The basics of design and experimental tests of the commutation unit of a hydraulic satellite motor

The article presents an analytical method to design the commutation unit in a hydraulic satellite motor. It is shown that the size of the holes feeding the working chambers and their location on the plates closing those chambers depends on the geometrical dimensions of the working mechanism. The overlap in the commutation unit depends on the rotational speed range. It is demonstrated that the geometrical dimensions of the commutation unit clearances change as a function of the angle of machine shaft rotation. The flow in these clearances is described as Q = f(Δpγ). It has been observed that during the transition from the cycle of filling to the cycle of emptying the working chamber, the pressure in the motor's working chamber changes linearly as a function of the shaft rotation angle which has a significant effect on leakage in the commutation unit clearances. The methodology of investigating the commutation unit in a satellite motor and the mathematical model of leakage in the commutation unit clearance described in the article may be successfully adopted to research the commutation unit in positive displacement machines of another type.