Study on Temperature Field Distribution of Hydraulic Motor Pump and Heat Dissipation Simulation of Flow-Solid-Heat Coupled with Spoiler Cooling Device

To explore the distribution law of the temperature field in the motor pump and the influence of the fan-shaped DC channel with spoiler in the pump housing on its heat dissipation performance. This study takes the arc-gear type hydraulic motor pump as the research object. In COMSOL, a coupled heat transfer simulation model of the motor pump’s fluid-solid coupling is established, and the internal temperature field characteristics are analyzed. To improve the heat dissipation effect of the motor pump, it is proposed to arrange spoiler in the fan-shaped DC channel of the pump housing to enhance heat dissipation. Three types of spoilers, namely, wing-shaped, inclined rectangle-shaped, and wave-shaped, are designed. The simulation results show that when the motor pump operates under rated conditions, due to the poor heat dissipation environment inside the motor pump, the high-temperature areas of the motor pump are concentrated in the rotor and permanent magnet parts. After arranging the spoiler, the turbulent kinetic energy and vorticity in the fan-shaped DC channel of the pump housing are significantly enhanced. All three spoiler structures can reduce the maximum temperature of each component of the motor. According to the comprehensive performance evaluation criterion (PEC), the inclined rectangle-shaped structure has the best comprehensive heat transfer performance (PEC = 1.114), while the wave-shaped structure has higher heat transfer efficiency but greater pressure loss. The wing-shaped structure has relatively limited enhancement effect on heat dissipation. This study systematically quantifies the influence of different spoiler structures on heat dissipation performance and flow resistance characteristics, providing a solution for enhancing the heat dissipation of the motor pump.