JP2002233091A - Electric motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce noise in an electric motor used for an air conditioner, a washing machine or the like. SOLUTION: Upper and lower insulator thin parts 5, 7 are firmly held by filling gaps 16a, 16b formed by an upper insulator 1 and a lower insulator 2 or by the upper insulator 1, the lower insulator 2 and a stator core 3 with a resin 11, vibration is reduced and noise generated from the electric motor is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to an electric motor used for an air conditioner, a washing machine and the like.

2. Description of the Related Art A conventional technique will be described with reference to FIGS. FIG. 8 is a cross-sectional view of a conventionally used motor in which an insulator is mounted on a stator core. FIG. 9 is a perspective view of the stator core of the conventionally used electric motor of FIG. 8 with an insulator mounted thereon, 41 is an upper insulator, 42 is a lower insulator, 47 is an upper insulator thick portion, and 48 is an upper insulator thin portion. , 49 is a lower insulator thick portion, and 60 is a lower insulator thin portion. In recent years, in a stator of an electric motor used for an air conditioner or the like, a stator core is divided as shown in FIG. 3 in order to improve a space factor of a winding, and then an insulator is mounted as shown in FIG. Then, the winding is applied as shown in FIG. 5, and then the unit stator winding products divided as shown in FIG. 6 are connected and rounded to form a stator winding product, which is then molded with resin to obtain a stator winding product as shown in FIG. Is a stator constituting the electric motor as shown in FIG. In a conventional motor in which the stator is molded with resin, the insulator used to insulate the stator core from the windings has a thick portion 47, as shown in FIG. The upper insulator 41 and the thick portion 49 that are in close contact with the core are divided into two, the lower insulator 42 that is in close contact with the core, and the upper and lower insulator thick portions 47 and 49 (up and down) that do not overlap each other in the slot. Insulator thick portions 47 and 49 have the same thickness), and upper and lower insulator thin portions 48 and 60 overlapping each other inside the slot. Upper and lower insulator thin portions 48,
60 has substantially the same thickness as the upper and lower insulator thick portions 47 and 49 by overlapping. In the conventional motor shown in FIG. 8 in which an insulator is mounted on a stator core, the length of the stator core 3 in the axial direction is L _c , and the thickness of the upper insulator that contacts the core along the axial direction on the inner wall of the slot of the upper insulator 41. The length of the meat portion 47 is L _ua , the length of the upper insulator thin portion 48 in the axial direction of the upper insulator is L _uu , and the lower insulator thick portion 49 that extends axially along the slot inner wall of the lower insulator 42 and contacts the core. Where L _{la is} the length of the lower insulator thin portion 60 in the axial direction of the lower insulator and L _lu is L _c = L _ua + L _uu + L _lu = L _ua + L _uu + L
_la , or the upper insulator thin portion 48 and the lower insulator thin portion 60 had only a gap to absorb the dimensional tolerance. Further, in a brushless motor using a permanent magnet in particular, it is necessary to change the voltage applied to the electric motor in order to change the rotation speed and the torque. As a method of changing the voltage applied to the motor,
Usually, a PWM method is used in which the voltage is turned on / off at a carrier frequency of about several kHz to 20 kHz. When such a PWM inverter is used, especially at a low voltage, the duty ratio becomes low, and the excitation force of the carrier frequency and its sideband is generated, so that the sound of the high frequency may become loud. This is because even when the stator core is molded, the vibration of the windings and the vibration of the stator core are transmitted to the entire stator, resonate, and generate sound.
In particular, when there is a minute gap between the insulators or between the insulator and the stator core or between the insulator and the winding, the sound tends to increase.

In an electric motor in which a stator winding product is molded with a resin using the above-described conventional insulator, the resin is overlapped with the inside of the slots of the two insulators. The overlapped portion vibrates and generates noise due to electromagnetic vibrations generated from the windings during operation of the electric motor during the operation of the motor, and noise reduction is strongly demanded. The present invention has been made in view of such a problem, and has as its object to provide an electric motor with low noise.

