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:
Aug. 02, 1977
Filed:
Oct. 14, 1975
Seizi Yamashita, Hitachi, JA;
Kazuo Onishi, Hitachi, JA;
Hitachi, Ltd., , JA;
Abstract
A cooling device for use in a low inertia electric motor, in which there are provided a plurality of main passages for cooling air, around the outer circumferential surface of a cylindrical armature which surface is surrounded by magnetic pole pieces with gaps left therebetween. The main passages extend in the axial direction of the armature, so that cooling air is introduced under pressure from the ends of the aforesaid main passages on one side and then discharged from the other ends of the main passages, so as to cool the outer circumferential surface of the armature. At least half of those main passages are of such an arrangement that the cross sectional areas of the main passages are gradually varied from inlets of the main passages towards the outlets thereof, respectively so that a circumferential flow of air through said gaps is created.