Three-phase motor and compressor

Abstract

A three-phase motor according to one embodiment of the present invention includes: a stator core having 3n (n is a natural number 2 or greater) teeth; an insulator having an outer wall formed in an annular shape and 3n winding bodies protruding inwardly from the outer wall; 3n coils formed by winding conductive wires around the teeth via the winding bodies; and a terminal connecting, with each other, three neutral wires extending from each of the coils of each of the three phases. The insulator is formed with a housing portion in which the terminal is housed, and each of the three neutral wires includes an outer circumferential conductor portion drawn from the outer wall to the outer diameter side and an inner circumferential conductor portion drawn from the outer wall to the inner diameter side, and one end of the inner circumferential conductor portion is electrically connected to the terminal.

Description

Three-phase motor and compressor

[0001] The present invention relates to a motor having an insulator integrated with a housing for terminals.

[0002] A three-phase motor has been known that includes a stator core having an annular yoke and a plurality of teeth extending radially from the yoke, an insulator attached to the stator core, and a plurality of coils formed by winding conductors around the teeth via the insulator, with the neutral wires extending from each coil connected in parallel.In the manufacturing process of a three-phase motor connected in parallel, it is necessary to connect the neutral wires extending from each coil after the coils are formed.

[0003] Some three-phase motors have a terminal housing integrally formed with an insulator. For example, in the three-phase motor described in Prior Art Document 1, three neutral wires (one for each of the three phases) are pulled into the housing and connected to each other by crimp terminals inserted into the housing, forming a neutral point.

[0004] JP 2016-063564 A

[0005] However, in the three-phase motor described in the above-mentioned Prior Art Document 1, of the three neutral wires drawn into the housing, the V-phase neutral wire comes close to the W-phase coil, which is a different phase (see Figure 5 in Prior Art Document 1). Furthermore, because the V-phase (+W-phase) neutral wire drawn from the coil is drawn directly into the housing, the V-phase neutral wire is prone to loosening, which may make it difficult to ensure the insulation distance between it and the W-phase coil. This poses a problem of the potential difference potentially causing partial discharge between the V-phase neutral wire and the W-phase coil, which are different phases.

[0006] In view of the above circumstances, an object of the present invention is to provide a three-phase motor and compressor in which a terminal housing is integrally formed with an insulator, and which can properly ensure insulation between the neutral wire and the coil, which are of different phases.

[0007] A three-phase motor according to one embodiment of the present invention comprises a stator core having 3n (n is a natural number of 2 or greater) tooth portions, an insulator having an annular outer wall portion and 3n winding drum portions protruding inward from the outer wall portion, 3n coils formed by winding conductors around the tooth portions via the winding drum portion, and terminals connecting three neutral wires extending from each of the coils for three phases, wherein the insulator has an accommodating portion for accommodating the terminals, and each of the three neutral wires includes an outer circumferential conductor portion drawn out from the outer wall portion to the outer diameter side and an inner circumferential conductor portion drawn in from the outer wall portion to the inner diameter side, and one end of the inner circumferential conductor portion is electrically connected to the terminal.

[0008] The three-phase motor has an insulator in which a housing for accommodating the terminal is formed, and each of the three neutral wires includes an outer conductor portion drawn out from the outer wall portion to the outer diameter side and an inner conductor portion drawn in from the outer wall portion to the inner diameter side, one end of the inner conductor portion being electrically connected to the terminal. This makes it possible to properly ensure insulation between the neutral wires and the coils of different phases in a three-phase motor in which a terminal housing is integrally formed with the insulator.

[0009] The insulator may have a pull-out portion for pulling each of the three neutral wires to the outer periphery of the insulator, and a pull-in portion for pulling each of the three-phase neutral wires pulled to the outer periphery by the pull-out portion to the inner periphery of the insulator.

[0010] When the three circumferentially adjacent tooth portions are designated as the first tooth portion, the second tooth portion, and the third tooth portion in the order arranged in the circumferential direction, the three neutral wires connected to the terminal are a first neutral wire extending from the coil wound around the first tooth portion, a second neutral wire extending from the coil wound around the second tooth portion, and a third neutral wire extending from the coil wound around the third tooth portion, and at least one of the inlet portions may be passed through by two of the first neutral wire, the second neutral wire, and the third neutral wire.

