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:
Nov. 13, 1990
Filed:
Feb. 02, 1989
James W Richmond, Carmel, IN (US);
Emhart Industries, Inc., Indianapolis, IN (US);
Abstract
There is described a speed sensor that is particularly adaptable to moving vehicles such as automobiles. A permanent magnet, stator assembly, and field coil are held within a ferromagnetic cup that is adapted to mate a bearing assembly of a non-driven wheel of the vehicle. A rotor assembly is carried by the wheel spindle. The rotor assembly has poles spaced entirely around the circumference of a circle while the stator assembly has only a few poles distributed over an arc of a portion of a circle. A magnetic flux is provided by the permanent magnet, which flux passes through the stator poles and the rotor poles. The ferromagnetic cup completes a flux path between the stator and rotor poles, and also to the magnet. The rotor poles rotate with the wheel, causing a changing magnetic flux which in turn generates an alternating voltage current in the field coil. The alternating current so generated is then fed through an electrical terminal to a vehicle computer.