Abstract: A power take-off device for use in a wave energy converter unit having a buoy includes a power take-off hull connectable to a mooring device, and connected to or connectable to the buoy, preferably by a link rope, and a power extracting device adapted to extract power as the buoy moves with the waves, by applying up to a predetermined maximum control force. A two-stage end-stop cushioning system comprises a first stage end-stop cushioning device having a first fluid cylinder adapted to apply an additional deceleration force on the device above the maximum control force, and a second stage end-stop cushioning device adapted to be extended like a spring in an end-stop operation after the first stage has been activated and when the power take-off force is higher than the above the maximum control force, to hold the buoy submerged through the crest of a large wave.

Abstract: A power take-off device for use in a wave energy converter unit having a buoy includes a power take-off hull connectable to a mooring device, and connected to or connectable to the buoy, preferably by a link rope, and a power extracting device adapted to extract power as the buoy moves with the waves, by applying up to a predetermined maximum control force. A two-stage end-stop cushioning system comprises a first stage end-stop cushioning device having a first fluid cylinder adapted to apply an additional deceleration force on the device above the maximum control force, and a second stage end-stop cushioning device adapted to be extended like a spring in an end-stop operation after the first stage has been activated and when the power take-off force is higher than the above the maximum control force, to hold the buoy submerged through the crest of a large wave.

Abstract: A buoy for a wave energy converter system comprises an attachment portion and a plurality of buoyancy block assemblies supported by support portions. By providing the support portions so that they form an integral support structure, an improved buoy design is provided which is easier to manufacture and which exhibits reduced weight and improved durability. A wave energy converter comprising the buoy and method of manufacturing a buoy are also provided.

Abstract: A buoy, preferably for a wave energy converter system, comprises a central portion; and one or a plurality of buoyancy blocks connected, directly or indirectly, to the central portion. By providing the central portion with a bell mouth opening and attachment means for a wire or rope, a buoy with improved characteristics is provided.

Abstract: A wave energy absorption device comprises a buoy adapted to move with movements of water, and a buoy oscillation device attached to the buoy, the buoy oscillation device comprising an elongated means and a rotary means adapted to interact with the elongated means. A hydraulic pump with variable displacement is connected to the rotary means and connectable to a hydraulic circuit. When the buoy moves with movements of water, relative movement is created between the elongated means and the rotary means, whereby the hydraulic pump transforms kinetic energy into hydraulic energy which to the hydraulic hose, and whereby a torque is applied to the rotary means by the hydraulic pump to dampen or amplify the movements of the buoy. The buoy oscillation device provides individual control of the force applied to the buoy by change of displacement in the hydraulic pump.

Abstract: A wave energy converter comprises an energy absorption unit arranged to absorb energy generated by movements of water, a power smoothing unit, a power generation unit and an energy storage device, these units being adapted to cooperate to achieve a smooth power output from the power generation unit. The power smoothing unit is arranged to accumulate energy from the energy absorption unit in the energy storage device when the energy absorption unit absorbs more power than the power generation unit generates and to release energy from the energy storage device to the power generation unit when the energy absorption unit absorbs less energy than the power generation unit generates.

Abstract: A wave energy converter (10) comprises an energy absorption unit (100) arranged to absorb energy generated by movements of water when the wave energy converter is arranged in a pool of water, an energy accumulation unit (200) connected to the energy absorption unit, and a power generation unit (300) connected to the energy absorption unit. The energy accumulation unit is arranged to accumulate energy from the energy absorption unit when the energy absorption unit absorbs more power than the power generation unit generates and to dissipate energy to the power generation unit when the energy absorption unit absorbs less power than the power generation unit generates. By providing hydraulic components in these units, an efficient and flexible wave energy converter is provided.

Abstract: A wave energy converter (10) comprises an energy absorption unit (100) arranged to absorb energy generated by movements of water when the wave energy converter is arranged in a pool of water, an energy accumulation unit (200) connected to the energy absorption unit, and a power generation unit (300) connected to the energy absorption unit. The energy accumulation unit is arranged to accumulate energy from the energy absorption unit when the energy absorption unit absorbs more power than the power generation unit generates and to dissipate energy to the power generation unit when the energy absorption unit absorbs less power than the power generation unit generates. By providing hydraulic components in these units, an efficient and flexible wave energy converter is provided.

Abstract: A wave power plant includes a buoy and a power train. In the power train a driveshaft is arranged, which is driven to rotate either when the buoy rises or sinks, but always in the same direction. The driveshaft is mechanically coupled to one of the rotating parts of an electric generator and drives it for generating electric current. Furthermore, an energy accumulation device is provided which is also coupled to the driveshaft to accumulate energy when the buoy is rising or sinking and the driveshaft is rotating for driving the generator during the other of the rising and sinking movements. The coupling between the energy accumulation device and the driveshaft can extend via the other rotatable part of the generator, the air gap between the parts of the generator and the first part of the generator. The coupling over the air gap gives a torque, which drives the second part to rotate in one direction and which also counteracts the rotation of the driveshaft.

Abstract: A wave energy converter includes a buoy and a power takeoff. A driveshaft in the power takeoff is driven to rotate by movements of the buoy and is mechanically coupled to an electric generator through a planetary gearbox and drives it for generating electric current at an even level, while storing excess energy in an energy accumulation device. The energy accumulation device is coupled to the generator through another part of the planetary gearbox for driving the generator during the other of the rising and sinking movements with continued torque, rotation speed and rotational direction. Major portions of the driveshaft can be located at a radial distance of the generator, allowing the generator and also components coupling the rotation of the portions of the driveshaft to the generator to be located in a sealed space, the only bearings that have to be sealed to the water being those that support said portions of the driveshaft.

Abstract: A wave energy converter includes a buoy and a transmission unit. In the transmission unit there is a driveshaft, which is driven to rotate either when the buoy rises or sinks, yet always in the same direction. The driveshaft is mechanically coupled to one of the rotating parts of an electric generator and drives this to generate electric current. Further on there is an energy accumulation device, which is also coupled to the driveshaft to accumulate energy when the buoy rises or sinks and the driveshaft rotates and which is then used to drive the generator at the other of the rising and sinking motions. The coupling between the energy accumulation device and the driveshaft can go by the generator's second rotatable part, the air gap between the generator's parts and the generator's first part. The coupling over the air gap gives a torque, which drives the second part to rotate along and which also counteracts the rotation of the driveshaft.