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:
Mar. 03, 2009
Filed:
Aug. 09, 2007
Masahiro Inagaki, Kariya, JP;
Shinya Yamamoto, Kariya, JP;
Makoto Yoshikawa, Kariya, JP;
Yuya Izawa, Kariya, JP;
Masahiro Inagaki, Kariya, JP;
Shinya Yamamoto, Kariya, JP;
Makoto Yoshikawa, Kariya, JP;
Yuya Izawa, Kariya, JP;
Kabushiki Kaisha Toyota Jidoshokki, Kariya-shi, JP;
Abstract
A screw pump includes a housing and a pair of intermeshing screw rotors. An end face of the rotor adjacent to an inlet port of the housing is provided with an inlet opening. Each rotor has a first portion whose lead angle changes. The first portions and the housing cooperate to form an inlet space. During rotation of the rotors, communication between the inlet space and the inlet port is blocked by the first portions and the housing thereby to form a closed pump space adjacent to the inlet space. Volume of the pump space is set smaller than the maximum volume of the inlet space. A closure member is provided which covers at least a part of the inlet openings. The closure member closes the inlet space when the volume of the inlet space exceeds that of the pump space.