JP2010063277A - Rotor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotor which prevents breakage of a bridge portion of a rotor core while increasing an output of an electric motor. <P>SOLUTION: In the rotor of the electric motor with a magnet 20 embedded in a magnet embedding hole 11 formed at the rotor core 10, the rotor core 10 is constituted so as to fix the magnet 20 at the inner peripheral side of the magnet embedding hole 11 or a portion in the circumferential direction (for example, a hanging part 12). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rotor of an electric motor, and more particularly to a rotor in which a magnet is embedded in a rotor core.

  In a rotor of an electric motor, a hole for embedding a magnet is formed in a columnar (cylindrical) rotor core, and a magnet is embedded in the hole for embedding a magnet. By reducing the shortest width (bridge width) between the outer peripheral surface of the rotor core and the hole for embedding the magnet, magnetic leakage in the circumferential direction of the rotor core is reduced, and magnetic flux can be transmitted outwardly in the radial direction of the rotor core. It is possible to improve the output of the electric motor. From such a viewpoint, the following techniques are disclosed.

  For example, in Patent Document 1, a laminated iron core formed by laminating plate-like magnetic members, and a plurality of holes formed in the vicinity of the outer periphery of the laminated iron core with a predetermined interval in the circumferential direction and penetrating in the axial direction And a plurality of permanent magnets that are respectively inserted into the respective hole portions, and are formed so as to communicate with the hole portions at positions corresponding to the permanent magnets, respectively, penetrating in the axial direction along the center side of the laminated cores of the respective hole portions. A plurality of injection holes, a communication groove formed on the both end surfaces of the laminated core to communicate between the hole and the injection hole, respectively, and injected through the injection hole and the communication groove. What is provided with the resin member with which a space is left in the axial center side of a permanent magnet is disclosed.

  In Patent Document 2, the magnet insertion hole is formed longer than the width of the permanent magnet in the width direction, and both end portions other than the permanent magnet embedded in the thickness direction are formed smaller than the thickness of the permanent magnet. It is disclosed.

  In Patent Document 3, the rotor has a rotor core formed by laminating disk-shaped magnetic thin plates, and the rotor core is arranged at substantially equal intervals along the circumferential direction, and along the axial direction. Four penetrating slit holes are formed, permanent magnets are inserted into the respective slit holes, and the outer peripheral surface of the rotor core is directed toward the inner peripheral direction of the rotor core by a mold having a curvature smaller than the curvature of the outer peripheral surface of the rotor core. The portion of the slit hole located near the end of the permanent magnet is plastically deformed in the inner circumferential direction over the longitudinal direction, and the permanent magnet is in direct contact with the rotor core, with respect to the rotor core inside the slit hole. A permanent magnet is disclosed.

JP 2002-34187 A JP 2006-74887 A JP 2004-328859 A

  However, in the rotors described in Patent Documents 1, 2, and 3, when the motor is rotated at a high rotation, the centrifugal force of the magnet is applied directly or via the resin to the outer peripheral wall surface of the magnet insertion hole. The thin-walled portion (bridge portion) may be broken.

  The main subject of this invention is providing the rotor which can prevent the fracture | rupture of the bridge part of a rotor core, aiming at the high output of an electric motor.

  In one aspect of the present invention, in a rotor of an electric motor in which a magnet is embedded in a magnet embedded hole formed in a rotor core, the rotor core fixes the magnet at an inner peripheral side or a circumferential direction portion of the magnet embedded hole. It is comprised so that it may do.

  In the rotor of the present invention, the magnet has a first hooking portion protruding from the inner peripheral side portions of both circumferential surfaces, and the rotor core is formed from an inner peripheral side of the magnet embedding hole or a circumferential wall surface. It has a protruding second hook portion, and the second hook portion engages with the first hook portion from the outer peripheral side.

  In the rotor of the present invention, the first hooking portion corresponds to the shape of the second hooking portion, and the hooking surface is a taper or a protrusion facing the outer peripheral side, and the second hooking portion is the first hooking portion. Corresponding to the shape of the part, the engaging surface is a taper or a protrusion facing the inner peripheral side.

  In the rotor of the present invention, the magnet embedding hole has a resin embedding portion for embedding the resin on both sides in the circumferential direction of the magnet, with the magnet embedded in the center when viewed from the axial direction.

  In the rotor of the present invention, in the outer peripheral portion of the magnet embedding hole in the rotor core, the outer peripheral portion of the resin embedding portion is configured to be thinner than the other portions.

