Abstract: A valve assembly for regulating the flow of working fluid between a working chamber of a fluid working machine and a working fluid gallery comprises: a valve comprising a valve member and one or more cooperating valve seats; an actuator actuatable to apply a force to urge the valve member away from or towards the one or more valve seats; and a coupling between the actuator and the valve member. The coupling comprises a connector located at least partially within a tube. A connector void provided between at least a portion of the connector and the tube is in fluid communication with a working fluid gallery outlet.

Abstract: A valve assembly for regulating the flow of working fluid between a working chamber of a fluid working machine and a working fluid gallery comprises: a valve comprising a valve member and one or more cooperating valve seats; an actuator actuatable to apply a force to urge the valve member away from or towards the one or more valve seats; and a coupling between the actuator and the valve member. The coupling comprises a connector located at least partially within a tube. A connector void provided between at least a portion of the connector and the tube is in fluid communication with a working fluid gallery outlet.

Abstract: A series hydrostatic transmission for a vehicle having a wheel where the transmission comprises a hydraulic pump and a hydraulic motor each having a pumping mode and motoring mode. The pump and motor each have cylinders of cyclically varying working volume in which hydraulic fluid displacement through each cylinder is regulated and in phased relationship to cycles of cylinder working volume with reference to a phase signal. The transmission has a first mode in which the pump and motor are fluidly connected to each other, a second mode in which energy from hydraulic fluid pressurised by the motor in the pumping mode is transferred to an energy store, and a third mode in which energy from the energy store drives the motor, and wherein the motor comprises a valve assembly disposed between a high pressure line and a working chamber of the motor.

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 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 power generating apparatus is provided with a hub rotated by the renewable energy received via a blade, a rotating shaft connected to the hub, a hydraulic pump mounted on the rotating shaft and driven by rotation of the rotating shaft, a hydraulic motor driven by pressurized oil from the hydraulic pump, a generator coupled to the hydraulic motor, a support providing reaction torque on the hydraulic pump from the rotating shaft while allowing a displacement of the hydraulic pump in a direction perpendicular to an axis of the rotating shaft, the hydraulic pump being supported by a nacelle through the support, and a pressurized-oil piping which is at least partially constituted of a flexible tube and which connects an outlet port of the hydraulic pump to an inlet port of the hydraulic motor to supply the pressurized oil from the hydraulic pump to the hydraulic motor.