INNER ROTOR-TYPE PERMANENT MAGNET MOTOR

• US 20130088114A1
• Filed: 10/09/2012
• Published: 04/11/2013
• Est. Priority Date: 10/07/2011
• Status: Abandoned Application

• Current Assignee: Minebea Company Limited (MinebeaMitsumi Inc.)
• Original Assignee: Minebea Company Limited (MinebeaMitsumi Inc.)
• Inventors: YAMASHITA, Fumitoshi, YAMADA, Osamu, OHYA, Shiho, YAMANE, Akihiro
• Application Number:
  US13/648,073
• Publication Number:
  US 20130088114A1
• Time in Patent Office: Days
• US Class Current: 310/156.38
• CPC Class Codes: H02K 1/02 characterised by the magnetic material
• CPC Class Codes: H02K 1/278 Surface mounted magnets; Inset magnets
• CPC Class Codes: H02K 15/03 having permanent magnets
• CPC Class Codes: H02K 2201/03 Machines characterised by aspects of the air-gap between rotor and stator
• CPC Class Codes: H02K 2213/03 Machines characterised by numerical values, ranges, mathematical expressions or similar information

Abstract

A motor includes poles P having a remanence Mr of 0.9 T or more, a coercivity HcJ of 0.80 MA/m or more, and a maximum energy product (BH)_max of 150 kJ/m³ or more, which sets a center point Pc of the magnetic poles in a circumferential direction on a rotor outer circumferential surface to a maximum thickness t_max, wherein when a line connecting the Pc and a rotational axis center Rc is Pc-Rc, a straight line connecting an arbitrary point Px in the circumferential direction on the rotor outer circumferential surface and the Rc is Px-Rc, an apex angle of the lines Pc-Rc and Px-Rc is θ, a number of pole pairs is Pn, a circumferential direction magnetic pole end is Pe, and a magnetic pole end biasing distance ΔL_Pe of the circumferential direction magnetic pole ends Pe is α×t_max (α is a coefficient).

Claims

1. An inner rotor-type permanent magnet motor including parallel oriented annular magnetic poles P having a remanence Mr of 0.9 T or more, a coercivity HcJ of 0.80 MA/m or more, and a maximum energy product (BH)_max of 150 kJ/m³ or more, which sets a center point Pc of the magnetic poles in a circumferential direction on a rotor outer circumferential surface to a maximum thickness t_max,

wherein when a straight line connecting the center point Pc of the magnetic poles in the circumferential direction and a rotational axis center Rc is Pc-Rc, a straight line connecting an arbitrary point Px in the circumferential direction on the rotor outer circumferential surface and the rotational axis center Rc is Px-Rc, an apex angle of the straight lines Pc-Rc and Px-Rc is θ

, a number of pole pairs is Pn, a circumferential direction magnetic pole end is Pe, and a magnetic pole end biasing distance Δ

L_Pe of the circumferential direction magnetic pole ends Pe is α

×

t_max (α

is a coefficient),

α

is 0.25±

0.3, a magnetic pole end biasing distance Δ

L_Px of the point Px on the straight line Px-Rc relative to the apex angle θ

is Δ

L_Pe×

cos(θ

×

Pn), and the circumferential direction magnetic pole ends Pe of the parallel oriented annular magnetic poles P are integrated to each other.

2. The inner rotor-type permanent magnet motor according to claim 1, wherein the straight line Pc-Rc which connects the center point Pc of the magnetic poles in the circumferential direction on an inner rotor outer circumferential surface and the rotational axis center Re is 25 mm or less.