[0011] When the three circumferentially adjacent tooth portions are designated as a first tooth portion, a second tooth portion, and a third tooth portion in the order in which they are arranged in the circumferential direction, the three neutral wires connected to the terminals are a first neutral wire extending from the coil wound around the first tooth portion, a second neutral wire extending from the coil wound around the second tooth portion, and a third neutral wire extending from the coil wound around the third tooth portion, and when viewed from the direction of the rotation axis of the three-phase motor, the terminals accommodated in the accommodating portion may be arranged so that the entire terminal overlaps with the coil wound around the second tooth portion in a radial direction perpendicular to the rotation axis.

[0012] The accommodating portion has an inner diameter sidewall located radially inward relative to the terminal, perpendicular to the rotation axis of the three-phase motor, and an outer diameter sidewall located radially outward relative to the terminal, perpendicular to the rotation axis of the three-phase motor, and a neutral conductor passage portion through which the neutral conductor passes is formed in each of the inner diameter sidewall and the outer diameter sidewall, and the neutral conductor may be cut at a position radially outward of the outer diameter sidewall.

[0013] The insulator may have a fall prevention portion formed therein that prevents the outer conductor portion of the neutral wire from falling off from the insulator, and the fall prevention portion may be formed between the pull-out portion and the pull-in portion in the circumferential direction.

[0014] The lead-in portion may be a slit through which the neutral conductor passes, and the bottom surface of the slit may be formed so as not to overlap the coil in the height direction.

[0015] The accommodating portion has an inner diameter sidewall located radially inward relative to the terminal, perpendicular to the rotation axis of the three-phase motor, and an outer diameter sidewall located radially outward relative to the terminal around the rotation axis of the three-phase motor, and a neutral conductor passage portion through which the neutral conductor is passed is formed in each of the inner diameter sidewall and the outer diameter sidewall, and the bottom surface of the slit may be located at approximately the same height in the height direction as the neutral conductor passage portion.

[0016] A compressor according to one aspect of the present invention includes a three-phase motor, a compressor main body container, and a compression mechanism. The compressor main body container houses the three-phase motor therein. The compression mechanism is housed inside the compressor main body container and is driven by the three-phase motor.

[0017] According to the present invention, in a three-phase motor in which a terminal housing is integrally formed with an insulator, it is possible to appropriately ensure insulation between the neutral wire and the coil, which are of different phases.

[0018] Fig. 1 is a longitudinal sectional view showing a compressor provided with a three-phase motor according to the present invention; Fig. 2 is a top view showing a stator core; Fig. 3 is a top view showing an upper insulator and coils; Fig. 4 is a view focusing on three coils out of a plurality of coils; Fig. 5 is a perspective view showing an insulator; Fig. 6 is a sectional view of the three-phase motor cut along the radial direction; Fig. 7 is an enlarged view showing a three-phase motor according to another embodiment;

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0020] [Configuration of Compressor] FIG. 1 is a vertical cross-sectional view showing a compressor 1 provided with a three-phase motor 5 according to the present invention.

[0021] As shown in FIG. 1 , the compressor 1 includes a housing 2 , a shaft 3 , a three-phase motor 5 , and a compression unit 6 .

[0022] A sealed, substantially cylindrical internal space 7 is formed inside the housing 2. The housing 2 is formed so that when placed upright on a horizontal surface, the central axis of the cylinder of the internal space 7 is parallel to the horizontal surface in the vertical direction.

[0023] The housing 2 has a U-phase power terminal 8U, a V-phase power terminal 8V, and a W-phase power terminal 8W. The U-phase power terminal 8U, the V-phase power terminal 8V, and the W-phase power terminal 8W are formed of conductors. The U-phase power terminal 8U penetrates the top of the housing 2 so that one end is located in the internal space 7 and the other end is located in the internal space 7. Similarly, the V-phase power terminal 8V penetrates the top of the housing 2 so that one end is located in the internal space 7 and the other end is located in the internal space 7. The W-phase power terminal 8W penetrates the top of the housing 2 so that one end is located in the internal space 7 and the other end is located in the internal space 7. The U-phase power terminal 8U, the V-phase power terminal 8V, and the W-phase power terminal 8W are attached to the housing 2 so as not to be electrically connected to each other and to the housing 2.

[0024] The housing 2 further includes a suction pipe 11 and a discharge pipe 12. A flow path 14 is formed inside the suction pipe 11. The suction pipe 11 is connected to the housing 2 such that the flow path 14 is connected to the lower part of the internal space 7. A flow path 15 is formed inside the discharge pipe 12. The discharge pipe 12 is connected to the housing 2 such that the flow path 15 is connected to the upper part of the internal space 7.

