JP7466495B2 - Electric motor, blower device, and method of manufacturing electric motor - Google Patents

Description

This disclosure relates to an electric motor having a rotor and a stator, a blower using the electric motor, and a method for manufacturing the electric motor.

The coils used in the stator of an electric motor are wound around the teeth of the stator core and placed in the slots, which are the spaces between the teeth. Since it is necessary to prevent current from flowing from the coil to the stator core, an insulating film is placed inside the slot to insulate the coil from the stator core. Part of the coil placed in the slot protrudes from the stator core. The coil ends, which are the parts of the coil that protrude from the stator core in the axial direction of the rotor, do not contribute to the output of the electric motor. Therefore, if the coil ends are large, they become an obstacle to high efficiency and low cost.

In a typical single-phase induction motor, a coil is wound around the teeth by covering the teeth with a preformed coil, so there must be some margin around the circumference of the coil, which results in a large coil end.

Patent document 1 discloses an electric motor in which a stator core is split into two in the axial direction after a coil is placed over the teeth, and an auxiliary core is inserted into the gap between the split stator cores. The electric motor disclosed in Patent document 1 splits the stator core into two after a coil is placed over the teeth, allowing the coil ends to be made smaller.

Japanese Patent Application Laid-Open No. 11-289696

However, in the electric motor disclosed in Patent Document 1, when the stator core is divided, an insulating distance must be maintained between the divided stator core and the coil, so the insulating film placed in the slot needs to have a standing portion that protrudes in the axial direction beyond the end face of the stator core. This causes a problem in that the coil end does not become smaller at the boundary between the teeth where the insulating film is placed and the slot.

The present disclosure has been made in consideration of the above, and aims to obtain an electric motor with small coil ends at the boundary between the teeth and slots of the stator core.

In order to solve the above-mentioned problems and achieve the object, the electric motor according to the present disclosure has a rotor and a stator. The stator has a ring-shaped core back portion and a plurality of teeth portions protruding from the core back portion to the inner circumferential side, and includes a stator core surrounding the rotor from the outer diameter direction of the rotor, a coil arranged in a slot which is a space between the teeth portions, and an insulating member and an insulating film that insulate the stator core and the coil. The stator core includes a first stator core and a second stator core divided in the axial direction of the rotor's rotation shaft, and an auxiliary core inserted in the gap in the axial direction between the first stator core and the second stator core. The insulating member includes a first insulating member that covers the axial end face of the first stator core and a part of a certain length from the axial end face of the part facing the slot. The first insulating member and the insulating film are partially overlapped in the slot, and the difference between the axial length of the stator core and the axial length of the insulating film is longer than the axial length of the auxiliary core.

The present disclosure has the effect of providing an electric motor with small coil ends at the boundary between the teeth and slots of the stator core.

