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:
Jul. 24, 2007
Filed:
Jul. 23, 2003
Takeshi Fuchida, Asahi-machi, JP;
Yoshitake Hisada, Asahi-machi, JP;
Takeshi Fuchida, Asahi-machi, JP;
Yoshitake Hisada, Asahi-machi, JP;
Advics Co., Ltd., Kariya, Aichi, JP;
Abstract
A motor-driven gear pump assembly includes a rotary shaft rotatably mounted in a housing, and a pump mounted on the rotary shaft. The pump has a pressure chamber. A high-pressure seal is disposed around the shaft between the pump and the motor. A low-pressure seal is provided around the shaft between the high-pressure seal and the motor. An annular oil seal chamber is formed between the high-pressure seal and the low-pressure seal to surround the shaft. A recess chamber is formed around the oil seal chamber. Oil is introduced into the oil seal chamber until the portion of the rotary shaft in the oil seal chamber is completely submerged in the oil introduced while leaving air in the oil seal chamber. The oil in the oil seal chamber thus serves as a seal which positively prevents infiltration of air into the pump. If oil in the pump leaks through the high-pressure seal into the oil seal chamber, the air is compressed, thus absorbing any increase in the volume of oil.