Stator, motor, blower, and air conditioning device

Abstract

This stator comprises a stator core, a winding that is wound around the stator core, a cover member that covers the stator core and the winding, and a lead wire that is electrically connected to the winding and extends from the inside of the cover member to the outside thereof. The electrical resistance of the lead wire is less than the electrical resistance of the winding.

Description

Stator, motor, blower and air conditioner

[0001] The present disclosure relates to a stator, a motor, a blower, and an air conditioning apparatus.

[0002] Conventionally, motors have been known that include a stator having a stator core and windings, and a rotor having permanent magnets. While copper wire is generally used for the windings, the use of aluminum wire has been proposed in recent years (see, for example, Patent Document 1). Aluminum wire has a smaller specific gravity than copper wire, which allows for a reduction in the weight of the motor.

[0003] JP 2016-77093 A (see abstract)

[0004] However, aluminum wires have a higher electrical resistance than copper wires, and therefore generate more heat when current is applied, which tends to increase the temperature of the stator.

[0005] A rise in the stator temperature can cause thermal demagnetization of the rotor's permanent magnets, which face the stator, leading to a decrease in motor output. Furthermore, if the insulating parts of the stator melt, this can lead to motor failure. Therefore, there is a demand for improved heat dissipation from the stator.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to improve the heat dissipation performance of a stator.

[0007] The stator of the present disclosure includes a stator core, a winding wound around the stator core, a cover member that covers the stator core and the winding, and a lead wire that is electrically connected to the winding and extends from the inside of the cover member to the outside. The lead wire has an electrical resistance smaller than that of the winding.

[0008] According to the present disclosure, the electrical resistance of the lead wires is smaller than that of the windings, so that the lead wires generate less heat and the heat generated in the windings can be dissipated from the lead wires, thereby improving the heat dissipation performance of the stator.

[0009] FIG. 1 is a longitudinal sectional view showing a motor of embodiment 1. FIG. 2 is a transverse sectional view showing a motor of embodiment 1. FIG. 3 is a schematic view showing a part of a stator core, an insulating portion, and windings of embodiment 1. FIG. 4 is a plan view showing a stator core, windings, lead wires, and a cover member of embodiment 1. FIG. 5 is a plan view showing a stator core, windings, lead wires, a cover member, and a holding member of embodiment 1. FIG. 6 is a longitudinal sectional view showing a stator of embodiment 1. FIG. 7 is a schematic view for explaining the arrangement of windings and lead wires of embodiment 1. FIG. 8 is a schematic view for explaining the arrangement of windings and lead wires of embodiment 1. FIG. 9 is a flowchart showing a manufacturing method of the motor of embodiment 1. FIG. 10 is a schematic view showing a mold for molding the stator of embodiment 1. FIG. 11 is a longitudinal sectional view showing a stator of embodiment 2. FIG. 12 is a view showing a blower of embodiment 3. FIG. 13 is a view showing an air conditioning apparatus of embodiment 4.

[0010] Embodiment 1. <Overall Configuration of Motor 1> A motor 1 according to embodiment 1 will now be described. Fig. 1 is a longitudinal cross-sectional view showing the motor 1 according to embodiment 1. The motor 1 is a synchronous motor, and is used, for example, in a blower of an air conditioning device 100 (Fig. 13). The motor 1 includes a rotor 2 having a rotating shaft 20, and a stator 3 surrounding the rotor 2.

[0011] Hereinafter, the direction of the center of rotation of the rotor 2, i.e., the central axis Ax of the rotating shaft 20, will be referred to as the "axial direction." The radial direction centered on the central axis Ax will be referred to as the "radial direction." The circumferential direction centered on the central axis Ax will be referred to as the "circumferential direction." Furthermore, a cross-sectional view taken along a plane perpendicular to the central axis Ax will be referred to as a "transverse cross-sectional view," and a cross-sectional view taken along a plane parallel to the central axis Ax will be referred to as a "longitudinal cross-sectional view."

[0012] The rotating shaft 20 protrudes from the stator 3 to one side in the axial direction. A load, such as an impeller 81 (FIG. 12) of a blower, is attached to the protruding portion of the rotating shaft 20. Therefore, the side from which the rotating shaft 20 protrudes is referred to as the "load side," and the opposite side is referred to as the "anti-load side."

[0013] <Configuration of Rotor 2> Figure 2 is a cross-sectional view showing the motor 1. As shown in Figure 2, the rotor 2 has a rotating shaft 20, a ferrite bond magnet 21 as a permanent magnet provided so as to surround the rotating shaft 20, and a resin portion 22 as a connecting portion provided between them. The ferrite bond magnet 21 and the resin portion 22 are collectively referred to as a rotor main body 23 (Figure 1).

[0014] The rotating shaft 20 is made of a metal such as carbon steel for mechanical construction (S45C), and is rotatably supported by bearings 25 and 26 (FIG. 1) disposed on both axial sides of the rotor body 23.

[0015] The ferrite bond magnet 21 is provided radially outside the rotating shaft 20 and extends in an annular shape centered on the central axis Ax. An outer periphery 21 a of the ferrite bond magnet 21 forms the outer periphery of the rotor 2.

[0016] The ferrite bonded magnet 21 is a magnet made by kneading ferrite magnet powder and resin and molding it. The resin contained in the ferrite bonded magnet 21 is, for example, nylon, PPS (polyphenylene sulfide), EEA (ethylene-ethyl acrylate copolymer), or epoxy resin.

[0017] The ferrite bonded magnet 21 is magnetized to have a polar anisotropic orientation. First magnetic poles P1, which are north poles, and second magnetic poles P2, which are south poles, are formed alternately in the circumferential direction on the outer periphery 21a of the ferrite bonded magnet 21. An inter-pole portion M is formed between the magnetic poles P1 and P2.

[0018] The outer periphery 21a of the ferrite bond magnet 21 extends so that the outer diameter is greatest at the pole center of the magnetic poles P1 and P2 and is smallest at the interpole portion M. However, the outer periphery 21a of the ferrite bond magnet 21 is not limited to this shape and may be, for example, circumferential.

