JP6885180B2 - Motors and motor manufacturing methods - Google Patents

Description

The present invention relates to a motor driven by an inverter used in an electric motor of an electric vehicle and a hybrid vehicle, a hoisting machine of an elevator, and the like.

Motors driven by inverters, which are characterized by high efficiency due to energy saving, are widely used. In a motor driven by an inverter, a steep surge voltage may be superimposed on the pulse voltage that is the output from the inverter. Here, the surge voltage is a high voltage that momentarily exceeds the steady state. When such a surge voltage is applied to the motor, there is a problem that partial discharge occurs and the insulation performance of the motor deteriorates.

The surge voltage with a steep rise is not evenly shared by the coils constituting the motor, and 80% of the surge voltage is concentrated and applied to the coils on the power feeding unit side. Therefore, in order to improve the withstand voltage of the coil on the power feeding unit side, a method of making the film thickness of the wire coating of the winding of the feeding unit side coil thicker than the film thickness of the wire coating of the winding of the other coil is disclosed. (See, for example, Patent Document 1). Further, the dielectric constant of the insulating coating of the winding of the feeding portion side coil is made lower than the dielectric constant of the insulating coating of the winding of the other coil, and the partial discharge start voltage (PDIV: Partial Discharge Voltage Voltage) on the feeding portion side is set. ) Is disclosed (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 2012-120405 (page 6, FIG. 5, FIG. 6) Japanese Unexamined Patent Publication No. 2012-175822 (page 11, FIG. 9A)

The method of making the film thickness of the wire coating of the winding of the feeding portion side coil thicker than the film thickness of the wire coating of the winding of the other coil has a problem that the space factor of the winding of the feeding portion side coil decreases. .. If the space factor of the winding of the coil on the power feeding unit side decreases, there is an adverse effect that the output of the motor decreases.

Further, in the method of lowering the dielectric constant of the insulating coating of the winding of the feeding portion side coil to be lower than the dielectric constant of the insulating coating of the winding of the other coil, the shared voltage of the feeding portion side coil becomes high and the feeding portion side. There was a problem that the surge voltage superimposed on the coil of the above was further increased.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to reduce the shared voltage of the feeding unit side coil without lowering the space factor of the feeding unit side coil.

The motor according to the present invention is a centralized winding motor including a plurality of coils composed of windings wound around a plurality of teeth, which are connected in series with each other and one terminal is connected to a power feeding unit. The dielectric constant of the molding material that molds the winding of the coil on the feeding part side, including the coil that is connected and most connected to the feeding part side, with the molding material on the feeding part side, and molds the winding of the coil located on the feeding part side. , It is higher than the dielectric constant around the winding of the coil other than the coil on the power feeding part side.
Further, it is a centralized winding motor driven by an inverter, having a rotor and a stator having a plurality of coils configured by winding windings around a tooth protruding toward the inner peripheral side where the rotor is located. Of the coils of, the winding of the coil on the power supply side located on the power supply side including the coil to which the power is supplied from the inverter and the voltage signal is first applied is molded on the corresponding teeth with the mold material on the power supply side. The dielectric constant of the feeding portion side molding material that molds the winding of the feeding portion side coil is higher than the dielectric constant around the coil winding of the coil other than the feeding portion side coil.
Further, it is a centralized winding motor driven by an inverter, which has a rotor and a stator having a plurality of coils configured by winding windings around a tooth protruding toward the inner peripheral side where the rotor is located. Of the coils, the winding of the power supply side coil located on the power supply side that receives power from the inverter is molded with the power supply side mold material on the corresponding tooth, and among the plurality of coils, the power supply side coil and The windings of the neutral point side coils located on different neutral point sides are molded with the neutral point side molding material on the corresponding teeth, and the dielectric constant of the feeding part side molding material is the neutral point side molding material. It is higher than the dielectric constant of.
Further, the method for manufacturing a motor according to the present invention includes a rotor and a stator having a plurality of centralized winding coils configured by winding windings around a tooth protruding toward the inner peripheral side where the rotor is located, and an inverter. It is a method of manufacturing a motor driven by The dielectric constant of the molding material that molds the winding of the side coil is higher than the dielectric constant around the coil winding of the coil located on the side other than the feeding portion side.

