Electric motor, method for manufacturing electric motor, compressor, and device

Abstract

Provided are an electric motor 14, a method for manufacturing the electric motor 14, a compressor 10 using the electric motor 14, and a device using the compressor 10. In the electric motor 14, a slot area can be prevented from being reduced due to an insulation film 60 in such a way that: an insulator 50 is formed on each stator end face in the sheet lamination direction of a divided stator 30A; the insulator 50 formed on one stator end face and the insulator 50 formed on the other stator end face are connected by a connection part 54 made of a resin material forming the insulator 50; a tooth exposed face 32E that is not covered with the resin material is formed on the circumferential side face of a tooth part 32; a yoke exposed face 31E that is not covered with the resin material is formed on the inner peripheral face of a yoke part 31; and the tooth exposed face 32E and the yoke exposed face 31E are covered with the insulation film 60.

Description

Electric motor, manufacturing method of electric motor, compressor, and equipment

[0001] The present invention relates to an electric motor in which a split stator and an insulator are integrally molded by insert molding, a method for manufacturing this electric motor, a compressor using this electric motor, and equipment using this compressor.

[0002] Patent Document 1 describes an electric motor in which an insulator, a split stator, and an insulating film are integrally molded from resin. Patent Document 2 describes an electric motor in which a split stator is stepped, an insulator is fitted into the stepped portion, and a film is attached to the slot portion. Patent Document 3 describes an electric motor in which a split stator and a film are sandwiched between upper and lower insulators.

[0003] JP 2013-158095 A JP 2017-103850 A International Publication No. 2016 / 132470

[0004] However, when the split stator and insulator are integrally molded by insert molding, as in the motor of Patent Document 1, separate interphase paper is required, and it is difficult to ensure an insulation distance between the split stator connecting surface and the winding. The present invention aims to solve these problems by using an insulating film when insert molding the split stator and insulator. Patent Document 1 uses an insulating film, but the process becomes complicated because the insulating film is integrally molded along with the insulator and split stator. Note that Patent Document 2 provides a step in the split stator, but this step is for fitting the insulator. Furthermore, in Patent Document 3, the thickness of the insulators above and below the teeth is increased to increase the insulation distance, which increases the circumferential length of the winding and increases copper loss.

[0005] The present invention aims to provide an electric motor that can prevent a reduction in slot area due to an insulating film when a split stator and an insulator are insert-molded and an insulating film is used, a manufacturing method for this electric motor, a compressor using this electric motor, and equipment using this compressor.

[0006] The electric motor 14 of the present invention according to claim 1 is an electric motor 14 in which split stators 30A, each split into a plurality of pieces for each tooth portion 32, are arranged in an annular shape, a rotor 20 is arranged on the inner periphery of the plurality of split stators 30A arranged in an annular shape, the split stators 30A have arc-shaped yoke portions 31 centered on the rotation axis 4 of the rotor 20, the teeth portions 32 extending from the yoke portions 31 toward the rotor 20, and umbrella portions 33 formed at the tips of the teeth portions 32, slots 34 are formed between adjacent split stators 30A, and an insulating film 60 is provided to electrically insulate windings 41 wound around the teeth portions 32. An insulator 50 is formed on each stator end face in the sheet stacking direction of the split stator 30A, and the insulator 50 formed on one stator end face and the insulator 50 formed on the other stator end face are connected by a connecting portion 54 made of a resin material that forms the insulator 50. A teeth exposed surface 32E that is not covered with the resin material is formed on the circumferential side of the tooth portion 32, and a yoke exposed surface 31E that is not covered with the resin material is formed on the inner surface of the yoke portion 31, and the teeth exposed surface 32E and the yoke exposed surface 31E are covered with the insulating film 60. The present invention of claim 2 is characterized in that, in the electric motor 14 of claim 1, tooth step portions 32S are formed on each tooth end face in the sheet stacking direction of the tooth portion 32 by narrowing the tooth width, yoke step portions 31S continuous with the tooth step portions 32S are formed on the inner peripheral surface of the yoke portion 31, umbrella step portions 33S continuous with the tooth step portions 32S are formed on the outer peripheral surface of the umbrella portion 33, the tooth step portions 32S, the yoke step portions 31S, and the umbrella step portions 33S are covered with the resin material, the space between the tooth step portions 32S formed on one of the tooth end faces and the tooth step portions 32S formed on the other tooth end face is defined as the tooth exposed surface 32E, and the inner peripheral surface of the yoke portion 31 excluding the yoke step portions 31S is defined as the yoke exposed surface 31E.The present invention of a third aspect is the electric motor 14 of the second aspect, wherein the insulating film 60 covers at least a portion of the tooth step portion 32S on the circumferential side surfaces of the tooth portion 32 and covers the yoke step portion 31S on the inner peripheral surface of the yoke portion 31. The present invention of a fourth aspect is the electric motor 14 of the first aspect, wherein the connecting portion 54 includes a yoke portion connecting portion 54a formed on the outer peripheral surface of the yoke portion 31 and an umbrella portion connecting portion 54b formed on the umbrella portion 33. The present invention of a fifth aspect is the electric motor 14 of the fourth aspect, wherein the umbrella portion connecting portion 54b is formed on the outer peripheral surface of the umbrella portion 33. The present invention of a sixth aspect is the electric motor 14 of the fourth aspect, wherein the umbrella portion connecting portion 54b is formed on both side surfaces of the umbrella portion 33. The present invention of claim 7 is characterized in that, in the electric motor 14 of claim 2, the tooth step width 32SW of the tooth step portion 32S is 96% or more of the non-step tooth portion width 32W where the tooth step portion 32S is not formed. The present invention of claim 8 is characterized in that, in the electric motor 14 of claim 2, the yoke step portion 31S and the umbrella step portion 33S are 3 mm or less. The present invention of claim 9 is characterized in that, in the electric motor 14 of claim 1, an engaging portion made of resin is formed on the outer peripheral surface of the umbrella portion 33, and a locking piece that engages with the engaging portion is formed on the insulating film 60. A manufacturing method for the electric motor 14 of claim 10 is characterized in that, in the manufacturing method for the electric motor 14 of claims 1 to 9, each of the multiple stator core sheets constituting the split stator 30A is placed in a mold without being connected, and the resin material is injected into the mold to insert-molde the insulator 50 and the connecting portion 54.A manufacturing method of the electric motor 14 of the present invention according to claim 11 is the manufacturing method of the electric motor 14 according to claims 1 to 9, characterized in that a plurality of stator core sheets constituting the split stator 30A are stacked, a portion that becomes the outer peripheral surface of the yoke portion 31 is integrated with the stacked stator core sheets by laser welding, the integrated stator core sheets are placed in a mold, and the resin material is injected into the mold to insert mold the insulator 50 and the connecting portion 54. A compressor 10 of the present invention according to claim 12 is the compressor 10 using the electric motor 14 of claims 1 to 9, characterized in that a compression mechanism 13 is connected to the rotating shaft 4 and the refrigerant is compressed by the compression mechanism 13. A device of the present invention according to claim 13 is the device using the compressor 10 according to claim 12, characterized in that the compressor 10, a condenser 17, a pressure reducing device 18, and an evaporator 19 are connected in a ring shape by piping.