FIG. 1 is an exploded perspective view of an electric motor according to a first embodiment; 1 is a side view of a stator of an electric motor according to a first embodiment of the present invention; FIG. 2 is a perspective view of a first stator core and a second stator core of the electric motor according to the first embodiment; FIG. 1 is a perspective view of an auxiliary core of an electric motor according to a first embodiment; FIG. 1 is a perspective view of an insulating member of an electric motor according to a first embodiment; FIG. 2 is a perspective view of a first stator core and a second stator core to which insulating members are attached of the electric motor according to the first embodiment; FIG. 2 is a cross-sectional view of a portion of a slot of a first stator core and a second stator core of the electric motor according to the first embodiment; FIG. 2 is a diagram showing a state in which coils are arranged in slots of a first stator core and a second stator core of the electric motor according to the first embodiment; FIG. 1 is a diagram showing a state in which the first stator core and the second stator core of the electric motor according to the first embodiment are separated after the coils are assembled; FIG. 2 is a cross-sectional view of a slot portion of a first stator core and a second stator core separated after the coil of the electric motor according to the first embodiment is assembled; FIG. 1 is a diagram showing a state in which an insulating member slot portion of a first insulating member of an electric motor according to a first embodiment is disposed between a first stator core and an insulating film; FIG. 1 is a cross-sectional view of a slot portion of a first insulating member of an electric motor according to a first embodiment, in which an insulating member slot portion of the first stator core and a second stator core are disposed between the first stator core and an insulating film, and which are separated after a coil is assembled; 1 is a cross-sectional view of an electric motor according to a first embodiment of the present invention; FIG. 1 is a side view of a first stator core and a second stator core of an electric motor according to a first modified example of the first embodiment; FIG. 11 is a cross-sectional view of a portion of a slot of a first stator core and a second stator core of an electric motor according to a first modification of the first embodiment; FIG. 1 is a side view of a first stator core and a second stator core separated from each other in a motor according to a first modified example of the first embodiment; FIG. 1 is a cross-sectional view of a portion of a slot of a first stator core and a second stator core separated from each other in a motor according to a first modified example of the first embodiment; FIG. 13 is a cross-sectional view of a portion of a slot of a first stator core and a second stator core of an electric motor according to a second modified example of the first embodiment; FIG. 11 is a cross-sectional view of a portion of a slot of a first stator core and a second stator core separated from each other in a motor according to a second modified example of the first embodiment; 1 is a cross-sectional view perpendicular to a rotation axis of a stator of an electric motor according to a first embodiment of the present invention; FIG. 2 is a plan view of a first stator core and a second stator core of the electric motor according to the first embodiment; FIG. 1 is a plan view of an insulating member of an electric motor according to a first embodiment; 1 is a side view of an insulating member for an electric motor according to a first embodiment of the present invention; 1 is a cross-sectional view of an insulating film for an electric motor according to a first embodiment of the present invention; FIG. 1 is an exploded view of a stator according to a first embodiment before a coil is attached thereto; 1 is a cross-sectional view of a stator according to a first embodiment before a coil is attached thereto; FIG. 1 is a cross-sectional view showing a state in which coils are attached to a first stator core and a second stator core of an electric motor according to a first embodiment; FIG. 1 is a cross-sectional view showing a state in which a first stator core and a second stator core of an electric motor according to a first embodiment are separated from each other; FIG. 1 is a diagram showing a state in which an auxiliary core is inserted into a gap between a first stator core and a second stator core that are separated from each other in an electric motor according to a first embodiment; FIG. 2 is a diagram showing the dimensional relationship between the first stator core, the second stator core, the insulating member, and the insulating film of the electric motor according to the first embodiment; FIG. 1 is a diagram showing the dimensional relationship between a stator core, an auxiliary core, an insulating member, and an insulating film of an electric motor according to a first embodiment. FIG. 1 is a diagram showing a configuration of a ventilation fan equipped with an electric motor according to a first embodiment;

The electric motor, blower device, and method of manufacturing the electric motor according to the embodiment are described in detail below with reference to the drawings.

Embodiment 1.
FIG. 1 is an exploded perspective view of an electric motor according to a first embodiment. The electric motor 20 is an inner rotor type induction motor. The electric motor 20 includes an annular stator 1, a rotor 2 installed inside the stator 1, a bearing fitted to the shaft of the rotor 2, and a frame 3a and a bracket 3b that support the bearing. The stator 1 and the rotor 2 are housed in an outer shell 3 formed by the frame 3a and the bracket 3b. In the following description, the term "axial direction" refers to the axial direction of the rotating shaft of the rotor 2. In addition, in the following description, the term "circumferential direction" refers to the circumferential direction of the rotating shaft of the rotor 2. In addition, in the following description, the term "radial direction" refers to the radial direction of the rotating shaft of the rotor 2.

Figure 2 is a side view of the stator of the electric motor according to the first embodiment. As shown in Figures 1 and 2, the stator 1 has a stator core 4, a coil 5, an insulating member 8, and an insulating film 9. Figure 3 is a perspective view of the first stator core and the second stator core of the electric motor according to the first embodiment. The first stator core 41 and the second stator core 42 are composed of a core back portion 72 extending in the circumferential direction of the rotating shaft and a plurality of teeth portions 71 protruding from the core back portion 72 toward the rotating shaft of the rotor 2. The core back portion 72 and the teeth portions 71 are integrated. The teeth portions 71 protrude from the core back portion 72 toward the inner periphery. At the tip of the teeth portion 71, a tip portion 73 extending in the circumferential direction is formed, and the teeth portion 71 has a wide tip portion. On the other hand, the slot 7 has a dovetail shape with a narrow slot opening.