In the present invention, the dielectric constant of the molding material for molding the winding of the coil located on the feeding portion side is higher than the dielectric constant around the winding of the coil located on the side other than the feeding portion side. The shared voltage of the coil on the power feeding unit side can be reduced without lowering the space factor of the coil.

It is a schematic diagram of the motor which concerns on Embodiment 1 of this invention. It is an equivalent circuit diagram of the motor which concerns on Embodiment 1 of this invention. It is sectional drawing of the mold coil in Embodiment 1 of this invention. It is an equivalent circuit which showed the capacitance of the motor in Embodiment 1 of this invention. It is an equivalent circuit which showed the capacitance of the coil of one phase in Embodiment 1 of this invention. It is a characteristic diagram of the shared voltage which concerns on Embodiment 1 of this invention. It is sectional drawing of the mold coil in Embodiment 2 of this invention. It is a schematic diagram of the motor which concerns on Embodiment 3 of this invention. It is a schematic diagram of the motor which concerns on Embodiment 4 of this invention. It is an equivalent circuit diagram of the motor which concerns on Embodiment 4 of this invention.

Embodiment 1.
FIG. 1 is a schematic view of a motor according to a first embodiment for carrying out the present invention. In FIG. 1, the motor 1 is composed of a rotor 2 and a stator 3. The stator 3 is composed of a cylindrical core 4, a tooth 5 protruding inward from the core 4, and a hollow mold coil 6 inserted into the tooth 5. The motor 1 in the present embodiment is a Y-connected centralized winding motor in which three-phase four-coils are connected in series. The coils are U1, V1 and W1, and U2, V2 and W2, U3, V3 and W3, and U4, V4 and W4 toward the coil on the neutral point side. Hereinafter, the coil on the feeding portion side will be referred to as a first coil 7, a second coil 8, a third coil 9 and a fourth coil 10 toward the neutral point side. All of these coils are composed of a mold coil 6.

FIG. 2 is an equivalent circuit diagram of the motor 1 of the present embodiment. In FIG. 2, the output from the inverter 11 is connected to the first coils U1, V1 and W1 of each phase. In each phase, four coils are connected in series, and in each phase, the first coil is followed by the second coil, the third coil, and the fourth coil in series toward the neutral point 12. There is.

FIG. 3 is a cross-sectional view of the mold coil 6 according to the present embodiment. In the present embodiment, the basic structure of each coil from the first coil to the fourth coil is the same. In FIG. 3, the cylindrical mold coil 6 has the teeth 5 inserted in the hollow portion thereof. The mold coil 6 is composed of a winding 13 and a molding material 14. The dielectric constant of the mold material of the first coil arranged on the power feeding portion side is ε _1, and the dielectric constant of the mold material of the other coils, that is, the second coil, the third coil, and the fourth coil is ε ₂ . In the motor of the present embodiment, the molding material is selected so that _{ε 1} is _{larger than ε 2.}

Usually, resin is used as the molding material. Examples of the resin that can be used as the molding material include epoxy resin, fluororesin, polyquinolin resin, poly (benzocyclobutene) resin, and amorphous polyolefin resin. Examples of molding materials having a high dielectric constant include aluminum nitride, aluminum oxide, barium titanate (BaTIO ₃ ), titanium oxide (TiO ₂ ), silicon carbide (SiC), and titanium-barium-neodium-based composite oxidation of these resins. High dielectric constant powders such as lead-calcium composite oxides, titanium dioxide ceramics, lead titanate ceramics, magnesium titanate ceramics, strontium titanate ceramics, bismuth titanate ceramics, lead zirconate ceramics, etc. Can be used. As the molding material having a low dielectric constant, a material composed of only these resins or a material containing a filler having a low dielectric constant can be used.

