Abstract: A wind turbine generator (100), or other energy extraction device, has a hydraulic circuit comprising a hydraulic pump (129) driven by a rotating shaft (125) and a hydraulic motor (131) driving an electricity generator (157), or other load. A high pressure manifold (133) extending between the pump and motor is in communication with an accumulator (145, 147, 149). A controller receives a control signal and regulates the displacement of working fluid by the hydraulic pump and the hydraulic motor relative to each other. Thus, power input through the rotating shaft and output to the load can be decoupled for at least a period of time and the energy output of energy extraction device can be varied, for example to smooth the total power output to an electricity grid (101), without compromising power input. A group of energy extraction devices can be controlled in concert to maximise power input while providing smooth power output.

Abstract: A hydraulic pump comprises (1) an outward ring (24), including demountable blocks (30) comprising piston cylinders (32), and an inward ring (21), comprising a ring cam (23), coupled through a drive shaft (8) to the blades of a turbine (4). To enable maintenance, the outward ring is decoupled from a torque limiting device (16, 17) and rotated relative to the inward ring. Demountable blocks are then removed from the outward ring using a crane (61) including a line (62) extending from above the centre of mass of the demountable block and including a resilient portion (66) so that although the crane supplies the majority of the force required to remove the demountable block, an operator provides some force, enabling the process to be controlled. The method is suitable for maintaining large hydraulic pumps in wind turbine nacelles (2).

Abstract: A fluid working machine has at least one working chamber of cyclically varying volume and low and high pressure valves to regulate the flow of working fluid into and out of the working chamber, from low and high pressure manifolds. The low and high pressure valves are actuated by electronically controlled valve actuation means which, when actuated, applies forces to the low and high pressure valve members to open and/or close the respective valves. The low and high pressure valve members are independently moveable and, although the low pressure valve member typically begins to move quickly in response to a shared valve control signal, the high pressure valve member typically moves only after a change in the pressure within the working chamber.

Abstract: An annular valve (1) has an annular valve member (4) and inner and outer annular valve seats (12, 14). Inner and outer sealing ridges (8, 10) are formed either on the annular valve member or on the valve seats. The inner sealing ridges are more resistant to plastic deformation than the outer sealing ridges. They may be thicker, or made from a harder material. Thus, the annular valve better resists damage arising from greater plastic deformation of the inner sealing ridge than the outer sealing ridge due to greater forces (Fi, Fo) acting on the inner sealing ridge than the outer sealing ridge in use.

Abstract: Disclosed is a cylinder assembly (1) for a fluid-working machine, the assembly comprising a body (2) having a first end (3) and a second end (4) and comprising a cylinder (5), a poppet valve seat (9) and a face-sealing annular valve seat 7). The cylinder is open to the first end and configured to receive a reciprocating piston (210) and the poppet and annular valve seats extend around an axis through the cylinder. An annular valve including the annular valve seat and an annular valve member extends around the cylinder. Thus, the cylinder assembly is compact. Advantageously, the body is a continuous unitary structure which comprises all of the parts of the body which must be made of, or coated with, a hardened material. Thus the body is stronger and may be constructed with less material than has previously been possible. Additionally, the arrangement of the cylinder body facilitates manufacture, assembly and maintenance of a cylinder assembly and its insertion into the body of a fluid working machine.

Abstract: Sail membrane preferably made of a woven fabric of synthetic fibers, with said membrane having a microroughness in the form of parallelly extending grooves arranged so as to achieve a density of 5 to 25 grooves/mm deposited on or integrated into said membrane surface.

Abstract: A power generating apparatus includes a rotating shaft, a hydraulic pump driven by the rotating shaft, a hydraulic motor driven by pressurized oil supplied from the hydraulic pump, and a generator coupled to the hydraulic motor. Each of the hydraulic pump and motor includes working chambers each defined by a cylinder and a piston, a high pressure manifold and a low pressure manifold. Each of the high and low pressure manifolds includes branch channels connected to the working chambers and a merging channel connected to a high or low pressure oil line. The branch channels are equipped with high or low pressures valves, joined together and merged into the merging channel.

Abstract: A large hydraulic radial piston pump suitable to be driven by the turbine of a wind turbine generator has a circular cover formed from at least three cover segments. Underneath the cover segments a seal in the form of a vulcanised rubber band extends around the entire periphery of the pump. Thus, the cover can be readily removed within the difficult to access location of a wind turbine nacelle, but a reliable seal can still be formed. An air pocket outside the seal, or within the seal, facilitates pulsatile flow into the cylinders of the pump during operation.

Abstract: A renewable energy turbine generator (1), such as a wind turbine generator, comprises a hydraulic pump (20), a hydraulic motor (24) and an oil circuit (26, 28) connecting the hydraulic pump and the hydraulic motor. Oil in the low pressure side (28) of the oil circuit is cooled and supplied to the working chambers (95) of the hydraulic pump. A reduced temperature oil feed provides additionally cooled oil to the bearings of the hydraulic pump and the hydraulic motor. Thus, cooler and more viscous oil is supplied to the bearings (84) of the hydraulic pump and/or hydraulic motor and warmer and less viscous oil is supplied to the working chambers, increasing the efficiency and lifetime of the bearings and of the working portions of the hydraulic pump and motor.

Abstract: A face sealing annular valve (1) for a fluid-working machine has an annular valve member (10, 50, 60, 70, 80, 90, 100, 110) having a relaxed configuration in which a first seat-engaging surface (14, 101) of the annular valve member can sealedly engage with a first sealing surface of an annular valve seat (8), but a second seat-engaging surface (15, 101) cannot sealedly engage with a second sealing surface (9), and is elastically deformable to a deformed configuration in which the second seat-engaging surface can sealedly engage with a second sealing surface, while the first seat-engaging surface remains sealedly engaged with the first sealing surface. The annular valve member can be made with relatively high tolerances and is only loosely retained by a guide in the relaxed configuration.

