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:
Jul. 31, 1979
Filed:
Aug. 18, 1977
James A Purdy, Sylvania, OH (US);
Eltra Corporation, Toledo, OH (US);
Abstract
A permanent magnet motor is provided which has first and second U-shaped sections comprising the motor stator. Each section is constructed of low reluctance magnetic material. The motor armature shaft passes through a hole in the bight of each section and carries a commutator. An air space separates the bight and shaft to provide a high reluctance path to the shaft. The two parallel sides of the first section fit between the two sides of the second section in a contact relation; the combination defining a two piece magnetic circuit that passes around the motor from end to end. The first section contains a permanent magnet mounted upon each of the sides at diametrically opposite locations adjacent the armature. The flux coupling the two magnets passes through the armature core. The magnets define a pole pair and are spaced very close to the edge of the armature core to minimize the air gap between the armature and the magnet. The first section is unbroken and provides a homogeneous flux path between the magnets. The second section provides a parallel-secondary flux path from the magnets. Additional low reluctance material is included on the bight of each section to compensate for the increased reluctance resulting from the hole through which the armature passes. Positioning stops are provided on the second section, which contact the first section as it is positioned, to establish the proper distal relation between the bights to accommodate the armature and commutator.