[0007] According to the present invention, even if an insulating film is provided to cover the exposed tooth surfaces and exposed yoke surfaces, a reduction in slot area can be prevented, and by providing the insulating film, an insulating distance between the split stator connecting surfaces and the windings can be ensured without the need for interphase paper. Furthermore, according to the present invention, by forming the exposed tooth surfaces and exposed yoke surfaces, cracking of the resin material due to heat shock or stress during winding can be prevented. Furthermore, according to the present invention, by forming the exposed tooth surfaces and exposed yoke surfaces, problems associated with insert molding, such as the need to increase the thickness of the insulator due to poor resin flow as the stack thickness increases and the need to use an expensive resin material with good flow properties, can be alleviated, thereby alleviating the problems of narrow slot area and increased costs.

[0008] 4(c) and 5(c) ; FIG. 3(c) is a diagram showing another embodiment corresponding to FIG. 3; FIG. 8(c) is a diagram showing an insulator formed by insert molding on the split stator; FIG. 9(c) is a diagram showing a state where a winding is wound around the split stator; FIG. 9(c) is a diagram showing another embodiment corresponding to FIG. 3; FIG. 9(c) is a diagram showing a state where a winding is wound around the split stator; FIG. 9(c) is a diagram showing another embodiment using a scroll compressor;

[0009] In a motor according to a first embodiment of the present invention, an insulator is formed on each stator end face of the split stator in the sheet stacking direction, and the insulator formed on one stator end face is connected to the insulator formed on the other stator end face by a connecting portion made of the resin material forming the insulator. Exposed teeth surfaces not covered with the resin material are formed on the circumferential side faces of the teeth, and exposed yoke surfaces not covered with the resin material are formed on the inner peripheral surface of the yoke, and the exposed teeth surfaces and exposed yoke surfaces are covered with an insulating film. In this embodiment, the insulator formed on one stator end face and the insulator formed on the other stator end face are connected by a connecting portion made of the resin material forming the insulator, and the split stator and the insulator are integrally molded by insert molding. In this embodiment, the insulator is integrally molded with the split stator by insert molding, but the slot area is expanded by forming exposed teeth surfaces not covered with the resin material on the circumferential side faces of the teeth and forming exposed yoke surfaces not covered with the resin material on the inner peripheral surface of the yoke. Therefore, according to this embodiment, even if an insulating film is provided to cover the tooth exposed surfaces and the yoke exposed surfaces, a reduction in slot area can be prevented, and by providing the insulating film, an insulating distance between the split stator connecting surfaces and the windings can be ensured without the need for interphase paper. Furthermore, according to this embodiment, by forming the tooth exposed surfaces and the yoke exposed surfaces, cracking of the resin material due to heat shock or stress during winding can be prevented. Furthermore, according to this embodiment, by forming the tooth exposed surfaces and the yoke exposed surfaces, problems associated with insert molding, such as the need to increase the thickness of the insulator due to poor resin flow as the stack thickness increases and the need to use an expensive resin material with good flow properties, can be alleviated, thereby alleviating the problems of a narrow slot area and increased costs.

