Abstract: The present invention provides a controller for a pendulum type wave-power generating apparatus. Electric power produced by wave-power generation has been pointed out as being of low efficiency and more expensive than wind-power generation. To overcome the above problems, the present invention uses resonance and impedance matching of the sea waves, thus making it possible to markedly enhance the efficiency of wave-power generation. The present invention does not use a wave-height meter which is generally expensive and controls the generating apparatus in response to variation of the conditions of the sea, thus automatically maintaining the resonance and impedance matching operation, thereby making high-efficiency operation possible. As a result, the cost of the wave-power generation can be reduced, so that the wave-power generation can be widely commercialized.

Abstract: The present invention provides a controller for a pendulum type wave-power generating apparatus. Electric power produced by wave-power generation has been pointed out as being of low efficiency and more expensive than wind-power generation. To overcome the above problems, the present invention uses resonance and impedance matching of the sea waves, thus making it possible to markedly enhance the efficiency of wave-power generation. The present invention does not use a wave-height meter which is generally expensive and controls the generating apparatus in response to variation of the conditions of the sea, thus automatically maintaining the resonance and impedance matching operation, thereby making high-efficiency operation possible. As a result, the cost of the wave-power generation can be reduced, so that the wave-power generation can be widely commercialized.

Abstract: Disclosed herein is an oscillating vane type pump actuator. The pump actuator of the present invention provides a method of preventing fretting corrosion from being caused on joined surfaces of elements. A cylinder (3c) has a comparatively low radial strength, and each of side covers (1c) and (2c) has a high radial strength. A cylindrical portion (1c-c), (2c-c) is provided on each side cover. Thus, when high pressure of work oil distorts the cylinder into a shape in which the cross-section of the cylinder becomes an ellipse-like shape, the cylindrical portions of the side covers act such that they are distorted in the same shape as that of the cylinder. Further, a passage that always communicates with a low-pressure side working chamber is formed in the contact surfaces between a fixed vane that is fixed to the cylinder and the side covers.

Abstract: The present invention provides a controller for a pendulum type wave-power generating apparatus. Electric power produced by wave-power generation has been pointed out as being of low efficiency and more expensive than wind-power generation. To overcome the above problems, the present invention uses resonance and impedance matching of the sea waves, thus making it possible to markedly enhance the efficiency of wave-power generation. The present invention does not use a wave-height meter which is generally expensive and controls the generating apparatus in response to variation of the conditions of the sea, thus automatically maintaining the resonance and impedance matching operation, thereby making high-efficiency operation possible. As a result, the cost of the wave-power generation can be reduced, so that the wave-power generation can be widely commercialized.

Abstract: Disclosed herein is an oscillating vane type pump actuator. The pump actuator of the present invention provides a method of preventing fretting corrosion from being caused on joined surfaces of elements. A cylinder (3c) has a comparatively low radial strength, and each of side covers (1c) and (2c) has a high radial strength. A cylindrical portion (1c-c), (2c-c) is provided on each side cover. Thus, when high pressure of work oil distorts the cylinder into a shape in which the cross-section of the cylinder becomes an ellipse-like shape, the cylindrical portions of the side covers act such that they are distorted in the same shape as that of the cylinder. Further, a passage that always communicates with a low-pressure side working chamber is formed in the contact surfaces between a fixed vane that is fixed to the cylinder and the side covers.

Abstract: According to the present invention, a simple, strong and economical resonant type apparatus for absorbing wave energy which can generate electric power at high efficiency, yet can withstand extraordinary sea phenomenon such as typhoon with minimum investment and maintainance costs.

Abstract: At least one caisson which is part or all of a breakwater forms a water chamber therein whose closure is a pendulum having a natural period in rocking or oscillating the same as a period of stationary wave surges caused in the water chamber by rocking movement of the pendulum owing to wave force impinging against the pendulum. At least one double-acting piston and cylinder assembly is connected to the pendulum, so that when a piston of the assembly is reciprocatively moved by the pendulum, pressure difference between cylinder chambers on both sides of the piston of the assembly controls a change-over valve which in turn controls hydraulic pressure discharged from the cylinder chambers to be supplied to a plurality of hydraulic motors respectively having accumulators of a type wherein accumulated pressure and volume of the hydraulic liquid are proportional to each other, whereby driving a common generator alternately by the hydraulic motors.

Abstract: A resonant type apparatus for absorbing wave energy arranged at wave-breaking facilities, which comprises, a caisson having a bottom plate, side plates, a backside plate and a top plate at least a part of which is omitted. A water chamber in the caisson has a length in a directional parallel to the side walls which is larger than 1/4 of the wave length Lc of a stationary wave within the water chamber, and a node of the stationary wave in the water chamber is formed at a distance Lc/4 from the backside plate. A pendulum is arranged at the position of the node of the stationary wave for swinging with a natural period Tp which is substantially the same value as the natural period Tw of the stationary wave, whereby the pendulum is swung by the stationary wave to absorb and convert wave energy to useful available energy at high efficiency.