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:
Sep. 14, 1999
Filed:
Oct. 24, 1997
Naoki Oogushi, Kariya, JP;
Aisin Seiki Kabushiki Kaisha, Aichi-pref., JP;
Abstract
A tandem pump apparatus having a first hydraulic pump for supplying operating fluid to a first actuator and a second hydraulic pump for supplying operating fluid to a second actuator in cooperation with each other is disclosed. Each hydraulic pump is provided with a flow rate control valve for refluxing a surplus of flow discharged from the pump to a suction side of the pump through a relief passage. A connecting passage connects the first relief passage downstream from the first flow rate control valve and the second relief passage downstream from the second flow rate control valve. A check valve is provided in the connecting passage for allowing operating fluid to flow from one of the relief passages that has a relatively great reflux flow rate to the other relief passage having a relatively small reflux flow rate, thereby ensuring sufficient supercharge into the two pump to achieve sufficient restraint of cavitation.