Abstract:Aircraft piston pumps generate a significant amount of heat due to reasons such as leakage flow and mechanical friction, which often leads to overheating failures. The piston pump dissipates heat through the casing return oil, and the flow rate of the casing return oil not only determines the working efficiency of the piston pump but also affects its temperature characteristics. Based on the analysis of the heat generation mechanism and heat transfer process of the piston pump, a temperature characteristic model of a constant pressure variable displacement piston pump is established and simulated using hydraulic simulation analysis software. The temperature variation of piston pump under different volumetric and mechanical efficiencies in typical working conditions are obtained. Analysis of the temperature variation trends reveals that in the early stages of the piston pump"s operation, the lower the volumetric efficiency, the more pronounced the temperature rise of the pump itself and the casing return oil. After the piston pump has been working for a while, the lower the volumetric efficiency, the greater the casing return oil flow, and the more obvious the heat dissipation effect of the casing return oil. It is also found that as the mechanical efficiency of the piston pump decreases, the heat generation of the system increases significantly, leading to a substantial rise in the temperature of the pump casing and the casing return oil. In the actual operation of the aircraft piston pump, it is necessary to consider the issue of overheating failure of the piston pump caused by wear and other reasons leading to a decrease in mechanical efficiency.