  In the rotor of the present invention, there is a gap between the outer peripheral surface of the magnet and the outer peripheral side wall surface of the magnet embedding hole.

  According to the present invention, the centrifugal force applied to the magnet is not applied to the thin portion (bridge portion) of the rotor core by fixing the magnet at the inner peripheral side or the circumferential direction portion of the magnet embedding hole in the rotor core. High rotation and high output are possible. In addition, since the bridge portion can be made thin, it is possible to reduce the magnetic leakage, thereby making it possible to reduce the size of the motor while improving the output of the motor. Furthermore, since the magnetic leakage is reduced, the output of the electric motor can be maintained even if the magnet is made smaller, and the electric motor can be reduced in size.

  In the embodiment of the present invention, in a rotor of an electric motor in which a magnet (20 in FIG. 2) is embedded in a magnet embedding hole (11 in FIG. 2) formed in the rotor core (10 in FIG. 2), the rotor core (in FIG. 2) 10) is configured to fix the magnet (20 in FIG. 2) at an inner circumferential side or a circumferential portion (for example, the hooking portion 12 in FIG. 2) of the magnet embedding hole (11 in FIG. 2). The

  A rotor according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view schematically showing a configuration of a rotor core according to the first embodiment of the present invention. FIG. 2 is a partially enlarged perspective view schematically showing a configuration in the vicinity of a magnet embedded portion of the rotor according to the first embodiment of the present invention.

  The rotor core 10 is, for example, a core (iron core) of a rotor (rotor) used in an electric motor (magnet embedded synchronous motor) mounted on an electric vehicle (not shown). The rotor core 10 rotates in a rotating magnetic field formed inside the stator core (40 in FIG. 3) at a rotational speed determined by the current frequency and the number of poles of the rotating magnetic field. The rotor core 10 is formed in an annular shape with a predetermined thickness, and has an insertion hole 14 for inserting and fixing a power transmission member (not shown, for example, a shaft) on the inner peripheral side. The rotor core 10 has a magnet embedded hole 11 and a hooking portion 12.

  The magnet embedding hole 11 is a hole for embedding the magnet 20 serving as a magnetic pole, and penetrates in the axial direction. The magnet embedding hole 11 is disposed in the vicinity of the outer peripheral surface of the rotor core 10. Each magnet embedding hole 11 is arranged at a predetermined interval in the circumferential direction. In the magnet embedding hole 11, the magnet 20 is embedded in the center when viewed from the axial direction, and a gap 11 b is provided between the outer peripheral surface of the magnet 20 and the outer peripheral side wall surface of the magnet embedding hole 11. The magnet embedding hole 11 has a resin embedding portion 11 a for embedding the resin 30 on both sides in the circumferential direction of the magnet 20. The resin embedding portion 11a in the magnet embedding hole 11 is formed so that the thickness of the bridge portion 13 is reduced. In the magnet embedding hole 11, the hook portion 12 protrudes from the inner peripheral side wall surfaces on both outer sides in the circumferential direction of the magnet 20.

  The hook portion 12 is a portion for hooking and fixing the magnet 20 in the magnet embedding hole 11. The hook 12 protrudes outward from the inner peripheral side wall surface of the magnet embedding hole 11 on both outer sides in the circumferential direction of the magnet 20. The hooking portion 12 engages with the hooking portion 21 of the magnet 20 from the outer peripheral side, and has a role of preventing the magnet 20 from going to the outer peripheral side by centrifugal force, and positioning in the radial direction and the circumferential direction in the magnet embedding hole 11. Have a role to play. The shape of the hooking portion 12 corresponds to the shape of the hooking portion 21 and can be a taper or a protrusion with the hooking surface facing the inner peripheral side. In addition, the hook part 12 may have a form protruding not only from the inner peripheral side wall surface of the magnet embedding hole 11 to the outer peripheral side but also from the circumferential wall surface to the magnet side.

  The bridge portion 13 is a portion in the vicinity of both ends in the circumferential direction of the magnet embedding hole 11 among the portions on the outer peripheral side of the magnet embedding hole 11 in the rotor core 10. In order to suppress magnetic leakage, the bridge portion 13 is thinner than the center of the outer peripheral side portion of the rotor core 10 relative to the magnet embedding hole 11. Since the bridge portion 13 has a gap 11b between the outer peripheral side wall surface of the magnet embedding hole 11 and the magnet 20, the bridge portion 13 has a thickness that can withstand the centrifugal force of the outer peripheral portion of the rotor core 10 relative to the magnet embedding hole 11. Can be set.

