Ocean tide energy converter

• US 4,208,878 A
• Filed: 07/06/1977
• Issued: 06/24/1980
• Est. Priority Date: 07/06/1977
• Status: Expired due to Term

• Current Assignee: Don E. Rainey
• Original Assignee: Don E. Rainey
• Inventors: Rainey, Don E.
• Primary Examiner(s): Ostrager, Allen M.
• Assistant Examiner(s): Husar, Stephen F.
• Application Number:
  US05/813,325
• Time in Patent Office: 1,084 Days
• Field of Search: 60/398, 60/495-498, 60/501, 60/504, 60/506, 60/503, 417/330, 417/331, 417/333, 290/53, 290/42
• US Class Current: 60/496
• CPC Class Codes: F03B 13/262 using the relative movement between a tide-operated member and another member
• CPC Class Codes: Y02E 10/30 Energy from the sea, e.g. using wave energy or salinity gradient

Abstract

A tide motor energy source includes a tidal piston with a valved chamber. The piston drives a hydraulic ram to generate electrical power through a pressure accumulator and hydraulic motor. The ram can be locked hydraulically to enable the tidal piston to be held fixed at a desired elevation and the valves in the chamber permit it to be filled with water or air. The piston with its chamber filled with air at its low tide position and then released for controlled ascent while submerged acts as a submerged float for driving the ram upwardly while the tide runs in during one phase of its operation. The piston with its chamber filled with water while locked at its highest position as the tide begins to run out, and then released to fall under control, acts as a weight suspended in air after the water level drops below the piston for driving the ram downwardly during the second phase of its operation. The rising and falling motion of the tidal piston is used as the energy source.

Claims

1. A tidal motor comprising:

(a) a vertically moveable buoyant member in the form of a piston including an enclosed chamber;

(b) valve means providing selective communication between the chamber interior and its exterior;

(c) control means for said valve means;

(d) a positive displacement hydraulic pump and hydraulic fluid in circuit with the pump, the pump having a moveable element connected to the piston and arranged to utilize both upward and downward motion of said piston to drive the moveable element of the pump to pressurize said hydraulic fluid;

(e) means for utilizing the pressurized hydraulic fluid to drain an electrical power generator;

(f) an hydraulic lock system capable of trapping said hydraulic fluid on opposite sides of said pump moveable element to selectively prevent vertical motion of the piston, said lock system being in circuit with said hydraulic fluid.

2. A method of utilizing the period changing level of a surface of water as a source of energy comprising:

(a) submerging a body in water having a cyclically rising and falling surface level in a manner limiting the body to move vertically, the body having a chamber associated therewith capable of being filled with and retaining air to provide positive buoyancy for the body, and valve means to selectively enable flooding of the chamber with water and to retain the water therein;

(b) locking the body while it is filled with air and positively buoyant in its lower position until it is totally submerged while the water surface level is rising;

(c) unlocking the body and utilizing the positive buoyancy of the body submerged in water as an energy source during a period while the water level is rising above the body;

(d) flooding the chamber with water and locking the body at an elevated position when the water has reached its maximum level and until it has dropped below the body a predetermined distance;

(e) unlocking the body and allowing it to fall in air at a controlled rate of descent, while utilizing the controlled falling weight of the filled body in air as an energy source during the period while the water level is dropping;

(f) wherein utilization of the vertical rising and falling motion of the body as an energy source is carried out by using a positive displacement hydraulic pump connected directly to the body and using the hydraulic fluid delivered by said pump as an energy source, and wherein the locking of the body is carried out by hydraulically trapping said fluid in the pump to prevent motion of its moveable part.