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. 20, 2012
Filed:
Apr. 30, 2008
Toshiyuki Sakai, Osaka, JP;
Kenichi Kawata, Osaka, JP;
Toshiyuki Sakai, Osaka, JP;
Kenichi Kawata, Osaka, JP;
Daikin Industries, Ltd., Osaka, JP;
Abstract
A hydraulic unit is switched among a first region A where a flow rate is adjusted by controlling a rotational speed of an electric motor while maintaining a displacement of a variable displacement pump at a maximum value, a second region B where the flow rate is adjusted by changing the displacement of the variable displacement pump while maintaining the rotational speed of the electric motor at a minimum value lower than the rotational speed in the first region A, and a third region C where, in a range where a discharge pressure of the variable displacement pump is larger than that in the first region A, the flow rate is adjusted by changing the rotational speed of the electric motor in a range larger than the minimum rotational speed, while maintaining the displacement of the variable displacement pump at an allowable maximum value that is derived from the discharge pressure and a maximum shaft torque of the electric motor.