[0010] In a second embodiment of the present invention, in the electric motor of the first embodiment, a tooth step is formed on each end surface of the teeth in the sheet stacking direction by narrowing the tooth width, a yoke step is formed on the inner peripheral surface of the yoke that is continuous with the tooth step, and an umbrella step is formed on the outer peripheral surface of the umbrella that is continuous with the tooth step, the tooth step, yoke step, and umbrella step are covered with a resin material, the area between the tooth step formed on one end surface of the teeth and the tooth step formed on the other end surface is an exposed teeth surface, and the inner peripheral surface of the yoke excluding the yoke step is an exposed yoke surface. According to this embodiment, the tooth step, yoke step, and umbrella step ensure an insulation distance, allowing the circumferential length of the winding to be shortened, reducing copper loss and cost.

[0011] In a third embodiment of the present invention, in the electric motor according to the second embodiment, an insulating film covers at least a portion of the tooth step portion on the circumferential side surface of the teeth and covers the yoke step portion on the inner circumferential surface of the yoke. According to this embodiment, since an insulation distance can be ensured, the circumferential length of the winding can be shortened, copper loss can be reduced, and costs can be reduced. Furthermore, since the circumferential length of the winding can be shortened and copper loss can be reduced, motor efficiency can be improved. On the other hand, if motor efficiency is kept the same, the number of stator core sheets required to improve motor efficiency can be reduced. Therefore, by downsizing the compressor, the amount of flammable refrigerant, such as R290, can be reduced.

[0012] In a fourth embodiment of the present invention, the electric motor of the first embodiment has a yoke portion connecting portion formed on the outer peripheral surface of the yoke portion and an umbrella portion connecting portion formed on the umbrella portion as connecting portions. According to this embodiment, by connecting the insulators arranged on one stator end face to the insulators arranged on the other stator end face by the yoke portion connecting portion and the umbrella portion connecting portion, stress when winding the winding is not applied to the split stator, preventing an increase in iron loss, and the stacked stator core sheets are in close contact with each other, thereby reducing noise.

[0013] In a fifth embodiment of the present invention, in the electric motor according to the fourth embodiment, the head portion connecting portion is formed on the outer circumferential surface of the head portion, which makes it possible to prevent cracking of the resin material due to stress when winding the winding.

[0014] In a sixth embodiment of the present invention, in the electric motor according to the fourth embodiment, umbrella portion connecting portions are formed on both side surfaces of the umbrella portion. According to this embodiment, by connecting the insulators arranged on one stator end face and the insulators arranged on the other stator end face at three or more locations, distortion of the split stator can be prevented and noise can be reduced.

[0015] In a seventh embodiment of the present invention, in the electric motor according to the second embodiment, the width of the tooth step portion at the tooth step portion is set to 96% or more of the width of the non-teeth step portion where no tooth step portion is formed, thereby preventing a decrease in motor efficiency.

[0016] In the eighth embodiment of the present invention, the yoke step portion and the umbrella step portion are each 3 mm or less in the electric motor according to the second embodiment. According to this embodiment, the increase in magnetic flux density can be suppressed by shortening the length of the step portion.

[0017] In a ninth embodiment of the present invention, in the electric motor according to the first embodiment, an engaging portion made of a resin material is formed on the outer circumferential surface of the head portion, and a locking piece that engages with the engaging portion is formed on the insulating film. According to this embodiment, the position of the insulating film can be regulated, and the insulating film can be prevented from shifting.

[0018] A manufacturing method of an electric motor according to a tenth embodiment of the present invention is a manufacturing method of an electric motor according to any one of the first to ninth embodiments, in which the multiple stator core sheets that make up the split stator are placed in a mold without being connected to each other, and a resin material is injected into the mold to insert-molde the insulator and the connecting portion. According to this embodiment, iron loss due to entanglement for connecting the individual stator core sheets does not occur, so it is possible to provide a compressor with high motor efficiency.

[0019] A manufacturing method of an electric motor according to an eleventh embodiment of the present invention is a manufacturing method of an electric motor according to any one of the first to ninth embodiments, in which a plurality of stator core sheets constituting a split stator are stacked, the stacked stator core sheets are integrated by laser welding at the portions that become the outer peripheral surfaces of the yoke portions, the integrated stator core sheets are placed in a mold, and a resin material is injected into the mold to insert-molde the insulator and the connecting portions. According to this embodiment, iron loss due to entanglement for connecting the respective stator core sheets does not occur, so it is possible to provide a compressor with high motor efficiency.

