Influence of Water and Mineral Oil on the Leaks in Satellite Motor Commutation Unit Clearances

Abstract

The article describes the flow rates of mineral oil and water flowing, as working media, through the commutation unit of a hydraulic satellite motor. It is demonstrated that geometrical dimensions of commutation unit clearances change as a function of the machine shaft rotation angle. Methods for measuring the rate of this flow and the pressure in the working chamber are presented. The results of pressure measurements in the working chamber during the transition from the filling cycle to the emptying cycle are included. The pressure in the motor’s working chamber changes linearly as a function of the shaft rotation angle, which has a significant effect on the leakage in the commutation unit clearances. The paper presents new mathematical formulas in the form: Q=f(Δpγ) to calculate the flow rate of water and mineral oil in the commutation unit clearances. The γ factor is described as a function of fluid viscosity and clearance length (the motor shaft rotation angle). The coefficients used in these formulas were determined based on the results of laboratory tests of a motor supplied with water and mineral oil.

Keywords

• flow in clearances
• commutation unit
• satellite motor
• degree of flow laminarity
• water
• oil