JP6316350B2 - Permanent magnet motor - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a permanent magnet motor, and in particular, a permanent magnet composed of a magnetic material such as an electromagnetic steel sheet and a nonmagnetic and anisotropic structural material such as fiber reinforced plastic (FRP). The present invention relates to a magnet motor.

  A motor using a magnet is used in the electric power steering apparatus. For example, in Japanese Patent Application Laid-Open No. 2011-259574 (Patent Document 1), in a surface permanent magnet (SPM) synchronous motor having a configuration in which permanent magnets are arranged on the surface (circumferential surface) of a rotor, permanent magnets are used. In order to hold against centrifugal force or the like, a configuration in which a ring of carbon fiber reinforced plastic (CFRP) is arranged on the outer diameter side of the magnet is disclosed.

  Further, for example, in Japanese Patent Application Laid-Open No. 2014-109773 (Patent Document 2), magnet poles and salient poles intended to suppress a decrease in detection accuracy of a magnetic angle sensor are arranged alternately in the rotation direction. A rotating electric machine including a provided contiguous pole type rotor is disclosed.

  Further, for example, Japanese Patent Laid-Open No. 6-245451 (Patent Document 3) discloses a synchronous motor including an embedded magnet rotor (IPM) having a configuration in which magnetic poles are arranged on the outer diameter of a rotor. Yes.

JP 2011-259574 A JP 2014-109773 A JP-A-6-245451

  In the synchronous motor disclosed in Patent Document 1, there is an air layer that prevents mechanical contact between the stator and the rotor, and a CFRP layer that is a protective tube for the permanent magnet. The distance of the electromagnetically non-magnetic region corresponding to the distance between the iron core and the rotor core is increased. For this reason, there is a problem that the magnetic resistance is large and the amount of magnetic flux is reduced, resulting in a decrease in torque.

  On the other hand, magnetic poles of a magnetic material are arranged on the outer diameter of the rotor, such as a continuous rotor disclosed in Patent Document 2 or an embedded magnet rotor (IPM) disclosed in Patent Document 3. In the configuration, since the region that was a permanent magnet in SPM is a magnetic body, the magnetic resistance is reduced, the amount of magnetic flux is increased, and the torque can be increased.

  However, as in the case of the continuous rotor disclosed in Patent Document 2, if the magnetic pole of one polarity is connected to the magnetic pole of a different polarity and the magnetic material is not made small, the magnetic flux of the magnetic pole is connected. There is a problem that the magnetic flux leaking through increases and the torque decreases. This is a problem that conflicts with a decrease in strength of the structural surface.

Further, in the rotor structure such as the magnet-embedded rotor disclosed in Patent Document 3, the surface of the magnetic body other than the magnetic pole on which the permanent magnet is arranged, that is, the magnetic contact with the other magnetic pole and the rotor core. For example, when used in an electric power steering device, the magnetic field of the rotation sensor magnet disposed at the end of the rotation shaft is distorted and the detection angle error of the rotation sensor disposed opposite to the body due to the polarity of the rotation shaft tip of the body being different. There is a problem that causes deterioration of the noise or causes abnormal noise due to poor fitting due to adhesion of magnetic waste to a boss or the like that is disposed at the other end of the rotary shaft and engages with the steering gear.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a permanent magnet motor having a large torque by reducing the leakage magnetic flux of the rotor.

A permanent magnet motor according to the present invention includes a stator core having a plurality of magnetic teeth and a stator winding wound around the magnetic teeth and housed in slots between the magnetic teeth; A permanent magnet motor including a rotor that is disposed relative to the stator via a magnetic gap and rotates about a rotation axis,
The rotor is provided on the outer peripheral surface, and is inserted into a plurality of magnetic poles made of magnetic bodies having different polarities adjacent to each other, and a magnet insertion hole formed in each of the plurality of magnetic poles. and permanent magnets arranged are magnetically oriented in the circumferential direction between the magnetic poles of, consists of a non-magnetic and non-isotropic material and a structure which rotates together with the rotary shaft, wherein the plurality of magnetic poles It is characterized by being integrated with the structure without being in direct contact with each other.

