| With the development of modern industry,hydraulic system gradually showing a high pressure,high flow,high performance and integration trends,gear pump as the important dynamic element in hydraulic system,its leakage and noise problems become a major obstacle limit the hydraulic system to develop in the direction of high pressure,high speed,so,development of zero leakage,high efficiency,low noise gear pump become an urgent problem of modern hydraulic system.In engineering practice,the selection of external gear pump working speed lack of theoretical basis,blind selection often brings inefficient,big noise practical problems,this is contrary to the requirements of the future development of the gear pump.To solve the above problem,the flow filed and speed characteristics of external gear pump is researched in this article,in different load pressure and speed conditions,research the variation of gear pumps’ trapped oil,leakage and flow pulsation,and make a comprehensive analysis of volumetric efficiency and noise of gear pump on this basis,finally put forward a reasonable working speed range of external gear pump,it provides a theoretical basis for performance optimization of external gear pump and variable speed hydraulic power source to determine a reasonable speed range.The main research contents of this article:(1)Using fluid dynamic principle,the structural characteristics and working principle of external gear pump are analyzed in detail,fluid dynamics theoretical of gear pump is calculated,it provides a theoretical basis for the subsequent research of gear pump performance and the simulation of internal flow field.(2)The CBK series external gear pumps is made as the research object,using Fluent fluid simulation platform,the simulation model of internal flow filed of gear pump is established,and the internal flow filed is analyzed,research the changing rule of gear pumps’ trapped oil,leakage and flow pulsation in different load pressure and working speed condition,the results show that,in working process of gear pump,trapped oil pressure occurs sharp surges and sags;with the increase of speed,coefficient of flow pulsation decrease,the pulse frequency increase;the higher the pressure load,the more severe the gear pump leakage,this provides theoretical support for the study of the speed characteristics of the gear pump.(3)On the basis of simulation and calculation of gear pumps’ internal flow filed,from the angle of energy-saving,noise reduction,optimize the performance of the gear pump,rotation speed,load pressure on the influence of volumetric efficiency and noise of the gear pump is analyzed,and on the basis of comprehensive consideration of both,finally proposed that when gear pump working at five MPa to eleven MPa,far as possible to control the speed at one thousand and one hundred r/min to one thousand and five hundred r/min range.(4)Using multi-source information hydraulic integrative testing and controlling experimental platform,volumetric efficiency and noise problems of external gear pumps are studied experimentally,the experimental data show that,the error between simulation and experimental results within the range of five percent,the correctness of simulation calculation and reasonableness of the conclusions are verified. |
