropriate, along with Figure 6.

[0048] The protective sheet S protects the lead wires L. The protective sheet S is made of a material having high insulation properties and a low coefficient of thermal expansion. The coefficient of thermal expansion of the protective sheet S is smaller than that of the lead wires L. The protective sheet S is, for example, a known mica sheet or a known glass cloth sheet. A mica sheet is a sheet in which flake-shaped mica is bound together with resin. A glass cloth sheet is a sheet woven from glass fibers. The shape of the protective sheet S is a rectangular sheet having a short side and a long side. The length of the protective sheet S in the longitudinal direction is greater than or equal to the length of the inner circumference on the inner circumferential surface 354 of the annular coil end 353. The length of the protective sheet S in the short direction is approximately the same as the length from the end of the stator core 351 to the open end of the coil end 353 at the annular coil end 353. The protective sheet S comprises a first protective sheet S1 and a second protective sheet S2.

[0049] The first protective sheet S1 protects the lead wire L. The first protective sheet S1 is positioned between the inner circumferential surface 354 of the coil end 353 and the lead wire L. In the radial direction, the first protective sheet S1 has a first surface S1a facing toward the inner circumferential surface 354 and a second surface S1b facing toward the inward side of the coil end 353 in the radial direction. The first surface S1a of the first protective sheet S1 is positioned in contact with the inner circumferential surface 354. The lead wire L is wired so as to be in contact with the second surface S1b of the first protective sheet S1. In the circumferential direction, the first protective sheet S1 is positioned along the inner circumferential surface 354, around its entire circumference. That is, the inner circumferential surface 354 is covered by a single first protective sheet S1. The first protective sheet S1 is an example of a protective sheet in the present invention.

[0050] Thus, the first protective sheet S1 is positioned between the inner circumferential surface 354 and the lead wire L. Therefore, in the area where the first protective sheet S1 is positioned, the lead wire L does not come into contact with the inner circumferential surface 354. In the area where the first protective sheet S1 is positioned, the tension due to the expansion of the coil end 353 is applied to the first protective sheet S1. In other words, in the longitudinal direction of the lead wire L, the tension due to the expansion of the coil end 353 does not directly act on the lead wire L. Therefore, the lead wire L is not subjected to a tension strong enough to cause it to break. In short, the tension along the longitudinal direction of the lead wire L is mitigated.

[0051] Furthermore, the first protective sheet S1 is positioned between the inner circumferential surface 354 and the lead wire L. Therefore, the lead wire L is not pinched between the conductors 352. Consequently, the lead wire L is not pressed from both sides by the expansion of the coil end 353.

[0052] In other words, the first protective sheet S1 mitigates the force exerted on the lead wire L due to the expansion / contraction caused by the heating / cooling of the coil end 353, thereby preventing the lead wire L from breaking.

[0053] The second protective sheet S2 protects the lead wire L. In the radial direction, the second protective sheet S2 is positioned inward of the first protective sheet S1 so as to face it. The second protective sheet S2, together with the first protective sheet S1, encloses the lead wire L. In the radial direction, the second protective sheet S2 has a first surface S2a facing toward the first protective sheet S1, and a second surface S2b facing toward the inward side of the coil end 353 in the radial direction. The first surface S2a of the second protective sheet S2 is positioned in contact with the second surface S1b of the first protective sheet S1 and the lead wire L. In the circumferential direction, the second protective sheet S2 is positioned along the inner circumferential surface 354, covering the entire circumference of the inner circumferential surface 354. That is, the second protective sheet S2 covers the entire circumference of the first protective sheet S1. The first protective sheet S1 and the lead wire L are covered by a single second protective sheet S2. The second protective sheet S2 is an example of a covering sheet in the present invention.

[0054] As described above, the lead wire L is covered by the second protective sheet S2. Therefore, breakage of the lead wire L due to expansion / contraction caused by heating / cooling of the coil end 353 is prevented. During the assembly of this pump 1, the second protective sheet S2 prevents breakage of the lead wire L due to accidental contact.

