Simulation Study On The Gear Flowmeter Based On AMESim

A new type gear flowmeter—the third type planetary flowmeter was designed.The flow pulsation is 1/9 of the common one ,about 1.4%,it can be used in high pressure hydraulic system to measure system flow .The basic measuring idea is to transform flow signal to a rotational speed ,and it would be accepted and changed into pulse signal by a photoelectric encoder. Pulse signal is sent into MCU AT89S52 or computer. System flow is to be shown on LCD after proceed.First ,the structure of third type of planetary gear folwmeter, it's work principle , were introduced .At the same time the transient flow of flowmeter was analyzed.The gear flowmeter mathematical model was established ,then it's transfer function has been obtained.After selecting different materials for gears,total equivalent rotary inertia was calculated. To study the influence of rotary inertia on the system dynamic characteristics , the Bode diagrams were analysed. The effect of leakage coefficient and damping coefficient on the dynamic characteristics of flowmeter were also analyzed.Then flow measurement system was designed. The hardware are composed of MCU, photoelectric encoder and external circuits, with the core AT89S52. Frequency or period testing was selected during to different frequency range in the software design .Reduces measurement error and improve the accuracy.To illustrate theAMESim and it's use in hydraulic system , as well as parameters set ,a simple example was given.AMESet plug in advanced modeling and simulation software AMESim is required for the development of the gear flowmeter sub-model.The gear flowmeter is replaced by three external and internal meshing gear pump.A model is established according the components which have been exist in the hydraulic signal and mechanical libraries.Run the simulation model after parameters setting correctly.Simulation results show that :flow pulse and it's pressure drop of the flowmeter very little ,the system pressure drop about 0.1 MPa .Finally ,a series of experiments have been carried out with the gear flowmeter prototype. Pressure,flow and speed signals have been measured .Instrument coeffience K , the pressure pulse,Δp ?Q andδ?p curve have been derived.Study shows that: the third type planetary gear flowmeter has a high frequency response, low flow pulsation, small pressure drop, it can be applied in high-pressure side of hydraulic system for flow measurement.