[0019] The resin part 22 is formed of a thermoplastic resin such as PBT (polybutylene terephthalate). The rotating shaft 20 is fixed to the inner periphery of the resin part 22, and the ferrite bond magnet 21 is fixed to the outer periphery of the resin part 22. The resin part 22 is formed, for example, by integrally molding the rotating shaft 20 and the ferrite bond magnet 21 with resin.

[0020] The rotor 2 is not limited to having the ferrite bonded magnet 21 and the resin portion 22. For example, a permanent magnet may be attached to a rotor core made of laminated elements such as electromagnetic steel sheets. Furthermore, the permanent magnet is not limited to a ferrite bonded magnet, and may be a rare earth bonded magnet, a ferrite sintered magnet, or a rare earth sintered magnet.

[0021] 1, the stator 3 includes a stator core 30, an insulating portion 35 attached to the stator core 30, a winding 40 wound around the stator core 30, and a cover member 50 that covers these components. The cover member 50 also holds bearings 25 and 26 that support the rotating shaft 20.

[0022] The stator core 30 has a laminated body in which a plurality of magnetic laminated elements are stacked in the axial direction. The laminated elements are thin plates whose main component is Fe, more specifically, electromagnetic steel sheets. The thickness of the laminated elements is, for example, 0.2 to 0.5 mm. Instead of the laminated body of laminated elements, processed ingots whose main component is Fe may also be used.

[0023] 2, the stator core 30 has an annular yoke 31 and N (N is an integer of 2 or more) teeth 32 extending radially inward from the yoke 31. The N teeth 32 are arranged at equal intervals in the circumferential direction. The number N of the teeth 32 is 9 in this example, but is not limited to this.

[0024] The teeth 32 have extending portions 32a extending radially inward from the yoke 31 and tooth tips 32b formed at the tips of the extending portions 32a. The tooth tips 32b face the outer peripheral surface of the rotor 2 in the radial direction.

[0025] A slot 33 is formed between circumferentially adjacent teeth 32. A winding 40 is wound around the teeth 32 with an insulating portion 35 interposed therebetween and is housed in the slot 33.

[0026] The insulating portion 35 is made of an insulating thermoplastic resin such as PBT, PPS, liquid crystal polymer (LCP), or PET (polyethylene terephthalate). An insulating film may also be provided to cover the inner surface of the slot 33. The insulating film is made of PET, for example, and has a thickness of 0.035 to 0.4 mm.

[0027] Fig. 3 is a perspective view showing a portion of stator core 30 including one tooth 32, and insulating portion 35 and winding 40 attached thereto. As shown in Fig. 3, insulating portion 35 has a body portion 35c (Fig. 6) surrounding extension portion 32a (Fig. 2) of tooth 32, a wall portion 35a located radially outward from body portion 35c, and a wall portion 35b located radially inward from body portion 35c (Fig. 6).

[0028] The windings 40 are wound around the teeth 32 via the insulating portions 35. More specifically, the windings 40 are wound around the extending portions 32a of the teeth 32 via the body portions 35c (FIG. 6) of the insulating portions 35. The windings 40 are guided from both radial sides by the wall portions 35a and 35b of the insulating portions 35.

[0029] The winding 40 is made of aluminum wire. The aluminum wire is an aluminum conductor covered with an insulating coating. The winding 40 is wound by concentrated winding here, but may also be wound by distributed winding.

[0030] Terminal portions 36 to which lead wires 10 (FIG. 4) described below are fixed, or pins 37 (FIG. 6) to which holding members 60 are fixed, are disposed on wall portions 35a of insulating portion 35. The stator core 30, insulating portion 35, and windings 40 are collectively referred to as a stator main body 4.

[0031] As shown in FIG. 1 , the cover member 50 is a component that forms the outer shell of the stator 3 and is made of resin, for example, molded resin. More specifically, the cover member 50 is made of a thermosetting resin such as unsaturated polyester resin or epoxy resin. Alternatively, a bulk molding compound (BMC) made by adding glass fiber to a thermosetting resin may be used. The cover member 50 is also referred to as a molded resin portion.

[0032] The cover member 50 covers the radially outer side and the anti-load side of the stator body 4. The cover member 50 has an opening 51 on the load side and a bottom 52 on the anti-load side. The rotor 2 is inserted into the inside of the stator 3 through the opening 51. The cover member 50 has an annular step 53 formed to surround the opening 51.

[0033] A metal bracket 27 that supports the load-side bearing 25 is attached to the stepped portion 53 of the cover member 50. The bracket 27 is an annular member centered on the central axis Ax. A waterproof cap 28 is attached to the rotating shaft 20 so as to cover the outside of the bracket 27.

[0034] The bottom portion 52 of the cover member 50 is formed so as to cover the anti-load side of the stator 3. The bottom portion 52 is formed with a bearing holding portion 54, which is a recess that accommodates the bearing 26.

[0035] The cover member 50 is not limited to a resin, and may be, for example, a metal shell. The shell is, for example, a cylindrical member whose main component is iron (Fe), and the stator 3 is fixed inside the shell by shrink fitting or the like.

[0036] 4 is a plan view showing the stator core 30, the windings 40, the lead wires 10, and the cover member 50. The windings 40 are three-phase windings, and include a U-phase winding 40U, a V-phase winding 40V, and a W-phase winding 40W.

[0037] When the stator core 30 has N teeth 32 (N is an integer of 2 or more), the windings 40U, 40V, and 40W have a total of N winding portions. N is 9 in this example.

[0038] 4 is referred to as the first tooth 32. The nine teeth 32 of the stator core 30, arranged clockwise from the first tooth 32, will be described as the first to ninth teeth.

[0039] The winding 40U has a winding portion U1 wound around the first tooth 32, a winding portion U2 wound around the second tooth 32, and a winding portion U3 wound around the third tooth 32. The winding portions U1, U2, and U3 are connected in series via crossover wires (not shown). The winding direction of the winding portion U2 as viewed from the rotor 2 side is opposite to the winding directions of the winding portions U1 and U3.