[0055] In the following explanation, the primary referenced drawing will be Figure 3. The string R maintains the shape of the coil end 353 formed from multiple conductors 352 by binding the multiple conductors 352 together. The coil end 353, consisting of multiple conductors 352, is bound together with the first protective sheet S1, the second protective sheet S2, and the lead wire L by the string R. The string R is a known heat-resistant string.

[0056] The coil end 353, bound by the string R, is impregnated with varnish (not shown) and hardened. That is, the first protective sheet S1, the second protective sheet S2, the lead wire L, and the string R are hardened with varnish together with the coil end 353. The varnish is a known varnish.

[0057] ● How to place the protective sheet

[0058] Next, a method for arranging the protective sheet S on the inner circumferential surface 354 of the coil end 353 will be described.

[0059] Figure 7 is a partially exploded view of the coil end 353, showing the state in which lead wires L are wired to the inner circumferential surface 354. The figure schematically shows the stator core 351 and coil end 353 in an unfolded state along the circumferential direction.

[0060] As described above, the coil end 353 is formed by bundling together multiple conductors 352. In the axial direction, a portion of each of the multiple conductors 352 protrudes from the stator core 351. The protruding multiple conductors 352 are bent in the circumferential direction and bundled together. The bundles of conductors 352 are combined with other bundles of conductors 352. Thus, in an axial view, an annular coil end 353 is formed.

[0061] First, the detection coil C is positioned on the teeth 35a of the stator core 351. At this time, the lead wire L is pre-connected to the connection end E by solder or the like. The detection coil C is fitted into the notch 35c of 35a and fixed in place. At this time, in the axial direction, the connection end E of the detection coil C is positioned from the end of the stator core 351 outward from that end. The lead wire L extending from the connection end E is positioned along the inner circumferential surface 354 in a bent state so as not to apply unnecessary tension to the lead wire L.

[0062] Next, the first protective sheet S1 is placed.

[0063] Figure 8 is a partially unfolded view of the coil end 353, showing the state in which the first protective sheet S1 is placed on the inner circumferential surface 354. The figure schematically shows the stator core 351 and coil end 353 in an unfolded state along the circumferential direction. Figure 9 is a schematic side view of the coil end 353 in an axial view, showing the state in which the first protective sheet S1 is placed on the inner circumferential surface 354 of Figure 8.

[0064] In the circumferential direction, the first protective sheet S1 is positioned along the inner circumferential surface 354 so as to cover the entire circumference of the inner circumferential surface 354. The first protective sheet S1 is inserted between the inner circumferential surface 354 and the lead wire L, sliding along the surface of the inner circumferential surface 354 from the open end of the coil end 353 toward the end of the stator core 351. At this time, the first protective sheet S1 is formed in a cylindrical shape along the inner circumferential surface 354.

[0065] Next, the first protective sheet S1 is pressed against the inner circumferential surface 354. Then, the first protective sheet S1 is temporarily fixed to the inner circumferential surface 354 with fixing tape (not shown). The fixing tape is a known tape that has heat resistance.

[0066] The lead wire L is routed in a bent state on the surface (second surface S1b) of the first protective sheet S1. The lead wire L is temporarily fixed to the surface (second surface S1b) of the first protective sheet S1 with fixing tape.

[0067] As shown in Figure 9, four detection coils C are positioned in the opening of the stator core 351. Lead wires L extending from the four detection coils C are routed along the inner circumferential surface 354. Two lead wires L are routed from each of the four detection coils C. The eight lead wires L are routed to the inner surface (second surface S1b) of the first protective sheet S1 located on the inner circumferential surface 354. The eight lead wires L are bundled together and routed to the outside of the stator 35.

[0068] Next, the second protective sheet S2 is placed.

[0069] Figure 10 is a partially unfolded view of the coil end 353, showing the state in which the second protective sheet S2 is placed on the inner circumferential surface 354. The figure schematically shows the stator core 351 and coil end 353 in an unfolded state along the circumferential direction. Figure 11 is a schematic side view of the coil end 353 in an axial view, showing the state in which the second protective sheet S2 is placed on the inner circumferential surface 354 (first protective sheet S1) of Figure 9.

