Establish The Internal Leakage Model And Research On The Best Clearance For Gear Pumps Under Random Uncertainty

Gear pumps' size is not a definite value because of gear pumps processing and assembly tolerance and measurement error during gear pump manufacturing process and actual work.In addition,external factors such as hydraulic oil viscosity is not a definite value.However,in the past,take all the parameters of the gear pump as determined value in the traditional study.There is always a certain mismatch between the theoretical results and the engineering practice.Based on the traditional mathematical model of gear pumps,this paper introduces the uncertainty theory into the traditional model of the gear pumps intend to formulate a more accurate internal leakage mathematical model and the best clearance mathematical model.The main work is:In this paper,random factor method and algebra synthesis method are implicated to establish the random internal leakage model for external gear pumps,converting the axial and radial clearances,the temperature,the pressure of working oil and input revolution to random variables.The data of the volumetric efficiency using uncertainty theory is obtained ultimately.New numerical results of random internal leakage model and traditional model are all compared to the experimental results.Random factor method and algebra synthesis method are also used to establish the random internal leakage model for internal gear pumps,converting the axial and radial clearances of gear pair,radial clearance of sliding bearing,hydraulic oil dynamic viscosity,the pressure of working oil and input revolution to random variables.New numerical results of random internal leakage model and traditional model are all compared to the experimental results.Taking the minimum total power loss which include leakage power loss and viscous friction loss as optimize goal.The axial and radial clearance as design variables,introduce the uncertainty theory to the design process,using the optimized design principle to calculate the gear pumps' the best axial and radial clearance.The results illustrate that the random model of internal leakage is correct and advantageous to the traditional model.It is proved that the uncertainty model is more near with the engineering practice than the traditional model.This study provides a more scientific calculation method for calculating the internal leakage flow of the gear pumps,and it's of great significance to guide the design structure of the gear pumps for saving the energy.