[0020] A compressor according to a twelfth embodiment of the present invention is a compressor using the electric motor according to any one of the first to ninth embodiments, in which a compression mechanism is connected to the rotating shaft and the refrigerant is compressed by the compression mechanism. According to this embodiment, a compressor with high motor efficiency can be provided.

[0021] The device according to the thirteenth embodiment of the present invention is a device using the compressor according to the twelfth embodiment, and has a compressor, a condenser, a pressure reducing device, and an evaporator connected in a ring shape by piping. According to this embodiment, a device with high motor efficiency and excellent compression performance can be realized.

[0022] A compressor according to an embodiment of the present invention will be described below, but the present invention is not limited to the following embodiment.

[0023] FIG. 1 is a schematic diagram of a compressor using an electric motor according to this embodiment, and a refrigeration system using this compressor. The compressor 10 according to this embodiment is a rotary compressor. A sealed container 1 is connected to a suction pipe 2 for drawing in a refrigerant and a discharge pipe 3 for discharging the refrigerant. Inside the sealed container 1, a compression mechanism 13 for compressing the refrigerant drawn through the suction pipe 2 and a motor 14 for driving the compression mechanism 13 are disposed. The bottom of the sealed container 1 forms an oil reservoir 11. The compression mechanism 13 is composed of a cylinder 13a, a piston 13b, a vane (not shown), a main bearing 13c, and an auxiliary bearing 13d. The main bearing 13c is fixed to the sealed container 1. The piston 13b is rotatably fitted to an eccentric portion 4a of a rotary shaft 4 that passes through the cylinder 13a. The vane reciprocates in a vane groove following the piston 13b rolling along the inner wall surface of the cylinder 13a. The main bearing 13c and the auxiliary bearing 13d seal the upper and lower end surfaces of the cylinder 13a and support the rotating shaft 4. The electric motor 14 comprises a stator 30 fixed to the sealed container 1 and a rotor 20 arranged on the inner periphery of the stator 30. The rotor 20 is fixed to the rotating shaft 4, and the stator 30 is fixed to the sealed container 1. The refrigerant is drawn into the compression mechanism 13 from the suction pipe 2 and compressed in the compression mechanism 13. The refrigerant then passes through the electric motor 14 and is discharged from the discharge pipe 3.

[0024] In the refrigeration system according to this embodiment, a compressor 10, a condenser 17, a pressure reducing device 18, and an evaporator 19 are connected in a ring shape by piping. The condenser 17 condenses the refrigerant discharged from the discharge pipe 3, the pressure reducing device 18 reduces the pressure of the refrigerant condensed in the condenser 17, and the evaporator 19 evaporates the refrigerant reduced in pressure by the pressure reducing device 18. The refrigerant evaporated in the evaporator 19 is returned to the compressor 10 via the accumulator 16.

[0025] FIG. 2 is a perspective view of the main components of the electric motor according to this embodiment, with FIG. 2(a) being a perspective view of the rotor and stator, and FIG. 2(b) being a perspective view of the stator alone. The rotor 20 includes a rotor core 21 formed into a cylindrical shape by laminating rotor core sheets, and permanent magnets 22 arranged in slits formed on the outer periphery of the rotor core 21. The rotor 20 has a plurality of permanent magnets 22 arranged around the rotating shaft 4. The rotor core sheets are electromagnetic steel sheets with a thickness of approximately 0.3 mm, and the rotor core 21 is made of a magnetic material. The rotor core 21 has a through hole 23 in its center through which the rotating shaft 4 is disposed, and a plurality of rotor refrigerant passages 24 are formed axially around the through hole 23. The rotor refrigerant passages 24 are formed concentrically between the through hole 23 and the permanent magnets 22. The stator 30 is arranged with an air gap between it and the rotor 20. The stator 30 is formed by laminating stator core sheets in the axial direction of the rotating shaft 4. The stator core sheet is an electromagnetic steel sheet with a thickness of approximately 0.3 mm, and the stator 30 is made of a magnetic material. The stator 30 is made up of a plurality of split stators 30A, each split into teeth 32 (see FIG. 3), arranged in a circular ring shape. The rotor 20 is arranged on the inner periphery of the plurality of split stators 30A arranged in a circular ring shape. A winding 41 is wound around each split stator 30A.

[0026] Figure 3 is a structural diagram showing a split stator according to this embodiment, with Figures 3(a) and 3(c) being perspective structural views seen from different directions, and Figure 3(b) being a plan structural view. As shown in Figure 3, the split stator 30A has an arc-shaped yoke portion 31 centered on the rotation axis 4 of the rotor 20, teeth portions 32 extending from the yoke portion 31 toward the rotor 20, and umbrella portions 33 formed at the tips of the teeth portions 32. Slots 34 are formed between adjacent split stators 30A. Grooves 35 are formed in the outer peripheral surface of the yoke portion 31, extending from one stator end face to the other. The umbrella portions 33 are formed to extend outward on both sides beyond the circumferential width of the teeth portions 32.

