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. 14, 2023
Filed:
Jun. 24, 2020
Applicant:
Pfeiffer Vacuum, Annecy, FR;
Inventors:
Assignee:
PFEIFFER VACUUM, Annecy, FR;
Primary Examiner:
Int. Cl.
CPC ...
F04C 25/02 (2006.01); F04C 23/00 (2006.01); F04C 28/26 (2006.01); F04C 18/12 (2006.01); F04C 29/00 (2006.01);
U.S. Cl.
CPC ...
F04C 25/02 (2013.01); F04C 18/126 (2013.01); F04C 23/001 (2013.01); F04C 28/26 (2013.01); F04C 29/0085 (2013.01); F04C 2220/12 (2013.01); F04C 2240/102 (2013.01); F04C 2240/20 (2013.01); F04C 2240/40 (2013.01);
Abstract
A pump unit includes a rough-vacuum pump and a Roots vacuum pump connected in series and upstream of the rough-vacuum pump in the direction of flow of the pumped gases. The Roots vacuum pump has three pumping stages in which the rotors are designed to be driven simultaneously in rotation by a motor of the Roots vacuum pump. A ratio of the flow rate generated by the first pumping stage of the rough-vacuum pump in the direction of flow of the pumped gases over the flow rate generated by the last pumping stage of the rough-vacuum pump is less than or equal to four.