Abstract: A fluid machine comprises a housing and a rotary cylinder block in the housing. The rotary cylinder block includes a cylinder in which a piston reciprocates. Valve plate means is connected with the housing and disposed in sliding engagement with the cylinder block. The valve plate means is provided with two arcuate openings. Vanes are placed in the arcuate openings in the valve plate means. The vanes divide the incoming flow into a cylinder into portions having different velocities (both in absolute value and direction). The valves direct each portion of the flow to a different portion of the arcuate opening so that the portions are fed to the cylinder in a sequence such that the velocity of a portion entering the cylinder corresponds to the rate of change of the volume of a chamber defined by the piston and cylinder as the respective portions of flow enters the chamber.

Abstract: A vehicle, especially a tracked vehicle, which is turned by imparting a speed differential to the drive wheels on opposite sides of the vehicle, is provided with a control member or lever which cooperates with four control-pressure transmitters. The transmitters are oriented symmetrically with respect to the manually operated member so that in its neutral position all four of the control pressure transmitters are ineffective. Each of two opposite control-pressure transmitters are connected with one side each of the respective servomotors controlling hydrostatic transmissions for the wheels. The other two transmitters are each connected to the opposite sides of the servomotors.