[0027] Figure 4 is a structural diagram showing the state in which insulators have been formed by insert molding on the split stator shown in Figure 3, with Figure 4(a) being a plan structural diagram and Figures 4(b) and 4(c) being perspective structural diagrams viewed from different directions. Insulators 50 are formed on each stator end surface in the sheet stacking direction of split stator 30A. Insulator 50 has insulator yoke portions 51 located in yoke portions 31, insulator teeth portions 52 located in teeth portions 32, and insulator umbrella portions 53 located in umbrella portions 33. Insulator teeth portions 52 cover the entire end surfaces of teeth portions 32.

[0028] The insulator 50X formed on one stator end face and the insulator 50Y formed on the other stator end face are connected by a connecting portion 54 made of the resin material forming the insulator 50. In this embodiment, the connecting portion 54 includes a yoke connecting portion 54a formed on the outer peripheral surface of the yoke portion 31 and an umbrella connecting portion 54b formed on the umbrella portion 33. By connecting the insulator 50X arranged on one stator end face and the insulator 50Y arranged on the other stator end face using the yoke connecting portion 54a and the umbrella connecting portion 54b, stress generated when winding the winding 41 is not applied to the split stator 30A, preventing an increase in iron loss. Furthermore, the laminated stator core sheets are tightly attached to each other, reducing noise. In this embodiment, the umbrella connecting portions 54b are formed on both sides of the umbrella portion 33. Therefore, by connecting the insulator 50X arranged on one stator end face and the insulator 50Y arranged on the other stator end face at three or more locations, distortion of the split stator 30A can be prevented and noise can be reduced. Also, as shown in Figure 4(c), by forming the umbrella portion connecting portion 54b on the outer peripheral surface of the umbrella portion 33 as well, cracking of the resin material due to stress when winding the winding 41 can be prevented.

[0029] The circumferential side surfaces of the teeth 32 are formed with exposed teeth surfaces 32E that are not covered with resin material. The inner peripheral surface of the yoke 31 is formed with exposed yoke surfaces 31E that are not covered with resin material. By forming the exposed teeth surfaces 32E and yoke surfaces 31E in this manner, cracking of the resin material due to heat shock or stress during winding of the windings 41 can be prevented. Furthermore, by forming the exposed teeth surfaces 32E and yoke surfaces 31E, problems associated with insert molding, such as the need to increase the thickness of the insulator 50 due to poor resin flow as the stack thickness increases, and the need to use expensive resin materials with good flow properties, can be alleviated. This also alleviates the problems of a narrow slot 34 area and increased costs. An engaging portion 55 made of resin is formed on the outer peripheral surface of the umbrella portion 33. The engaging portion 55 is formed by protruding a portion of the umbrella portion connecting portion 54b formed on the outer peripheral surface of the umbrella portion 33.

[0030] Fig. 5 is a structural diagram showing the state in which an insulating film is disposed on the split stator shown in Fig. 4, and Fig. 6 shows the state in which windings 41 are wound around the split stator shown in Fig. 5. Insulating film 60 electrically insulates windings 41 from split stator 30A. Teeth exposed surface 32E and yoke exposed surface 31E shown in Fig. 4 are covered with insulating film 60. Insulating film 60 includes teeth film surfaces 61 that abut against the circumferential side surfaces of teeth 32, slot film surfaces 62 that abut against the inner peripheral surface of yoke portion 31 and extend into slots 34 to insulate adjacent windings 41, and umbrella film surfaces 63 that abut against the inner peripheral surface of umbrella portion 33. Teeth exposed surface 32E is covered with teeth film surface 61, and yoke exposed surface 31E is covered with slot film surface 62.

[0031] Insulator 50X formed on one stator end face and insulator 50Y formed on the other stator end face are connected by connecting portion 54 made of the resin material forming insulator 50, and split stator 30A and insulator 50 are integrally molded by insert molding. In this embodiment, insulator 50 is integrally molded with split stator 30A by insert molding, but the area of ​​slot 34 is increased by forming tooth exposed surfaces 32E not covered with resin material on the circumferential side of tooth portion 32 and forming yoke exposed surfaces 31E not covered with resin material on the inner peripheral surface of yoke portion 31. Therefore, even if insulating film 60 is provided to cover tooth exposed surfaces 32E and yoke exposed surfaces 31E, a reduction in the area of ​​slot 34 can be prevented, and the provision of insulating film 60 eliminates the need for interphase paper and ensures an insulating distance between the split stator connecting surfaces and winding 41.

