An asymmetric bistable shape memory alloy inertial actuator capable of preventing accidental actuation caused by environmental temperature variations but preserving temperature-related safety features and its use in devices.

A turbine of a power generating system includes a rotary shaft, blades, stoppers and elastic members. Each of the blades includes a connecting side and an active side opposite to the connecting side, and the blades are disposed on the rotary shaft at intervals by a predetermined distance, in which the blades are pivotally connected to the rotary shaft through the connecting sides. The stoppers respectively correspond to the blades and are disposed over the rotary shaft for limiting expansion angles of the blades. Each of the elastic members includes a fixed end and a moving end opposite to the fixed end, and the fixed ends attach to the rotary shaft, and the moving ends respectively attach to the blades. Each of the blades pivots between an expanded position and a closed position.

A hydrokinetic energy based power generation system is described, including several modules filled with fluid or vacuum and anchored to a stream bed of water body, multiple basic units associated with each module for converting hydrokinetic energy into electrical energy, wherein each basic unit includes two springs affixed with a top and bottom portion of the modules in such a way that the hydrokinetic energy induces vibrations within the springs, a cylindrical tube positioned between the springs, and contained with a ferromagnetic fluid, two fixed magnets and a movable magnet, wherein the movable magnet oscillates in between the fixed magnets due to the induced disturbances caused by waves/ocean and repulsive forces caused by the fixed magnets, an electric coil associated with the tube, for generating electric current by harnessing the relative motion of the movable magnet and electric coil due to electromagnetism phenomenon and in accordance with laws of electromagnetic induction.

An asymmetric bistable shape memory alloy inertial actuator capable of preventing accidental actuation caused by environmental temperature variations but preserving temperature-related safety features and its use in devices.

A wind turbine includes a rotation axis suited to be positioned in space in any way and N blades indirectly constrained to the axis through one or more radial arms that are integral with the axis, wherein the blades can translate in a radial direction with respect to the axis during the rotation of the blades.

A lightning current transfer unit for a wind turbine, the wind turbine comprising a first part and a second part being rotatable relative to each other, wherein the lightning current transfer unit is arranged to provide electrical contact between the first and second parts, the lightning current transfer unit comprising: a first current transfer portion comprising a first slider and configured to be electrically coupled to a first electrically conducting slideway of the first part of the wind turbine, the first slider being rotatable relative to the first slideway; a second current transfer portion configured to be electrically coupled to an electrically conducting portion of the second part of the wind turbine; a first main spring biasing the first slider towards the first slideway; wherein the first slider comprises: a primary contact biased towards the first slideway by the first main spring; a secondary contact arranged to move relative to the primary contact; and a secondary spring arranged between the first main spring and the secondary contact such that the secondary spring biases the primary contact away from the first slideway and biases the secondary contact towards the first slideway.

Disclosed is a method of adaptively adjusting lift and drag on an airfoil-shaped sail. The method includes: (1) mounting at least one airfoil-shaped sail body having an airfoil-shaped cross section; (2) defining a Y-shaped air jet channel in the airfoil-shaped sail body; (3) arranging a flow regulating gate in the Y-shaped air jet channel; (4) adjusting the flow regulating gate to automatically adjust the gate opening extent and the cross section opening or closing extent in response to an oncoming flow with a varying direction and speed, to regulate the airflow within the air jet channel and accordingly change the angle of attack, so that the lift and drag on the sail body can be automatically adjusted as the wind speed changes. Further disclosed are an airfoil-shaped sail implementing the above method as well as a vertical-axis wind turbine employing the airfoil-shaped sail.

A linear compressor according to an embodiment of the present invention comprises: a shell; a cylinder which is provided inside the shell and forms a compression space of a refrigerant; a frame which is coupled to the outer side of the cylinder; a piston which is provided so as to perform a reciprocating movement in an axial direction inside the cylinder; a motor which supplies power to the piston; and a spring mechanism which is coupled to the piston to allow the piston to perform a resonant movement, wherein the spring mechanism may comprise: a support which is connected to the piston and comprises a spring support unit having one or more insertion holes formed therein; a first coupling protrusion which extends from the rear side of the spring support unit along the edge of the insertion hole; a support cap which is inserted into the insertion hole and comprises a second coupling protrusion protruding from the front side of the spring support unit; a first resonant spring which is inserted into the outer circumferential surface of the second coupling protrusion; and a second resonant spring which is inserted into the outer circumferential surface of the first coupling protrusion.

An oscillation damper for damping unwanted oscillations in oscillation-sensitive systems, such as tall edifices and towers, especially wind turbines. The oscillation damper has a vertical spring mechanism and the oscillation characteristics, such as the frequency and amplitude, and thus the damping capabilities, can be adjusted across a wide range of values.

A generating apparatus for converting kinetic energy from a water flow to electrical energy includes a housing including an inlet, a passage, and an outlet; an actuation device including a cylindrical member secured to the housing; an actuation member pivotably secured to the cylindrical member and having a spring biased downward extension in the passage and a horizontal lever; and a striking member disposed on an end of the lever; a rotational device including a power wheel rotatably mounted on a column; and a generator operatively connected to the rotational device. The generator produces electrical power output in response to water currents flowing through the inlet and impinging the extension, both the extension and the lever pivoting counterclockwise, the striking member hitting the power wheel, and the power wheel rotating about to the column. There is a guide member at an end of the downward extension.