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:
May. 11, 2010
Filed:
Mar. 06, 2006
Tsutomu Udagawa, Tsukuba, JP;
Eiji Egawa, Tsuchiura, JP;
Akira Nakayama, Tsuchiura, JP;
Kazuo Takiguchi, Moriya, JP;
Tsukasa Toyooka, Ibaraki-ken, JP;
Makoto Sugaya, Narita, JP;
Kensuke Sato, Ushiku, JP;
Tsutomu Udagawa, Tsukuba, JP;
Eiji Egawa, Tsuchiura, JP;
Akira Nakayama, Tsuchiura, JP;
Kazuo Takiguchi, Moriya, JP;
Tsukasa Toyooka, Ibaraki-ken, JP;
Makoto Sugaya, Narita, JP;
Kensuke Sato, Ushiku, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
A hydro-static transmission travel system for a working machine enables the working machine to travel over a range from low speed to high speed with a simplified circuit arrangement. By referring to a machine traveling speed (vehicle speed) based on a detected signal from a rotation sensor, a controller computes respective target tilting amounts of hydraulic motorsand controls the tilting amount for the hydraulic motors and a clutch. Depending on whether the traveling speed exceeds a setting speed as a reference boundary, the controller selectively switches over a drive mode between low-speed four-wheel drive, in which travel unitsare both driven, and high-speed two-wheel drive, in which the front-wheel side hydraulic motoris controlled to zero displacement and only the rear-wheel side travel unitis driven.