[0040] Similarly, the winding 40V has a winding portion V1 wound around the fourth tooth 32, a winding portion V2 wound around the fifth tooth 32, and a winding portion V3 wound around the sixth tooth 32. The winding portions V1, V2, and V3 are connected in series via crossover wires (not shown). The winding direction of the winding portion V2 as viewed from the rotor 2 side is opposite to the winding directions of the winding portions V1 and V3.

[0041] Similarly, winding 40W has winding portion W1 wound around the seventh tooth 32, winding portion W2 wound around the eighth tooth 32, and winding portion W3 wound around the ninth tooth 32. Winding portions W1, W2, and W3 are connected in series via crossover wires (not shown). Furthermore, the winding direction of winding portion W2 as viewed from the rotor 2 side is opposite to the winding directions of winding portions W1 and W3.

[0042] A terminal portion 36U is formed on the insulating portion 35 (FIG. 3) around which one of the winding portions U1, U2, and U3 (winding portion U3 in this example) of the winding 40U is wound. The winding 40U and the terminal portion 36U are connected by soldering, fusing, or the like.

[0043] Furthermore, a terminal portion 36V is formed on insulating portion 35 (FIG. 3) around which one of winding portions V1, V2, and V3 (winding portion V3 in this case) of winding 40V is wound. Winding 40V and terminal portion 36V are connected by soldering, fusing, or the like.

[0044] Furthermore, a terminal portion 36W is formed on insulating portion 35 (FIG. 3) around which one of winding portions W1, W2, and W3 (winding portion W3 in this case) of winding 40W is wound. Winding 40W and terminal portion 36W are connected by soldering, fusing, or the like.

[0045] The windings 40U, 40V, and 40W are molded together with the stator core 30 and the insulating portion 35. In other words, the windings 40U, 40V, and 40W, together with the stator core 30 and the insulating portion 35, are covered by the cover member 50.

[0046] Lead wires 10U, 10V, and 10W are provided on the stator 3. The lead wires 10U, 10V, and 10W electrically connect a control circuit disposed outside the motor 1 to the windings 40U, 40V, and 40W of the stator 3. A driving current is supplied to the windings 40U, 40V, and 40W via the lead wires 10U, 10V, and 10W.

[0047] The lead wires 10U, 10V, and 10W are all made of copper wire. The copper wire is made by covering a copper conductor with an insulating coating. The lead wires 10U, 10V, and 10W may also be made of a twisted wire made by twisting together multiple thin wires.

[0048] Lead wire 10U is connected to terminal portion 36U and is drawn out to the outside of stator 3. That is, lead wire 10U has an extension portion 11U that extends within stator 3 and reaches terminal portion 36U, and a drawn-out portion 12U that is drawn out to the outside of stator 3.

[0049] Similarly, lead wire 10V is connected to terminal portion 36V and is drawn out to the outside of stator 3. That is, lead wire 10V has extension portion 11V that extends within stator 3 and reaches terminal portion 36V, and lead portion 12V that is drawn out to the outside of stator 3.

[0050] Similarly, lead wire 10W is connected to terminal portion 36W and is drawn out to the outside of stator 3. That is, lead wire 10W has an extending portion 11W that extends within stator 3 and reaches terminal portion 36W, and a drawn-out portion 12W that is drawn out to the outside of stator 3.

[0051] Lead portions 12U, 12V, 12W of lead wires 10U, 10V, 10W are drawn out from an outlet portion 15 provided at one location in the circumferential direction of stator 3. In the example shown in Fig. 4, lead portion 15 is arranged between terminal portions 36V, 36W in the circumferential direction and at a position close to terminal portion 36W.

[0052] Therefore, among the extending portions 11U, 11V, and 11W of the lead wires 10U, 10V, and 10W, the extending portion 11U is the longest, the extending portion 11V is the second longest, and the extending portion 11W is the shortest.

[0053] <Holding member 60> A holding member 60 (FIG. 1) is provided to hold the lead wires 10U, 10V, and 10W. The holding member 60 is disposed on one axial side of the stator core 30, more specifically, on the anti-load side of the stator core 30.

[0054] 5 is a plan view showing the stator core 30, the windings 40, the lead wires 10U, 10V, and 10W, the cover member 50, and the holding member 60. The holding member 60 is an annular plate-like member centered on the central axis Ax.

[0055] The holding member 60 is made of resin. The holding member 60 is made of an insulating thermoplastic resin such as PBT, PPS, LCP, or PET. The resin that forms the holding member 60 has a higher thermal conductivity than the resin that forms the cover member 50. This will be described later.

[0056] Holding member 60 faces windings 40U, 40V, and 40W in the axial direction. More specifically, holding member 60 faces all winding portions U1 to U3, V1 to V3, and W1 to W3 (FIG. 4) of windings 40U, 40V, and 40W in the axial direction.

[0057] The holding member 60 has an outer periphery 63 and an inner periphery 64. The radial width of the holding member 60 (i.e., the distance between the outer periphery 63 and the inner periphery 64) is set to cover the ranges in which the extending portions 11U, 11V, and 11W of the lead wires 10U, 10V, and 10W extend.

[0058] When there is no particular need to distinguish between the lead wires 10U, 10V, and 10W, they will be described as lead wire 10. When there is no particular need to distinguish between the windings 40U, 40V, and 40W, they will be described as winding wire 40.

[0059] Fig. 6 is a longitudinal cross-sectional view showing the stator 3. Note that hatching of the cover member 50 is omitted in Fig. 6. The holding member 60 has a first surface 61 that faces the stator core 30 in the axial direction, and a second surface 62 that is opposite the stator core 30.

[0060] The holding member 60 is supported by the wall portion 35a of the insulating portion 35. A pin 37 is formed in the wall portion 35a of the insulating portion 35. The holding member 60 is formed with an attachment hole 66, which is a through hole through which the pin 37 is inserted.