[0032] As shown in Figure 5(c), the insulating film 60 is formed with locking pieces 64 that engage with the engaging portions 55. In this embodiment, a recess is formed in the umbrella portion film surface 63, and the locking pieces 64 are formed on both sides of the recess. By abutting the locking pieces 64 against the engaging portions 55 formed on the outer peripheral surface of the umbrella portion 33, the position of the insulating film 60 can be regulated and displacement of the insulating film 60 can be prevented.

[0033] Figure 7 shows another embodiment corresponding to Figures 4(c) and 5(c). The engaging portion 55 shown in Figure 7(a) is formed by recessing a portion of the umbrella portion connecting portion 54b formed on the outer peripheral surface of the umbrella portion 33. On the other hand, the insulating film 60 shown in Figure 7(b) has a locking piece 64 formed thereon that corresponds to the engaging portion 55. By abutting the locking piece 64 against the engaging portion 55 formed on the outer peripheral surface of the umbrella portion 33, the position of the insulating film 60 can be regulated and displacement of the insulating film 60 can be prevented.

[0034] Figure 8 is a structural diagram showing another embodiment corresponding to Figure 3, with Figures 8(a) and 8(c) being perspective structural views seen from different directions, and Figure 8(b) being a plan structural view. Note that a description of the same configuration as Figure 3 will be omitted, and only the differences from Figure 3 will be described below. In the split stator 30A shown in Figure 8, the tooth width is narrowed to form tooth step portions 32S on each end face of the tooth portion 32 in the sheet stacking direction. The inner peripheral surface of the yoke portion 31 forms a yoke step portion 31S that continues from the tooth step portion 32S. The outer peripheral surface of the umbrella portion 33 forms an umbrella step portion 33S that continues from the tooth step portion 32S. The tooth step width 32SW of the tooth step portion 32S is set to be 96% or more of the non-step tooth portion width 32W, which does not form the tooth step portion 32S. By making the tooth step width 32SW at least 96% of the non-teeth step width 32W, a decrease in motor efficiency can be prevented. The yoke step width 31S and the umbrella step width 33S are preferably between 2 mm and 3 mm. Setting them at 2 mm or more ensures an insulation distance, while setting them at 3 mm or less prevents an increase in magnetic flux density.

[0035] Figure 9, which corresponds to Figure 4(b), is a structural diagram showing the state in which insulators are formed by insert molding on the split stator shown in Figure 8. Note that a description of the same configuration as in Figure 4 will be omitted, and only the differences from Figure 4 will be described below. Although not shown, this embodiment also has a yoke connecting portion 54a and an engaging portion 55. The tooth step portions 32S, yoke step portions 31S, and umbrella step portions 33S are covered with resin. That is, the tooth step portions 32S are covered with resin as insulator teeth 52, the yoke step portions 31S are covered with resin as insulator yoke portions 51, and the umbrella step portions 33S are covered with resin as insulator umbrella portions 53. Therefore, in this embodiment, the space between tooth step 32S formed on one tooth end face and tooth step 32S formed on the other tooth end face is tooth exposed surface 32E, and the inner peripheral surface of yoke portion 31 excluding yoke step 31S is yoke exposed surface 31E. According to this embodiment, an insulation distance can be ensured by tooth step 32S, yoke step 31S, and umbrella step 33S, so the circumferential length of winding 41 can be shortened, reducing copper loss and costs.

[0036] FIG. 10( a ) shows the state in which windings are wound around the split stator shown in FIG. 9 , FIG. 10( b ) is a top view of FIG. 10( a ), FIG. 10( c ) is a view taken along the arrows B-B in FIG. 10( a ), and FIG. 10( d ) is a view taken along the arrows C-C in FIG. 10( a ). The insulating film 60 covers at least a portion of the tooth step portion 32S on the circumferential side of the tooth portion 32, and covers the yoke step portion 31S on the inner circumferential surface of the yoke portion 31. In this way, the insulating film 60 covers at least a portion of the tooth step portion 32S and the yoke step portion 31S, ensuring an insulation distance. This allows the circumferential length of the winding 41 to be shortened, reducing copper loss and cost. Furthermore, the shortened circumferential length of the winding 41 and the reduced copper loss improve motor efficiency. On the other hand, if the motor efficiency is kept the same, the number of stator core sheets required to improve motor efficiency can be reduced, and by making the compressor smaller, the amount of flammable refrigerant such as R290 can be reduced.

[0037] When manufacturing the electric motor 14, it is preferable to insert-mold the insulator 50 and the connecting portion 54 by placing the multiple stator core sheets constituting the split stator 30A in a mold without connecting them and injecting a resin material into the mold. This method eliminates iron loss due to entanglement when connecting the individual stator core sheets, thereby providing a compressor 10 with high motor efficiency. Another method for manufacturing the electric motor 14 involves stacking the multiple stator core sheets constituting the split stator 30A, laser-welding the stacked stator core sheets to form the outer peripheral surface of the yoke portion 31, placing the integrated stator core sheets in a mold, and injecting a resin material into the mold, thereby insert-molding the insulator 50 and the connecting portion 54. This method eliminates iron loss due to entanglement when connecting the individual stator core sheets, thereby providing a compressor 10 with high motor efficiency.

