Design And Analysis Of Gear Pump Contamination Wear Test Oriented To Its Residual Life

The gear pump acts as a dynamic component of the hydraulic system, and it plays a key role in the working capacity and the reliability of the entire hydraulic systems. The research has showed that the oil pollution particles not only become the bottleneck in the development of high-quality hydraulic pump, but also restrict the process of hydraulic transmission technique. The contamination wear of hydraulic gear pumps largely determines their service ability and working life. In this paper, aiming at assessing the residual life of hydraulic gear pump, the influence mechanism model of hydraulic gear pump pollution wears life should be analyzed and obtained. In order to solve the problem, the relative research should be taken as follows.1 The wear failure mode of the hydraulic pump can be determined through the pump failure analysis and the evolution mechanism of contamination wear is studied. Factors affecting the volumetric efficiency which is acted as an indicator of the pump pollution wear life are analyzed. The relative weight of those factors affecting the pump life is determined based on FAHP method.2 The size dimension and size distribution of contaminant particles in the hydraulic system are studied, and a modified logarithmic model is proposed to describe the particle size distribution. The commonly used standards of ISO4406, NAS1638 and GB/T14309 are introduced to uniformly quantify the size dimension and size distribution of contamination particles. The theory of pollution sensitivity of hydraulic gear pump is deeply discussed. Considering the oil pollution particles and the pump working pressure, the pollution wear life test of hydraulic gear pump is designed on the basis of pollution sensitivity theory.3 The basic process of regression analysis is discussed, and the principle of estimating the unknown parameters of regression models based on least square regression model is analyzed. Gauss-Newton iterative algorithm to solve the nonlinear regression problem is studied. Based on the theory of pollution sensitivity, the mathematical form of the regression model of the influence mechanism of pump pollution wear-life is determined. 4 According to the test scheme of the hydraulic pump pollution wear life, the test program is formulated and the pollution sensitivity test of hydraulic pump is carried out. Based on the test data(hydraulic pump output flow), the pump pollution sensitivity coefficientsiS, with the consideration of pump working pressure, are calculated during different particle size range. Through the analysis of statistical relationship between the pollution sensitivity coefficient and the pump working pressure, the unknown parameters of the theoretical model of the influence mechanism of the hydraulic pump wear life are estimated by nonlinear fitting. The correctness of the regression model is verified by the corresponding tests and the mechanistic model of the pump wear life, with time as a parameter and the volumetric efficiency as a life indicator,is finally obtained by taking into account the oil pollution particles and working pressure.