JP2010166787A - Rotating electrical machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotating electrical machine that can suppress occurrence of cogging torque by a permanent magnet in the rotating electrical machine that supplies power to the field winding of a rotor by non-contact power supply. <P>SOLUTION: A permanent magnet M is arranged in a rotor 20. The permanent magnet M is so arranged as to generate a magnetic field along a magnetic circuit by a field winding 23 when power is supplied, and as to form a magnetic circuit that rotates the magnetism of the rotor 20 in the circumferential direction at a circumferentially continued part 22 apart from a stator 14 when power is not supplied. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rotating electrical machine that supplies power to a field winding of a rotor in a non-contact manner.

Conventionally, as shown in Patent Document 1, for example, a rotating electrical machine that performs non-contact power supply to a coil of a rotor has been devised.
In such a rotating electrical machine, a primary coil arranged on the stator side and a secondary coil arranged on the rotor side facing the primary coil are provided. A magnetic circuit is formed between the primary coil and the secondary coil by supplying power (flowing current) from the primary coil. Therefore, a current is induced in the secondary coil, the current of the secondary coil is supplied to the field winding of the rotor, and the field winding acts as an electromagnet. For this reason, it is possible to rotate the rotor and the rotating shaft by flowing an electric current so that a rotating action is generated with respect to the armature winding on the stator side.

  In such a rotating electrical machine, as shown in FIG. 5 of Patent Document 1, a permanent magnet having N and S poles is provided on the outer periphery of the rotating shaft, and a field winding is provided on the axial end face of the permanent magnet. Is provided. Therefore, the rotational force (torque) of the rotor can be increased by combining the magnetic field generated by supplying current to the field winding and the magnetic field of the permanent magnet.

JP 2005-269868 A

  However, in the above rotating electric machine, since the permanent magnets are arranged opposite to each other in the vicinity of the stator (armature winding), there is a problem that so-called cogging torque is generated between the rotor and the stator by the magnetic poles of the permanent magnets. Improvement is desired.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to suppress the generation of cogging torque by a permanent magnet in a rotating electrical machine that supplies power to a rotor field winding by non-contact power supply. An object of the present invention is to provide a rotating electrical machine that can perform the above.

  In order to solve the above-mentioned problems, the invention described in claim 1 includes a stator in which armature windings are wound around teeth of a stator core, and a rotor in which field windings are wound around teeth of a rotor core. The rotor with respect to the stator by non-contact power feeding by a primary coil disposed on the stator side and a secondary coil disposed on the rotor side so as to be opposed to the primary coil. A rotating electric machine configured so that a permanent magnet is disposed on the rotor, and the permanent magnet forms a magnetic field along the magnetic circuit by the field winding during power feeding In addition, the gist is that the magnetic circuit of the rotor is arranged to form a magnetic circuit that rotates in the circumferential direction at a position away from the stator when power is not supplied.

  In the present invention, a permanent magnet is disposed on the rotor. The permanent magnet forms a magnetic field along the magnetic circuit by the field winding during power feeding, and forms a magnetic circuit that rotates the magnetism of the rotor in the circumferential direction at a position away from the stator during non-power feeding. Be placed. In other words, the permanent magnet is arranged so as to form a magnetic circuit that rotates the magnetism of the rotor when not supplied with power in the circumferential direction at a position away from the stator, so that cogging generated between the rotor and the stator by the magnetic pole of the permanent magnet. Torque can be suppressed. In addition, by forming a magnetic field along the magnetic circuit by the field winding during power feeding, the magnetic circuit (magnetic field) by the field winding and the magnetic field of the permanent magnet are combined to increase the rotational force (torque) of the rotor. It becomes possible.

  According to a second aspect of the present invention, in the rotating electric machine according to the first aspect, the rotor core is provided with a circumferential continuous portion such that a side opposite to the stator between the plurality of teeth is continuous in the circumferential direction. The gist of the present invention is that the permanent magnet is disposed in the circumferentially continuous portion between the teeth of the rotor core.

  In this invention, the circumferential direction continuous part is provided in the rotor core so that the opposite side of the stator between the plurality of teeth is continuous in the circumferential direction. And a permanent magnet is arrange | positioned at the circumferential direction continuous part between the teeth of a rotor core. By adopting such a configuration, the permanent magnet can be positioned away from the stator, so that the magnetism of the permanent magnet is prevented from being transmitted to the stator side, and cogging generated between the rotor and the stator by the magnetic pole of the permanent magnet. Torque can be suppressed.

  According to a third aspect of the present invention, in the rotating electrical machine according to the second aspect, the permanent magnet is arranged at every other circumferential direction of the circumferentially continuous portion between the teeth of the rotor core. To do.

