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:
Feb. 03, 2009
Filed:
Aug. 09, 2007
Yuya Izawa, Kariya, JP;
Shinya Yamamoto, Kariya, JP;
Masahiro Inagaki, Kariya, JP;
Makoto Yoshikawa, Kariya, JP;
Yuya Izawa, Kariya, JP;
Shinya Yamamoto, Kariya, JP;
Masahiro Inagaki, Kariya, JP;
Makoto Yoshikawa, Kariya, JP;
Kabushiki Kaisha Toyota Jidoshokki, Kariya-Shi, JP;
Abstract
A screw pump includes a housing and a pair of intermeshing screw rotors. The housing has an inlet port and an outlet port. Each rotor has a first portion whose lead angle decreases. The first portion and the housing form an inlet space and a pump space. Winding angle of the first portion has a first region and a second region. The first region is located in a predetermined range from the end on the first portion adjacent to the inlet port toward the outlet port. The second region is located adjacent to the first region. Reduction rate of the lead angle of the first portion in the first region is set smaller than that in the second region. The maximum lead angle of the first portion is set smaller than a lead angle which decreases at a constant rate in the first region and the second region.