[0025] The shaft 3 is formed in a rod shape and is disposed in the internal space 7 along a rotation axis 16, which is the central axis of the cylinder formed by the internal space 7. The shaft 3 is supported by the housing 2 so as to be rotatable around the rotation axis 16.

[0026] The three-phase motor 5 has a rotor 21 formed in a substantially cylindrical shape and a stator 22 formed in a substantially cylindrical shape. The rotor 21 is fixed to the shaft 3 and supported by the housing 2 so as to be rotatable about the rotation axis 16. The rotor 21 also has a plurality of permanent magnets (not shown) embedded and fixed inside the rotor 21.

[0027] The compression unit 6 is, for example, a rotary compression mechanism, and compresses the refrigerant supplied via the suction pipe 11 as the shaft 3 rotates. The compression unit 6 also supplies the compressed refrigerant to the space between the three-phase motor 5 and the compression unit 6 in the internal space 7.

[0028] The stator 22 is disposed so as to surround the outer periphery of the rotor 21 and is fixed to the housing 2. The stator 22 also has a stator core 23, an upper insulator 24, a lower insulator 25, and a plurality of windings 26. The upper insulator 24 is fixed to the upper part of the stator core 23. The lower insulator 25 is fixed to the lower part of the stator core 23. The upper insulator 24 and the lower insulator 25 are formed from an insulating resin and insulate the stator core 23 from the windings 26 (conductors).

[0029] 2 is a top view showing the stator core 23. The stator core 23 is formed into a cylindrical shape by stacking multiple plates made of a soft magnetic material, such as silicon steel plates. The stator core 23 also has nine teeth.

[0030] 2, the stator core 23 has a yoke portion 31 and a plurality of teeth 32-1, 32-2, 32-3, 32-4, 32-5, 32-6, 32-7, 32-8, and 32-9. The yoke portion 31 is formed in a substantially cylindrical shape and is disposed so that the central axis of the yoke portion 31 overlaps with the rotational shaft 16 of the rotor 21. The plurality of teeth 32-1 to 32-9 are formed so that one end protrudes from the inner circumferential surface 33 of the yoke portion 31 toward the rotational shaft 16 (toward the radially inward direction). In this embodiment, nine of the plurality of teeth 32-1 to 32-9 are formed on the inner circumferential surface 33 of the yoke portion 31 and are arranged at equal intervals in the circumferential direction.

[0031] The radial direction is the direction of the diameter of a circle that is centered on the rotation axis 16 and is perpendicular to the rotation axis 16. The circumferential direction is the direction of the circumference of an imaginary circle that is centered on the rotation axis 16.

[0032] Fig. 3 is a top view showing the upper insulator 24 and the coils 50. Fig. 4 is a view focusing on three of the multiple coils 50. Fig. 5 is a perspective view showing the insulator 24. Fig. 6 is a cross-sectional view of the three-phase motor 5 cut along the radial direction.

[0033] As shown in FIG. 3 , the upper insulator 24 has an outer wall portion 41, a plurality of hoisting drum portions 42-1, 42-2, 42-3, 42-4, 42-5, 42-6, 42-7, 42-8, and 42-9, and a plurality of flange portions 43-1, 43-2, 43-3, 43-4, 43-5, 43-6, 43-7, 43-8, and 43-9. The outer wall portion 41 is formed in a substantially cylindrical shape. The outer wall portion 41 has an inner circumferential surface 44 facing radially inward (toward the rotating shaft 16) and an outer circumferential surface 45 facing radially outward (away from the rotating shaft 16). The outer wall portion 41 further has a storage portion 46, which will be described later.

[0034] The plurality of winding drum portions 42-1 to 42-9 are formed integrally with the outer wall portion 41 so as to protrude from the inner peripheral surface 44 of the outer wall portion 41 toward the rotating shaft 16, and are arranged on the inner peripheral surface 44 so as to be spaced at equal intervals in the circumferential direction. The plurality of flange portions 43-1 to 43-9 correspond to the plurality of winding drum portions 42-1 to 42-9, and are each formed in a substantially semicircular plate shape. The plurality of flange portions 43-1 to 43-9 are also formed contiguous to the inner diameter side end portions of the plurality of copper wound portions 42-1 to 42-9 (the other end different from the one end connected to the inner peripheral surface 44 of the outer wall portion 41).

[0035] The multiple winding drum portions 42-1 to 42-9 correspond to the multiple tooth portions 32-1 to 32-9 of the stator core 23. Nine coils 50-1 to 50-9 are formed by winding the wire 26 (conductor) around each of the teeth 32 via the winding drum portion 42. In this embodiment, the coils 50-1 to 50-9 are arranged such that the order of the U phase, V phase, and W phase is repeated in the circumferential direction.

