JP2005192264A - Motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of an embedded magnet type rotor that the degree of freedom in the shape of a permanent magnet is very low when a permanent magnet of different shape is inserted into a magnet embedding part of a rotor core because one and one correspondence exists between the shape at the magnet embedding part and the shape of the permanent magnet of the rotor core, and the amount of a flux being generated from the rotor decreases significantly due to an increase in the magnet embedding part of the rotor core and an air gap of the permanent magnet except an injection molded resin magnet. <P>SOLUTION: When a permanent magnet is inserted into the magnet embedding part of a stator core larger than the shape of the magnet, it is secured to its air gap part through a magnetical conductive resin. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a structure of an electric motor that realizes high efficiency and high reliability.

  2. Description of the Related Art Conventionally, an embedded magnet type electric motor generally used for an air conditioner, a compressor of a refrigerator, and the like includes a stator 10 and a rotor 20, as shown in FIG. It is concentrically held in a rotatable manner. In the rotor 20, a permanent magnet 22 is embedded in a rotor core 21. End plates (not shown) are attached to both ends of the rotor core, and are fixed by passing rivets (not shown) through caulking holes provided in the rotor core. A shaft is inserted into the shaft hole 24.

  In addition, the stator 10 directly attaches the three-phase windings 13U, 13V, and 13W to the six teeth portions 12 provided on the stator core 11 via an insulator (insulation film, insulator, etc .: not shown). It is given.

  The windings are three phases of U, V, and W phases and are star-connected to each other, and are 120 ° rectangular wave energization driven by energizing two phases of the three phases at the same time. The applied voltage is changed by PWM control.

  The rotor 20 is rotated around the shaft by a rotating force that combines the magnet torque and the reluctance torque by the rotating magnetic field generated by the current flowing through the windings 13U, 13V, and 13W applied to the stator 10.

Since the permanent magnet of the rotor is inserted with a certain gap in the magnet embedding portion 23 installed in the rotor core, the permanent magnet and the rotor core rub against each other. In particular, at the time of magnetizing, starting, stopping, and overload operation, scratches and peeling of the coating film occur due to the vibration, and it is usually mechanically processed by molding with a thermoplastic resin or the shape of the end plate. It is fixed to.
Japanese Patent Laid-Open No. 9-163649

  When a permanent magnet having a different shape is inserted into the magnet embedded portion of the rotor core, in the embedded magnet type rotor, there is a one-to-one correspondence between the shape of the magnet embedded portion of the rotor core and the shape of the permanent magnet. Since the amount of magnetic flux generated from the rotor is greatly reduced by the increase in the gap between the magnet embedded portion of the rotor core and the permanent magnet, except for the resin magnet injection molding, the degree of freedom of the permanent magnet shape is reduced. Very low.

  In order to solve these problems, the electric motor of the present invention includes a magnet embedded portion in which a plurality of rotors are arranged in the circumferential direction, a permanent magnet is inserted into the magnet embedded portion, and the magnet embedded portion and the permanent magnet are guided. It is characterized by being molded and fixed with a magnetic resin.

According to the electric motor of the present invention, when a permanent magnet is inserted into the magnet embedded portion of the stator core larger than the magnet shape, the permanent magnet is fixed to the gap with a conductive resin, thereby fixing the resin with a conventional non-magnetic resin. Compared to the case, the magnetic resistance can be greatly reduced, and the decrease in the amount of magnetic flux generated from the stator can be suppressed.

  In addition, the permanent magnet shape can be changed without renewing the mold even in the magnet embedded part shape uniquely manufactured by the mold according to the present invention, and the amount of magnetic flux generated from the rotor can be economically reduced. Adjustments can be made.

  Hereinafter, the best mode for carrying out the present invention will be described.

(Embodiment of the Invention)
FIG. 1 shows a conventional example. In a general embedded magnet stator, the relationship between the radial width T1 of the magnet embedded portion 23 of the stator core and the thickness T2 of the permanent magnet 22 is T1-T2 <0. 20 mm, and the magnetic resistance of the magnet embedded portion and the permanent magnet is small.

  FIG. 2 shows an embodiment in which a permanent magnet 24 is inserted into the stator core 21. The thickness T3 of the permanent magnet 24 is (1/2) * T2. Since the magnet moves due to the air gap, it must be fixed. Table 1 shows the amount of magnetic flux from the stator when the magnetic conductive resin of the present invention is used for fixing and when the resin without magnetism is used.

表１の通り、永久磁石量を１／２にすることにより、実施例２、３は磁束量が１／２以下に低下する。実施例１の場合には、空隙による磁気抵抗の増加は無視できるが、実施例２の場合、空隙による磁気抵抗が大幅に増加し、パーミアンスの低下により磁束量が低下したものと推測できる。これを実施例３の通り、導磁性の樹脂を使用することにより、その低減量を抑え、１０％の磁束量の増加を得ることができた。

As shown in Table 1, the magnetic flux amount in Examples 2 and 3 is reduced to ½ or less by reducing the permanent magnet amount to ½. In the case of Example 1, the increase in the magnetic resistance due to the air gap can be ignored, but in the case of Example 2, it can be assumed that the magnetic resistance due to the air gap is greatly increased and the amount of magnetic flux is reduced due to the decrease in permeance. By using a magnetically conductive resin as in Example 3, the reduction amount was suppressed and an increase in the magnetic flux amount of 10% could be obtained.

  The electric motor according to the present invention can greatly reduce the magnetic resistance and suppress the decrease in the amount of magnetic flux generated from the stator.

  In addition, the permanent magnet shape can be changed without renewing the die even in the magnet embedded portion shape uniquely manufactured by the die according to the present invention, and the amount of magnetic flux generated from the rotor can be economically reduced. It is possible to make adjustments and is effective for various electric motors.

Diagram showing a general magnet-embedded motor The figure which shows the rotor of the magnet embedded electric motor in embodiment of this invention

Explanation of symbols

10: Stator 20: Rotor 21: Rotor core 22, 24: Permanent magnet 23: Magnet embedded part 25: Shaft hole

Claims (8)

In an electric motor having a stator and a rotor, an embedded magnet type motor in which a plurality of the rotors are arranged in a circumferential direction and an embedded magnet type electric motor in which a permanent magnet is inserted into the embedded magnet part. An electric motor characterized by being molded and fixed with a magnetic conductive resin. 2. The electric motor according to claim 1, wherein the magnetic material of the magnetic conductive resin is soft ferrite. 2. The electric motor according to claim 1, wherein the magnetic material of the magnetic conductive resin is atomized iron powder. 4. The electric motor according to claim 1, wherein the magnetically conductive resin according to claim 2 and 3 is a thermoplastic resin. 5. The electric motor according to claim 1, wherein the thermoplastic resin according to claim 4 is PBT. 5. The electric motor according to claim 1, wherein the thermoplastic resin according to claim 4 is PET. 5. The electric motor according to claim 1, wherein the thermoplastic resin according to claim 4 is PPS. 5. The electric motor according to claim 1, wherein the thermoplastic resin according to claim 4 is LCP.

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