Abstract: The invention to a valve unit (1) for a synthetically commutated fluid working machine (51), comprising a valve body (19,57), a movably arranged valve unit (3) and a separate fluid flow influencing unit (13, 25, 31, 35, 46, 56). The fluid flow influencing unit (13, 25, 31, 35, 46, 56) comprises a fluid flow influencing means part (18) and an attachment means part (28, 34, 38) for mechanical connection with the valve body (19). The attachment means part (28, 34, 38) and the fluid flow influencing unit (18) are connected to each other by a connection means part (27, 30, 33, 40, 47). The circumferential extent of the attachment means part (28, 34, 38) is larger as compared to the circumferential extent of the connection means part (27, 30, 33, 40, 47).

Abstract: The invention to a valve unit (1) for a synthetically commutated fluid working machine (51), comprising a valve body (19,57), a movably arranged valve unit (3) and a separate fluid flow influencing unit (13, 25, 31, 35, 46, 56). The fluid flow influencing unit (13, 25, 31, 35, 46, 56) comprises a fluid flow influencing means part (18) and an attachment means part (28, 34, 38) for mechanical connection with the valve body (19). The attachment means part (28, 34, 38) and the fluid flow influencing unit (18) are connected to each other by a connection means part (27, 30, 33, 40, 47). The circumferential extent of the attachment means part (28, 34, 38) is larger as compared to the circumferential extent of the connection means part (27, 30, 33, 40, 47).

Abstract: An electronically controlled valve includes a valve member moveable between a first position and a second position. A valve member moving mechanism is operable to receive energy from a fluid-working machine crankshaft, or other rotating shaft, and to provide a valve member moving force to urge the valve member from the first position to the second position using the received energy. Thus, the energy used for movement of the valve against a pressure gradient is derived from the crankshaft. Energy received from the crankshaft can be stored and used subsequently to urge the valve member from the first position, allowing the valve to function despite timing differences between the availability of energy from the crankshaft and the requirement for energy to move the valve member.

Abstract: An electronically controlled valve for regulating the supply of fluid between a working chamber of a fluid working machine and a manifold, which valve includes a pilot valve and a pilot valve elastic member charged in use by the movement of the armature towards the electromagnet during closure of the valve to provide a return force urging the pilot valve sealing member away from the pilot valve seat. The valve is especially useful as the low pressure valve of a fluid working motor.

Abstract: An electronically controlled valve includes a travelling member with a sealing member and operable between a closed position in which the sealing member forms a seal with a valve seat, and an open position. The valve further has a decelerating mechanism operable to slow the movement of the armature during closure of the valve. The sealing member and armature are decoupled and thereby moveable relative to each other such that the armature can continue to move and decelerate due to the action of the damping mechanism after the sealing member has impacted the valve seat. The peak deceleration force on the armature is thereby reduced, increasing the lifetime of the valve or the maximum rate at which it can be closed without damage.