[0070] In the radial direction, the second protective sheet S2 is positioned inward of the first protective sheet S1, so as to be aligned with the first protective sheet S1. The second protective sheet S2 covers the first protective sheet S1 and the lead wire L, and faces the first protective sheet S1. The second protective sheet S2 is positioned so as to cover the entire circumference of the inner circumferential surface 354. In this case, the second protective sheet S2 is formed in a cylindrical shape that is aligned with the first protective sheet S1 and the inner circumferential surface 354.

[0071] Next, the second protective sheet S2 is pressed against the first protective sheet S1. Then, the second protective sheet S2 is temporarily fixed to the inner circumferential surface 354 with fixing tape.

[0072] As shown in Figure 11, the eight lead wires L are wired between the first protective sheet S1 and the second protective sheet S2. In other words, the eight lead wires L are enclosed within the first protective sheet S1 and the second protective sheet S2.

[0073] Next, the coil end 353 is tied with string R.

[0074] Figure 12 is a schematic side view of the coil end 353 in an axial view, showing the coil end 353 tied with string R.

[0075] The coil end 353 is tied together with the first protective sheet S1, the second protective sheet S2, and the lead wire L by a string R. That is, the first protective sheet S1, the second protective sheet S2, and the lead wire L, which are temporarily fixed to the inner circumferential surface 354 with fixing tape, are tied together with the fixing tape by the string R and bundled (fixed).

[0076] Next, the coil end 353, bound by the string R, is immersed in varnish. That is, the first protective sheet S1, the second protective sheet S2, the lead wire L, and the string R are immersed in varnish together with the coil end 353. Then, as the varnish dries, the first protective sheet S1, the second protective sheet S2, the lead wire L, and the string R are solidified with the varnish together with the coil end 353.

[0077] ●Variations● Next, a modified version of the pump 1 will be described below, focusing on the differences from the embodiment described earlier (hereinafter referred to as the "first embodiment"). In the following description of the modified version, for convenience of explanation, the same reference numerals as in the first embodiment are used for the same components and components having common functions. Figures 1 to 12 will be referenced as appropriate in the following description of the modified version.

[0078] ●First variation First, the first variation will be explained.

[0079] Figure 13 is an enlarged cross-sectional view of a coil end 353, showing a modified version of the stator 35.

[0080] As shown in Figure 13, the first modified example differs from the first embodiment in that the coil end 353 does not have a second protective sheet S2. The first protective sheet S1 is positioned between the inner circumferential surface 354 and the lead wire L. The lead wire L is wired on the surface (second surface S1b) of the first protective sheet S1. The lead wire L is then temporarily fixed to the inner circumferential surface 354 together with the first protective sheet S1 using fixing tape.

[0081] Thus, the first protective sheet S1 is positioned between the inner circumferential surface 354 and the lead wire L. Therefore, in the portion where the first protective sheet S1 is positioned, the lead wire L does not come into contact with the inner circumferential surface 354. In the portion where the first protective sheet S1 is positioned, the tension due to the expansion of the coil end 353 is applied to the first protective sheet S1. As a result, the tension along the longitudinal direction of the lead wire L is relieved in the same manner as in the first embodiment.

[0082] Furthermore, the first protective sheet S1 is positioned between the inner circumferential surface 354 and the lead wire L. Therefore, the lead wire L is not pinched between the conductors 352. Consequently, the lead wire L is not pressed from both sides by the expansion of the coil end 353.

[0083] In other words, the first protective sheet S1 reduces the force exerted on the lead wire L due to the expansion / contraction caused by the heating / cooling of the coil end 353, thereby preventing the lead wire L from breaking.

[0084] ● Second variation Next, a second modified example will be explained.

[0085] Figure 14 is a partially exploded view of a coil end 353, showing another modification of the stator 35. The figure schematically shows the stator core 351 and coil end 353 in an unfolded state along the circumferential direction.

