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:
Mar. 03, 2015
Filed:
Apr. 12, 2012
Hajime Kurikuma, Koka, JP;
Tatsuo Takishita, Koka, JP;
Yuta Nakamura, Koka, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
An electromotive drive device of an electric motor-driven mini-excavator, which is capable of lengthening its operating time, includes an electric power storage device, a motor-generator, a hydraulic pump, a plurality of directional control valves which respectively control the flow of pressurized fluid, and a plurality of operating devices which respectively operate the plurality of directional control valves. The electromotive drive device is provided with a bidirectional converter which decelerates the motor-generator to an idle revolution speed when X seconds have elapsed in a state in which the plurality of directional control valves are all not operated. The bidirectional converter performs regenerative control to convert an inertial force of a rotor of the motor-generator to power and charge the electric power storage device when it decelerates the motor-generator from a standard revolution speed to the idle revolution speed.