[0061] The pin 37 of the insulating portion 35 is inserted into the mounting hole 66 of the holding member 60, and the tip 38 of the pin 37 is heat-welded, thereby fixing the holding member 60 to the insulating portion 35. Note that it is sufficient that the pin 37 is provided on at least one of the insulating portions 35 provided on the N teeth 32.

[0062] The lead wire 10 described above is held on a first surface 61 of the holding member 60. That is, the holding member 60 holds the lead wire 10 so that the lead wire 10 faces the windings 40 of the stator 3.

[0063] The holding member 60 is provided with a pressing portion 65 that presses the lead wire 10 to prevent it from falling off. The pressing portion 65 has a pillar portion 65a that extends from the first surface 61 toward the stator core 30, and a mounting portion 65b that extends from the tip of the pillar portion 65a to face the first surface 61, and the lead wire 10 is held between the first surface 61 and the mounting portion 65b.

[0064] As shown by the broken lines in FIG. 5, the pressing portions 65 are arranged at a plurality of locations along each of the lead wires 10U, 10V, and 10W.

[0065] For example, the pressing portions 65 that hold the lead wire 10U are arranged at five locations on the path from the lead portion 15 to the terminal portion 36U. The pressing portions 65 that hold the lead wire 10V are arranged at three locations on the path from the lead portion 15 to the terminal portion 36V. The pressing portions 65 that hold the lead wire 10W are arranged at two locations on the path from the lead portion 15 to the terminal portion 36W. However, the number and arrangement of the pressing portions 65 can be changed.

[0066] Since the lead wires 10 are molded together with the stator core 30 and the holding member 60, the pressing portion 65 only needs to hold the lead wires 10 to a degree that prevents them from falling off the holding member 60. The shape of the pressing portion 65 is not limited to the shape shown in Fig. 6, and may be any shape that can hold the lead wires 10.

[0067] <Configuration for Heat Dissipation in Stator 3> Next, a description will be given of the configuration for heat dissipation in the stator 3. To reduce the cost of the motor 1, it has been considered to change the windings 40 from copper wire to aluminum wire, which has a low specific gravity. It has also been considered to reduce the wire diameter of the windings 40 of the stator 3.

[0068] Here, one of the losses that occurs when the motor 1 is driven is copper loss, which can be calculated using the electrical resistance R [ohm] of the winding 40, the current I [A], and the number of phases n as follows: ２ That is, the copper loss is proportional to the electrical resistance R of the winding 40.

[0069] The electrical resistance R [Ω] of a conductor is calculated by the resistivity ρ [Ω m], the length L [m] and the cross-sectional area S [m ２ ], R=ρL / S. Changing from copper wire to aluminum wire leads to an increase in resistivity ρ, and reducing the wire diameter D2 of winding 40 leads to a reduction in cross-sectional area S. Therefore, the above measures to reduce costs increase copper loss, leading to an increase in the amount of heat generated.

[0070] An increase in the amount of heat generated in the stator 3 can lead to a breakdown of the motor 1 due to melting or deformation of the insulating portion 35 between the stators 3. In addition, since the heat of the stator 3 is also transferred to the rotor 2, if rare earth magnets are used as permanent magnets, this can lead to a decrease in output due to thermal demagnetization of the permanent magnets.

[0071] Therefore, the stator 3 of the first embodiment has a configuration that allows the heat generated in the windings 40 to be efficiently dissipated to the outside.

[0072] 7 is a schematic diagram illustrating the positional relationship between the lead wire 10 and the windings 40 in the stator 3. The lead wire 10 faces the windings 40 wound around the teeth 32 of the stator 3 in the axial direction.

[0073] As described above, the conductor of the lead wire 10 is made of copper, and the conductor of the winding 40 is made of aluminum. The resistivity of the conductor of the lead wire 10 is lower than the resistivity of the conductor of the winding 40. For example, the resistivity of copper is 1.7×10 －８ [Ω m], and the resistivity of aluminum is 2.8 × 10 －８ [Ω·m].

[0074] Furthermore, the thermal conductivity of the conductor of the lead wire 10 is higher than the thermal conductivity of the conductor of the winding 40. For example, the thermal conductivity of copper is 395 [W / m·K], and the thermal conductivity of aluminum is 230 [W / m·K].

[0075] Furthermore, the wire diameter D1 of the lead wire 10 is larger than the wire diameter D2 of the winding 40. The wire diameter D1 of the lead wire 10 is 0.64 to 1.0 mm, and the wire diameter D2 of the winding 40 is 0.3 to 0.5 mm. If the lead wire 10 is a twisted wire formed by twisting together a plurality of thin wires, the wire diameter D1 is the outer diameter of the bundle of thin wires.

[0076] The length of lead wire 10 is shorter than the length of winding 40. For example, the length of lead wire 10U shown in Fig. 4 is the sum of the length of extension portion 11U from terminal portion 36U to lead portion 15 and the length of lead portion 12U from lead portion 15 to the control circuit. The same applies to the lengths of lead wires 10V and 10W.

[0077] 4 is the sum of the circumferential lengths of the winding portions U1, U2, and U3 and the length of the crossover wires connecting the winding portions U1, U2, and U3 to each other. The same is true for the lengths of the windings 40V and 40W.

[0078] As described above, the resistivity of the conductor of lead wire 10 is lower than the resistivity of the conductor of winding 40, the wire diameter D1 of lead wire 10 is larger than the wire diameter D2 of winding 40, and the length of lead wire 10 is shorter than the length of winding 40. Therefore, due to the above-mentioned relationship R = ρL / S, the electrical resistance of lead wire 10 is smaller than the electrical resistance of winding 40.

[0079] When the motor 1 is driven, a current flows through the winding 40 via the lead wire 10, and heat is generated by Joule heat in both the lead wire 10 and the winding 40. At this time, the electrical resistance of the lead wire 10 is smaller than the electrical resistance of the winding 40, so the amount of heat generated in the lead wire 10 is smaller than the amount of heat generated in the winding 40. Therefore, the temperature rise in the lead wire 10 is smaller than the temperature rise in the winding 40.

