The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 06, 2011
Filed:
Apr. 08, 2008
Keiji Aota, Shiga, JP;
Yoshinari Asano, Shiga, JP;
Keiji Aota, Shiga, JP;
Yoshinari Asano, Shiga, JP;
Daikin Industries, Ltd., Osaka, JP;
Abstract
The present invention relates to a field element which reduces a harmonic component of a magnetic flux density. Permanent magnets () are in contact with first magnetic plates () in a direction parallel to a rotation axis (P). The first magnetic plate () includes first and second magnetic members () and first and second non-magnetic members (). The first magnetic member () includes a pole center and is in contact with one of the permanent magnets. The first magnetic member (), the first non-magnetic member (), the second magnetic member () and the second non-magnetic member () are disposed in the stated order in a circumferential direction with the pole center and the rotation axis being as a starting point and a center, respectively. When Pn represents the number of pole pairs and i represents an odd number equal to or more than three, an angle θ1 defined by an end portion () of the second non-magnetic member () on the pole center side with respect to a pole gap is 0<θ1<180/(i·Pn). An angle θ2 defined by an end portion () of the first non-magnetic member () on the pole center side with respect to the pole gap is 180/(i·Pn)≦θ2≦180·2/(i·Pn).