Abstract: Aiming at the problem of rapid heating of axial piston pump under high-pressure and high-speed operating conditions, the thermal characteristics and thermodynamic modeling of plunger pump were simulated and tested. Firstly, based on the theory of frictional pair heating, the heat sources of oil agitation friction and bearing friction in the pump were considered, and the thermal characteristics theory of the internal heating mechanism and heat transfer analysis of the plunger pump was studied. Then, based on the complex components of the plunger pump and the high differentiation of the solid flow regime, the principle of the control volume method used was explained. After dividing the pump into five control volumes, a thermodynamic model guided by temperature changes in each control volume was established. Finally, fiber bragg grating temperature sensors and bluetooth wireless temperature sensor were used, and sensor packaging structures and layout methods were designed for different control body nodes to jointly form an axial piston pump online thermal monitoring system. Comparative experiments were conducted under different pressure conditions to verify and analyze the effectiveness of the theoretical model. The research results show that comparing the experimental and simulation results, the temperature change of the model and the actual value have an error value of about 5%, which verifies that the model can accurately reflect and predict the thermodynamic change process of the pump. This result provides a fault diagnosis basis for the thermodynamic state monitoring of plunger pump, and provides a theoretical basis and design basis for the design of hydraulic system thermal management systems.
Key words: axial piston pump heating; high pressure and high-speed working conditions; thermodynamic modeling; temperature calculation; heat transfer theory; on-line monitoring of thermodynamic states