[0080] In this way, the temperature rise of the lead wire 10 is smaller than the temperature rise of the winding 40, and the thermal conductivity of the conductor of the lead wire 10 is higher than the thermal conductivity of the conductor of the winding 40, so that the heat generated in the winding 40 is dissipated to the outside of the stator 3 via the lead wire 10. In other words, the lead wire 10 functions as a heat dissipation path from the winding 40. This makes it possible to suppress the temperature rise of the winding 40.

[0081] 8 is a schematic diagram illustrating the positional relationship between the lead wire 10 and the winding 40 in the stator 3. The region that axially overlaps the region in which the winding 40 is disposed is referred to as the winding overlap region A. At least a portion of the lead wire 10 (more specifically, the extending portion 11) is disposed within the winding overlap region A.

[0082] This allows the lead wire 10 and the winding 40 to face each other in the axial direction and be close to each other, which makes it easier for heat from the winding 40 to be transferred to the lead wire 10, improving the heat dissipation from the winding 40 by the lead wire 10.

[0083] The lead wire 10 and the winding 40 are arranged apart from each other (i.e., not in contact with each other). If the lead wire 10 and the winding 40 come into contact with each other, the insulating coating may be scraped off and thinned by the contact when the stator 3 is assembled, which may result in a deterioration in the insulating performance of the lead wire 10 and the winding 40.

[0084] Furthermore, a part of the cover member 50 is interposed between the lead wires 10 and the windings 40. This makes it possible to stably ensure the distance between the lead wires 10 and the windings 40. In other words, contact between the lead wires 10 and the windings 40 due to vibrations or the like while the motor 1 is running can be avoided, and a decrease in the insulation performance of the lead wires 10 and the windings 40 can be prevented.

[0085] Furthermore, the shortest distance L1 between the lead wire 10 and the winding 40 is greater than 0.1 mm (i.e., L1>0.1 mm).

[0086] Generally, the variation in the wire diameter D1 of the lead wire 10 is ±0.05 mm. The variation in the wire diameter D2 of the winding 40 depends on the size of the wire diameter D2, but when the wire diameter D2 is 3.0 mm, which is larger than the above range (0.3 to 0.5 mm), the variation is ±0.05 mm. The combined variation in the wire diameters D1 and D2 of the lead wire 10 and the winding 40 is 0.1 mm. Therefore, if the shortest distance L1 is longer than 0.1 mm, contact between the lead wire 10 and the winding 40 can be avoided even taking into account the variation in the wire diameters D1 and D2.

[0087] Furthermore, the cover member 50 is made of resin, which has a higher thermal conductivity than air. By having a portion of the resin cover member 50 between the lead wire 10 and the winding 40, the thermal resistance between the lead wire 10 and the winding 40 can be reduced, and the heat dissipation effect from the winding 40 by the lead wire 10 can be improved.

[0088] The shortest distance L1 between the lead wire 10 and the winding 40 is shorter than half the shortest distance L2 from the winding 40 to the axial end face 55 of the cover member 50 (i.e., L1<L2 / 2). The end face 55 of the cover member 50 is the end face on the anti-load side of the cover member 50 in this case.

[0089] In order to improve heat dissipation, it is effective to increase the area of ​​the surface that contributes to heat dissipation by diffusing heat over a wide range. When the above relationship L1 < L2 / 2 is satisfied, the distance between the winding 40 and the lead wire 10 is short, so heat from the winding 40 easily moves to the lead wire 10, which has high thermal conductivity. The heat from the lead wire 10 is diffused widely into the cover member 50 or the holding member 60, etc., and is dissipated to the outside of the stator 3 from a wide area on the outer surface of the cover member 50. This further improves the heat dissipation effect from the winding 40.

[0090] As described above, the cover member 50 is made of a thermosetting resin such as unsaturated polyester, which has a thermal conductivity of 0.20 [W / m·K].

[0091] In contrast, the holding member 60 is formed of an insulating thermoplastic resin such as PBT, PPS, LCP, or PET. The thermal conductivity of PBT is 0.27 [W / m·K], and the thermal conductivity of LCP is 0.39 [W / m·K].

[0092] That is, the thermal conductivity of the first resin forming the holding member 60 is higher than the thermal conductivity of the second resin forming the cover member 50 .

[0093] The thermosetting resin that forms the cover member 50 generally has excellent heat resistance but low thermal conductivity. Therefore, by forming the holding member 60 from a second resin that has a higher thermal conductivity than the first resin that forms the cover member 50, the thermal resistance inside the stator 3 can be reduced and heat dissipation from the windings 40 can be promoted.

[0094] <Method of Manufacturing Motor 1> Next, a method of manufacturing the motor 1 will be described. Fig. 9 is a flowchart showing the manufacturing steps of the motor 1. First, a plurality of laminated elements are stacked in the axial direction and fixed by caulking or the like to form the stator core 30 (step S101).

[0095] Next, the insulating portion 35 is attached to the stator core 30 or is molded integrally therewith (step S102). Furthermore, the winding 40 is wound around the stator core 30 via the insulating portion 35 (step S103). In this way, the stator main body 4 (FIG. 1) is formed.

[0096] Next, holding member 60 holding lead wire 10 is attached to insulating section 35 (step S104). Specifically, holding member 60, with lead wires 10U, 10V, and 10W held by pressing section 65 (FIG. 6), is placed on insulating section 35. Furthermore, pins 37 (FIG. 6) of insulating section 35 are inserted into mounting holes 66 of holding member 60, and tips 38 of pins 37 are heat-welded. Furthermore, windings 40U, 40V, and 40W are connected to terminal sections 36U, 36V, and 36W (FIG. 4) by soldering, fusing, or the like.

[0097] Next, the stator core 30, the insulating portion 35, the windings 40, the lead wires 10, and the holding member 60 are molded (step S105).