[0086] As shown in Figure 14, the second modified example differs from the first embodiment in that the first protective sheet S11 is positioned on a portion of the inner circumferential surface 354. The first protective sheet S11 is positioned between the inner circumferential surface 354 and the connection ends E of each of the multiple detection coils C. The shape of the first protective sheet S11 is rectangular. In the circumferential direction, the first protective sheet S11 is slightly larger than the distance (width) between the pair of connection ends E. The first protective sheet S11 is positioned on a specific region of the inner circumferential surface 354 along the axial direction of the rotation axis 31 from the connection ends E.

[0087] The "specific region" is the region in the axial direction from the end on the stator core 351 side to the open end of the coil end 353, and in a radial view, the region where at least the connecting end E of the detection coil C is located. That is, the specific region has an area that is slightly larger in the circumferential direction than the maximum length between at least the pair of connecting end E, and larger in the axial direction than at least the length of the connecting end E.

[0088] The detection coil C and the lead wire L are connected by solder. Therefore, structurally, the strength of the connection between the connection end E and the lead wire L is weaker than the strength of other parts of the lead wire L. Consequently, due to the expansion / contraction caused by heating / cooling of the coil end 353, the lead wire L may detach from the detection coil C at this connection point before the lead wire L breaks. In other words, this connection point is more prone to breakage than other parts of the lead wire L. For this reason, a specific region includes at least the region where the connection end E is located.

[0089] The first protective sheet S11 is positioned at eight locations on the inner circumferential surface 354, corresponding to the eight detection coils C (C1 to C8). Specifically, the first protective sheet S11 is positioned at the end of the stator 35 between the connection end E of the corresponding detection coil C and the inner circumferential surface 354. At this time, the lead wires L are routed in a bent state on the surface of the first protective sheet S11. The lead wires L are then temporarily fixed to the inner circumferential surface 354 together with the first protective sheet S11 using fixing tape.

[0090] The first protective sheet S11 is positioned at least between the connection end E and the inner circumferential surface 354. Therefore, the connection end E (the connection point between the connection end E and the lead wire L) does not come into contact with the inner circumferential surface 354. In other words, the tension caused by the expansion of the coil end 353 does not act on the connection point. Therefore, the expansion / contraction associated with the heating / cooling of the coil end 353 prevents the lead wire L from detaching from the connection end E.

[0091] ●Summary According to the embodiment described above, the pump 1 comprises a motor bearing wear monitoring device 5, a rotating shaft 31, a bearing 32, a rotor 34, a stator 35, a can 36, a plurality of detection coils C, lead wires L, and a protective sheet S (first protective sheet S1). The lead wires L are connected to the detection coils C and the motor bearing wear monitoring device 5. The protective sheet S protects the lead wires L. The stator 35 comprises a stator core 351 and a plurality of conductors 352. The conductors 352 are attached to the stator core 351. In the axial direction, a portion of each of the plurality of conductors 352 protrudes from the stator core 351, forming an annular coil end 353. A portion of the lead wires L is routed along the inner circumferential surface 354 of the coil end 353. The first protective sheet S1 is placed between the inner circumferential surface 354 and the lead wires L. With this configuration, in the portion where the first protective sheet S1 is placed, the lead wires L do not come into contact with the inner circumferential surface 354. In other words, the tension caused by the expansion of the coil end 353 does not directly act on the lead wire L. Therefore, the lead wire L is not subjected to a tension strong enough to cause it to break. That is, the tension along the longitudinal direction of the lead wire L is mitigated. Therefore, breakage of the lead wire L due to the expansion and contraction of the coil end 353 is prevented.

[0092] Furthermore, according to the embodiment described above, each of the multiple detection coils C is provided with a connection end E connected to a lead wire L. The first protective sheet S1 is positioned between the inner circumferential surface 354 and the connection end E of each of the multiple detection coils C. With this configuration, since the first protective sheet S1 is positioned at least between the connection end E (connection part) and the inner circumferential surface 354, the connection end E (connection part) does not come into contact with the inner circumferential surface 354 of the coil end 353. In other words, the tension due to the expansion of the coil end 353 does not directly act on the connection end E (connection part). Therefore, the lead wire L is prevented from coming off the connection end E due to the expansion and contraction of the coil end 353.

