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:
May. 20, 2008
Filed:
Apr. 29, 2005
John M. Rosenbaum, Richmond, CA (US);
Nancy K. Smrcka, Richmond, CA (US);
John M. Rosenbaum, Richmond, CA (US);
Nancy K. Smrcka, Richmond, CA (US);
Chevron Corporation, San Ramon, CA (US);
Abstract
A lubricating oil having a CCS viscosity at −15° C. less than 7000 cP, good shear stability, and a TBN between 8 and 20 comprising: a) a lubricating base oil made from a waxy feed, b) an engine oil additive package formulated to protect silver bearings, and c) less than 2.0 wt % viscosity index improver. Also a process to make a lubricating oil having a CCS viscosity at −15° C. less than 7000 cP, good shear stability, and a TBN between 8 and 20. Additionally, a lubricating oil having low CCS viscosity comprising specified amounts of lubricating base oil made from a waxy feed, engine oil additive package formulated to protect silver bearings, up to 55 wt % bright stock with a VI greater than 120, and no viscosity index improver or conventional pour point depressant additives. Also, a method for operating a railroad engine using the lubricating oil of this invention.