Electrically controlled pressure control valve for an adjustable hydrostatic pump

An electroproportional pressure control valve of cartridge type construction is screwed into a housing bore of a hydrostatic pump. The cartridge includes an adjusting pressure port, a pump port, and a tank port. The adjustment pressure port is relived to the tank port in a normal position of a spring biased valve plunger of the pressure control valve. A connection from the pump port to the adjusting pressure port is opened counter to the force of the spring by increasing a current of an electromagnet and increasing the pump pressure at the pump port. The spring, the electromagnet, and the resultant force of the pump pressure act along a common axis of movement of the valve plunger. A first nozzle connects the adjusting pressure port to an adjusting pressure chamber. A second nozzle connects the adjusting pressure port to the tank port.