[0093] Furthermore, according to the embodiments described above, the first protective sheet S1 is positioned in a specific region along the axial direction of the rotating shaft 31 from the connection end E. With this configuration, in the specific region along the axial direction of the rotating shaft 31 from the connection end E, the lead wire L does not come into contact with the inner circumferential surface 354 of the coil end 353. That is, the tension due to the expansion of the coil end 353 does not directly act on the lead wire L in the specific region along the axial direction of the rotating shaft 31 from the connection end E. Therefore, breakage of the lead wire L in the specific region due to the expansion and contraction of the coil end 353 is further prevented.

[0094] Furthermore, according to the embodiments described above, the first protective sheet S1 is arranged along the inner circumferential surface 354 in the circumferential direction. With this configuration, the lead wire L does not come into contact with the inner circumferential surface 354 of the coil end 353. That is, the lead wire L is less likely to be pulled in the circumferential direction of the coil end 353. Therefore, breakage of the lead wire L due to expansion and contraction of the coil end 353 is further prevented.

[0095] Furthermore, according to the embodiments described above, in the pump 1, the first protective sheet S1 is arranged around the entire circumference of the inner circumferential surface 354. With this configuration, the lead wires L of the pump 1 do not come into contact with the inner circumferential surface 354 of the coil end 353 over the entire circumference of the inner circumferential surface 354. In other words, the lead wires L are less likely to be pulled in the circumferential and radial directions of the coil end 353. Therefore, regardless of where the lead wires L are wired on the inner circumferential surface 354, breakage of the lead wires L due to expansion and contraction of the coil end 353 is further prevented.

[0096] Furthermore, according to the embodiment described above, the pump 1 has a second protective sheet S2 positioned opposite the first protective sheet S1. The second protective sheet S2 covers the first protective sheet S1 such that the lead wire L is enclosed between the first protective sheet S1 and the second protective sheet S2. With this configuration, since the lead wire L is covered and protected (enclosed) by the second protective sheet S2, malfunctions to the lead wire L due to accidental contact (e.g., disconnection) during the assembly of the pump 1 are prevented.

[0097] Furthermore, according to the embodiments described above, the thermal expansion coefficient of the first protective sheet S1 of the pump 1 is smaller than that of the lead wire L. With this configuration, the lead wire L is wired to the inner circumferential surface 354 of the coil end 353 via the first protective sheet S1, which has a thermal expansion coefficient smaller than that of the lead wire L. In other words, the tension on the lead wire L due to the expansion of the coil end 353 is mitigated by the first protective sheet S1. Therefore, breakage of the lead wire L due to the expansion and contraction of the coil end 353 is prevented.

[0098] Furthermore, according to the embodiments described above, the material of the first protective sheet S1 of the pump 1 is an insulating material. With this configuration, the insulation between the coil end 353 and the lead wire L is improved.

[0099] ●Other embodiments In the first embodiment described above, the protective sheets S (first protective sheet S1 and second protective sheet S2) covering the inner circumferential surface 354 are not limited to insulating mica sheets or glass cloth sheets. That is, for example, the material of the protective sheet S may be paper or resin. Also, the protective sheet S does not have to be insulating.

[0100] Furthermore, in the first embodiment described above, the first protective sheet S1 and the second protective sheet S2 covering the entire circumference of the inner circumferential surface 354 are not limited to a single sheet each. That is, for example, the first protective sheet S1 and the second protective sheet S2 may consist of multiple sheets to cover the entire circumference of the inner circumferential surface 354.