[MEANS FOR SOLVING THE PROBLEMS] To solve this problem
The present invention relates to an electric motor comprising a stator and a rotor.
And the stator core and the windings applied to the stator core
And an insulator that insulates the stator core from the windings
Of stator windings made of resin
Wherein the insulator is at least a slot.
Two insets with overlapping parts inside
Splitters and do not overlap each other in the slot
The part forms a thick part and the overlapping part is two
The overlapping parts of the insulators
The thinner part has the same thickness as the thicker part.
In the insulator, the thin part is in close contact with the core.
The insulator is the lower insulator and the thin part is in close contact with the winding
Is used as the upper insulator, and the insulator
The axial length of the data core is L_c, On the insulator slot
The length of the thick wall part that runs along the inner wall of the
L_ua, The length of the thin part in the axial direction of the upper insulator
L_uuAxially along the inner wall of the lower insulator slot
And the length of the thick part in contact with the core is L_la, Lower Insule
The length of the thin part in the axial direction of the motor is L_luAnd L_c
> L_ua+ L_uu+ L_laOr L_c> L_ua+ L _lu+ L_laage
It is a thing.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention
Is a stationary motor in a motor consisting of a stator and a rotor.
And the windings applied to the stator core,
The insulator consists of an insulator that insulates the core from the windings.
It is a stator made by molding a data winding product with resin.
The insulators at least inside the slots.
Two insulators with overlapping parts
Divided, the parts that do not overlap each other in the slot are thick
Part, the overlapped part is two insulation
Thickness due to the overlapping parts
Insulation that has a thin part that has the same thickness as the part
Insulation where the thin part is in close contact with the core
With the lower insulator and the thin part
The insulator is the upper insulator and the stator core
L is the axial length_cOn the inner wall of the upper insulator slot
L is the length of the thick part along the axial direction and in contact with the core._ua,
The length of the thin portion in the axial direction of the upper insulator is L_uu, Lower b
Along the inner wall of the slot of the insulator,
The length of the thick part that contacts_la, The axis of the lower insulator
The length of the thin part in the direction is L_luAnd L_c> L_ua+ L
_uu+ L_laThe motor is characterized in that
L_c> L_ua+ L_uu+ L_laCaused by
Resin during molding in the gap between insulators
To make it easier for the insulator to come in contact with the insulator.
Generated from the wire to hold the wire in place
Electromagnetic vibration is reduced, and the resin
In order to hold the thin part of the insulator firmly, two
Reduces vibration of overlapping parts of insulator
Has the effect of reducing the noise generated by the motor.
I do. The invention described in claim 2 of the present invention is described in claim 1
Motor, L_c> L_{u a}+ L_lu+ L_laBeing
L_c> L_ua+ L
_lu+ L_laBetween insulators caused by
Makes it easier for resin to enter when molding
Resin embedded firmly thin parts of two insulators
To hold the two insulators together
Vibration at the part where the motor is
It has the effect of reducing. According to claim 3 of the present invention
The invention is an electric motor according to claim 1, wherein_c> L_{u a}+
L_uu+ L_laFilling the gap created by the
The motor is characterized in that L_c>
L_ua+ L_uu+ L_laInsulation caused by
Filling the gap between the radiators with resin allows the filled resin
Is firmly holding the wire in contact with the insulator.
To reduce electromagnetic vibrations generated from electric wires,
Resin firmly holds the thin portions of the two insulators.
To hold the two insulators together
The vibration of the motor and the noise generated by the motor
It has the effect of doing. The invention according to claim 4 of the present invention.
Akira is a motor according to claim 2, wherein L_c> L_{u a}+ L
_lu+ L_laThe core and the inner
It is characterized by pouring resin into the boundary surface of the insulator
It is a motor and the boundary between the core and the insulator
When resin is poured into the surface, noise generated by the motor
This reduces noise and improves insulation between the winding and core.
It has the effect of increasing. According to claim 5 of the present invention
The invention is an electric motor according to claim 2, wherein L_c> L_{u a}+
L_lu+ L_laFilling the gap created by the
The motor is characterized in that L_c>
L_ua+ L_lu+ L_laInsulation caused by
Filling the resin when molding the gap between the radiators
The filled resin is a thin insulator of two insulators
Weight of the two insulators to hold the part firmly.
Reduce the vibration of the overlapping parts and generate the electric motor
This has the effect of reducing noise. Claims of the invention
The invention according to claim 6 is the electric motor according to claim 1, wherein
