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. 28, 2000
Filed:
Mar. 24, 1999
George Codina, North Hollywood, CA (US);
Donna J Murr, Dunlap, IL (US);
Caterpillar Inc., Peoria, IL (US);
Abstract
An apparatus and method for sensing a parameter of a hydraulic pump. The hydraulic pump includes a housing and an input shaft. The shaft is rotationally driven relative to the housing and electrically coupled to the housing. The hydraulic pump forms a variable capacitor. The apparatus includes an electrode portion positioned adjacent to the input shaft and is electrically isolated from the housing and input shaft. The electrode portion and the input shaft form a fixed capacitor. The fixed capacitor and the variable capacitor are coupled. The apparatus supplies electrical energy to the electrode portion and produces a capacitive signal indicative of the capacitance value of the variable capacitor. The apparatus further applies a filter to the capacitive signal and produces a filtered capacitive signal. The parameter of the hydraulic pump is determined as a function of the filtered capacitive signal.