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. 07, 2019
Filed:
Jan. 07, 2015
Kobelco Construction Machinery Co., Ltd., Hiroshima-shi, JP;
Hidekazu Oka, Hiroshima, JP;
KOBELCO CONSTRUCTION MACHINERY CO., LTD., Hiroshima-shi, JP;
Abstract
Provided is a hydraulic drive apparatus for a construction machine capable of achieving both of cavitation prevention and improvement of regeneration efficiency. The apparatus includes a regenerative motor configured to regenerate energy of hydraulic fluid discharged from a slewing motor, a first regeneration tank line for returning regeneration discharge fluid from the regenerative motor to a tank through a back pressure valve which is provided in a makeup line, a second regeneration tank line for returning the regeneration discharge fluid directly to the tank so as to bypass the back pressure valve, a regeneration-tank-line selector valve, and a regeneration-tank-line-selection control section configured to shift the regeneration-tank-line selector valve to pass the regeneration discharge fluid through the first regeneration tank line during slewing deceleration and otherwise through the second regeneration tank line.