[0101] Furthermore, in the first embodiment described above, the first protective sheet S1 and the second protective sheet S2 covering the inner circumferential surface 354 are not limited to a rectangular sheet shape. That is, the shapes of the first protective sheet S1 and the second protective sheet S2 may be other than rectangular, as long as they can be positioned between the inner circumferential surface 354 and the lead wire L.

[0102] Furthermore, in the first embodiment described above, the first protective sheet S1 and the second protective sheet S2 may have a plurality of through holes. In this configuration, some of the heat generated from the coil end 353 can be released through the through holes.

[0103] Furthermore, in the first embodiment described above, the number of detection coils C1 to C8 is not limited to "8". In this case, for example, in the second modified example described above, the number of first protective sheets S11 corresponds to the number of detection coils C.

[0104] Furthermore, in the second modified example described above, a second protective sheet having the same shape as the first protective sheet S11 may be arranged so as to face the first protective sheet S11 and the connecting end E.

[0105] ●Embodiments of the present invention● Next, embodiments of the present invention as understood from the embodiments described above will be described below, with reference to the terms and reference numerals described in each embodiment.

[0106] A first embodiment of the present invention comprises a rotor (e.g., rotor 34), a stator (e.g., stator 35) that rotates the rotor, a rotating shaft (e.g., rotating shaft 31) that rotates with the rotor, a bearing (e.g., bearing 32) that supports the rotating shaft, a cylindrical can (e.g., can 36) that houses the rotor, the rotating shaft, and the bearing, a plurality of detection coils (e.g., detection coil C) that detect changes in magnetic flux corresponding to changes in the position of the rotor relative to the stator, a motor bearing wear monitoring device (e.g., motor bearing wear monitoring device 5) that monitors the wear state of the bearing based on detection signals output from each of the plurality of detection coils, and the detection coils and the motor bearing wear monitoring device are connected. A canned motor pump (e.g., pump 1) comprises a lead wire (e.g., lead wire L) and a protective sheet (e.g., first protective sheet S1) protecting the lead wire, the stator comprising a stator core (e.g., stator core 351) and a plurality of conductors (e.g., conductors 352) attached to the stator core, wherein a portion of each of the plurality of conductors protrudes from the stator core in the axial direction of the rotating shaft to form an annular coil end (e.g., coil end 353), a portion of the lead wire is routed along the inner circumferential surface (e.g., inner circumferential surface 354) of the coil end, and the protective sheet is positioned between the inner circumferential surface and the lead wire. In this configuration, the lead wires do not come into contact with the inner surface of the coil end in the area where the protective sheet is placed. Therefore, breakage of the lead wires due to expansion and contraction of the coil end is prevented.

[0107] A second embodiment of the present invention is a canned motor pump in which, in the first embodiment, each of the plurality of detection coils has a connecting end (e.g., connecting end E) connected to the lead wire, and the protective sheet is disposed between the inner circumferential surface and the connecting end of each of the plurality of detection coils. This configuration prevents the lead wires from detaching from the connection ends of the detection coil due to the expansion and contraction of the coil ends.

[0108] A third embodiment of the present invention is a canned motor pump in which, in the second embodiment, the protective sheet is positioned in a specific region along the axial direction of the rotating shaft from the connecting end. This configuration further prevents lead wire breakage in specific areas due to expansion and contraction of the coil ends.

[0109] A fourth embodiment of the present invention is a canned motor pump in which, in the third embodiment, the protective sheet is arranged along the inner surface in the circumferential direction of the rotating shaft. With this configuration, the lead wires do not come into contact with the inner surface of the coil end. In other words, the lead wires are less likely to be pulled in the circumferential direction of the coil end. Therefore, breakage of the lead wires due to expansion and contraction of the coil end is prevented.

[0110] A fifth embodiment of the present invention is a canned motor pump in which, in the fourth embodiment, the protective sheet is arranged around the entire circumference of the inner surface. With this configuration, the lead wires do not come into contact with the inner surface of the coil end. In other words, the lead wires are less likely to be pulled in the circumferential and radial directions of the coil end. Therefore, regardless of where the lead wires are routed on the inner surface, breakage of the lead wires due to expansion and contraction of the coil end is prevented.

