The Key Technology Research On Hydraulic Power System Based On Gear Pump Driven By Ac Servo Motor

Aiming at improving some shortcomings of traditional hydraulic power source, such as low efficiency, complicated structure, poor ability to resist pollution, slow response and so on, this paper presents the design of hydraulic power source based on AC servo motor drive internal gear pump. This power source has the advantages of fast response speed,good speed regulation performance, high efficiency of AC servo motor,and combine with the high reliability, low ripple coefficient, simple structure and low price of internal gear pump.On the basis of the design of the power source and its experimental system, the low speed stability, pump cavitation and energy saving characteristics of the power source were studied, and the specific jobs were as follows:(1)The advantages and disadvantages of different drive motors and hydraulic pumps were analyzed and compared,than this article designed the hydraulic power source which build by AC servo motor drive internal gear pump and its experimental platform on this foundation. Combined with the working process of the hydraulic press, the energy saving mechanism of the power source was studied. The energy saving performance of the servo pump control power source was studied in the aspects of the efficiency of the hydraulic system, the temperature rise caused by the energy loss and the noise.The results show that the servo pump control hydraulic system has a good energy saving effect, the performance is outstanding in the temperature rise, noise and other aspects compared with the traditional hydraulic pump control system.(2) The flow pulsation calculation method of the straight conjugate internal gear pump was established by the sweep area method, the calculation formulas of internal leakage of gear pump were derived by using the gap flow theories,so the instantaneous output flow of the gear pump was calculated, then we studied the low speed stability of the servo pump control hydraulic system by simulation in AMESim. The main measures to improve the low speed stability of hydraulic system were put forward. Based on the PID control algorithm and the closed-loop control of the output flux of pump, the speed of the motor was adjusted in real time, and the stability of the power source was improved.(3)The 3D and watershed model of a certain type of internal gear pump were established,then the watershed model was imported into Pumplinx for cavitation analysis,found that cavitation phenomenon easily occur in tooth meshing area of suction chamber,and the clearance between top gear and the fixed crescent block. The cavitation condition in the pump at different speed and inlet pressure was analyzed,and the mechanism of cavitation was revealed.The hydraulic power source of AC servo motor drive internal gear pump will be used more and more widely, the results of study have certain reference significance for further research and practical application.