  In this invention, a permanent magnet is arrange | positioned every other circumferential direction of the circumferential direction continuous part between the teeth of a rotor core. Here, the case where non-contact power feeding is performed between the primary coil and the secondary coil to feed the field winding of the rotor will be described. By feeding, the tip side of each tooth of the rotor core (circumferential continuous portion and radial direction) N poles or S poles are generated on the opposite side), and magnetic poles are generated so that the N poles and S poles alternate in the circumferential direction. In this case, a magnetic circuit is formed between adjacent N-pole and S-pole teeth. And it can be set as arrangement | positioning on the magnetic circuit formed between the teeth of the adjacent N pole and S pole by arrange | positioning a permanent magnet every other circumferential direction of the circumferential direction continuous part. At this time, by magnetizing the permanent magnet from the S pole side to the N pole side, the magnetic force of the permanent magnet works and contributes to the improvement of the rotational force (torque) without disturbing the formation of the magnetic circuit. It becomes possible.

  According to a fourth aspect of the present invention, in the rotating electrical machine according to any one of the first to third aspects, a plurality of the permanent magnets are provided, and the magnetization directions of the permanent magnets are the same in the circumferential direction. The gist of the configuration is as follows.

  In the present invention, a plurality of permanent magnets are provided, and the magnetization direction of each permanent magnet is configured to be the same in the circumferential direction. That is, since the permanent magnets are all magnetized in the same direction, it is possible to form a magnetic circuit that rotates in the circumferential direction in the rotor when no power is supplied. Further, at the time of power feeding, it is possible to improve the rotational force (torque) in one direction by the magnetism in the same direction.

  Therefore, according to the above-described invention, it is possible to provide a rotating electrical machine that can suppress the occurrence of cogging torque by a permanent magnet in a rotating electrical machine that supplies power to the field winding of the rotor in a non-contact manner.

It is a schematic block diagram of the rotary electric machine in this embodiment. It is explanatory drawing for demonstrating arrangement | positioning of a permanent magnet. (A) (b) is explanatory drawing for demonstrating generation | occurrence | production of the magnetic field at the time of non-power feeding and at the time of power feeding.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
FIG. 1 shows a schematic configuration of a brushless motor as a rotating electrical machine of the present embodiment. As shown in FIG. 1, the brushless motor 10 includes a motor case 13 including a yoke housing 11 having a substantially bottomed cylindrical shape and an end frame 12 that closes the opening of the yoke housing 11. A cylindrical stator 14 is fixed to the inner peripheral surface of the yoke housing 11.

  The stator core 15 of the stator 14 includes a plurality of teeth 15 a (only two are shown in FIG. 1) arranged side by side in the circumferential direction, and the teeth 15 a included in the stator core 15 are connected on the outer peripheral side of the stator core 15. Are integrally configured. An armature winding 16 is wound around the teeth 15a of the stator core 15 via an insulator (not shown). The armature winding 16 is supplied with U-phase, V-phase, and W-phase AC power from a three-phase AC power source 17.

  A rotor 20 that is rotatably supported is provided on the inner periphery of the stator 14. The rotor core 21 of the rotor 20 includes a plurality of teeth 21 a arranged side by side in the circumferential direction, and each tooth 21 a provided in the rotor core 21 is connected and integrated by a circumferential continuous portion 22 on the inner circumferential side of the rotor core 21. It is structured. A field winding 23 is wound around the teeth 21 a of the rotor core 21. A plurality of permanent magnets M are provided on the circumferentially continuous portion 22 on the radially inner side (center side) of the rotor core 21. More specifically, a total of four permanent magnets M (only two are shown in FIG. 2) are arranged in the circumferential continuous portion 22, one for every other circumferential continuous portion 22. Further, these permanent magnets M are arranged so that their magnetization directions are the same in the circumferential direction.

  A rotary shaft 32 that is rotatably supported by a bearing 30 provided on the bottom side of the yoke housing 11 and a bearing 31 provided on the end frame 12 is provided on the inner periphery of the rotor core 21. The rotor core 21 is configured to be integrally rotatable.

  The rotating shaft 32 is provided with a fixing frame 33 so as to be rotatable integrally with the rotating shaft 32. An accommodation groove 33a is formed in the fixing frame 33 in the circumferential direction, and a secondary coil 34 is provided in the accommodation groove 33a. The secondary coil 34 is provided so as to face the primary coil 36 provided in the receiving groove 35 a of the fixing frame 35 of the end frame 12 in the axial direction, and is connected to the DC power source ( The direct current from the battery 37 is converted into an alternating current by an inverter (not shown) and supplied to the primary coil 36, so that an alternating current is induced in the secondary coil 34.