_c− (L_ua+ L_uu+ L_la) Is 2 mm or more.
Motor_c− (L_ua+ L_uu
+ L_la) Is 2 mm or more, so that L_c> L_ua+
L _uu+ L_laInsulator generated by
Make it easier for resin to enter when molding in the gap between
The insulator is secured by securing 2 mm or more.
When molding in the gap between the resin, let the resin enter enough,
The effect that the noise generated from the motor can be reduced sufficiently
Having. The invention described in claim 7 of the present invention is directed to claim 2
The motor of claim_c− (L_ua+ L_lu+ L_la)But
It is an electric motor characterized by being 2 mm or more.
Yes, L_c− (L_ua+ L_lu+ L_la) Should be 2mm or more
L_c> L_ua+ L_lu+ L_laBy doing
When molding into the gap between insulators
Makes it easy for fat to enter, and secures 2 mm or more
When molding in the gap between insulators,
Oil, and reduce the noise generated by the motor.
It has the effect that it can be reduced to. Claim 8 of the present invention
The invention described in claim 1 is the electric motor according to claim 1, wherein
Lower insulator thinner than insulator thinner
The motor is characterized by a thin
Of the thin part of the insulator below the thin part of the insulator
By making it thinner, L_c> L_ua+ L_uu+ L_laIn
The gap created by the
Has the effect of making it easier for resin to enter when
I do. The invention described in claim 9 of the present invention is the invention described in claim 2
Motor below the thin portion of the upper insulator.
Electric motor characterized in that the thin part of the insulator is thicker
Lower than the thin part of the upper insulator
By making the thinner part of the insulator thicker, L
_c> L_ua+ L_lu+ L_laThe gap created by
Make it larger and inject resin when molding into gaps
It has the effect of making it easier. Claim 10 of the present invention
The invention described in the above is an electric motor according to the first or second aspect.
It is characterized by winding the teeth directly on the teeth
The motor is wound directly on the teeth.
This reduces insulation and increases noise caused by rubbing.
It has the effect of reducing the disadvantage of addition. Claim of the invention
The invention according to claim 11 is the invention according to claim 1 or claim 2.
An electric motor, wherein the resin material for molding the stator is
From the start of resin injection into the mold until the end
Is a thermosetting resin that does not start curing.
The motor used to mold the stator
After injecting the resin material into the mold,
Use a thermosetting resin that does not start curing until
And L_c> L_ua+ L_uu+ L_laOr L_c> L_ua+ L
_lu+ L_laResin completely fills the gaps created by
Filled and resin at the interface between insulator and core
Flow, reducing noise and improving insulation performance between the wire and core.
It has the effect of being able to aim up. Claim 1 of the present invention
The invention described in 2 is driven by a PWM inverter
The method according to any one of claims 1 to 11, wherein
The motor is as described, and the gap between the insulators
Make sure resin enters during molding
Then, secure the winding or insulator with resin
Because it will cover and increase the rigidity, PWM Invar
High frequency vibration during motor drive is suppressed, reducing sound
Is done. The PWM inverter referred to here is 12
If you only want to adjust the voltage when energizing 0 ° square wave
Instead, it may be a PWM inverter for sine wave drive.
And P used for variable speed operation of the induction motor
It is also applicable to WM inverters. Claim 1 of the present invention
The invention described in claim 3 is the invention according to any one of claims 1 to 11
A washing machine equipped with the electric motor described in the above, wherein the noise is small.
Provide a washing machine. The invention described in claim 14 of the present invention
An electric motor according to any one of claims 1 to 11 is mounted.
Air conditioner with low noise provided
I do. The invention described in claim 15 of the present invention is based on claim 1.
A pump equipped with the electric motor according to claim 11.
To provide a highly reliable and low noise pump
You.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIG.
This will be described with reference to FIGS. 2, 3, 4, 5, 6, and 7.
You. FIG. 1 is a perspective view of an electric motor according to the present invention.
FIG. 4 is a cross-sectional view taken along a line AB of a state where a lator is mounted. FIG.
Insulator attached to stator core of motor of the present invention
It is a perspective view of what was done. FIG. 3 shows one stator core.
It is a perspective view of a case. FIG. 4 is a view showing a stay of the electric motor according to the present invention.
It is an exploded perspective view of a taco and an insulator. FIG.
Insulator attached to stator core of motor of the present invention
FIG. 2 is a perspective view of a part of a stator winding product on which a winding is applied.
You. FIG. 6 shows a structure in which a part of the stator winding product of FIG.
It is the perspective view of the formed stator winding product. FIG. 7 shows FIG.
