Abstract:The process was understood on purpose of oil trapping phenomenon and the impact of trapped oil pressure for gear pump operating condition. Under oil trapping condition, according to vibration model of the gear of gear pump and internal flow field numerical analysis, where trapped oil pressure was taken as a coupled variable, a dynamic coupled model of vibration of gears and internal flow was established. Through decoupling of the model, the effect was analyzed of trapped oil pressure on vibration for gear and the manifestation of the trapped oil pressure in practice. It was made clear that at magnitude and location of trapped oil pressure and the degree of trapping impact, through internal flow field simulation of gear pump and processing and analysis of vibration signal of acquisition by sensors. Finally, it is shown that the established dynamic coupled model is right and reliable, which can be used for forecast on trapped oil pressure, as well as vibration impact analysis along with simulated analysis of process of trapping.