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:
Apr. 03, 2012
Filed:
Nov. 28, 2007
Tsutomu Udagawa, Tsukuba, JP;
Akira Nakayama, Tsuchiura, JP;
Tsukasa Toyooka, Omitama, JP;
Makoto Sugaya, Narita, JP;
Tsutomu Udagawa, Tsukuba, JP;
Akira Nakayama, Tsuchiura, JP;
Tsukasa Toyooka, Omitama, JP;
Makoto Sugaya, Narita, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
A travel drive system for a work vehicle includes: an HST drive device comprising a hydraulic pump driven by a prime mover and a hydraulic motor connected to the hydraulic pump by a closed circuit; an electric motor driven by using electric power generated by drive of the prime mover; a first drive wheel driven by the HST drive device; a second drive wheel driven by the electric motor; a vehicle speed detector that detects a vehicle speed; and a control unit that distributes output of the prime mover to the HST drive device and to the electric motor such that, as the vehicle speed detected by the vehicle speed detector increases, a proportion of a first power distributed to the HST drive device decreases and a proportion of a second power distributed to the electric motor increases.