Abstract: In a face sealing annular valve, an annular valve member is retained around or within a guide. The annular valve member is configured so that, when the annular valve member and the annular valve seat are coaxial, the spacing between the guide means and the guide-engaging surface region increases with distance along the central axis from a minimum of spacing between the annular valve member and the guide means. An end stop limits the tilt of the annular valve member. Advantageously, the annular valve member has restricted radial movement, enabling a good seal to be formed, while being unable to simultaneously contact diametrically opposite sides of the guide and jam.

Abstract: An object of the present invention is to provide a wind turbine generator and a tidal current generator equipped with a hydraulic transmission with a combination of a hydraulic pump and a hydraulic motor and which has a superior productivity and maintainability. The wind turbine generator 1 has the hydraulic transmission 10 for transmitting the rotation energy of a main shaft 8 to a generator 20. The hydraulic transmission 10 includes a hydraulic pump 12 of variable displacement type which is driven by the main shaft 8, a hydraulic motor 14 of variable displacement type which is connected to the generator 20, and a high pressure oil line and a low pressure oil line which are arranged between the hydraulic pump 12 and the hydraulic motor 14. The hydraulic transmission 10 is at least partially constituted of a plurality of modules (M1 to M7).

Abstract: A wind turbine generator, or other energy extraction device, has a hydraulic circuit comprising a hydraulic pump driven by a rotating shaft and a hydraulic motor driving an electricity generator. When the electricity generator is switched off, it executes one or more pumping cycles to pressurise the high pressure manifold and therefore recover angular kinetic energy from the electricity generator rotor which can later be used to reaccelerate the electricity generator rotor to the correct operating speed for an electricity grid. Overall energy efficiency is increased and the minimum operating high pressure manifold pressure may be reduced as a result.

Abstract: An object of the present invention is to provide a wind turbine generator and a tidal current generator equipped with a hydraulic transmission with a combination of a hydraulic pump and a hydraulic motor and which has a superior productivity and maintainability. The wind turbine generator 1 has the hydraulic transmission 10 for transmitting the rotation energy of a main shaft 8 to a generator 20. The hydraulic transmission 10 includes a hydraulic pump 12 of variable displacement type which is driven by the main shaft 8, a hydraulic motor 14 of variable displacement type which is connected to the generator 20, and a high pressure oil line and a low pressure oil line which are arranged between the hydraulic pump 12 and the hydraulic motor 14. The hydraulic transmission 10 is at least partially constituted of a plurality of modules (M1 to M7).

Abstract: An object of the present invention is to provide a hydraulic pump structure which improves the ease of mounting the hydraulic pump on the main shaft, and a method of mounting the hydraulic pump which can be performed in a simplified manner. A hydraulic pump unit 10 is formed by unitizing a cylindrical member 46 fit into an outer circumference of the main shaft 12 and a hydraulic pump body 76 arranged on an outer circumferential side of the cylindrical member 46. The hydraulic pump body 76 comprises a ring cam 52 mounted on the outer circumference of the cylindrical member 46, a pump bearing 54, a pump housing 34, a plurality of piston 58 housed in the pump housing 34 and actuated by the ring cam, and a plurality of cylinders 60 which guide the plurality of pistons in a radial direction and are arranged in a circumferential direction, and the hydraulic pump unit 10 is configured such that the pump unit 10 is insertably fixed to the main shaft 12 by the cylindrical member 46.

Abstract: In usual hydraulic pumps, a separate assembly opening is provided for every valve of the hydraulic pump. This design causes sealing problems. It is proposed, that the fluid inlet valve (67) and the fluid outlet valve (74) can be assembled through a common assembly access port (38).

Abstract: Sailcloth of longitudinal direction (machine direction) including a carrier layer, an intermediate layer with several plies of laid yarn as well as a finishing layer, with the yarns being bonded under pretension with the carrier layer and the layers joined with each other, the intermediate layer includes at least three yarn layers the yarns of which being laid at an angle ranging between 55 and 125° relative to the longitudinal direction so that at angles of 60° to 120° and 240° to 300° in relation to the longitudinal direction the cloth has a stretching resistance at 1% of expansion of at least 150 Ibf (667 N).

Abstract: Sail membrane made of a woven fabric of synthetic fibers, with said fabric having a microroughness in the form of groove families crossing one another arranged so as to achieve a density of 5 to 25 grooves/mm deposited on or integrated into said fabric structure.

Abstract: Sail membrane preferably made of a woven fabric of synthetic fibers, with said membrane having a microroughness in the form of parallelly extending grooves arranged so as to achieve a density of 5 to 25 grooves/mm deposited on or integrated into said membrane surface.

Abstract: A fluid-working machine has working chambers (4), each of which is connected to a fluid commutating means (2) which alternately connects the working chamber to either of two fluid manifolds (A, B). An electronically controlled valve (1) is inserted into the flow path between each chamber (4) and the commutating means. This valve is commanded by a controller (6) receiving an input signal of the phase angle of the shaft (5) of the machine or at least one electronic pulse per revolution which informs the controller that the shaft is passing a known phase angle. The valve (1) allows overriding of fixed mechanical commutation by closing the valve cyclically, synchronised with the angular position of the shaft (5). Thus the controller (6) is able to vary the time-averaged fluid flow into or out of the machine by varying the proportion of chambers (4) which are isolated from or connected to the mechanical commutating means (2), to control the torque, speed, and/or fluid flow into and out of the machine.