Researches On Non-Symmetrical Double Line Medium And High Pressure Gear Pump

As a kind of positive displacement device,the gear pump has the advantages of simple structure,small size,light weight,convenient manufacturing and maintenance,low price,reliable work,strong self-priming ability and insensitive to oil pollution.It is widely used in hydraulic system.With the development of China’s railway transportation industry,the requirements for the hydraulic gear pump in the hydraulic system of diesel locomotives are gradually improved,and the gear pumps should develop towards low noise,high pressure,low flow pulsation and large displacement.Through the thorough investigation and analysis of the hydraulic system of the diesel locomotive,a new type of gear pump with asymmetric tooth shape is designed to meet the high and high pressure demand in the hydraulic system of the diesel locomotive.By increasing the tooth height and increasing the displacement of the gear pump.The working side tooth profile of the gear is designed as a sine curve with a continuous contact,which solves the problem of oil trapped in the gear pump,reduces the flow and pressure pulsation of the gear pump,and reduces the noise.The non-working side tooth profile is designed into involute tooth profile to increase the tooth thickness and improve the bending strength of the gear.According to the design standard of circular arc gear and involute gear,the parameters of asymmetric double line gear are designed,tooth surface equation of gear is deduced,gear material is selected,and gear is modeled and finite element analysis is used to check the strength of gear.The whole structure of the gear pump is designed according to the structure of the gear,and the gear pump is modeled by Creo software,and the wall thickness of the pump body is analyzed and checked by the ANSYS finite element analysis software.According to the structure size of gear and gear pump,the main and subordinate shaft is designed.Through theoretical calculation and finite element analysis,the strength and stiffness of the main and subordinate shaft are checked to ensure that it meets the strength requirements.Design other parts of gear pump,make gear pump prototype and install it on the test stand for testing.The non-symmetric double line gear pump improves the bending strength of the gear while increasing the displacement and increasing the working pressure.It solves the problem of oil trapped in the gear pump,reduces the flow pulsation and reduces the noise of the gear pump.