[0098] 10 is a cross-sectional view showing a molding die 9 used for molding, and the stator core 30, insulating portion 35, windings 40, lead wires 10, and holding member 60 placed therein. The molding die 9 has a fixed die 91, which is a lower die, and a movable die 92, which is an upper die. The fixed die 91 and the movable die 92 have mating surfaces 91a, 92a that face each other.

[0099] The fixed mold 91 has a cavity 93 which is a hollow portion, a central core portion 94 formed in the center of the cavity 93, and a supply port 95 which supplies resin to the cavity 93. Between the fixed mold 91 and the movable mold 92, an extraction hole 96 is formed which extracts the lead wire 10 to the outside of the molding mold 9.

[0100] 10, a molding space is formed between the cavity 93 of the fixed mold 91 and the movable mold 92. When the movable mold 92 is raised from the position shown in FIG. 10, the cavity 93 is opened.

[0101] In the molding process, the movable mold 92 is raised, and the stator core 30, to which the insulating portion 35, the windings 40, and the holding member 60 are attached, is placed in the cavity 93 of the fixed mold 91. The lead wires 10 are also drawn out through the drawing holes 96. A center core 94 is fitted onto the inner periphery of the stator core 30.

[0102] In this state, movable mold 92 is lowered so that mold mating surfaces 91 a and 92 a come into contact with each other. Molten molding resin is then injected from supply port 95 of molding mold 9. The molding resin, which is a thermosetting resin, fills cavity 93 and covers stator core 30, insulating portion 35, windings 40, lead wires 10, and holding member 60.

[0103] Thereafter, the molding die 9 is heated to the hardening temperature of the molding resin to harden the molding resin, thereby forming the cover member 50 shown in FIG.

[0104] This completes the stator 3, in which the stator core 30, the insulating portion 35, the windings 40, the lead wires 10 and the holding member 60 are covered with the cover member 50. Steps S101 to S105 correspond to the manufacturing process of the stator 3.

[0105] Separately from steps S101 to S105, rotor 2 is formed. That is, ferrite bond magnet 21 is molded using a molding die equipped with a magnetizer for orientation. Then, ferrite bond magnet 21 is placed together with rotating shaft 20 in another molding die, and resin portion 22 is molded using a thermoplastic resin such as PBT. In this way, rotating shaft 20 and ferrite bond magnet 21 are integrated via resin portion 22, and rotor 2 is formed.

[0106] Thereafter, bearings 25 and 26 are attached to the rotating shaft 20 and inserted into the opening 51 of the cover member 50 of the stator 3 (step S106). In addition, the bracket 27 is attached to the stepped portion 53 of the cover member 50, and the waterproof cap 28 is attached to the rotating shaft 20. In this way, the motor 1 is completed.

[0107] Although an example in which copper wire is used for the lead wire 10 and aluminum wire is used for the windings 40 has been described here, other combinations are also possible. For example, copper wire may be used for the lead wire 10 and clad wire for the windings 40. Alternatively, clad wire may be used for the lead wire 10 and aluminum wire for the windings 40. A clad wire is a core material made of aluminum or an aluminum alloy that is covered with copper and then with an insulating coating.

[0108] Although the case where three-phase windings 40U, 40V, and 40W are used has been described here, the number of phases of winding 40 may be two or more.

[0109] <Effects of the embodiment> As described above, the stator 3 of the first embodiment includes the stator core 30, the windings 40 wound around the stator core 30, the cover member 50 that covers the stator core 30 and the windings 40, and the lead wires 10 that are electrically connected to the windings 40 and drawn from the inside to the outside of the cover member 50. The electrical resistance of the lead wires 10 is smaller than the electrical resistance of the windings 40. Therefore, the lead wires 10 generate less heat, and the heat generated in the windings 40 can be dissipated from the lead wires 10. This improves the heat dissipation of the stator 3 and suppresses temperature rise.

[0110] Furthermore, since the thermal conductivity of the conductor of the lead wire 10 is higher than the thermal conductivity of the conductor of the winding 40, the heat generated in the winding 40 can be efficiently dissipated from the lead wire 10, thereby improving the heat dissipation performance of the stator 3.

[0111] Furthermore, since the resistivity of the conductor of the lead wire 10 is lower than the resistivity of the conductor of the winding 40, the wire diameter D1 of the lead wire 10 is larger than the wire diameter D2 of the winding 40, and the length of the lead wire 10 is shorter than the length of the winding 40, as described above, the electrical resistance of the lead wire 10 can be made smaller than the electrical resistance of the winding 40, and the heat dissipation properties of the stator 3 can be improved.

[0112] Furthermore, since the conductor of the lead wire 10 is formed of copper and the conductor of the winding 40 is formed of aluminum, the resistivity of the conductor of the lead wire 10 can be made smaller than the resistivity of the conductor of the winding 40, and further the thermal conductivity of the conductor of the lead wire 10 can be made higher than the thermal conductivity of the conductor of the winding 40, thereby improving the heat dissipation properties of the stator 3.

[0113] Furthermore, at least a portion of the lead wire 10 is arranged in an area that overlaps the arrangement area of ​​the winding 40 in the axial direction (i.e., the winding overlap area A shown in Figure 8), so that the winding 40 and the lead wire 10 face each other in the axial direction, and heat transfer from the winding 40 to the lead wire 10 can be promoted.

[0114] Furthermore, since the lead wire 10 is arranged in an area that axially overlaps the arrangement area of ​​the windings 40U, 40V, and 40W, heat transfer from the windings 40U, 40V, and 40W of each phase to the lead wire 10 can be promoted.

[0115] Furthermore, since the lead wire 10 and the winding 40 are spaced apart from each other, wear of the insulating coating due to contact between the lead wire 10 and the winding 40 can be prevented, and deterioration of the insulating performance can be avoided.

[0116] Furthermore, since the shortest distance L1 between the lead wire 10 and the winding 40 is longer than 0.1 mm, even when variations in the wire diameters D1, D2 of the lead wire 10 and the winding 40 are taken into consideration, wear of the insulating coating due to contact between the lead wire 10 and the winding 40 can be prevented, and deterioration of the insulating performance can be avoided.

