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 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: 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 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).