Next, a method of manufacturing the stator 3 will be described. A winding 13 is wound with a diameter larger than the outer diameter of the teeth 5, and the wound winding 13 is molded with a molding material 14 to produce a mold coil 6, and the teeth 5 are mounted on the mold coil 6. The stator 3 can be manufactured by inserting the stator 3. Further, as another manufacturing method, the winding 13 is first wound around the teeth 5, and the winding 13 is molded with the molding material 14 in a state where the winding 13 is wound around the teeth 5 to manufacture the stator 3. You can also do it. With this method, since no gap is generated between the mold material and the tooth, improvement in withstand voltage performance against surge voltage and further improvement in thermal conductivity between the mold material and the tooth can be expected. The teeth 5 and the core 4 are not integrated but are configured as separate members, and may have a structure in which these are combined at the time of manufacturing the stator 3.

In this way, by making the dielectric constant ε _{1 of the molding material of the feeding portion side coil larger than the dielectric constant ε 2} of the molding material of the other coils, the distributed capacitance of the feeding portion side coil becomes other than that. It is larger than the distributed capacitance of the coil. Generally, when the rise time of the voltage pulse of the inverter output is less than the pulse reciprocating propagation time in the cable connecting the inverter and the motor, the surge voltage reaches twice the voltage pulse of the inverter output between the terminals of the motor. Occurs. Furthermore, when the rise time of the surge voltage generated in the motor is steep and the high frequency component of the surge voltage exceeds the resonance frequency of the motor winding, the capacitance component of the motor becomes remarkable, so the voltage shared by each coil is The voltage is concentrated on the coil on the power supply side without being even. Along with this, when any of the potential difference between the windings in the feeding unit coil, the potential difference between the feeding unit side coil and the core, and the potential difference between the coils of each phase on the feeding unit side exceeds the partial discharge start voltage, Partial discharge occurs.

FIG. 4 is an equivalent circuit showing the capacitance of each coil of the motor according to the present embodiment. The U phase, V phase, and W phase are connected in series from the first coil 7 to the second coil 8, the third coil 9, and the fourth coil 10 on the feeding portion side, respectively. The capacitance equivalent circuit of each coil can be represented by the distributed capacitance 15 and the ground capacitance 16. The fourth coil 10 of each phase is connected to the neutral point 12. The U-phase first coil 7 is connected to the U-phase feeding unit 17, the V-phase first coil 7 is connected to the V-phase feeding unit 18, and the W-phase first coil 7 is connected to the W-phase feeding unit 19.

FIG. 5 is an equivalent circuit showing the capacitance of the coil of one phase of the motor according to the present embodiment. Hereinafter, it will be described assuming that the U phase is selected as one phase. As shown in FIG. 5, the equivalent circuit showing the capacitance of the U phase is represented as the distributed capacitance 15 of the first coil 7 of the U phase and the capacitance 16 to the ground, and the first coil 7 of the U phase. Other than the above, it is expressed as a coupled capacitance 20 in which the capacitances of the U-phase second to fourth coils and the V-phase and W-phase coils are combined.

5, the voltage applied from the U-phase power supply unit 17 to the entire motor and E, distributed capacitance 15 of the first coil 7 of the voltage applied to the first coil 7 of the U-phase V _1, U-phase _Let C _{1 be the value of, C 2 be} the value of the capacitance to ground 16, and Ca be the value of the coupling capacitance 20 other than the first coil 7 of the U phase. A steep surge voltage is applied to the motor by driving the inverter, and V ₁ can express the voltage applied to the U-phase first coil 7 at that time by the following equation.

