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. 18, 2017
Filed:
May. 11, 2012
Koji Yamashita, Hiroshima, JP;
Masayuki Komiyama, Hiroshima, JP;
Kazushige Koiwai, Hiroshima, JP;
Koji Ueda, Hiroshima, JP;
Kengo Maeda, Kobe, JP;
Koji Yamashita, Hiroshima, JP;
Masayuki Komiyama, Hiroshima, JP;
Kazushige Koiwai, Hiroshima, JP;
Koji Ueda, Hiroshima, JP;
Kengo Maeda, Kobe, JP;
KOBELCO CONSTRUCTION MACHINERY CO., LTD., Hiroshima-shi, JP;
Kobe Steel, Ltd., Kobe-shi, JP;
Abstract
A slewing-type working machine includes: a slewing motor which is a hydraulic motor for slewing; a variable-displacement hydraulic pump; a slewing operation device including an operation member; a control valve controlling the slewing motor based on an operation signal thereof; a pump regulator; a relief valve letting excess fluid to a tank; operation detectors detecting an operation direction and amount of the operation member; a motor rotational speed detector; and a controller controlling a discharge flow rate of the hydraulic pump. The controller obtains a deviation between a target rotational speed of the slewing motor obtained from a slewing operation amount and an actual rotational speed detected by the motor rotational speed detector, and controls the discharge flow rate to make the deviation closer to 0.