The stator winding product is molded with resin to assemble the rotor
FIG. 4 is a cross-sectional view of the electric motor after being set. In the figure, 1 is the upper
Insulator, 2 is lower insulator, 3 is stator core
A, 4 is the thick part of the upper insulator, 5 is the upper insulator
Thin part, 6 is the lower insulator thick part, 7 is the lower insulator
Thin part, 8 is a winding, 9 is a stator, 10 is low
11, 11 is a resin, 12 is a bearing, 13 is a shaft,
14 is a bracket, and 15 is a stator winding product. next
An embodiment of the present motor will be described. First, shown in FIG.
In such an insulator, the upper insulator 1
Then, L_c− (L_ua+ L_uu+ L_la) = 2mm, lower in
In the insulator 2, L_c− (L_ua+_Llu+ L_la) = 2
mm, as shown in FIG.
The insulators 1 and 2 are attached, and the winding 8 is connected as shown in FIG.
7 to obtain a stator winding product 15 as shown in FIG.
As shown in the figure, the resin 11 is an unsaturated polyester resin molding material.
The rotor 10, bearing 12,
The shaft 13 and the bracket 14 were attached to form an electric motor. Ma
The unsaturated polyester molding material used at this time was not saturated.
Styrene monomer to thermoplastic polyester resin
Fat, liquid resin consisting of hardener, aluminum hydroxide,
Filling with calcium carbonate, glass fiber, release agent, coloring agent, etc.
It is a thermosetting resin mixed with a curing agent and used as a curing agent.
By selecting the type and amount of peroxide used, 15
Curing started at 0 ° C. in 50 seconds. Also,
Mold temperature at the time of cold
From the beginning of the injection of resin 11 to the end
20 seconds, the curing time in the mold is 350 seconds
did. The upper insulator 1 is L_c> L_ua+ L_uu+
L_laMay be. The lower insulator 2 is L_c> L_ua
+ L_lu+ L_laMay be. Also, two upper and lower insulation
It is more effective if resin 11 enters between
The result is improved. Also, the stator core 3 and the upper insulation
The effect is further improved if resin enters the boundary surface of
You. In addition, the upper insulator is L_c> L_ua+ L_uu+ L_la
In the case of, lower insulator than upper insulator thin part 5
The upper and lower insulators have two thinner parts 7
Because the gap 16a formed by 1 and 2 becomes large.
No. The lower insulator 2 is L_c> L_ua+ L_lu+ L
_laIn the case of, lower insulator than upper insulator thin part 5
The upper and lower insulators have two thinner parts 7
1 and 2 and a gap 16 formed by the stator core 3
This is good because b becomes large. FIG. 8 shows a conventional example.
In such upper and lower insulators 41 and 42, L_c
− (L_ua+ L_uu+ L_la) = 0, L_c− (L_ua+ L_lu+ L
_la) = 0, and the thickness of the upper insulator thin portion 48
Thickness obtained by adding the thickness of the lower insulator thin portion 60
Are two upper insulators 47 or lower insulators.
The thickness of the thick section 49 is the same as the thickness of the thick section 49 as shown in FIG.
The stator winding product 15 is the same as that used in the above embodiment.
In the same unsaturated polyester resin molding material,
In this case, molding was performed to obtain an electric motor as shown in FIG. Said,
The motor of the embodiment and the conventional example are used for the indoor fan motor of the air conditioner.
As a result of measuring noise at rated operation,
The air conditioner incorporating the motor of the embodiment is the conventional motor
Noise is reduced by 2dB compared to air conditioners incorporating
Was. Further, the stator 9 of the electric motor of the embodiment is disassembled and_c
− (L_ua+ L_lu+ L_la), L_c− (L _ua+ L_uu+ L_la)
Insulation caused by making the length more than 2 mm
It was confirmed that the resin had entered the gap between the pieces.
Further, when the stator of the conventional motor was disassembled,
Overlap with the upper and lower insulator thin portions 48 and 60
No resin had penetrated into the part where it was. This result
From the result, upper insulator 1 and lower insulator 2 or
Are the upper insulator 1, the lower insulator 2 and the
The gaps 16a and 16b formed by the
Winding in which the resin 11 that has entered is in contact with the insulator
Electromagnetic vibration generated from the windings 8 in order to firmly hold 8
And the resin 11 that has entered the upper and lower
To firmly hold insulator thin parts 5 and 7
Two overlapping upper and lower insulator thin sections
Reduce the vibration of 5 and 7 and reduce the noise generated by the motor
Can be reduced. In the example, a divided core was used.
However, the same effect can be obtained even if the core is not divided. Ma
Also, even if the core is split, the insulator is split
Instead of being divided for each core,
Has the same effect. The motor has a large inner
A washing tub with a shear is connected directly or via a mechanism
In such a case, it is particularly effective in reducing noise. In addition, water
When used for such pumps or outside the air conditioner
When used for fan motors, insulation between the windings and core
Since there is an effect that can be improved, water resistance can be improved.

