Patent ID: 7530224

Claim:
A hydraulic transmission system for deriving power from a flow of water, the system comprising: a water current turbine assembly submerged in a body of water containing a current, the water current turbine assembly including a flowing water actuatable rotor coupled to a rotor shaft, the rotor operationally responsive to the water current to rotate the rotor shaft, a pump system for a hydraulic fluid supplied from the body of water to avoid pollution of the body of water when leakage of the hydraulic fluid occurs, the pump system configured to pressurize the hydraulic fluid to actuate a power producing assembly, the pump system comprising at least one low speed, high pressure pump directly coupled to the rotor shaft, and a pressure circuit comprising a fluid supply line and a fluid return line connected between the at least one pump and the power producing assembly, wherein the rotor shaft is configured to drive the at least one pump to pressurize the hydraulic fluid within the fluid supply line to be applied to the power producing assembly and thereafter the hydraulic fluid is returned by way of the fluid return line to the at least one pump for retransmission in the pump system, and wherein the power producing assembly is positioned above the water current turbine assembly and includes a hydraulic motor configured to rotate in response to the pressurized hydraulic fluid at a rotation rate higher than and independent of the rotor shaft, the hydraulic motor being coupled to a drive shaft of a power generator, and an intake adapted to receive make up hydraulic fluid from the body of water, and a header tank configured to store the make up hydraulic fluid, the header tank connected to the intake through a make up fluid supply line and connected to the at least one pump through a make up fluid return line, wherein the header tank is disposed such that a water static level thereof is immediately below the power producing assembly, and when the level of the hydraulic fluid in the fluid return line falls below the water static level, make up hydraulic fluid stored in the header tank flows therefrom through the make up fluid return line to the at least one pump.