[0117] Furthermore, because a portion of the cover member 50 is disposed between the lead wires 10 and the windings 40, it is possible to reduce the thermal resistance between the lead wires 10 and the windings 40 and promote heat transfer from the windings 40 to the lead wires 10. In addition, it is possible to stably maintain the distance between the lead wires 10 and the windings 40, preventing contact between the two even when the motor 1 is subjected to vibration.

[0118] Furthermore, the shortest distance L1 in the axial direction between the winding 40 and the lead wire 10 and the shortest distance L2 between the winding 40 and the axial end face 55 of the cover member 50 satisfy L1 < L2 / 2, which promotes heat transfer from the winding 40 to the lead wire 10 and enables heat to be dissipated over a wide area via the lead wire 10 and the cover member 50 or the holding member 60.

[0119] Furthermore, because the lead wires 10 are supported on the first surface 61 of the holding member 60 facing the stator core 30, the distance between the lead wires 10 and the windings 40 is reduced, reducing the thermal resistance between them. This promotes heat transfer from the windings 40 to the lead wires 10.

[0120] Furthermore, since the thermal conductivity of the second resin forming the retaining member 60 is higher than the thermal conductivity of the first resin forming the cover member 50, the retaining member 60 can reduce the thermal resistance inside the stator 3 and promote heat dissipation from the windings 40 to the outside of the stator 3.

[0121] Furthermore, since the holding member 60 is axially opposed to all of the winding portions U1 to U3, V1 to V3, and W1 to W3 of the winding 40, heat transfer from the winding 40 to the holding member 60 is promoted, and local temperature increases within the stator 3 can be suppressed.

[0122] Furthermore, although thermoplastic resin, which is one example of the material for the holding member 60, is generally expensive, because the holding member 60 is formed in a ring shape, it can perform the functions of holding the lead wire 10 and promoting heat dissipation while keeping the amount of material used to a minimum.

[0123] 11 is a longitudinal cross-sectional view showing a stator 3A according to embodiment 2. The stator 3A according to embodiment 2 differs from the stator 3 according to embodiment 1 in that a portion of a holding member 60A that holds the lead wires 10 is exposed to the outside of the cover member 50.

[0124] The holding member 60A of the second embodiment has a protrusion 67 extending from its second surface 62 (i.e., the surface opposite to the stator core 30) toward the axial end surface 55 of the cover member 50. An exposed surface 68, which is the surface of the protrusion 67, is exposed from the axial end surface 55 of the cover member 50.

[0125] The protrusion 67 is formed, for example, in a ring shape centered on the central axis Ax. However, the shape is not limited to this. For example, a plurality of protrusions may be arranged in a ring shape centered on the central axis Ax. Furthermore, the exposed surface 68 of the protrusion 67 is not limited to the end surface 55 of the cover member 50, and may be exposed from the outer peripheral surface of the cover member 50.

[0126] 11, the convex portion 67 is formed on a part of the second surface 62, but the entire second surface 62 may be exposed from the axial end surface 55 of the cover member 50. In this case, the entire second surface 62 becomes the exposed surface 68.

[0127] Except for the above-mentioned points, the stator 3A of the second embodiment is configured similarly to the stator 3 of the first embodiment.

[0128] In stator 3A of embodiment 2, holding member 60A has exposed surface 68 that is exposed to the outside of cover member 50, so a path is formed for heat generated in windings 40 to dissipate directly from holding member 60A to the outside of stator 3A (i.e., without passing through cover member 50). Therefore, heat dissipation can be improved compared to stator 3 of embodiment 1, in which holding member 60 is completely covered by cover member 50.

[0129] Third Embodiment Next, a description will be given of the configuration of a blower 80 according to a third embodiment. Fig. 12 is a diagram showing the configuration of a blower 80 according to the third embodiment.

[0130] 12, blower 80 includes motor 1 described in the first embodiment and impeller 81 driven by motor 1. Impeller 81 is attached to rotating shaft 20 of motor 1.

[0131] When the rotating shaft 20 of the motor 1 rotates, the impeller 81 rotates and generates an airflow. The blower 80 is used, for example, as an outdoor blower in an outdoor unit 120 of an air conditioning apparatus 100 (FIG. 13) described below. The impeller 81 is, for example, a propeller fan.

[0132] Since fan 80 of the third embodiment has motor 1 described in the first embodiment, stable operation over a long period of time is possible due to the improved heat dissipation of motor 1. Therefore, the reliability of fan 80 can be improved.

[0133] The same effect can be obtained when a motor having the stator 3A of the second embodiment is used instead of the motor 1 of the first embodiment.

[0134] Fourth Embodiment Next, a description will be given of the configuration of an air conditioning apparatus 100 according to a fourth embodiment. Fig. 13 is a diagram showing the configuration of an air conditioning apparatus 100 according to the fourth embodiment.

[0135] 13, the air conditioning apparatus 100 has an indoor unit 110 and an outdoor unit 120. The indoor unit 110 and the outdoor unit 120 are connected by a refrigerant pipe 130 to form a refrigerant circuit through which a refrigerant circulates.

[0136] The indoor unit 110 has a blower 111 as an indoor blower, an indoor heat exchanger 113, and a housing 112 that houses these components. The blower 111 has a motor 111a and an impeller 111b driven by the motor 111a. The impeller 111b is attached to the rotating shaft of the motor 111a. Rotation of the motor 111a rotates the impeller 111b, generating an airflow. The impeller 111b is, for example, a crossflow fan.

[0137] The outdoor unit 120 has a blower 80 as an outdoor blower, a compressor 121, an outdoor heat exchanger 123, and a housing 122 that houses these components. The blower 80 has a motor 1 and an impeller 81 as described in the third embodiment ( FIG. 12 ). The compressor 121 has a compression mechanism 121a that compresses the refrigerant, a motor 121b that drives the compression mechanism 121a, and a rotating shaft 121c that connects these components. Note that the motor 1 of the first embodiment may be used as the motor 121b of the compressor 121.