V ₁ = (C _a + C ₂ ) / (C ₁ + C ₂ + C _a ) × E

As can be seen from this equation, increasing the distributed capacitance C ₁ of the first coil of the U phase when the C _a is constant, by decreasing the ground between the electrostatic capacitance C _2, V1 is reduced. Distribution of the first coil of the U phase In order to increase the _{capacitance C 1 and decrease the capacitance C 2 to ground, the permittivity ε 1} of the molding material of the first coil of the U phase is used to mold other coils. The dielectric constant of the material may be higher than _{ε 2.} That is, by making the dielectric constant of the molding material that molds the winding of the coil located on the power feeding portion side higher than the dielectric constant around the winding of the coil located on the side other than the feeding portion side, it is located on the feeding portion side. The shared voltage of the coil becomes low, and it is possible to prevent partial discharge of the coil located on the feeding portion side due to the surge voltage.

Further, since the dielectric constant of the mold material is only changed, the coil structure of the coil located on the feeding portion side and the coil structure of the coil located on the side other than the feeding portion side can be made the same, so that the feeding portion side. The space factor of the coil is not reduced.

In the motor configured in this way, the shared voltage of the coil on the power feeding unit side can be reduced without reducing the space factor of the coil on the power feeding unit side.

The effect of lowering the shared voltage of the coil on the power feeding unit side in the present embodiment will be described in more detail. As the molding material for the coil located on the feeding part side, a molding material in which 75% by weight of aluminum oxide having a relative permittivity of 9.2 is added as a filler to an epoxy resin having a relative permittivity of 3.5 is used, and the feeding part is used. As the mold material for the coils other than the side, only the epoxy resin is used to form the mold coil. At this time, the dielectric constant ε ₁ of the coil molding material located on the feeding portion side is 7.8, and the dielectric constant ε ₂ of the coil molding material located on the side other than the feeding portion side is 3.5, ε _1. / Ε ₂ becomes 2.2. In this way, the dielectric constant of the molding material that molds the winding of the coil located on the feeding portion side can be made higher than the dielectric constant around the winding of the coil located on the side other than the feeding portion side.

It is assumed that a pulse voltage having a steep rise is applied to a Y-connected concentrated winding motor in series with a three-phase four-coil shown in FIG. 1 equipped with such a mold coil. The peak voltage of the applied pulse voltage is E, and the rise time until the peak voltage is reached is 200 ns. In a motor driven under such conditions, the applied voltage can be regarded as a high frequency, so that the capacitance component of the motor becomes remarkable and can be represented by the capacitance equivalent circuit shown in FIG. _{The voltage V 1} applied to the coil located on the power feeding unit side can be obtained by calculation using the equivalent circuit represented by this capacitance.

FIG. 6 is a characteristic diagram obtained by calculation of the voltage (shared voltage) applied to the coil on the power feeding unit side in the present embodiment. In FIG. 6, the vertical axis is V ₁ / E. The horizontal axis is ε ₁ / ε _{2 , and ε 1} / ε ₂ is changed by appropriately selecting the resin and filler constituting the molding material as described above. ε ₁ / ε ₂ = 1 means that the dielectric constant of the coil molding material located on the feeding portion side and the dielectric constant of the coil molding material located on the side other than the feeding portion side are the same. In this case, it can be seen that 80% of the input voltage to the motor is concentrated on the coil on the power feeding unit side.

As can be seen from FIG. 6, when ε ₁ / ε ₂ is 1.5 or more, the shared voltage of the coil on the feeding portion side is 75% or less. In the range from ε _{1 /} ε ₂ is 1.5 to 5, ε _{1 /} ε ₂ although the divided voltage of the power supply portion side of the coil in accordance with increases decreases, when ε _{1 /} ε ₂ is more than 5, The rate of decrease decreases. Further, when ε ₁ / ε ₂ exceeds 5, if peeling or void defects occur in a coil having a high relative permittivity, electric field concentration may occur and a problem that the partial discharge start voltage may decrease may occur. ..

