Theoretical And Experimental Research Of Multi-gear Flowmeter

With the rapid development of the hydraulic technology, nowadays hydraulic system has been widely used in industrial production, equipment and laborator equipment system, etc. Flow rate signal, as one of the main monitor parameters of hydraulic system, must be measured and controlled by technicians and researchers. Among the many kinds of the flowmeters, positive displacement flowmeters have its certain advantages, like high measuring accuracy, insensitive to the fluid medium, strong adaptability to the working environment and so on. However, if the positive displacement flowmeters be set up in the hydraulic system, flow and pressure ripple will be generated after the fluid get through the meter which will cause the system vibration. So, at present, positive displacement flowmeters can not be usd in the high pressure side of the hydraulic system, just can be used in the low pressure side. So how to solve or decrease the problem of the flow and pressure ripple caused by the positive displacement flowmeters, improve its sensitivity to the transient flow, has become an urgency to do in the application of the positive displacement flowmeters.A new gear flowmeter structure with three radial gears dislocated parallel on a center gear based on the structure of the traditional gear flowmeters has been present in this paper. This new multi-gear flowmeter can decrease flow and pressure ripple because of its special structure. The paper introduces the new structure, the measuring method of the center gear rotation speed in turns to the readers. From the theoretical analysis, we get to know that the flow ripple generate by this multi-gear flowmeter can be reduced to1/9of the original, with proper gear modification coefficient, the ripple can be decreased more.In this paper, a multi-gear flowmeter3D model has been set up, with the help of the Solidworks Flow Simulation software, we did a flow field research on gear side clearance leakage and radial clearance leakage, got the law between the leakage and pressure difference, and the size of the gap.With the use of the AMESim system simulation software, a hydraulic system model has been built to study the relationship between the flow signal in the main pipe and the flow signal in the branch pipe, and the result from this study will be used in the bypass flow measurement method. At the end of this research, a prototype of the multi-gear flowmeter has been we manufactured. On the calibration system using the standard container, we calibrated this flowmeter and got its measurement accuracy was about0.75%.