  The magnet 20 is a plate-like permanent magnet and is embedded in the magnet embedding hole 11. The magnet 20 has a hook portion 21 that protrudes from the inner peripheral side portions of both circumferential surfaces. The hook portion 21 is engaged with the hook portion 12 of the rotor core 10 and has a role of preventing the magnet 20 from going to the outer peripheral side by centrifugal force. The shape of the hooking portion 21 corresponds to the shape of the hooking portion 12, and can be a taper or a protrusion with the hooking surface facing the outer peripheral side. The outer peripheral surface of the magnet 20 is separated from the wall surface of the magnet embedding hole 11. Both surfaces of the magnet 20 in the circumferential direction are in contact with the resin 30.

  The resin 30 is a resin embedded in the resin embedded portion 11 a in the magnet embedded hole 11. The resin 30 may be an adhesive. The resin 30 is not embedded in the gap 11b.

  Next, the operation of the rotor according to the first embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a schematic diagram showing transition of magnetic lines of force in the electric motor using the rotor according to the first embodiment of the present invention.

  In the electric motor shown in FIG. 3, cylindrical stator cores 40 are arranged at predetermined intervals on the outer peripheral side of the rotor core 10 shown in FIGS. The stator core 40 has a plurality of teeth 41 on the inner peripheral side, and a coil (not shown) is wound around the teeth 41. When a current flows through this coil, a rotating magnetic field is formed inside. The rotating magnetic field generates a repulsive force and an attractive force between the stator (stator core 40) and the rotor (rotor core 10), and the rotor (rotor core 10) rotates in a certain direction to generate torque. With respect to the lines of magnetic force inside the rotor core 10, the bridge portion (13 in FIG. 2) is thin, so that the number of lines of magnetic force is small and magnetic leakage is small. As a result, the number of magnetic flux lines crossing from the rotor core 10 to the stator core 40 increases, and the output of the electric motor can be increased.

  According to the first embodiment, the magnet 20 is fixed at the inner peripheral side of the magnet embedding hole 11 in the rotor core 10 or the circumferential portion (the hooking portion 12), so that the centrifugal force applied to the magnet 20 is a thin portion of the rotor core 10. Since it is not added to the (bridge portion 13), it is possible to increase the rotation speed and output of the electric motor. In addition, since the bridge portion 13 can be made thin, it is possible to reduce the magnetic leakage, thereby making it possible to reduce the size of the motor while improving the output of the motor. Furthermore, since the magnetic leakage is reduced, the output of the electric motor can be maintained even if the magnet 20 is reduced, and the electric motor can be downsized.

It is the perspective view which showed typically the structure of the rotor core which concerns on Example 1 of this invention. It is the elements on larger scale which showed typically the composition near the magnet embedding part of the rotor concerning Example 1 of the present invention. It is the schematic diagram which showed transition of the magnetic force line in the electric motor using the rotor which concerns on Example 1 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Rotor core 11 Magnet embedding hole 11a Resin embedding part 11b Crevice 12 Hook part 13 Bridge part 14 Insertion hole 20 Magnet 21 Hook part 30 Resin 40 Stator core 41 Teeth 50 Magnetic field line

Claims (6)

In the rotor of an electric motor in which a magnet is embedded in a magnet embedding hole formed in the rotor core,
The rotor core is configured to fix the magnet at an inner circumferential side or a circumferential portion of the magnet embedding hole. The magnet has a first hook portion projecting from the inner peripheral side portion of both circumferential surfaces,
The rotor core has a second hook portion protruding from an inner peripheral side of the magnet embedding hole or a wall surface in the circumferential direction,
The rotor according to claim 1, wherein the second hooking portion is engaged with the first hooking portion from the outer peripheral side. The first hooking part corresponds to the shape of the second hooking part, and the hooking surface is a taper or a protrusion facing the outer peripheral side,
3. The rotor according to claim 2, wherein the second hooking portion corresponds to a shape of the first hooking portion, and a hooking surface is a taper or a protrusion facing the inner peripheral side.   2. The magnet embedding hole is characterized in that the magnet is embedded in the center when viewed from the axial direction, and has a resin embedding portion for embedding resin on both sides in the circumferential direction of the magnet. The rotor as described in any one of thru | or 3.   5. The rotor according to claim 4, wherein a portion on the outer peripheral side of the resin embedding portion in the outer peripheral portion of the magnet embedding hole in the rotor core is configured to be thinner than other portions.   The rotor according to any one of claims 1 to 5, wherein a gap is provided between a surface on an outer peripheral side of the magnet and an outer peripheral side wall surface of the magnet embedding hole.

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