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:
Jun. 19, 2012
Filed:
Sep. 26, 2007
Toshihiko Nishiyama, Oyama, JP;
Shuuji Hori, Oyama, JP;
Takahisa Iino, Oyama, JP;
Daisuke Kozuka, Oyama, JP;
Toshihiko Nishiyama, Oyama, JP;
Shuuji Hori, Oyama, JP;
Takahisa Iino, Oyama, JP;
Daisuke Kozuka, Oyama, JP;
Komatsu Ltd., Tokyo, JP;
Abstract
A hydraulic servo drive device for driving a swing mechanism of a variable geometry turbocharger includes a servo piston connected to a driveshaft of the swing mechanism and a pilot spool that is accommodated in a center hole of the servo piston and slides by pilot pressure. A first hydraulic chamber to and from which pressure oil flows are provided in a housing. The servo piston separately includes a pressure port for introducing pressure oil from an outside, a first piston port for intercommunicating the center hole and the first hydraulic chamber, a second piston port for intercommunicating the center hole and the second hydraulic chamber, and a return port for exiting pressure oil.