  According to the present invention, a permanent magnet motor having a large torque can be obtained by reducing the leakage magnetic flux of the rotor by the above configuration.

It is front sectional drawing of the rotor in the permanent magnet motor by Embodiment 1 of this invention. It is the sectional view on the AA line of FIG. It is front sectional drawing of the rotor in the permanent magnet motor by Embodiment 2 of this invention. FIG. 4 is a sectional view taken along line BB in FIG. 3.

  Preferred embodiments of a permanent magnet motor according to the present invention will be described below in detail with reference to the drawings.

Embodiment 1 FIG.
1 is a front sectional view of a rotor used in a permanent magnet motor according to Embodiment 1 of the present invention. 2 is a cross-sectional view taken along line AA in FIG.
The permanent magnet motor according to the first embodiment includes a stator (not shown) and a rotor 10 arranged inside the stator. The stator is composed of a winding and a stator core. The stator core includes an annular core back made of a magnetic material such as an electromagnetic steel sheet and teeth extending inward in the circumferential direction from the core back. Windings are housed in slots formed between adjacent teeth, and windings wound around the teeth form coil ends at both axial ends of the stator. This configuration is well known and is not shown.

A rotor 10 is provided inside the stator. The rotor 10 includes a permanent magnet 2 in a magnet insertion hole 1 a formed in the magnetic pole 3 constituting the rotor core 1. The magnetic pole 3 of the rotor core 1 is composed of a magnetic material having a sectoral cross section, and a permanent magnet 2 that is magnetized and oriented in the circumferential direction is disposed between the magnetic materials. The magnetic pole 3 is composed of, for example, 14 poles, and the NS magnetic poles 3 are alternately arranged with the permanent magnet 2 interposed therebetween. On the inner diameter side of the magnetic pole 3, the magnetic poles 3 are integrated with a structure 4 made of a nonmagnetic and non-directional material such as FRP. The structure 4 is fitted to a rotating shaft 5 made of a magnetic material equivalent to the structure 4 or a nonmagnetic and anisotropic material such as FRP, and rotates together with the rotating shaft 5. In FIG. 2, reference numeral 5 a indicates a boss part fitted to the steering gear, and reference numeral 6 indicates a magnetic detection type rotation sensor magnet attached to the end of the rotating shaft 5.

  In the permanent magnet motor according to the first embodiment, since the rotor 10 is coupled with the structure 4 composed of the nonmagnetic and non-directional materials as described above, the magnetic poles 3 are coupled to each other as shown in FIG. In FIG. 2, the leakage magnetic flux indicated by φ is reduced, and the motor weight can be reduced. Therefore, for example, when used in an electric power steering apparatus, the torque can be increased, the vehicle weight can be reduced, and the fuel efficiency improvement effect can be improved.

  Further, when the handle is rotated at a high speed for emergency avoidance or the like, the nonmagnetic and anisotropic structure 4 such as FRP that supports the magnetic pole 3 and the permanent magnet 2 is pulled against the outer side in the radial direction. An orientation suitable for strength can be obtained. In particular, unlike the SPM motor, the magnetic pole 3 made of a magnetic material having a large inertia is disposed on the outer peripheral side of the rotor 10 on the inner diameter of the stator, so that the fitting to the rotating shaft 5 is reduced in order to reduce the leakage magnetic flux. It is possible to eliminate such trade-offs. Therefore, when used in the electric power steering apparatus, a remarkable effect that both fuel efficiency improvement and steering performance improvement can be obtained is obtained.