[0038] FIG. 11 is a configuration diagram of a compressor using a scroll compressor according to another embodiment, and a refrigeration system using this compressor. The compressor 10 according to this embodiment includes a sealed container 1, a compression mechanism 13 for compressing refrigerant gas, and an electric motor 14 for driving the compression mechanism 13. The sealed container 1 is divided into one internal space and another internal space by the compression mechanism 13. The electric motor 14 is disposed in the other internal space. The other internal space is also divided by the electric motor 14 into a compression mechanism side space and an oil storage side space. An oil storage section 11 is disposed in the oil storage side space. A suction pipe 2 and a discharge pipe 3 are fixed to the sealed container 1 by welding. The suction pipe 2 and the discharge pipe 3 lead to the outside of the sealed container 1 and are connected to components constituting the refrigeration cycle. The suction pipe 2 introduces refrigerant gas from outside the sealed container 1, and the discharge pipe 3 discharges refrigerant gas from one internal space to the outside of the sealed container 1.

[0039] The main bearing member 7a is fixed inside the sealed container 1 by welding, shrink fitting, or the like, and supports the rotating shaft 4. One end of the rotating shaft 4 is supported by the main bearing member 7a, and the other end is supported by a bearing 7b. A fixed scroll 13j is bolted to the main bearing member 7a. The orbiting scroll 13k, which meshes with the fixed scroll 13j, is sandwiched between the main bearing member 7a and the fixed scroll 13j. The fixed scroll 13j and the orbiting scroll 13k form a scroll-type compression mechanism 13. A rotation restraining mechanism 9, such as an Oldham ring, is provided between the orbiting scroll 13k and the main bearing member 7a. The rotation restraining mechanism 9 prevents the orbiting scroll 13k from rotating and guides the orbiting scroll 13k to move in a circular orbit. The orbiting scroll 13k is eccentrically driven by an eccentric portion 4a provided at the upper end of the rotating shaft 4. By this eccentric drive, the compression chamber formed between the fixed scroll 13j and the orbiting scroll 13k moves from the outer periphery toward the center of the compression mechanism 13, reducing the volume and performing compression.

[0040] The electric motor 14 has a rotor 20 that is rotatably disposed about the rotary shaft 4, and a stator 30 that is disposed via an air gap with the rotor 20. The configuration of the electric motor 14 is the same as that shown in Fig. 2, and therefore a description thereof will be omitted.

[0041] Refrigerant is drawn into the compression mechanism 13 through the suction pipe 2 and compressed in the compression mechanism 13. The refrigerant is then discharged from the discharge pipe 3. In the refrigeration system according to this embodiment, a compressor 10, a condenser 17, a pressure reducing device 18, and an evaporator 19 are connected in a ring shape by piping. The condenser 17 condenses the refrigerant discharged from the discharge pipe 3, the pressure reducing device 18 reduces the pressure of the refrigerant condensed in the condenser 17, and the evaporator 19 evaporates the refrigerant reduced in pressure by the pressure reducing device 18. The refrigerant evaporated in the evaporator 19 is returned to the compressor 10 through the suction pipe 2.

[0042] The electric motor 14 according to this embodiment is suitable for a compressor 10 in which a compression mechanism 13 is connected to a rotary shaft 4 and a refrigerant is compressed by the compression mechanism 13. While this embodiment has been described using a vertical compressor 10, the same effects are achieved with a horizontal compressor 10, and the electric motor 14 according to this embodiment is also suitable for, for example, an on-vehicle compressor. While FIG. 1 shows a rotary compressor and FIG. 11 shows a scroll compressor, a reciprocating compressor or other compressors may also be used. Since low noise is particularly important for on-vehicle compressors, the use of the electric motor 14 according to this embodiment, which can achieve high efficiency and low vibration, significantly reduces noise due to low vibration. Furthermore, in a refrigeration system in which the compressor 10 using the electric motor 14 according to this embodiment is connected in a ring shape with a condenser 17, a pressure reducing device 18, and an evaporator 19 by piping, low noise due to low vibration and high efficiency can be achieved without reducing torque.

[0043] As described above, the compressor 10 according to this embodiment has the compression mechanism 13 connected to the rotary shaft 4, and the refrigerant is compressed by the compression mechanism 13, thereby providing a compressor 10 with high motor efficiency. In addition, R32 or R410A can be used as the refrigerant, and natural refrigerants such as R290 and CO ２ A refrigerant may also be used.

[0044] The compressor of the present invention is useful for appliances such as hot water heating systems, indoor air conditioners, vehicle air conditioners, water heaters, refrigerators, showcases, chillers, and freezers.