For this reason, it is preferable that the dielectric constant of the coil molding material located on the feeding portion side is 1.5 times or more and 5 times or less the dielectric constant of the coil molding material located on the side other than the feeding portion side.

Embodiment 2.
FIG. 7 is a cross-sectional view of the mold coil according to the second embodiment for carrying out the present invention. The structure of the motor in the present embodiment is the same as the structure of the motor shown in FIG. 1 of the first embodiment. 7 (a) is a cross-sectional view of the molded coil of the coil located on the feeding portion side, and FIG. 7 (b) is a cross-sectional view of the molded coil of the coil located on the side other than the feeding portion side. The dielectric constant of the molding material of the first coil arranged on the power feeding portion side shown in FIG. 7 (a) is ε _1, and the other coils shown in FIG. 7 (b), that is, the second coil, the third coil, and the fourth coil. Let the dielectric constant of the molding material be ε ₂ . In the motor of the present embodiment, the molding material is selected so that _{ε 1} is _{larger than ε 2.}

Further, the thickness A of the mold material 14 between the winding 13 of the first coil and the core 4 and the teeth 5 arranged on the power feeding portion side shown in FIG. 7A is the feeding portion shown in FIG. 7B. It is set to be larger than the thickness B of the molding material 14 between the winding 13 of the second and fourth coils arranged other than the side and the core 4 and the teeth 5. The number of turns of the winding 13 of the first coil arranged on the feeding portion side is the same as the number of windings of the winding 13 of the second to fourth coils arranged on the side other than the feeding portion side.

In the motor configured in this way, as in the first embodiment, the shared voltage of the coil on the power feeding unit side can be reduced without reducing the space factor of the coil on the power feeding unit side. Further, the thickness A of the molding material between the winding of the first coil arranged on the feeding portion side and the core 4 and the teeth 5 is such that the winding and the core of the second coil arranged on the side other than the feeding portion side. Since the thickness B between the 4 and the teeth 5 is set to be larger than the thickness B of the molding material, the capacitance between the ground and the coil arranged on the feeding portion side is set to be static on the ground of the coil arranged on the side other than the feeding portion side. It can be smaller than the electric capacity.

Embodiment 3.
FIG. 8 is a schematic view of a motor according to a third embodiment for carrying out the present invention. Similar to the first embodiment, the motor 1 in the present embodiment is a centralized winding motor in which a three-phase four coil is connected in series with a Y connection, and the coil receiving power from the inverter is supplied to each of the three phases on the power feeding unit side. The coils on the feeding part side are U1, V1 and W1, and the coils on the neutral point side are U2, V2 and W2, U3, V3 and W3, and U4, V4 and W4.

In the present embodiment, the first coil 7 (U1, V1 and W1) of the power feeding unit side coil is composed of the mold coil 6 molded with the molding material as in the first embodiment, but other than that. The second coil 8 (coils U2, V2 and W2), the third coil 9 (U3, V3 and W3), and the fourth coil 10 (U4, V4 and W4) are composed of only the winding 13. That is, the coil other than the coil located on the feeding portion side is air having a dielectric constant of 1 around the winding.

In the motor configured in this way, the dielectric constant of the molding material that molds the winding of the coil located on the feeding portion side may be higher than the dielectric constant around the winding of the coil located on the side other than the feeding portion side. Therefore, as in the first embodiment, the shared voltage of the coil on the power feeding unit side can be reduced without reducing the space factor of the coil on the power feeding unit side.

