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:
Aug. 28, 2012
Filed:
May. 31, 2007
Christian Von Der Ohe, Kristiansand, NO;
Christian von der Ohe, Kristiansand, NO;
National Oilwell Norway AS, Kristiansand, NO;
Abstract
A system for active heave compensation of the running block in a drilling derrick on board a floating off shore platform comprises a double-acting hydraulic cylinder () which is connected to a hydraulic power unit () for the supply of hydraulic pressure fluid to the hydraulic cylinder (), a control unit () which regulates the supply conditions of the pressure fluid to the at any time active side (A, B) of the hydraulic cylinder, the hydraulic fluid concurrently being permitted to leave the passive side (B, A) of the hydraulic cylinder. The hydraulic power unit () comprises a pump unit () which via respective conduits () are directly connected to the two sides (A, B) of the hydraulic cylinder () in order to form a generally closed hydraulic system therewith. The hydraulic fluid delivered by the pump unit () to the conduits () to the active cylinder side is drawn from the conduit () to the passive cylinder side, while the control unit regulates the output of the pump unit. The hydraulic system further comprises an accumulator () which equalizes the volumetric difference between the two sides of the hydraulic cylinder when it is a common double-acting cylinder. The system may also be provided with a hydraulic transformer () for regeneration of hydraulic power during passive operation of the compensation system.