As described above, according to the first aspect of the present invention, the resin that has entered the gap between the insulators firmly holds the wires in contact with the insulators, thereby reducing the electromagnetic vibration generated from the wires. Further, since the resin that has entered firmly holds the thin portions of the two insulators, the advantageous effects of reducing the vibration of the overlapping portion of the two insulators and reducing the noise generated from the electric motor can be obtained. . According to the second aspect of the present invention, when molding the resin into the gap between the insulators, the resin easily enters, and the entered resin firmly holds the thin portions of the two insulators. This has the advantageous effect of reducing the vibration of the part where the motor is running and reducing the noise generated from the electric motor. According to the third aspect of the present invention, by filling the gap between the insulators with the resin, the filled resin firmly holds the wire in contact with the insulator, thereby reducing the electromagnetic vibration generated from the wire. Further, since the filled resin firmly holds the thin portions of the two insulators, the advantageous effects of reducing the vibration of the overlapping portion of the two insulators and reducing the noise generated from the electric motor can be obtained. Can be According to the fourth aspect of the present invention, by pouring the resin into the boundary surface between the core and the insulator, it is possible to reduce the noise generated from the electric motor and to improve the insulation performance between the winding and the core. The effect is obtained. According to the fifth aspect of the present invention, the resin is filled when the gap between the insulators is molded, so that the filled resin firmly holds the thin portions of the two insulators. This has the advantageous effect of reducing the vibration of the overlapping portion of the motor and reducing the noise generated from the electric motor. According to the sixth aspect of the present invention, L
_{c - (L ua + L uu} + L la) by more than 2mm, and is intended to easily enter the resin during the molding in a gap between the insulator, obtained advantageous effect of reducing the noise generated from the electric motor Can be According to the seventh aspect of the present invention, L _c − (L _ua + L _lu + L _la )
Is set to 2 mm or more, so that the resin can easily enter when molding into the gap between the insulators, and an advantageous effect of reducing noise generated from the electric motor can be obtained. According to the invention of claim 8, the gap between the insulators is made larger by making the thinner portion of the lower insulator thinner than the thinner portion of the upper insulator, so that the resin can easily enter the gap. An advantageous effect of reducing noise generated from the electric motor can be obtained. According to the ninth aspect of the present invention, the gap between the insulators is made larger by making the thinner portion of the lower insulator thicker than the thinner portion of the upper insulator, so that the resin can easily enter the gap. An advantageous effect of reducing noise generated from the electric motor can be obtained. According to the tenth aspect of the present invention,
An advantageous effect is obtained in that a reduction in insulation and an increase in noise caused by directly winding the teeth are reduced. According to the eleventh aspect,
The resin is completely filled in the gap between the insulators, and the resin flows into the interface between the insulator and the core, which has an advantageous effect that noise can be reduced and insulation performance between the wire and the core can be improved. can get. According to the twelfth aspect of the present invention, by molding the resin into the gap between the insulators, the winding or the insulator is firmly covered with the resin, and the rigidity is improved. Therefore, high-frequency vibration in the case of PWM inverter driving is suppressed, and sound is reduced. The PWM inverter referred to here is 1
A PWM inverter for sine wave driving may be used as well as a case of adjusting the voltage in the case of 20 ° rectangular wave conduction, and the present invention is also applicable to a PWM inverter used for variable speed operation of an induction motor. Claim 1
According to the invention described in the third aspect, a washing machine with low noise can be provided. According to the invention of claim 14, an air conditioner with low noise can be provided. According to the fifteenth aspect of the present invention, a highly reliable pump with low noise can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state in which an insulator is mounted on a stator core of a motor of the present invention.