Embodiment 4.
FIG. 9 is a schematic view of a motor according to a fourth embodiment for carrying out the present invention. In FIG. 9, the motor 1 is composed of a rotor 2 and a stator 3. The stator 3 is composed of a cylindrical core 4, a tooth 5 protruding inward from the core 4, and a mold coil 6 inserted into the tooth 5. The motor 1 in the present embodiment is a Y-connected centralized winding motor in which three phases and three coils are connected in parallel. When the coil that receives power from the inverter is referred to as a feeding portion coil, the feeding portion side coil of each phase is two parallel. The first group is U11, V11, W11 and the second group is U21, V21, W21, and the first group is U12, V12 and W12, U13, V13 and W13 toward the coil on the neutral point side. The second group is U22, V22 and W22, U23, V23 and W23. Hereinafter, the coil on the feeding portion side will be referred to as a first coil 7, a second coil 8 toward the neutral point side, and a third coil 9. All of these coils are composed of a mold coil 6.

FIG. 10 is an equivalent circuit diagram of the motor according to the present embodiment. In FIG. 10, the output from the inverter 11 is connected to the first coils U11, U12, V11, V12 and W11, W12 of each phase. Each phase consists of two groups, each group having three coils connected in series, with the first coil followed by the second and third coils in series towards neutral point 12 in each phase. It is connected to the.

The configuration of the mold coil 6 shown in FIG. 9 is the same as that of the first embodiment, and is represented by a cross-sectional view of the mold coil 6 shown in FIG. 3 of the first embodiment. The teeth 5 are inserted in the hollow portion. The mold coil 6 is composed of a winding 13 and a molding material 14. The dielectric constant of the molding material of the first coil arranged on the power feeding portion side is ε _1, and the dielectric constant of the other, that is, the molding materials of the second coil and the third coil is ε ₂ . In the motor of the present embodiment, the molding material is selected so that _{ε 1} is _{larger than ε 2.}

In the motor configured in this way, the dielectric constant of the molding material that molds the winding of the coil located on the feeding portion side may be higher than the dielectric constant around the winding of the coil located on the side other than the feeding portion side. Therefore, as in the first embodiment, the shared voltage of the coil on the power feeding unit side can be reduced without reducing the space factor of the coil on the power feeding unit side. As a result, partial discharge of the coil located on the feeding portion side due to the surge voltage can be prevented.

In this embodiment, the example of two parallels has been described, but the number of parallels can be increased. Even when the number of parallels is increased, each coil group is connected in parallel, so that the same phase voltage as in the case of series connection is generated in each coil group. As a result, as in the first embodiment, the shared voltage of the coil on the power feeding unit side can be reduced without reducing the space factor of the coil on the power feeding unit side.

Further, in the present embodiment, an example in which the first coil 7, the second coil 8 and the third coil 9 are all configured by the mold coil 6 has been described, but as described in the third embodiment, the power feeding unit side has been described. Only the first coil 7, which is a coil, may be composed of a molded coil, and the other second coil 8 and the third coil 9 may be a coil composed of only windings 13.

1 motor, 2 rotor, 3 stator, 4 core, 5 teeth, 6 molded coil, 7 1st coil, 8 2nd coil, 9 3rd coil, 10 4th coil, 11 inverter, 12 neutral point, 13 winding , 14 Mold material, 15 Distributed capacitance, 16 Ground-to-ground capacitance, 17 U-phase feeding section, 18 V-phase feeding section, 19 W-phase feeding section, 20 Coupling capacitance

Claims (11)

