Study on Flow Characteristics of New Variable Displacement External Meshing Gear Pump

Gear pump is widely used in hydraulic system due to compact structure, small volume, large speed range and strong impact resistance. However, compared with piston pump and vane pump, gear pump is difficult to achieve variable control, which limits its application. Therefore, a variable displacement mode of gear pump with variable slider position-trapped area is proposed. The theory of variable gear pump is analyzed, and the characteristics of variable gear pump are analyzed through joint simulation and flow field visualization simulation. Finally, a test-bench is established to verify the theory and simulation results. The results show that the displacement of gear pump can vary from 88% to 100% by changing the position of variable module and adjusting the trapped area. The research work will help the variable design of gear pump.