[0111] A sixth embodiment of the present invention is a canned motor pump comprising, in any of the first to fifth embodiments, a covering sheet (for example, a second protective sheet S2) positioned opposite the protective sheet, wherein the covering sheet covers the protective sheet such that the lead wires are enclosed between the protective sheet and the covering sheet. With this configuration, the lead wires are covered and protected (enclosed) by a protective sheet, thus preventing malfunctions to the lead wires due to accidental contact (e.g., breakage) during the assembly of the canned motor pump.

[0112] A seventh embodiment of the present invention is a canned motor pump in which, in the first embodiment, the thermal expansion coefficient of the protective sheet is smaller than that of the lead wire. In this configuration, the lead wires are routed to the inner surface of the coil end via a protective sheet with a thermal expansion coefficient smaller than that of the lead wires. In other words, the tension on the lead wires due to the expansion of the coil end is mitigated by the protective sheet. Therefore, breakage of the lead wires due to the expansion and contraction of the coil end is prevented.

[0113] An eighth embodiment of the present invention is a canned motor pump in which, in the first embodiment, the material of the protective sheet is an insulating material. This configuration improves the insulation between the coil end and the lead wire.

[0114] A ninth embodiment of the present invention is a canned motor pump in which, in the first embodiment, the protective sheet has a plurality of through holes. In this configuration, the multiple through-holes allow heat generated from the coil ends to dissipate. Therefore, the protective sheet can efficiently dissipate the heat generated from the coil ends to the outside. [Explanation of Symbols]

[0115] 1. Canned motor pump 2 Pump section 3. Motor section 31 Rotation axis 32 bearings 34 rotors 35 stata 351 Stator Core 352 Conductor 353 Coil End 354 Inner peripheral surface 36 Can 5. Motor bearing wear monitoring device C1~C8 detection coils E Connection end L Lead wire S Protective Sheet S1 1st protective sheet S2 2nd protective sheet

Claims

1. Rotor and, A stator that rotates the rotor, A rotating shaft that rotates together with the rotor, A bearing that supports the aforementioned rotating shaft, A cylindrical can housing the rotor, the rotating shaft, and the bearing, A plurality of detection coils for detecting magnetic flux changes corresponding to changes in the position of the rotor relative to the stator, A motor bearing wear monitoring device that monitors the wear state of the bearing based on detection signals output from each of the multiple detection coils, A lead wire to which the detection coil and the motor bearing wear monitoring device are connected, A protective sheet for protecting the lead wires, It has, The stator is, Stator core and Multiple wires attached to the stator core, Equipped with, In the axial direction of the rotating shaft, a portion of each of the plurality of conductors protrudes from the stator core, forming an annular coil end. A portion of the lead wire is routed along the inner surface of the coil end. The protective sheet is placed between the inner circumferential surface and the lead wire. Canned motor pump.

2. Each of the multiple detection coils is The connection end that connects to the aforementioned lead wire is Be prepared, The protective sheet is positioned between the inner circumferential surface and the connection ends of each of the plurality of detection coils. The canned motor pump according to claim 1.

3. The protective sheet is positioned in a specific region along the axial direction of the rotation shaft from the connecting end. The canned motor pump according to claim 2.

4. In the circumferential direction of the rotation axis, the protective sheet is arranged along the inner circumferential surface. The canned motor pump according to claim 3.

5. The protective sheet is arranged around the entire circumference of the inner surface. The canned motor pump according to claim 4.

6. A covering sheet positioned opposite the protective sheet, It has, The covering sheet covers the protective sheet so as to enclose the lead wire between the protective sheet and the covering sheet. A canned motor pump according to any one of claims 1 to 5.

7. The thermal expansion coefficient of the protective sheet is smaller than that of the lead wire. The canned motor pump according to claim 1.

8. The material of the protective sheet is an insulating material. The canned motor pump according to claim 1.

9. The aforementioned protective sheet is Multiple through holes, Equipped with, The canned motor pump according to claim 1.

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