[0045] REFERENCE SIGNS LIST 1 sealed container 2 suction pipe 3 discharge pipe 4 rotating shaft 4a eccentric portion 7a main bearing member 7b bearing 9 rotation restraint mechanism 10 compressor 11 oil reservoir 13 compression mechanism 13a cylinder 13b piston 13c main bearing 13d auxiliary bearing 13j fixed scroll 13k orbiting scroll 14 electric motor 16 accumulator 17 condenser 18 pressure reducing device 19 evaporator 20 rotor 21 rotor core 22 permanent magnet 23 through hole 24 rotor refrigerant passage 30 stator 30A split stator 31 yoke portion 31E yoke exposed surface 31S yoke portion step portion 32 teeth portion 32E teeth exposed surface 32S teeth portion step portion 32SW Width of tooth step 32W Width of tooth without step 33 Umbrella portion 33S Umbrella step 34 Slot 35 Groove 41 Winding 50, 50X, 50Y Insulator 51 Insulator yoke portion 52 Insulator tooth portion 53 Insulator umbrella portion 54 Connecting portion 54a Yoke connecting portion 54b Umbrella connecting portion 55 Engagement portion 60 Insulating film 61 Tooth film surface 62 Slot film surface 63 Umbrella film surface 64 Locking piece

Claims

1. An electric motor comprising: a plurality of split stators, each split into one tooth portion and arranged in a circular pattern; a rotor disposed on the inner periphery of the plurality of split stators arranged in a circular pattern; the split stators each having an arc-shaped yoke portion centered on the rotation axis of the rotor, the teeth extending from the yoke portion towards the rotor, and umbrella portions formed at the tips of the teeth; slots formed between adjacent split stators; and an insulating film that electrically insulates the windings wound around the teeth; wherein an insulator is formed on each stator end face in the sheet lamination direction of the split stator; the insulator formed on one stator end face and the insulator formed on the other stator end face are connected by a connecting portion made of resin material that forms the insulator; exposed teeth surfaces that are not covered by the resin material are formed on circumferential side faces of the teeth; an exposed yoke surface that is not covered by the resin material is formed on the inner circumferential surface of the yoke portion; and the exposed teeth surfaces and the exposed yoke surfaces are covered with the insulating film.

2. The electric motor according to claim 1, wherein: a teeth step is formed on each tooth end face in the sheet stacking direction by narrowing the tooth width; a yoke step contiguous with the teeth step is formed on the inner peripheral surface of the yoke; an umbrella step contiguous with the teeth step is formed on the outer peripheral surface of the umbrella; the teeth step, yoke step and umbrella step are covered with the resin material; the area between the teeth step formed on one teeth end face and the teeth step formed on the other teeth end face is defined as the teeth exposed surface; and the inner peripheral surface of the yoke excluding the yoke step is defined as the yoke exposed surface.

3. The electric motor according to claim 2, characterized in that the insulating film covers at least a portion of the tooth portion step portion on the circumferential side surface of the tooth portion, and covers the yoke portion step portion on the inner circumferential surface of the yoke portion.

4. The electric motor according to claim 1, characterized in that the connecting portion comprises a yoke portion connecting portion formed on the outer peripheral surface of the yoke portion, and an umbrella portion connecting portion formed on the umbrella portion.

5. The electric motor according to claim 4, wherein the head portion connecting portion is formed on the outer circumferential surface of the head portion.

6. The electric motor according to claim 4, wherein the umbrella portion connecting portions are formed on both side surfaces of the umbrella portion.

7. The electric motor according to claim 2, characterized in that the width of the tooth step portion at the tooth step portion is 96% or more of the width of the non-step portion where the tooth step portion is not formed.

8. The electric motor according to claim 2, characterized in that the yoke portion step and the umbrella portion step are 3 mm or less.

9. The electric motor according to claim 1, wherein an engaging portion made of the resin material is formed on the outer peripheral surface of the umbrella portion, and a locking piece that engages with the engaging portion is formed on the insulating film.

10. A method for manufacturing an electric motor as set forth in any one of claims 1 to 9, characterized in that the plurality of stator core sheets constituting the split stator are placed in a mold without being connected to each other, and the resin material is injected into the mold, thereby insert-molding the insulator and the connecting portion.

11. A method for manufacturing an electric motor as set forth in claims 1 to 9, comprising stacking a plurality of stator core sheets that constitute the split stator, integrating the stacked stator core sheets by laser welding the outer peripheral surface of the yoke portion, placing the integrated stator core sheets in a mold, and injecting the resin material into the mold to insert-mold the insulator and the connecting portion.

12. A compressor using an electric motor as claimed in any one of claims 1 to 9, characterized in that a compression mechanism is connected to the rotary shaft, and the refrigerant is compressed by the compression mechanism.

13. An apparatus using the compressor according to claim 12, characterized in that the compressor, condenser, pressure reducing device, and evaporator are connected in a circular configuration by piping.

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