[0138] The outdoor unit 120 further includes a four-way valve (not shown) for switching the flow direction of the refrigerant. The four-way valve of the outdoor unit 120 directs the high-temperature, high-pressure refrigerant gas delivered from the compressor 121 to the outdoor heat exchanger 123 during cooling operation and to the indoor heat exchanger 113 during heating operation.

[0139] For example, during cooling operation of the air conditioning apparatus 100, the heat released when the refrigerant compressed by the compressor 121 of the outdoor unit 120 condenses in the outdoor heat exchanger 123 is released to the outside by the air blown by the blower 80. In addition, the air from which heat has been removed when the refrigerant evaporates in the indoor heat exchanger 113 of the indoor unit 110 is supplied into the room by the blower 111.

[0140] The air conditioning apparatus 100 of embodiment 4 includes the blower 80 described in embodiment 3, and therefore is capable of stable operation over a long period of time. In other words, the reliability of the air conditioning apparatus 100 can be improved.

[0141] The blower 80 is not limited to being a blower for the outdoor unit 120, but may also be used as the blower 111 for the indoor unit 110. The blower 80 is not limited to being provided in the air conditioning apparatus 100, but may also be provided in other electrical equipment.

[0142] The motor 1 of the first and second embodiments is used in the blower 80 of the outdoor unit 120 here, but may also be used in the blower 111 of the indoor unit 110, or in both the blowers 80, 111.

[0143] Although the preferred embodiments have been specifically described above, the present disclosure is not limited to the above-described embodiments, and various improvements and modifications can be made.

[0144] DESCRIPTION OF SYMBOLS 1 Motor, 2 Rotor, 3, 3A Stator, 9 Molding die, 10, 10U, 10V, 10W Lead wire, 11, 11U, 11V, 11W Extension portion, 12, 12U, 12V, 12W Pull-out portion, 15 Lead portion, 20 Rotating shaft, 21 Ferrite bond magnet (permanent magnet), 22 Resin portion (connecting portion), 30 Stator core, 31 Yoke, 32 Teeth, 33 Slot, 35 Insulating portion, 35a, 35b Wall portion, 35c Body portion, 36, 36U, 36V, 36W Terminal portion, 37 Pin, 40, 40U, 40V, 40W Winding, 50 Cover member (molded resin portion), 55 End surface, 60, 60A Holding member, 61 first surface, 62 second surface, 65 pressing portion, 66 mounting hole, 67 convex portion, 68 exposed surface, 80 blower, 81 impeller, 91 fixed mold, 92 movable mold, 95 supply port, 96 withdrawal hole, 100 air conditioning device, 110 indoor unit, 111 blower, 120 outdoor unit.

Claims

1. A stator having a stator core, a winding wound around the stator core, a cover member covering the stator core and the winding, and a lead wire electrically connected to the winding and extending from the inside to the outside of the cover member, wherein the electrical resistance of the lead wire is smaller than the electrical resistance of the winding.

2. The stator according to claim 1, wherein the thermal conductivity of the conductor of the lead wire is higher than the thermal conductivity of the conductor of the winding.

3. The stator according to claim 1 or 2, wherein the resistivity of the conductor of the lead wire is lower than the resistivity of the conductor of the winding, the wire diameter of the lead wire is larger than the wire diameter of the winding, and the length of the lead wire is shorter than the length of the winding.

4. The stator according to any one of claims 1 to 3, wherein the conductor of the lead wire is formed of copper and the conductor of the winding is formed of aluminum.

5. The stator according to any one of claims 1 to 4, wherein at least a part of the lead wire is disposed in a region overlapping in the axial direction of the stator core in the arrangement region of the winding.

6. The stator according to any one of claims 1 to 5, wherein the winding has winding portions of two or more phases, and at least a part of the lead wire is disposed in a region overlapping in the axial direction of the stator core in the arrangement regions of all the winding portions of the two or more phases.

7. The stator according to any one of claims 1 to 6, wherein the lead wire and the winding are separated from each other.

8. The stator according to any one of claims 1 to 7, wherein the shortest distance L1 between the lead wire and the winding is longer than 0.1 [mm].

9. The stator according to any one of claims 1 to 8, wherein a part of the cover member is located between the lead wire and the winding.

10. The stator according to any one of claims 1 to 9, wherein the shortest distance L1 in the axial direction of the stator core between the winding and the lead wire and the shortest distance L2 between the winding and the end face in the axial direction of the cover member satisfy L1 < L2 / 2.

11. The stator according to any one of claims 1 to 10, having a holding member for holding the lead wire, wherein the holding member holds the lead wire on a first surface facing the stator core.

12. The stator according to claim 11, wherein the holding member has a pressing portion that holds the lead wire on the first surface.

13. The stator according to claim 11 or 12, wherein the thermal conductivity of the second resin forming the holding member is higher than the thermal conductivity of the first resin forming the cover member.

14. The stator according to any one of claims 11 to 13, wherein the winding has N winding portions arranged in the circumferential direction of the stator core, and the holding member faces all of the N winding portions in the axial direction of the stator core.

15. The stator according to any one of claims 11 to 14, wherein the holding member is formed in an annular shape centered on the central axis of the stator core.

16. The stator according to any one of claims 11 to 15, wherein the holding member has an exposed surface that is exposed to the outside from the cover member.

17. The stator according to claim 16, wherein the exposed surface of the holding member is exposed to the outside from the end surface of the cover member in the axial direction of the stator core.

18. The stator according to any one of claims 11 to 17, wherein an insulating portion around which the winding is wound is attached to the stator core, and the holding member is fixed to the insulating portion.

19. The stator according to any one of claims 11 to 18, wherein the cover member is a molded resin portion that covers the stator core, the winding, and the holding member.

20. A motor comprising the stator according to any one of claims 1 to 19 and a rotor surrounded by the stator.

21. A blower comprising the motor according to claim 20 and an impeller attached to the rotating shaft of the motor.

22. An air conditioner comprising an outdoor unit and an indoor unit, wherein at least one of the outdoor unit and the indoor unit has the blower according to claim 21.

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