[0036] The number of teeth 32, winding drums 42, and coils 50 is not limited to nine, and the present invention is applicable as long as the number is 3n (n is a natural number of 2 or more).

[0037] The accommodating portions 46 accommodate the terminals 60. In this embodiment, the accommodating portions 46 are formed integrally with the insulator 24 at three equal positions in the circumferential direction of the outer circumferential surface 45.

[0038] Here, the three circumferentially adjacent tooth portions are defined as the first tooth portion, the second tooth portion, and the third tooth portion in the order in which they are arranged in the circumferential direction, and the three neutral wires 52 connected to the terminal 60 are defined as the first neutral wire 52-1 extending from the coil wound around the first tooth portion, the second neutral wire 52-2 extending from the coil wound around the second tooth portion, and the third neutral wire 52-3 extending from the coil wound around the third tooth portion.

[0039] 3, for example, the three circumferentially adjacent teeth are teeth 32-9, 32-1, and 32-2. Similarly, the three circumferentially adjacent teeth can be teeth 32-3, 32-4, and 32-5, or teeth 32-6, 32-7, and 32-8. In this case, teeth 32-9, 32-3, and 32-6 correspond to the first teeth. Teeth 32-1, 32-4, and 32-7 correspond to the second teeth. Teeth 32-2, 32-5, and 32-8 correspond to the third teeth. 3, the coils wound around the first teeth correspond to coils 50-9, 50-3, and 50-6. The coils wound around the second teeth correspond to coils 50-1, 50-4, and 50-7. The coils wound around the third teeth correspond to coils 50-2, 50-5, and 50-8.

[0040] 4, for example, the three circumferentially adjacent teeth are teeth 32-3, 32-4, and 32-5. Teeth 32-3 corresponds to the first teeth, teeth 32-4 corresponds to the second teeth, and teeth 32-5 corresponds to the third teeth. Similarly, in FIG. 4, the coil wound around the first teeth corresponds to coil 50-3. The coil wound around the second teeth corresponds to coil 50-4. The coil wound around the third teeth corresponds to coil 50-5.

[0041] When defined in this way, when viewed from the direction of the rotating shaft 16 of the three-phase motor 5 (as viewed from above), the terminal 60 accommodated in the accommodation portion 46 is arranged so that the entire terminal 60 overlaps with the coil 50 wound around the second tooth portion in a radial direction perpendicular to the rotating shaft 16. For example, as shown in FIG. 3 , when viewed from the direction of the rotating shaft 16 (assuming that the dotted line 17 is the line of sight as viewed from the rotating shaft 16), the terminal 60 is arranged so that the entire terminal 60 overlaps with the coil 50-4 wound around the tooth portion 32-4, which is the second tooth portion, in the radial direction. That is, when viewed from the direction of the rotating shaft 16, the angle θ1 formed between each of the circumferential ends of the terminal 60 and the rotating shaft 16 is smaller than the angle θ2 formed between each of the circumferential ends of the coil 50-4 and the rotating shaft 16, and the entire terminal 60 is located within the range of the angle θ2 in the circumferential direction.

[0042] In addition, the first neutral conductor 52-1, the second neutral conductor 52-2, and the third neutral conductor 52-3 shown in the figure are shown with their wire paths (trajectories) illustrated schematically for ease of understanding.

[0043] Three neutral wires 52 extending from each of the three phase coils 50 are connected to terminals 60 housed in housings 46 formed on the outer circumferential surface 45. Each of the three neutral wires 52 includes an outer circumferential conductor portion 56 drawn out from the outer wall portion 41 to the outer diameter side, and an inner circumferential conductor portion 57 drawn in from the outer wall portion 41 to the inner diameter side, and one end of the inner circumferential conductor portion 57 is electrically connected to the terminal 60.

[0044] In this embodiment, as shown in Figure 4, the upper insulator 24 has a pull-out portion 70 for pulling each of the three-phase neutral wires 52 out to the outer periphery of the insulator 24, and a pull-in portion 80 for pulling each of the three-phase neutral wires 52 pulled out to the outer periphery by the pull-out portion 70 into the inner periphery of the insulator 24.

