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. 14, 2008
Filed:
Mar. 11, 2005
John M. Rosenbaum, Richmond, CA (US);
Susan M. Abernathy, Hercules, CA (US);
Stephen J. Miller, San Francisco, CA (US);
Nancy J. Bertrand, Lafayette, CA (US);
John M. Rosenbaum, Richmond, CA (US);
Susan M. Abernathy, Hercules, CA (US);
Stephen J. Miller, San Francisco, CA (US);
Nancy J. Bertrand, Lafayette, CA (US);
Chevron U.S.A. Inc., San Ramon, CA (US);
Abstract
This invention provides a hydraulic oil comprising: 1) a lubricant base oil having an average molecular weight greater than 475, a viscosity index greater than 140, and a weight percent olefins less than 10; and 2) an antiwear hydraulic oil additive package. The hydraulic oil of this invention has an air release by ASTM D 3427-03 of less than 0.8 minutes at 50 degrees C., and a sequence II foam tendency by ASTM D 892-03 of less than 50 ml. We describe a process for making the hydraulic oil of this invention, and a method of operating a hydraulic pump without pump cavitation using the hydraulic oil of this invention.