Figure 4 is a perspective view of an auxiliary core of an electric motor according to embodiment 1. The auxiliary core 12 has a core back 14 and straight teeth 13. Because the teeth 13 are straight, the auxiliary core 12 can be inserted from the outer periphery into the gaps 11 of the stator core 4 in which the coils 5a, 5b have already been placed in the slots 7. The core back 14 is arc-shaped, and by arranging multiple auxiliary cores 12, the core backs 14 are connected in a ring shape. Note that the auxiliary core 12 shown in Figure 4 has a structure with only one tooth 13, but one auxiliary core 12 may have a structure with multiple teeth 13.

As shown in FIG. 2, the stator core 4 is composed of a first stator core 41, an auxiliary core 12, and a second stator core 42 arranged in this order in the axial direction. Each of the first stator core 41 and the second stator core 42 is formed by stacking multiple electromagnetic steel sheets in the axial direction. The stator core 4 is cylindrical, and the axial direction of the stator core 4 coincides with the axial direction of the rotor 2.

The coil 5 is placed in a slot 7, which is the space between the teeth 71, and is wound around the teeth 71. The insulating member 8 and insulating film 9 insulate the coil 5 from the stator core 4.

Figure 5 is a perspective view of an insulating member of an electric motor according to embodiment 1. Figure 6 is a perspective view of a first stator core and a second stator core to which an insulating member of an electric motor according to embodiment 1 is attached. The insulating member 8 has an insulating member end face portion 81 that covers the end face of the first stator core 41 or the second stator core 42, and an insulating member slot portion 82 that extends in the axial direction within the slot 7. The insulating member end face portion 81 covers the end face of the first stator core 41 or the second stator core 42. The insulating member slot portion 82 covers a portion of a certain length from the axial end face of the portion of the first stator core 41 or the second stator core 42 that faces the slot 7. The insulating member 8 is attached to the first stator core 41 and the second stator core 42, respectively. When distinguishing between the part attached to the first stator core 41 and the part attached to the second stator core 42, the part attached to the first stator core 41 is referred to as the first insulating member 8a, and the part attached to the second stator core 42 is referred to as the second insulating member 8b.

Figure 7 is a cross-sectional view of the slots of the first stator core and the second stator core of the electric motor according to the first embodiment. An insulating film 9 is disposed in the slot 7. The insulating film 9 is sandwiched between the insulating member slot portion 82 of the insulating member 8 and the stator core 4 within the slot 7. The insulating film 9 is not fixed to either the insulating member slot portion 82 or the stator core 4.

Figure 8 is a diagram showing the state in which coils are arranged in the slots of the first stator core and the second stator core of the electric motor according to the first embodiment. The coils 5 include four coils 5a with a 6-slot pitch and four coils 5b with a 4-slot pitch. Two of the four-slot pitch coils 5b are inserted in one slot 7. The four-slot pitch coils 5b have half the number of turns of the six-slot pitch coil 5a. The coils 5a and 5b are wound around a winding frame in advance and are assembled to the first stator core 41 and the second stator core 42 using an inserter or by hand. The coils 5a and 5b are made to include a slack required when covering the teeth portion 71 during the assembly work. Since the coils 5b include a slack during the assembly work, a gap 10a is generated between the first insulating member 8a, the second insulating member 8b and the coils 5b. When a gap 10a occurs between the insulating member 8 and the coil 5b, the coil end 10, which is the portion of the coil 5 that protrudes axially beyond the stator core 4, becomes larger.

Figure 9 is a diagram showing the first and second stator cores of the electric motor according to embodiment 1 separated after the coils are assembled. Figure 10 is a cross-sectional view of the slot portion of the first and second stator cores separated after the coils are assembled in the electric motor according to embodiment 1. By separating the first and second stator cores 41 and 42, the gap 10a between the first and second insulating members 8a and 8b and the coils 5b disappears, and a gap 11 is created between the first and second stator cores 41 and 42.

