Study on the Churning Loss Torque of New Type of Wet Motor for Motor Pump

doi:10.3901/JME.2025.10.464

Abstract

Abstract: In order to remove the dynamic seal inherent on the pump shaft of the motor pump, a new structure of a simple and easy to use wet motor is proposed. Based on the churning loss of the wet motor, the analytical model of the churning moment loss of the wet motor is derived in order to study the churning mechanism, and the churning loss is divided into three parts, namely, the circumferential frictional resistance moment, the pushing oil resistance moment and the end frictional resistance moment. Based on CFD numerical simulation, the flow field distribution and churning loss mechanism caused by rotor rotation in the oil are studied. A prototype is designed and built to test the churning torque at different rotational speeds. The results show that the churning torque increases with the increase of rotational speed. At 12 000 r/min, the churning torque is measured to be 0.87 N·m, and the CFD simulation results showed that the thrust resistance torque is 0.55 N·m, accounting for 62% of the total resistance torque. It is shown that when designing high-speed wet motors, emphasis should be placed on optimizing the structural parameters related to the thrust oil resistance torque. Three sets of churning torque at different temperatures are also tested, and it is found that there is a small decrease in torque as the temperature increases. The research results have good guidance for the churning loss mechanism and resistance reduction optimization of wet high-speed motors for motor pumps.

Key words: wet motor, churning loss, analytical model, CFD simulation, motor pump

CLC Number:

TH137

MENG Bin, CHEN Yi, ZHANG Chenchen, ZHANG Zhenzhou, LI Sheng, RUAN Jian. Study on the Churning Loss Torque of New Type of Wet Motor for Motor Pump[J]. Journal of Mechanical Engineering, 2025, 61(10): 464-478.

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