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:
Feb. 05, 1991
Filed:
Aug. 21, 1989
Richard A Gabellini, Aptos, CA (US);
Lynn A Stuart, Portland, OR (US);
Hydra-Power Systems, Inc., Portland, OR (US);
Abstract
The hydraulic piston cylinder assembly which operates the governor of a turbine which powers a hydropower generator has a servo valve capable of flowing only a portion of its flow requirements during normal low power fluctuation conditions of the turbine's operation. During high power fluctuation conditions of the turbine's operation, such as during start-up, hydraulic fluid also flows to and from the piston and cylinder assemblies through high flow pressure and return conduits that bypass the servo valve. Control of fluid flow in the high flow conduits is accomplished by a proportional throttling valve located in the high flow return line. The servo valve and proportional throttling valve together have a flow capacity which is equal to the flow requirements of the piston and cylinder assembly and they are both actuated by the same electronic controller. However, the electronic controller only actuates the proportional throttling valve when the flow requirement of the piston and cylinder assembly exceeds the flow capacity of the servo valve. A hydraulic logic circuit activated by the electronic controller allows the high flow pressure and return conduits to be reversed for two-way operation of the piston and cylinder assembly.