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:
Mar. 03, 1998
Filed:
Jun. 17, 1996
Applicant:
Inventors:
Assignee:
Nippondenso Co., Ltd., Kariya, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02K / ;
U.S. Cl.
CPC ...
310248 ; 310251 ; 310239 ; 310247 ; 310245 ; 4174237 ;
Abstract
A liquid pump has a DC motor and a pump in a cylindrical casing. A pair of brushes are slidably contacted with a commutator of an armature while being biased by springs. The specific resistance of the positive brush is lower than the specific resistance of the negative brush to enable the voltage drop at the brushes to be decreased and motor efficiency to be increased without increasing commutator wearing speed. The biasing force provided by the spring biasing the positive brush is lower than the biasing force provided by the spring biasing the negative brush.