  Further, the fixing frame 33 provided with the primary coil 36 is provided with a smoothing circuit 38 on the side opposite to the secondary coil 34 in the axial direction. The smoothing circuit 38 includes a diode and a capacitor (not shown), converts an alternating current induced in the secondary coil 34 into a direct current, and is wound around a tooth 21a of the rotor 20 (rotor core 21). 23 is supplied.

Generation of magnetic flux of the rotor 20 when the so-called inner rotor type motor 10 configured as described above is not supplied with power and when supplied with power will be described with reference to FIGS.
FIG. 3A shows a state where power is not supplied to the field winding 23 (when power is not supplied), and FIG. 3B shows a case where power is supplied to the field winding 23 (when power is supplied). Shows the state. In FIGS. 3A and 3B, the direction of magnetism is indicated by an arrow.

  As shown in FIG. 3A, the permanent magnet M is arranged in the circumferential continuous portion 22 so that the magnetization direction of the permanent magnet M is the same direction (counterclockwise in the figure) in the circumferential direction. . For this reason, when power is not supplied to the field winding 23, the magnetic flow by the permanent magnet M passes through the circumferential continuous portion 22, and the root of the rotor core 21 (rotor 20) extends in the circumferential direction. A rotating magnetic circuit is generated. Therefore, N pole and S pole magnetic poles are not generated at the tips of the teeth 21a of the rotor core 21, so that cogging torque is not generated.

  In addition, as shown in FIG. 3B, when power is supplied to the field winding 23, an electromagnetic field due to a current passing through the field winding 23 causes the tip of the teeth 21 a of the rotor core 21 to be applied. N and S magnetic poles are alternately generated in the circumferential direction. A magnetic circuit is formed between adjacent N-pole and S-pole teeth 21a. At this time, since the permanent magnets M are arranged every other circumferential direction of the circumferential continuous portion 22, the permanent magnets M may be arranged on the magnetic circuit formed between adjacent N pole and S pole teeth 21 a. it can. As described above, the permanent magnet M is arranged so that the magnetization direction of the permanent magnet M is the same in the circumferential direction, and the magnetization direction of the permanent magnet M is changed from the S pole side to the N pole side in the magnetic circuit. The magnetic force of the permanent magnet M also works and contributes to the improvement of the rotational force (torque) without disturbing the formation of the magnetic circuit.

Next, characteristic effects of the present embodiment will be described.
(1) A permanent magnet M is disposed on the rotor 20. And the permanent magnet M forms a magnetic field along the magnetic circuit by the field winding 23 at the time of power feeding, and rotates the magnetic circuit of the rotor 20 in the circumferential direction at a position away from the stator 14 at the time of non-power feeding. Arranged to form. In other words, the permanent magnet M is arranged so as to form a magnetic circuit that rotates the magnetism of the rotor 20 in the circumferential direction at a position away from the stator 14 when no power is supplied. The cogging torque generated between the fourteen can be suppressed. Further, by forming a magnetic field along the magnetic circuit by the field winding 23 at the time of feeding, the magnetic circuit (magnetic field) by the field winding 23 and the magnetic field of the permanent magnet M are combined and the rotational force ( Torque) can be increased.

  (2) The rotor core 21 is provided with a circumferential continuous portion 22 so that the opposite side (diameter inner side) of the stator 14 between the plurality of teeth 21a is continuous in the circumferential direction. And the permanent magnet M is arrange | positioned at the circumferential direction continuous part 22 between the teeth 21a of the rotor core 21. As shown in FIG. With such a configuration, the permanent magnet M can be positioned away from the stator 14, so that the magnetism of the permanent magnet M is prevented from being transmitted to the stator 14 side, and the rotor 20 and the magnetic poles of the permanent magnet M are controlled by the magnetic poles of the permanent magnet M. Cogging torque generated between the stators 14 can be suppressed.

  (3) The permanent magnets M are disposed at every other circumferential direction of the circumferential continuous portion 22 between the teeth 21 a of the rotor core 21. Here, a case where non-contact power feeding is performed between the primary coil 36 and the secondary coil 34 to feed the field winding 23 of the rotor 20 will be described. N-pole or S-pole magnetic poles are generated on the opposite side of the direction continuous portion 22 in the radial direction), and magnetic poles are generated so that N-poles and S-poles alternate in the circumferential direction. In this case, a magnetic circuit is formed between adjacent N-pole and S-pole teeth 21a. Then, by arranging the permanent magnets M every other circumferential direction of the circumferential direction continuous portion 22, the permanent magnet M can be disposed on the magnetic circuit formed between the adjacent N-pole and S-pole teeth 21 a. At this time, by magnetizing the permanent magnet M from the S pole side to the N pole side, the magnetic force of the permanent magnet M works and contributes to the improvement of the rotational force (torque) without disturbing the formation of the magnetic circuit. It becomes possible.