Even when the first stator core 41 and the second stator core 42 are separated, the insulating film 9 overlaps the insulating material slot portion 82, so that the stator core 4 is not exposed in the slot 7, and insulation between the coils 5a, 5b and the stator core 4 is ensured. In order to ensure insulation between the coils 5a, 5b and the stator core 4, the dimension of the overlapping portion between the insulating material slot portion 82 and the insulating film 9 before the first stator core 41 and the second stator core 42 are separated is set to be equal to or larger than the gap 11 formed by separating the first stator core 41 and the second stator core 42. The overlapping margin between the insulating material slot portion 82 of the insulating member 8 installed at both ends of the axial direction of the stator core 4 and the insulating film 9 does not have to be the same. The dimensional relationship between the stator core 4, the insulating member 8, the insulating film 9, and the gap 11 will be described in more detail later.

In order to prevent the insulating member 8 from being pushed up by the coils 5a and 5b and coming off when the coils 5a and 5b are assembled to the first stator core 41 and the second stator core 42, one of the first insulating member 8a and the second insulating member 8b may have an insulating member slot portion 82 disposed between the first stator core 41 or the second stator core 42 and the insulating film 9. FIG. 11 is a diagram showing a state in which the insulating member slot portion of the first insulating member of the electric motor according to the first embodiment is disposed between the first stator core and the insulating film. FIG. 12 is a cross-sectional view of the slot portion of the first stator core and the second stator core separated after the coils are assembled, in which the insulating member slot portion of the first insulating member of the electric motor according to the first embodiment is disposed between the first stator core and the insulating film. By arranging the insulating member slot portion 82 of the first insulating member 8a between the first stator core 41 and the insulating film 9, the coils 5a and 5b slide on the insulating film 9 when they are inserted into the slot 7, so that the coils 5a and 5b do not push up the first insulating member 8a. As in the case of arranging the insulating film 9 between the insulating member slot portion 82 and the stator core 4, the dimension of the overlapping portion between the insulating member slot portion 82 and the insulating film 9 before the first stator core 41 and the second stator core 42 are separated is set to be equal to or larger than the gap 11 formed by separating the first stator core 41 and the second stator core 42.

Figure 13 is a cross-sectional view of the electric motor according to the first embodiment. The auxiliary core 12 inserted into the gap 11 between the first stator core 41 and the second stator core 42 is restrained from the outer periphery by the outer casing 3, so that the auxiliary core 12 can be prevented from falling off without performing crimping or the like.

By separating the first stator core 41 and the second stator core 42 in the axial direction and inserting the auxiliary core 12 into the gap 11, the coil end 10 becomes smaller and the amount of iron in the stator core 4 increases by the amount of the auxiliary core 12. Therefore, the electric motor 20 according to the first embodiment can increase output without increasing the amount of copper, realizing resource conservation and low cost.

Figure 14 is a side view of the first stator core and the second stator core of the electric motor according to the first modified example of the first embodiment. Figure 15 is a cross-sectional view of the slot portion of the first stator core and the second stator core of the electric motor according to the first modified example of the first embodiment. Note that the coils 5a and 5b are not shown. In the electric motor 20 according to the first modified example, the second insulating member 8b is not installed on the second stator core 42, and the insulating film 9 is folded back to form the standing portion 9c.

The standing portion 9c is formed by bending the end of the insulating film 9 toward the teeth portion 71 or the core back portion 72 by approximately 180 degrees, and bringing the end into contact with the end face of the second stator core 42. Since the coils 5a and 5b are wound around the standing portion 9c that is bent and protrudes from the end face of the second stator core 42, the axial length of the standing portion 9c can maintain insulation between the second stator core 42 and the coil 5b, even if the end face of the second stator core 42 is not covered with the second insulating member 8b.

Figure 16 is a side view of the separated first and second stator cores of a motor according to a first modified example of embodiment 1. Figure 17 is a cross-sectional view of the slots of the separated first and second stator cores of a motor according to a first modified example of embodiment 1. As in the case of installing insulating members 8 at both axial ends of the stator core 4, the dimension of the portion where the insulating member slot portion 82 and the insulating film 9 overlap before separating the first stator core 41 and the second stator core 42 is equal to or larger than the gap 11 formed by separating the first stator core 41 and the second stator core 42.