FIG. 2 is a perspective view showing a state in which an insulator is mounted on a stator core of the electric motor of the present invention.

FIG. 3 is a perspective view of a stator core.

FIG. 4 is an exploded perspective view of a stator core and an insulator of the electric motor of the present invention.

FIG. 5 is a partial perspective view of a stator winding product in which an insulator is mounted on a stator core of a motor of the present invention and a winding is applied.

FIG. 6 is a perspective view of a stator winding product formed by connecting a part of the stator winding product of FIG. 5;

FIG. 7 is a cross-sectional view of the motor after the stator winding product of FIG. 6 is molded with resin and a rotor is assembled.

FIG. 8 is a cross-sectional view of a conventionally used motor in which an insulator is mounted on a stator core.

FIG. 9 is a perspective view of a conventionally used motor in which an insulator is mounted on a stator core.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper insulator 2 Lower insulator 3 Stator core 4 Upper insulator thick part 5 Upper insulator thin part 6 Lower insulator thick part 7 Lower insulator thin part 8 Winding 9 Stator 10 Rotor 11 Resin 12 Bearing 13 Shaft 14 Bracket 15 Stator winding product 16a, 16b gap

Continued on the front page (72) Inventor Masahiko Morisaki 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. Inventor Hiroyuki Miyoshi 1006 Kadoma, Kazuma, Osaka Pref.F-term (reference) in Matsushita Electric Industrial Co., Ltd. DB12 PB03 PB04 PE06

Claims (15)

[Claims] 1. An electric motor comprising a stator and a rotor, wherein the stator is formed by molding a stator winding product made of resin with a stator core, windings applied to the stator core, and an insulator for insulating the stator core and the windings. The insulator is divided into two insulators each having an overlapping portion at least inside the slot, a portion not overlapping each other within the slot of the insulator forms a thick portion, and the overlapping portion is an overlap of the two insulators. When the mating parts are joined together, the insulator that forms a thin part that has almost the same thickness as the thick part, the insulator whose thin part is in close contact with the core is the lower insulator, and the thin part is in close contact with the winding. The upper insulator is the upper insulator, Let L _{c be} the axial length of the stator core,
The length of the thick portion that extends along the inner wall of the slot of the upper insulator and contacts the core is _Lua , the length of the thinner portion of the upper insulator in the axial direction is _Luu , and the length of the lower insulator in the axial direction extends along the inner wall of the lower insulator slot. and the length L _la of the thick portion in contact with the core, the length of the thin portion in the axial direction of the lower insulator is taken as L _lu, characterized in that it is a _{L c> L ua + L uu} + L la Electric motor. 2. The electric motor according to claim 1, wherein L _c >
Motor, which is a _{L ua + L lu + L la} . 3. The electric motor according to claim 1, wherein when the stator winding product is molded with resin, L _c > L _ua + L _uu.
An electric motor characterized in that a resin is filled into a gap generated between two insulators and a winding due to + L _la . 4. The electric motor according to claim 2, wherein when the stator winding product is molded with resin, L _c > L _ua + L _lu.
An electric motor characterized in that resin is poured into a boundary surface between a core and an insulator from a gap generated by + L _la . 5. The electric motor according to claim 2, wherein when the stator winding product is molded with resin, L _c > L _ua + L _lu.
An electric motor characterized in that a resin is filled into a gap generated between two insulators and a winding due to + L _la . 6. The electric motor according to claim 1, wherein L _c −
_{(L ua + L uu + L} la) motor, characterized in that is 2mm or more. 7. The electric motor according to claim 2, wherein L _c −
_{(L ua + L lu + Lla} ) motor, characterized in that is 2mm or more. 8. The electric motor according to claim 1, wherein a thin portion of the lower insulator is thinner than a thin portion of the upper insulator. 9. The electric motor according to claim 2, wherein a thin portion of the lower insulator is thicker than a thin portion of the upper insulator. 10. The electric motor according to claim 1, wherein the teeth are directly wound. 11. The electric motor according to claim 1, wherein the resin material for molding the stator is a thermosetting resin whose curing does not start until the resin is injected into the molding die until the resin material is completely injected. An electric motor characterized by the following. 12. The electric motor according to claim 1, wherein the electric motor is driven by a PWM inverter. 13. A washing machine equipped with the electric motor according to claim 1. 14. An air conditioner equipped with the electric motor according to claim 1. 15. A pump equipped with the electric motor according to claim 1.