[0045] That is, the outer conductor portion 56 refers to the portion of the neutral conductor 52 that is drawn out from the lead-out portion 70 to the outer circumferential side and drawn in to the lead-in portion 80. Similarly, the inner conductor portion 57 refers to the portion of the neutral conductor 52 that is drawn in from the lead-in portion 80 to the inner circumferential side and connected to the terminal 60 of the housing portion 46.

[0046] In this embodiment, two neutral wires 52 out of the first neutral wire 52-1, the second neutral wire 52-2, and the third neutral wire 52-3 pass through at least one lead-in section 80. That is, in this embodiment, six lead-in sections 80 are formed, two on either side of each housing section 46. Nine lead-out sections 70 are formed, one on each side, to lead out the neutral wires 52 extending from the nine coils 50-1 to 50-9.

[0047] 3, the second neutral conductor 52-2 extending from the coil 50-1 and the third neutral conductor 52-3 extending from the coil 50-2 pass through the lead-in section 80-2. The second neutral conductor 52-2 extending from the coil 50-4 and the third neutral conductor 52-3 extending from the coil 50-5 pass through the lead-in section 80-4. The second neutral conductor 52-2 extending from the coil 50-7 and the third neutral conductor 52-3 extending from the coil 50-8 pass through the lead-in section 80-6.

[0048] The lead-in portions 80 may be formed independently for each of the three phases, i.e., U phase, V phase, and W phase. That is, the same number of lead-in portions 80 as the lead-out portions 70 from which the neutral conductors 52 are drawn may be formed so as to correspond to each other.

[0049] In this embodiment, the insulator 24 is formed with a fall prevention portion 90 that prevents the outer conductor portion 56 of the neutral conductor 52 from falling off the insulator 24. The fall prevention portion 90 is formed as a protrusion 75 that protrudes radially outward from the outer circumferential surface of the insulator 24. The fall prevention portion 90 restricts the outer conductor portion 56 of the neutral conductor 52 from moving up and down (toward the rotation shaft 16). The fall prevention portion 90 is also formed circumferentially between the lead-out portion 70 and the lead-in portion 80. For example, in FIG. 4 , the first neutral conductor 52-1 drawn out from the lead-out portion 70-3 passes through the lead-in portion 80-3 while being caught by the fall prevention portion 90a. Similarly, the second neutral conductor 52-2 drawn out from the lead-out portion 70-4 passes through the lead-in portion 80-4 while being caught by the fall prevention portion 90b.

[0050] 4, the third neutral conductor 52-3 drawn out from the lead-out portion 70-5 passes through the lead-in portion 80-4 while its movement in the vertical direction is restricted by the fall-off prevention portions 90b, 90c, and 90d. The number and positions of the fall-off prevention portions 90 are not limited, and the fall-off prevention portions 90 may be formed at any position between the lead-out portion 70 and the lead-in portion 80 as long as they can prevent the outer conductor portion 56 of the neutral conductor 52 from falling off.

[0051] 4 and 6 , the accommodating portion 46 has an inner diameter sidewall 54 facing the radially inward direction of the three-phase motor 5, and an outer diameter sidewall 55 facing the radially outward direction of the three-phase motor 5. A neutral conductor passage portion (slit) 47 through which the neutral conductor 52 passes is formed in each of the inner diameter sidewall 54 and the outer diameter sidewall 55. A protrusion 75 protruding radially outward from the outer diameter sidewall 55 is formed in the outer diameter sidewall 55 near the lower end of the slit 47. The neutral conductor 52 is cut while being supported by the protrusion 75 at a position radially outward from the outer diameter sidewall 55.

[0052] The lead-in portion 80 is a slit through which the neutral conductor 52 passes. The bottom surface of the slit of the lead-in portion 80 is formed so as not to overlap the coil 50 in the height direction.

[0053] As described above, according to this embodiment, in a three-phase motor 5 having a stator core 23 having 3n (n is a natural number of 2 or more) tooth portions 32, an insulator 24 having an annular outer wall portion 41 and 3n winding drum portions 42 protruding inward from the outer wall portion 41, 3n coils 50 formed by winding conductors around the tooth portions 32 via the winding drum portions 42, and terminals 60 connecting three neutral wires 52 (52-1, 52-2, 52-3) extending from each of the coils 50 for three phases, the insulator 24 has an accommodating portion 46 for accommodating the terminal 60, and each of the three neutral wires 52 includes an outer circumferential conductor portion 56 drawn out radially outward from the outer wall portion 41 and an inner circumferential conductor portion 57 drawn in radially inward from the outer wall portion 41, and one end of the inner circumferential conductor portion is electrically connected to the terminal 60. As a result, each of the three-phase neutral wires 52 is first pulled out to the outer periphery of the insulator 24, then pulled in to the inner periphery, and then pulled from the center into the accommodating portion 46. This prevents the neutral wires 52 of each phase from coming close to the coils 50 of different phases. This ensures appropriate insulation between the neutral wires 52 and coils 50 of different phases.

