Measurement of elliptical gear flowmeter is mainly composed of two meshing elliptical gear and shell (measurement room) composed of oval gear in the measured medium pressure difference of p=pl-p2, which make the rotation torque. 在(a)所示位置时，由于P1>P2，在P1和P2的作用下所产生的合力矩使轮A产生顺时针方向转动，把轮A和壳体间的半月形容积内的介质排至出口，并带动轮B作逆时针方向转动，这时A为主动轮，B为从动轮，在 (b)上所示为中间位置，A和B均为主动轮；而在（c）上所示位置，P1和P2作用在A轮上的合力矩为零，作用在B轮上的合力矩使B轮作逆时针方向转动，并把已吸入半月形容积内的介质排至出口，这时B为主动轮，A为从动轮，与 (a)上所示情况刚好相反．如此往复循环，轮A和轮B互相交替地由一个带动另一个转动，将被测介质以半月形容积为单位一次一次地由进口排至出口． Obviously, on the map (a), (b), (c) shows, only said elliptic gear turned 1/4 weeks, and the discharge of the measured medium is a half moon volume. Therefore, the elliptical gear per week to the ratio of measured medium quality for half 4 times the product description the volume flow of Q through the oval gear meter meteor: Q=4n V 0 type: n - rotation frequency of elliptical gears (Rev / sec);

The 0 part of the volume V - half moon (beckham. ).

In this way, as described in the elliptical gear flowmeter half product 0 V under certain conditions, as long as the measured elliptical gear rotation speed n, can know the measured medium flow.