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:
Aug. 27, 1996
Filed:
Oct. 25, 1993
Eduard Mischler, Regensdorf, CH;
Roger Stehr, Bulach, CH;
Maag Pump Systems AG, Zurich, CH;
Abstract
A gear pump comprises rotors disposed in roller bearings. For the delivery of very viscous polymer meltings, bearings surfaces of at least one of inner races, outer races of the bearings and bearing surfaces of roller elements are made of a steel with a high-temperature stability. Bearing takes place on material pairings consisting of one of S6-5-2 high-speed steel and silicon nitride Si.sub.3 N.sub.4. The roller bearings are either unlubricated or lubricated by a lubricant remaining in the bearing, preferably a solid-substance lubrication. A distance of supported shafts, from a gearwheel face to a supporting area of the shafts, determined by the outer contact point in the roller bearing, is smaller than twice the median diameter of the shafts therealong.