[0054] Furthermore, if the neutral wire 52 is pulled directly into the accommodating section 46 (housing) after the coil has been formed by the automatic winding machine, the neutral wire 52 will loosen once it is released from the hand, as it is not temporarily fixed. If the terminal is inserted into the accommodating section 46 in this loosened state, the neutral wire 52 may loosen and become closer to the coil 50 of a different phase, which may result in the insulation being compromised.

[0055] In contrast, in the present invention, after winding the coil 50 around the tooth portion 32, the neutral conductor 52 is not directly drawn into the accommodation portion 46, but the neutral conductors 52 of all three phases are drawn once to the outer periphery of the insulator 24. This allows the neutral conductor 52 to be drawn under tension when drawn to the outer periphery of the insulator 24, thereby minimizing the length of the conductor from the coil 50 to the lead-out portion 70 of the insulator 24 and preventing loosening. Furthermore, by drawing the neutral conductor 52 to the inner periphery of the insulator 24 again after being drawn to the outer periphery of the insulator 24, the neutral conductor 52, which has been folded when passing through the lead-out portion 70 and the lead-in portion 80, friction occurs between the lead-out portion 70 and the lead-in portion 80 of the insulator 24, causing the neutral conductor 52 to be temporarily fixed to the insulator 24, and allowing the neutral conductor 52 to maintain a state in which tension is applied. This prevents the neutral conductor 52 from loosening before the terminal 60 is inserted into the accommodating portion 46 in a state where the neutral conductor 52 is pulled into the accommodating portion 47 from the inner circumferential side of the insulator 24 .

[0056] Furthermore, according to this embodiment, the insulator 24 has lead-out portions 70 for leading each of the three neutral wires 52 to the outer periphery of the insulator 24, and lead-in portions 80 for leading each of the three-phase neutral wires 52 led to the outer periphery by the lead-out portions 70 to the inner periphery of the insulator 24. This allows for appropriate formation of outer periphery lead-out portions for preventing the neutral wires 52 from coming close to coils of different phases.

[0057] Furthermore, according to this embodiment, when the three circumferentially adjacent tooth portions 32 are arranged in circumferential order as the first tooth portion (tooth portion 32-3), the second tooth portion (tooth portion 32-4), and the third tooth portion (tooth portion 32-5), the three neutral wires 52 connected to the terminal 60 are the first neutral wire 52-1 extending from the coil 50 (coil 50-3) wound around the first tooth portion, the second neutral wire 52-2 extending from the coil 50 (coil 50-4) wound around the second tooth portion, and the third neutral wire 52-3 extending from the coil 50 (coil 50-5) wound around the third tooth portion, and at least one lead-in portion 80 is passed through by two neutral wires 52 out of the first neutral wire 52-1, the second neutral wire 52-2, and the third neutral wire 52-3. As a result, although the three neutral wires, the first neutral wire 52-1 to the third neutral wire 52-3, are of different phases, they are all connected to the same neutral point, so that there is little electromagnetic influence between the neutral wires 52 even when they are close to each other. By utilizing this and allowing neutral wires 52 of multiple phases to pass through at least one lead-in section 80, the lead-in section 80 can be brought closer to the housing section 46 in the circumferential direction, and an appropriate insulation distance can be ensured between the neutral wires 52 of different phases and the coil 50.

[0058] Furthermore, according to this embodiment, when the three circumferentially adjacent teeth 32 are arranged in the order of the first teeth (teeth 32-3), the second teeth (teeth 32-4), and the third teeth (teeth 32-5), the three neutral wires 52 connected to the terminal 60 are the first neutral wire 52-1 extending from the coil 50 (coil 50-3) wound around the first teeth and the third neutral wire 52-2 extending from the coil 50 (coil 50-4) wound around the second teeth. The terminals 60 housed in the housing 46 are a second neutral wire 52-2 extending from the coil 50 (coil 50-4) wound around the third tooth portion, and a third neutral wire 52-3 extending from the coil 50 (coil 50-5) wound around the third tooth portion. When viewed from the direction of the rotating shaft 16 of the three-phase motor 5, the terminal 60 housed in the housing 46 is arranged so that the entire terminal 60 overlaps with the coil 50 (coil 50-4) wound around the second tooth portion (tooth portion 32-4) in the radial direction perpendicular to the rotating shaft 16. This allows the drawing portion 70 to be appropriately formed to prevent the neutral wire 52 from coming close to the coil 50 of a different phase. In addition, it is difficult to mistakenly combine the three neutral wires 52 drawn into the housing 46. In contrast, if the terminal 60 does not overlap with the coil 50 of the second tooth portion in the circumferential direction, the neutral conductor 52 of one of the three phases cannot form the outer circumferential conductor portion 56, i.e., the neutral conductor cannot be pulled out to the outer circumferential side of the insulator 24.