Figure 18 is a cross-sectional view of the slots of the first stator core and the second stator core of the electric motor according to the second modified example of the first embodiment. By disposing the insulating member slot portion 82 of the first insulating member 8a between the first stator core 41 and the insulating film 9, the coils 5a and 5b slide on the insulating film 9 when they are inserted into the slots 7, so that the coils 5a and 5b do not push up the first insulating member 8a.

Figure 19 is a cross-sectional view of the slot portion of the separated first and second stator cores of an electric motor according to a second modified example of embodiment 1. As in the case where an insulating film 9 is disposed between the first stator core 41 and the insulating material slot portion 82, the dimension of the portion where the insulating material slot portion 82 and the insulating film 9 overlap before the first stator core 41 and the second stator core 42 are separated is set to be equal to or larger than the gap 11 formed by separating the first stator core 41 and the second stator core 42.

The procedure for assembling the electric motor 20 according to the first embodiment will be described. In the following explanation, for the sake of simplicity, the stator 1 is assumed to have a two-pole, four-pair structure.

Figure 20 is a cross-sectional view perpendicular to the rotation axis of the stator of the electric motor according to embodiment 1. The coils 5 arranged in the slots 7 and the stator core 4 are electrically insulated by the insulating member 8 and the insulating film 9.

Figure 21 is a plan view of the first stator core and the second stator core of the electric motor according to the first embodiment. In Figure 21, the second stator core 42 is hidden by the first stator core 41 and is not shown in the figure. The first stator core 41 and the second stator core 42 are formed by laminating electromagnetic steel sheets. Each of the first stator core 41 and the second stator core 42 has a plurality of teeth portions 71 arranged radially and forming a circular area on the inner periphery side in which the rotor 2 is arranged, and a core back portion 72 connecting the outer periphery sides of the plurality of teeth portions 71. The slot 7 is a space surrounded by adjacent teeth portions 71 and core back portions 72.

Figure 22 is a plan view of an insulating member of an electric motor according to embodiment 1. Figure 23 is a side view of an insulating member of an electric motor according to embodiment 1. The insulating member 8 has an insulating member end face portion 81 that covers the end face of the stator core 4, and an insulating member slot portion 82 that covers a certain portion of the stator core 4 from the end face of the slot 7. The insulating member 8 is formed by resin molding.

Figure 24 is a cross-sectional view of the insulating film of the electric motor according to embodiment 1. The insulating film 9 is arranged for each slot 7, sandwiched between the outer stator core 4 and the inner insulating material slot portion 82. The insulating film 9 is formed by cutting and folding a sheet material having a thickness of about 0.1 mm to 0.5 mm.

Figure 25 is an exploded view of the stator according to the first embodiment before the coil is assembled. Figure 26 is a cross-sectional view of the stator according to the first embodiment before the coil is assembled. First, in the first step, the first stator core 41 and the second stator core 42 are stacked in the axial direction, and an insulating film 9 is placed inside the slot 7. Next, in the second step, the first insulating member 8a and the second insulating member 8b are fitted into the slot 7 from both sides in the axial direction, and the first insulating member 8a is installed on the first stator core 41, and the second insulating member 8b is installed on the second stator core 42.

Next, in the third step, the coil 5 is wound around the teeth 71, and the coil 5 is placed in the slot 7. FIG. 27 is a cross-sectional view showing the state in which the coils are assembled to the first stator core and the second stator core of the electric motor according to the first embodiment. The coil 5 is wound around one or more teeth 71. At the coil end 10, the coil 5 is passed over the insulating member end surface 81 that covers the teeth 71. The coil 5 is wound around the end surface of the first stator core 41 or the second stator core 42 from within the slot 7 and bent by about 90 degrees, so that as shown in FIG. 27, the coil 5 is raised above the insulating member end surface 81 by the bending radius of the coil 5.

