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. 07, 2002
Filed:
Apr. 10, 2000
Rudolf Bahnen, Roetgen, DE;
Thomas Dreifert, Köln, DE;
Leybold Vakuum GmbH, Cologne, DE;
Abstract
A screw vacuum pump ( ) has rotors ( ), bearings ( ), a casing ( ), a suction side ( ), and a delivery side ( ). Each of the rotors includes at least two rotor sections, a suction side rotor section ( ) and a delivery side rotor section ( ). The two rotor sections are separately constructed and joined together in a positive, form-fitting or friction locking manner. The suction side rotor section is preferably larger in diameter and constructed with looser tolerances as compared to the delivery side rotor section. The suction side rotor is preferably of an inexpensive material such as aluminum while the discharge side rotor is preferably constructed of a higher performance material such as stainless steel. The rotor sections are supported on a rotor shaft ( ) into which cooling fluid is injected through a cooling pipe ( ). Cooling fluid from the shaft is also circulated through the bearings and passages in the casing eventually reaching a sump ( ) in preparation for recirculation.