It is a centralized winding motor equipped with a plurality of coils composed of windings wound around a plurality of teeth.
The plurality of the coils are connected in series with each other, one terminal is connected to the feeding portion, and the winding of the feeding portion side coil including the coil most connected to the feeding portion side is a feeding portion side molding material. The dielectric constant of the feeding portion side molding material that is molded and molds the winding of the coil located on the feeding portion side is higher than the dielectric constant around the coil winding of the coil other than the feeding portion side coil. A motor characterized by that. It is a centralized winding motor driven by an inverter, having a rotor and a stator having a plurality of coils configured by winding windings around a tooth protruding toward the inner peripheral side where the rotor is located.
Of the plurality of the coils, the winding of the feeding portion side coil located on the feeding portion side including the coil to which the feeding is received from the inverter and the voltage signal is first applied is molded with the feeding portion side molding material on the corresponding teeth. The dielectric constant of the feeding portion side molding material that molds the winding of the feeding portion side coil is higher than the dielectric constant around the coil winding of the coil other than the feeding portion side coil. Motor to do. Of the plurality of the coils, the winding of the neutral point side coil located on the neutral point side, which is a coil other than the power feeding portion side coil, is molded on the corresponding teeth with the neutral point side molding material.
The motor according to claim 1 or 2, wherein the dielectric constant of the power feeding portion side mold material is higher than that of the neutral point side mold material. It is a centralized winding motor driven by an inverter, having a rotor and a stator having a plurality of coils configured by winding windings around a tooth protruding toward the inner peripheral side where the rotor is located.
Of the plurality of coils, the winding of the power feeding unit side coil located on the power feeding unit side that receives power from the inverter is molded with the power feeding unit side molding material on the corresponding teeth.
Of the plurality of coils, the winding of the neutral point side coil located on the neutral point side different from the power feeding unit side coil is molded in the corresponding teeth with the neutral point side molding material.
A motor characterized in that the dielectric constant of the power feeding portion side mold material is higher than the dielectric constant of the neutral point side mold material. The motor is a three-phase Y-connected centralized winding motor.
Of the plurality of coils, the windings of the feeding portion side coils of each phase located on the feeding portion side are molded into the feeding portion side molding material.
Claim 3 or 4, wherein the winding of the neutral point side coil of each phase located on the neutral point side different from the power feeding portion side coil is molded into the neutral point side molding material. The motor described in. The motor is a Y-connected centralized winding motor in series with three phases and four coils.
Of the plurality of coils, the windings of the feeding portion side coils of each phase located on the feeding portion side are molded into the feeding portion side molding material.
Claim 3 or 4, wherein the winding of the neutral point side coil of each phase located on the neutral point side different from the power feeding portion side coil is molded into the neutral point side molding material. The motor described in. The motor is a three-phase, three-coil, multiple-parallel, Y- connected motor.
Of the plurality of coils, the windings of the plurality of parallel feeding portion side coils of each phase located on the feeding portion side are molded into the feeding portion side molding material.
3. The winding of the plurality of parallel neutral point side coils of each phase located on the neutral point side different from the power feeding unit side coil is molded into the neutral point side molding material, according to claim 3 or The motor according to claim 4. At least one of the windings of the coil located on the neutral point side is molded with the neutral point side molding material, and the feeding portion side molding material for molding the winding of the coil located on the feeding portion side. Dielectric constant of
The invention according to any one of claims 3 to 7, wherein the dielectric constant is higher than the dielectric constant of the neutral point side molding material that molds the winding of the neutral point side coil located on the neutral point side. motor. The thickness of the mold material on the power supply side located between the winding of the coil located on the power supply side and the teeth is
Any one of claims 3 to 8, which is thicker than the thickness of the neutral point side mold material located between the winding of the neutral point side coil located on the neutral point side and the teeth. The motor described in the section. The dielectric constant of the power feeding portion side molding material that molds the winding of the feeding portion side coil located on the feeding portion side is the dielectric constant around the winding of the neutral point side coil located on the neutral point side. The motor according to any one of claims 3 to 9, wherein the rate is 1.5 times or more and 5 times or less. It is a method for manufacturing a centralized winding motor driven by an inverter, which has a rotor and a stator having a plurality of coils configured by winding windings around a tooth protruding toward the inner peripheral side where the rotor is located. ,
The winding of the coil on the power supply side located on the side of the power supply unit that receives power from the inverter has a process of being molded with a molding material.
A method for manufacturing a motor, wherein the dielectric constant of the molding material for molding the winding of the coil on the feeding portion side is higher than the dielectric constant around the coil winding of the coil located on a side other than the feeding portion side.

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