Next, in the fourth step, the first stator core 41 and the second stator core 42 are separated in the axial direction. Subsequently, in the fifth step, the auxiliary core 12 is inserted between the separated first stator core 41 and the second stator core 42. FIG. 28 is a cross-sectional view showing the state in which the first stator core and the second stator core of the electric motor according to the first embodiment are separated. As shown in FIG. 28, the first stator core 41 and the second stator core 42 are opened on both sides in the axial direction until the coil end 10 and the insulating member end surface portion 81 are in close contact with each other, and the auxiliary core 12 is inserted from the outer periphery into the gap 11 formed between the first stator core 41 and the second stator core 42. FIG. 29 is a diagram showing the state in which the auxiliary core is inserted into the gap between the separated first stator core and the second stator core of the electric motor according to the first embodiment. The auxiliary core 12 is inserted into the gap 11 between the separated first stator core 41 and second stator core 42 to form the stator core 4 and complete the stator 1.

Next, the size of the overlap between the insulating member 8 and the insulating film 9 will be described. FIG. 30 is a diagram showing the dimensional relationship between the first stator core, the second stator core, the insulating member, and the insulating film of the electric motor according to the first embodiment. FIG. 31 is a diagram showing the dimensional relationship between the stator core, the auxiliary core, the insulating member, and the insulating film of the electric motor according to the first embodiment. The insulating film 9 is closer to the second insulating member 8b, and there is a gap between the insulating member end surface portion 81 of the first insulating member 8a and the insulating film 9. There is no gap between the insulating member end surface portion 81 of the second insulating member 8b and the insulating film 9.

The length by which the first insulating member 8a and the insulating film 9 overlap in the axial direction when the first stator core 41 and the second stator core 42 are in close contact before the auxiliary core 12 is inserted is defined as X0. The overlap length must be such that the insulating film 9 does not come off the first insulating member 8a even when the first stator core 41 and the second stator core 42 are separated when the auxiliary core 12 is inserted. In other words, the length X0 of the overlapping portion between the insulating member slot portion 82 and the insulating film 9 must be greater than the axial length L3 of the auxiliary core 12, so X0 > L3.

Also, as shown in FIG. 27, the first stator core 41 and the second stator core 42 are in close contact with each other during winding, and the insulating film 9 is installed on the portions of the first stator core 41 and the second stator core 42 that face the slot 7. Therefore, the length H3 of the insulating film 9 needs to be shorter than the sum of the length L1 of the first stator core 41 and the length L2 of the second stator core, so L1 + L2 ≧ H3.

In addition, even when the auxiliary core 12 is inserted into the gap 11 as shown in FIG. 29, the insulating film 9 must be held by the insulating member slot portion 82 of the first insulating member 8a and the insulating member slot portion 82 of the second insulating member 8b, so L1+L2+L3<H1+H2+H3.

In addition, since the insulating film 9 is not restrained in the axial direction, it needs to be long enough so that it will not come out of the insulating member slot portion 82 even if it is close to either end in the axial direction, so L1+L2+L3<H1+H3 and L1+L2+L3<H2+H3.

When the auxiliary core 12 is inserted into the gap 11, the size X1 of the gap between the insulating member end surface 81 of the first insulating member 8a and the insulating film 9 is longer than the axial length L3 of the auxiliary core 12, so X1 > L3.

The insulating film 9 is sandwiched between the core back portion 72 of the first stator core 41 or the second stator core 42 and the insulating material slot portion 82 within the slot 7. Therefore, if the outer diameter of the insulating material slot portion 82 is R1, the inner diameter of the core back portion 72 of the first stator core 41 and the second stator core 42 is R2, and the thickness of the insulating film 9 is T3, then R1 + T3 = R2.

In the electric motor 20 according to the first embodiment, an insulating member 8 is installed on at least one of the first stator core 41 and the second stator core 42, and on at least one of the axial end faces of the stator core 4, the standing portion 9c of the insulating film 9 does not protrude from the end face of the stator core 4. Therefore, compared to an electric motor having a structure in which the standing portion of the insulating film protrudes from both axial end faces of the stator core, the coil end 10 at the boundary between the teeth portion 71 and the slot 7 is smaller.