[0059] Furthermore, according to this embodiment, the accommodating portion 46 has an inner diameter sidewall 54 located radially inward relative to the terminal 60 in a direction perpendicular to the rotation shaft 16 of the three-phase motor 5, and an outer diameter sidewall 55 located radially outward relative to the terminal 60 in a direction perpendicular to the rotation shaft 16 of the three-phase motor 5. A slit 47 serving as a neutral conductor passage through which the neutral conductor 52 passes is formed in each of the inner diameter sidewall 54 and the outer diameter sidewall 55. The neutral conductor 52 is cut while supported by the protrusion 75 at a position radially outward from the outer diameter sidewall 55. As a result, the connecting wire 51 passing through the housing is pulled out from the radially outer side and cut at a position outer than the insulator 24. Since the neutral conductor 52 is cut with the blade while it is on the protrusion 75 serving as a receiving portion radially outward from the coil 50 to prevent crimping failure, reliability in manufacturing can be improved.

[0060] Furthermore, according to this embodiment, the insulator 24 is formed with a fall-off prevention portion 90 that prevents the outer conductor portion 53 of the neutral conductor 52 from falling off from the insulator 24, and the fall-off prevention portion 90 is formed circumferentially between the pull-out portion 70 and the pull-in portion 80. As a result, the fall-off prevention portion 90 can prevent the outer conductor portion 56 of the neutral conductor 52 from coming off the insulator 24, which could cause the insulation distance to be lost.

[0061] Furthermore, according to this embodiment, the lead-in portion 80 is a slit through which the neutral conductor 52 passes, and the bottom surface of the slit is formed so as not to overlap the coil 50 in the height direction. This prevents the different-phase connection wire 51 from coming close to the coil 50 when the connection wire 51 of a different phase from the coil 50 in which the accommodation portion 46 (housing) is formed, is led into the accommodation portion 46, thereby ensuring a sufficient insulation distance.

[0062] Furthermore, according to this embodiment, the accommodation portion 46 has an inner diameter sidewall 54 located radially inward relative to the terminal 60 in a direction perpendicular to the rotation shaft 16 of the three-phase motor 5, and an outer diameter sidewall 55 located radially outward relative to the terminal 60 in a direction perpendicular to the rotation shaft 16 of the three-phase motor 5. Slits 47 serving as neutral conductor passages through which the neutral conductor 52 passes are formed in each of the inner diameter sidewall 54 and the outer diameter sidewall 55, and the bottom surfaces of the slits forming the lead-out portion 70 are located at approximately the same height in the height direction as the slits 47 serving as neutral conductor passages. As a result, when the neutral conductor 52 of a different phase from the coil 50 in which the accommodation portion 46 (housing) is formed is drawn into the accommodation portion 46, the neutral conductor 52 of the different phase can be prevented from coming close to the coil 50, ensuring a sufficient insulation distance.

[0063] Furthermore, according to this embodiment, the compressor 1 includes a three-phase motor 5, a housing 2 that houses the three-phase motor 5, and a compression unit 6 that is housed inside the housing 2 and driven by the three-phase motor 5. This ensures insulation of the three-phase motor 5, thereby providing a compressor 1 with improved reliability.

[0064] FIG. 7 is an enlarged view of a three-phase motor 5 according to another embodiment. This embodiment is characterized in that the height of the bottom surface of the slit serving as the lead-in portion 80 (height from the lower end of the insulator 24) is substantially the same as the height of the bottom surface of the neutral conductor passage 47 (height from the lower end of the insulator 24) (see H1 and H2 in FIG. 7 ). Otherwise, this embodiment is similar to the three-phase motor 5 according to the embodiment shown in FIG. 5 . That is, the bottom surface of the lead-in portion 80 (slit) is located at substantially the same height as the bottom surface of the neutral conductor passage 47. This allows the inner conductor portion 57 to be stretched parallel to the horizontal direction when the direction perpendicular to the rotating shaft 16 is defined as the horizontal direction. This ensures appropriate insulation between the neutral conductor 52 and the coil 50, which are out of phase with each other, while further suppressing loosening of the neutral conductor 52.

