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:
Oct. 01, 1991
Filed:
Aug. 04, 1989
Roland Sudler, Frankfurt am Main, DE;
VDO Adolf Schindling AG, Frankfurt am Main, DE;
Abstract
In a motor, in particular for the electrical driving of a clockwork, a rotor (32) which is mounted rotatably together with a shaft (3) consists of a permanent magnet having diametrically opposite permanent magnet poles. A coil arrangement in the motor comprises two coils (10 and 11) arranged at angular distances of, in particular, 90.degree. apart from each other. In order to produce in the motor, without a stator with salient poles of ferro-magnetic material, detent moments which permit feeding the coils with short pulses, a coil body (14) of non-ferromagnetic material is provided for receiving the coils (10, 11), the coil body being shaped cylindrically inside and outside with webs (17-20) which are arranged at equal distances apart over the circumference and extend cylindrically on the outside, and a screening ring (48) of a material of high residual coercive field strength is disposed concentrically on the coil body for interacting with magnetic fields produced by currents in the coils to produce a remanent bias field retained after deenergization of the coils.