Permanent magnet motor, position estimation apparatus and motor drive control apparatus

Patent metadata

Field	Value
Publication number	US-2016149443-A1
Application number	US-201514948500-A
Country	US
Kind code	A1
Filing date	Nov 23, 2015
Priority date	Nov 26, 2014
Publication date	May 26, 2016
Grant date	—

Abstract

A permanent magnet motor is provided, which includes a rotor including a rotation axle and a plurality of magnetized rotor magnets on a periphery, which rotor magnets are magnetized to form alternately N-poles and S-poles; first and second ring-shaped-claw-pole units, whose inner circumferences face the rotor magnets, including a plurality of first and second claw-poles along the inner circumference, the first and the second claw-poles being closely adjacent to each other extending alternately in upward and downward axis directions of the rotation axle, bottom sides of the first and the second claw-poles forming a ring shape. A first opening portion is formed in a first joint surface of the first ring-shaped-claw-pole unit, to be joined to the second ring-shaped-claw-pole unit, and the second opening portion is formed in a second joint surface of the second ring-shaped-claw-pole unit, to be joined to the first ring-shaped-claw-pole unit.

First claim

What is claimed is:

1 . A permanent magnet motor comprising:
a rotor configured to include a rotation axle and a plurality of magnetized rotor magnets on a periphery, which rotor magnets are magnetized to form alternately N-poles and S-poles; a first ring-shaped claw-pole unit, whose inner circumference faces the rotor magnets, is configured to include a plurality of first claw-poles along the inner circumference, the first claw-poles being closely adjacent to each other and extending alternately in an upward axis direction of the rotation axle and in a downward axis direction of the rotation axle, a bottom side of the first claw-poles forming a ring shape; a second ring-shaped claw-pole unit, whose inner circumference faces the rotor magnets, is configured to include a plurality of second claw-poles along the inner circumference, the second claw-poles being closely adjacent to each other and extending alternately in an upward axis direction of the rotation axle and in a downward axis direction of the rotation axle, a bottom side of the second claw-poles forming a ring shape, a first opening portion formed in a first joint surface of the first ring-shaped claw-pole unit, to be joined to the second ring-shaped claw-pole unit; and a second opening portion formed in a second joint surface of the second ring-shaped claw-pole unit, to be joined to the first ring-shaped claw-pole unit.

2 . The permanent magnet motor according to claim 1 ,
wherein the first opening portion and the second opening portion are formed in such a way that a center of the first opening portion and a center of the second opening portion are on the same straight line as a center of the claw-pole extending downward to the first joint surface.

3 . The permanent magnet motor according to claim 1 ,
wherein a plurality of the first opening portions and a plurality of the second opening portions are formed, a plurality of magnetic-path-narrowing portions are formed between the opening portions, the first opening portions, the second opening portions, and the magnetic-path-narrowing portions are formed in such a way that a width of at least one of the magnetic-path-narrowing portions in the circumferential direction is equal to or less than a width of at least one of the first opening portions and the second opening portions.

4 . The permanent magnet motor according to claim 3 ,
wherein the first opening portions and the second opening portions are formed in an inner edge portion of the first ring-shaped claw-pole unit and in an inner edge portion of the second ring-shaped claw-pole unit, respectively.

5 . The permanent magnet motor according to claim 3 ,
wherein the first opening portions and the second opening portions are formed in an outer edge portion of the first ring-shaped claw-pole unit and in an outer edge portion of the second ring-shaped claw-pole unit, respectively.

6 . The permanent magnet motor according to claim 1 ,
wherein a plurality of the first opening portions and a plurality of the second opening portions are formed in the first ring-shaped claw-pole unit and the second ring-shaped claw-pole unit, respectively, along the circumferential direction, wherein in the first ring-shaped claw-pole unit and the second ring-shaped claw-pole unit along the circumferential direction in which the first opening portions and the second opening portions are formed, arc-shaped grooves are formed between the first opening portions and the second opening portions.

7 . The permanent magnet motor according to claim 6 ,
wherein a width of the grooves of the first and the second ring-shaped claw-pole units in the radial direction is equal to or less than a width of the first and the second opening portions in the radial direction.

8 . The permanent magnet motor according to claim 6 ,
wherein a width of the grooves of the first and the second ring-shaped claw-pole units in the radial direction is greater than a width of the first and the second opening portions in the radial direction.

9 . A position estimation apparatus comprising:
the permanent magnet motor according to claim 1 ; a high-frequency generation unit configured to generate a high-frequency signal supplied to an armature coil of the permanent magnet motor; a current detection unit configured to detect a high-frequency current component which is a response to the high-frequency signal; and a position estimation unit configured to, based on the high-frequency signal and the high-frequency current component, estimate a position of the rotor included in the permanent magnet motor.

10 . A motor drive control apparatus comprising the position estimation apparatus according to claim 9 .

Assignees

• Hashimoto Takashi
• Koike Takahisa
• Suzuki Haruyuki
• Yoshimizu Eiki
• Yamamoto Norihiro
• Ricoh Co Ltd

Inventors

• Hashimoto Takashi
• Koike Takahisa
• Suzuki Haruyuki
• Yoshimizu Eiki
• Yamamoto Norihiro

Classifications

• H02K1/145 Primary

  having an annular coil, e.g. of the claw-pole type · CPC title

• H02P6/183

  using an injected high frequency signal · CPC title

• H02K1/278

  Surface mounted magnets; Inset magnets · CPC title

• H02K37/14

  with magnets rotating within the armatures · CPC title