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.

Date of Patent:
Dec. 25, 2012

Filed:

Nov. 26, 2007
Applicants:

Yuuji Matsuura, Kobe, JP;

Naoki Sugano, Kobe, JP;

Takao Nanjo, Kobe, JP;

Hiroshi Togo, Hiroshima, JP;

Hidekazu Oka, Hiroshima, JP;

Inventors:

Yuuji Matsuura, Kobe, JP;

Naoki Sugano, Kobe, JP;

Takao Nanjo, Kobe, JP;

Hiroshi Togo, Hiroshima, JP;

Hidekazu Oka, Hiroshima, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F15B 21/14 (2006.01); E02F 9/22 (2006.01);
U.S. Cl.
CPC ...
Abstract

A hydraulic drive device capable of utilizing return oil effectively while maintaining a driven speed of a hydraulic actuator, as well as a working machine having the hydraulic drive device, are provided. The hydraulic drive device includes a controller. During an external force applying period in which a return oil pressure exceeds a discharge pressure from a hydraulic pump, the controller specifies a regenerating flow rate capable of being conducted to a regeneration oil passage and a surplus flow rate other than the regenerating flow rate on the basis of power required of the hydraulic pump out of return oil other than return oil which is conduced to a tank through a control valve, then conducts the return oil of the regenerating flow rate to the regeneration oil passage and controls an MO valve and a regulator so that the return oil of the surplus flow rate is conducted to an outlet oil passage.


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