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:
Nov. 20, 2012
Filed:
Sep. 25, 2008
Hiroyuki Azuma, Ushiku, JP;
Atsushi Shimazu, Toride, JP;
Masaki Yoshikawa, Kasama, JP;
Kosei Suzuki, Ryugasaki, JP;
Hiroyuki Azuma, Ushiku, JP;
Atsushi Shimazu, Toride, JP;
Masaki Yoshikawa, Kasama, JP;
Kosei Suzuki, Ryugasaki, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
A first hydraulic circuit leads, as clutch control pressure, pressurized oil supplied from a first hydraulic pump, to a transmission control device after regulating the pressurized oil, and leads, as torque converter operation oil, pressured oil to a torque converter, and leads pressurized oil to an oil cooler. Through a second hydraulic circuit, pressurized oil from a second hydraulic pump is distributed to a circuit portion downstream of the pressure regulation valve and upstream of a safety valve and to a circuit portion downstream of the torque converter and upstream of the oil cooler. A flow control device changes a proportion of a rate of flow in the second hydraulic circuit so that a proportion of the rate of flow to the circuit portion downstream of the torque converter and upstream of the oil cooler increases as pressure at an entrance of the torque converter increases.