  (4) A plurality of permanent magnets M are provided, and each permanent magnet M is configured such that the magnetization direction of the permanent magnets M is the same in the circumferential direction. In other words, since the magnetization directions of the permanent magnets M are all the same direction, it is possible to form a magnetic circuit that rotates in the rotor 20 in the circumferential direction when no power is supplied. Further, at the time of power feeding, it is possible to improve the rotational force (torque) in one direction by the magnetism in the same direction.

In addition, you may change embodiment of this invention as follows.
-In the above-mentioned embodiment, every other permanent magnet M is arranged, but every other magnet is not necessary. A plurality of permanent magnets M may be provided in each circumferential continuous portion 22.

  -In above-mentioned embodiment, although the permanent magnet M was provided in the circumferential direction continuous part 22 of the rotor core 21, it is not restricted to this. In short, it suffices to arrange it at a distant position that hardly affects the magnetic field generated by the armature winding 16 of the stator 14, and with this arrangement it is possible to suppress the occurrence of cogging torque. Become.

  In the above embodiment, the permanent magnet M is provided in the circumferential continuous portion 22 that is a part of the rotor core 21, but the circumferential continuous portion 22 is configured by a member different from the rotor core 21, and the permanent magnet is included in the member. The structure which arrange | positions M may be sufficient.

In the above embodiment, the magnetization direction of the permanent magnet M is the same in the circumferential direction, but other configurations may be used.
In the above embodiment, the inner rotor type rotating electrical machine (motor) has been described. However, the present invention is not limited thereto, and the above embodiment may be applied to an outer rotor type rotating electrical machine (motor).

  In the above embodiment, a direct current is supplied from the direct current power source (battery) 37, the direct current is converted into an alternating current by an inverter (not shown), and power is supplied to the primary coil 36. An alternating current may be supplied to the primary coil 36 from an alternating current power source.

Next, a technical idea that can be grasped from the above embodiment and another example will be added below.
(A) In the rotating electrical machine according to any one of claims 1 to 4, the rotor is provided radially inward of the stator, and the teeth of the rotor core have their tips facing radially outward. A rotating electric machine characterized by being arranged.

  By providing such a configuration, a so-called inner rotor type rotating electrical machine having a rotor on the radially inner side of the stator provides a rotating electrical machine that exhibits the same effect as the effect described in any one of claims 1 to 4. can do.

  DESCRIPTION OF SYMBOLS 10 ... Brushless motor as a rotary electric machine, 14 ... Stator, 15 ... Stator core, 15a ... Teeth, 16 ... Armature winding, 20 ... Rotor, 21 ... Rotor core, 21a ... Teeth, 22 ... Circumferential continuous part, 23 ... Field Magnetic winding, 34 ... secondary coil, 36 ... primary coil, M ... permanent magnet.

Claims (4)

A stator in which armature windings are wound around the teeth of the stator core, and a rotor in which field windings are wound around the teeth of the rotor core,
The rotor is rotated with respect to the stator by non-contact power feeding by a primary coil disposed on the stator side and a secondary coil disposed on the rotor side so as to face the primary coil. A rotating electric machine configured to have
A permanent magnet is disposed on the rotor, and the permanent magnet forms a magnetic field along the magnetic circuit by the field winding when power is supplied and separates the magnetism of the rotor from the stator when power is not supplied. A rotating electrical machine, wherein the rotating electrical machine is arranged to form a magnetic circuit that rotates in a circumferential direction at a certain position. In the rotating electrical machine according to claim 1,
The rotor core is provided with a circumferential continuous portion such that the side opposite to the stator between the plurality of teeth is continuous in the circumferential direction,
The rotating electric machine according to claim 1, wherein the permanent magnet is disposed in the circumferentially continuous portion between the teeth of the rotor core. The rotating electrical machine according to claim 2,
The rotating electric machine according to claim 1, wherein the permanent magnets are arranged at every other circumferential direction of the circumferential continuous portion between the teeth of the rotor core. In the rotary electric machine according to any one of claims 1 to 3,
A rotating electric machine characterized in that a plurality of the permanent magnets are provided and the magnetization directions of the permanent magnets are the same in the circumferential direction.

Images