The epicyclic gear flowmeter is introduced used to measure the flow of the high pressure side in hydraulic system. The flow signal is firstly converted into the gear rotational speed signal

the flow of hydraulic system can be measured by the micro-controller. The gear kinetic energy and the fluid kinetic energy in flowmeter are changed with the flow of hydraulic system changed. The variation of both kinetic energy that influence the fluid have been investigated. The results show as compared with the variable of hydraulic energy

the influence of the gear kinetic energy can be neglected when the rate of the flow varies in 1-1000Hz

and

the influence of the fluid kinetic energy can also be neglected and is irrelative to the rate range of the flow.