Figure 32 is a diagram showing the configuration of a ventilation fan equipped with an electric motor according to embodiment 1. The electric motor 20 according to embodiment 1 is used as a power source for rotating the fan 101 of the ventilation fan 100. By using the electric motor 20 as a power source for rotating the fan 101 of the ventilation fan 100, it is possible to increase the air volume and pressure and reduce noise.

Note that, although the ventilation fan 100 equipped with the electric motor 20 has been described here, the electric motor 20 is not limited to the ventilation fan 100, but can be used in general air blowing devices such as blowers and circulators.

The configurations shown in the above embodiments are merely examples of the contents, and may be combined with other known technologies, and parts of the configurations may be omitted or modified without departing from the spirit of the invention.

REFERENCE SIGNS LIST 1 stator, 2 rotor, 3 outer shell, 3a frame, 3b bracket, 4 stator core, 5, 5a, 5b coil, 7 slot, 8 insulating member, 8a first insulating member,
8b second insulating member, 9 insulating film, 9c standing portion, 10 coil end, 10a, 11 gap, 12 auxiliary core, 13 teeth, 14 core back, 20 electric motor, 41 first stator core, 42 second stator core, 71 teeth portion, 72 core back portion, 73 tip portion, 81 insulating member end face portion, 82 insulating member slot portion, 100 ventilation fan, 101 fan.

Claims (6)

A rotor and a stator are included.
the stator includes a stator core having an annular core back portion and a plurality of teeth protruding from the core back portion to an inner peripheral side, the stator core surrounding the rotor from an outer radial direction of the rotor, coils disposed in slots which are spaces between the teeth, and an insulating member and an insulating film which insulate the stator core from the coils;
the stator core includes a first stator core and a second stator core divided in an axial direction of a rotation shaft of the rotor, and an auxiliary core inserted into a gap between the first stator core and the second stator core in the axial direction,
the insulating members include a first insulating member covering the axial end face of the first stator core and a portion of a certain length from the axial end face of a portion facing the slot , and a second insulating member covering the axial end face of the second stator core and a portion of a certain length from the axial end face of a portion facing the slot ,
each of the first insulating member and the second insulating member and the insulating film partially overlap each other within the slot;
a difference between the axial length of the stator core and the axial length of the insulating film is longer than the axial length of the auxiliary core;
an electric motor characterized in that the sum of the axial length of the first insulating member, the axial length of the insulating film, and the axial length of the second insulating member is longer than the axial length of the stator core . The electric motor according to claim 1, characterized in that the insulating film has a standing portion protruding from the axial end face of the second stator core. 3. The electric motor according to claim 1 , wherein the insulating member is in contact with the coil in the axial direction. 4. The electric motor according to claim 1, wherein the first insulating member is disposed in the slot between the insulating film and the stator core. A blower comprising the electric motor according to any one of claims 1 to 4 . A method for manufacturing an electric motor in which a rotor is disposed on an inner periphery side of a stator, comprising the steps of:
a first step of disposing an insulating film in slots, which are spaces between the teeth of a first stator core and a second stator core, each of which is cylindrical and has an annular core back portion and a plurality of teeth protruding from the core back portion to the inner circumferential side and is arranged side by side in the axial direction;
a second step of installing a first insulating member that covers the axial end face of the first stator core and a portion of a certain length from the axial end face of a portion of the first stator core facing the slots, and a second insulating member that covers the axial end face of the second stator core and a portion of a certain length from the axial end face of a portion of the second stator core facing the slots ;
a third step of placing a coil in the slot;
a fourth step of separating the first stator core and the second stator core in the axial direction;
and a fifth step of inserting an auxiliary core between the separated first stator core and the separated second stator core.
a manufacturing method for an electric motor, characterized in that, when the first insulating member and the second insulating member are installed in the second step, the axial length of a portion where each of the first insulating member and the second insulating member and the insulating film overlap within the slot is longer than the axial length of the auxiliary core, and the sum of the axial length of the first insulating member, the axial length of the insulating film, and the axial length of the second insulating member is longer than the axial lengths of the first stator core and the second stator core .

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