IP Library Granted Patent US 7,839,046
Granted Patent B2
US 7,839,046 · App. 12/232,556 · Granted Nov 23, 2010

Claw pole type motor and pump

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Quick Facts
Patent No.
US 7,839,046
App. No.
12/232,556
Granted
Nov 23, 2010
Kind
B2
Abstract

A claw pole type motor includes a rotor having a magnet arranged on an outer circumferential surface thereof and a stator including an annular iron core and an annular coil received within the iron core. The iron core includes a yoke portion opened in an inner circumferential surface opposite to the rotor, a plurality of upper claw-shaped magnetic poles and a plurality of lower claw-shaped magnetic poles which are arranged along an inner circumferential surface of the annular coil. The upper/lower claw-shaped magnetic poles are curved to extend axially downwardly/upwardly from an upper/lower inner edge of the yoke portion, respectively. The upper and the low claw-shaped magnetic poles are alternately arranged along a circumferential direction of the iron core. The yoke portion has cutout portions formed in non-magnetic path regions which do not include magnetic paths through which magnetic flux flows between neighboring claw-shaped magnetic poles across the annular coil.

Claims (8)

1. A claw pole motor comprising:

a rotatably supported rotor having a magnet arranged on an outer circumferential surface thereof; and

a stator including an annular iron core arranged around the outer circumferential surface of the rotor in a facing relationship with the rotor and an annular coil received within the iron core,

wherein the iron core includes a yoke portion having a generally C-like cross sectional shape and opened in an inner circumferential surface opposite to the rotor, a plurality of upper claw-shaped magnetic poles arranged along an inner circumferential surface of the annular coil and curved to extend axially downwardly from an upper inner edge of the yoke portion and a plurality of lower claw-shaped magnetic poles arranged along an inner circumferential surface of the annular coil and curved to extend axially upwardly from a lower inner edge of the yoke portion, the upper claw-shaped magnetic poles and the lower claw-shaped magnetic poles being alternately arranged along a circumferential direction of the iron core, the yoke portion having cutout portions formed outside of regions demarcated by straightly interconnecting position-corresponding boundary points of the neighboring claw-shaped magnetic poles along an outer circumferential surface of the yoke portion, and

wherein the yoke portion includes a cylindrical sidewall portion covering an outer circumferential surface of the annular coil and a pair of end surface portions, the annular coil being interposed in a vertical direction between the pair of end surface portions, and the cutout portions being formed over the end surface portions and the sidewall portion.

2. The claw pole motor of claim 1 , wherein the iron core is formed of a dust core made of compression-molding of insulation-coated iron powder and a binder.

3. The claw pole motor of claim 1 , wherein the iron core is made of injection-molding a magnetic material formed of a mixture of insulation-coated iron powder and a binder.

4. A pump comprising the claw pole motor of claim 1 as a driving power source.

Assignments (2)
CHANGE OF NAME Recorded May 15, 2009
From: MATSUSHITA ELECTRIC WORKS, LTD.
To: PANASONIC ELECTRIC WORKS CO., LTD.
Reel/Frame 022692/0305 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 19, 2008
From: HASHIMOTO, TOSHIHARU; INOUE, HIROKI; YABUUCHI, HIDEKAZU; NISHIKATA, MASSAKI; SUEMATSU, SHINJI
To: MATSUSHITA ELECTRIC WORKS, LTD.
Reel/Frame 021898/0829 →