Hydraulic valve control device

A motor-operable fluid valve for a pump, said valve comprising a valve body defining an open central portion, means defining at least one high pressure inlet port in fluid communication with the open central portion, means defining a plurality of lower pressure inlet and/or outlet ports in fluid communication with the open central portion via an array of individual flow passages and a valve rotor means comprising a rotor having means defining a plurality of openings and disposed for movement in both rotation and translation within the open central portion in the line of flow from the high pressure to the lower pressure ports and a centrally mounted shaft operable to rotate and translate the rotor selectively, relative to the axis of the shaft, to connect selected inlet and outlet ports;

• said valve further comprising a rotational means carried on the shaft of the valve rotor;
• wherein the rotational means cooperates with a drive gear and in that the drive gear includes a top face and a bottom face, of which the top face is sloped so as to form a cam surface against which a bottom face of the rotational means acts as a cam follower, such that when the drive gear is rotated the rotational means and hence the valve rotor are raised and lowered by the camming action.