[0065] DESCRIPTION OF SYMBOLS 1...Compressor 5...Three-phase motor 16...Rotating shaft 23...Stator core 24...Upper insulator 26...Multiple windings 32...Teeth portion 42...Winding body portion 46...Accommodation portion 47...Neutral conductor passage portion (slit) 50...Coil 54...Inner diameter side wall 55...Outer diameter side wall 56...Outer circumferential conductor portion 57...Inner circumferential conductor portion 60...Terminal 70...Outlet portion (slit) 75...Protrusion portion 80...Inlet portion (slit) 90...Fall prevention portion

Claims

1. A three-phase motor having a stator core with 3n (n is a natural number of 2 or greater) teeth, an insulator having an annular outer wall and 3n winding bodies protruding inward from the outer wall, 3n coils formed by winding conductors around the teeth via the winding body, and terminals connecting three neutral wires extending from each of the coils for three phases, wherein the insulator has a housing portion for housing the terminals, and each of the three neutral wires includes an outer circumferential conductor portion drawn out from the outer wall to the outer diameter side and an inner circumferential conductor portion drawn in from the outer wall to the inner diameter side, and one end of the inner circumferential conductor portion is electrically connected to the terminal.

2. A three-phase motor as claimed in claim 1, wherein the insulator has a lead-out section for leading each of the three neutral wires to the outer periphery of the insulator, and a lead-in section for leading each of the three neutral wires led to the outer periphery by the lead-out section to the inner periphery of the insulator.

3. A three-phase motor as set forth in claim 2, wherein when the three circumferentially adjacent teeth are arranged in the order of the circumferential direction as first teeth, second teeth, and third teeth, the three neutral wires connected to the terminals are a first neutral wire extending from the coil wound around the first teeth, a second neutral wire extending from the coil wound around the second teeth, and a third neutral wire extending from the coil wound around the third teeth, and at least one of the lead-in sections is a three-phase motor through which two of the first, second, and third neutral wires pass.

4. A three-phase motor as claimed in claim 1, wherein when the three circumferentially adjacent teeth are arranged in the order of the first teeth, the second teeth and the third teeth, the three neutral wires connected to the terminals are a first neutral wire extending from the coil wound around the first teeth, a second neutral wire extending from the coil wound around the second teeth and a third neutral wire extending from the coil wound around the third teeth, and when viewed from the direction of the rotation axis of the three-phase motor, the terminals accommodated in the accommodating parts are arranged so that the entire terminals overlap the coil wound around the second teeth in a radial direction perpendicular to the rotation axis.

5. A three-phase motor as claimed in claim 1, wherein the accommodating section has an inner diameter sidewall located radially inward relative to the terminals and perpendicular to the rotation axis of the three-phase motor, and an outer diameter sidewall located radially outward relative to the terminals and perpendicular to the rotation axis of the three-phase motor, a neutral conductor passage section through which the neutral conductor passes is formed in each of the inner diameter sidewall and the outer diameter sidewall, and the neutral conductor is cut at a position radially outward of the outer diameter sidewall.

6. A three-phase motor as claimed in claim 2, wherein the insulator is formed with a fall-off prevention part that prevents the outer circumferential conductor part of the neutral conductor from falling off the insulator, and the fall-off prevention part is formed between the lead-out part and the lead-in part in the circumferential direction.

7. A three-phase motor as claimed in claim 2, wherein the lead-in portion is a slit through which the neutral conductor passes, and the bottom surface of the slit is formed so as not to overlap with the coil in the height direction.

8. A three-phase motor as set forth in claim 7, wherein the accommodating section has an inner diameter sidewall located radially inward relative to the terminals and perpendicular to the rotation axis of the three-phase motor, and an outer diameter sidewall located radially outward relative to the terminals around the rotation axis of the three-phase motor, a neutral conductor passage section through which the neutral conductor passes is formed in each of the inner diameter sidewall and the outer diameter sidewall, and the bottom surface of the slit is located at approximately the same height in the height direction as the bottom surface of the neutral conductor passage section.

9. A compressor comprising: a three-phase motor according to any one of claims 1 to 8; a compressor main body container that houses said three-phase motor; and a compression mechanism section that is housed inside said compressor main body container and is driven by said three-phase motor.

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