  Further, when the permanent magnet motor according to the first embodiment is used in an electric power steering device, by reducing the leakage magnetic flux of the rotor, the magnetic field of the rotation sensor magnet disposed at the end of the rotation shaft is not distorted, Since the deterioration of the torque ripple due to the angle detection error can be reduced, an electric power steering device with good steering feeling can be provided.

Embodiment 2. FIG.
Next, a permanent magnet motor according to Embodiment 2 of the present invention will be described. The permanent magnet motor according to the second embodiment includes a stator (not shown) and a rotor 20 arranged inside the stator. The stator is well known with the same configuration as in the first embodiment, and is not shown here. As shown in FIG. 3, the rotor 20 is composed of a permanent magnet serving as an N pole and a pseudo pole serving as an S pole on one magnetic body. Since the other configuration of the rotor 20 is the same as that of the first embodiment, the description thereof is omitted.

  In the rotor 20 configured as described above, similarly to the first embodiment, the magnetic pole 3 having a large inertia is held by the structure 4 capable of increasing the tensile strength, and as shown in FIG. Since the magnetic flux flows through the rotating shaft 5 and both ends of the rotating shaft 5 do not become S poles, the angle detection error is deteriorated by the magnetic detection type rotation sensor magnet 6 attached to the end of the rotating shaft 5. Can be prevented. Further, no foreign matter is caught in the boss portion 5a fitted to the steering gear at the other end of the rotating shaft 5. Accordingly, it is possible to prevent uneven rotation of the motor due to an angle detection error, noise vibration during rotation due to foreign matter being caught, and the like, and a remarkable effect of improving steering feeling can be obtained in the electric power steering apparatus.

  As described above, the first and second embodiments of the present invention have been described. However, within the scope of the present invention, the embodiments can be freely combined, or each embodiment can be appropriately modified or omitted. Is possible.

DESCRIPTION OF SYMBOLS 1 Rotor core, 1a Magnet insertion hole, 2 Permanent magnet, 3 Magnetic poles, 4 Structure, 5 Rotating shaft, 5a Boss part, 6 Rotation sensor magnet 10, 20 Rotator

Claims (4)

A stator core having a plurality of magnetic teeth, a stator winding wound around the magnetic teeth and housed in a slot between the magnetic teeth, and the stator and a magnetic gap A permanent magnet motor having a rotor that is relatively disposed and rotates about a rotation axis,
The rotor is
A plurality of magnetic poles that are provided on the outer peripheral surface and are composed of magnetic materials having adjacent polarities different from each other ;
A permanent magnet that is inserted into a magnet insertion hole formed in each of the plurality of magnetic poles, and is magnetized and arranged in a circumferential direction between the plurality of magnetic poles;
Nonmagnetic, is composed of a non-isotropic material and a structure which rotates together with the rotary shaft,
The permanent magnet motor, wherein the plurality of magnetic poles are integrated with the structure without directly contacting each other.   The permanent magnet motor according to claim 1, wherein the rotation shaft is made of the same material as the structure and is integrally formed with the structure. The permanent magnet motor according to claim 1, wherein the nonmagnetic and anisotropic material is a carbon fiber reinforced plastic. A stator core having a plurality of magnetic teeth, a stator winding wound around the magnetic teeth and housed in a slot between the magnetic teeth, and the stator and a magnetic gap A permanent magnet motor having a rotor that is relatively disposed and rotates about a rotation axis,
The rotor is
A magnetic pole made of a magnetic material disposed on the outer periphery of the rotor;
A plurality of permanent magnets inserted and arranged in a plurality of magnet insertion holes formed in the circumferential direction of the magnetic poles, and having the same polarity with each other;
A structure that rotates together with the rotating shaft, is made of a nonmagnetic and anisotropic material, and is integrated with the magnetic pole;
And the polarity of the plurality of permanent magnets, the plurality of formed therebetween a permanent magnet, wherein the plurality of the polarity different from the polarity pseudo poles of the permanent magnet, permanently you characterized in that it constitutes a magnetic pole by magnets motor.

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