Patent ID: 7905141

Claim:
A path structure related to a flow of a fluid to be measured and pressure difference detection in a servo type volumetric flowmeter, comprising: an outflow port for the fluid to be measured and an inflow port for the fluid to be measured formed in a metering chamber, the outflow port being above a location where a first rotor and a second rotor engage each other, the inflow port being below the location where the first rotor and the second rotor engage each other, and the second rotor having a rotor shaft; a first outflow path extending in an axial direction of the rotor shaft, the first outflow path being formed in a main body casing so as to be continuous with the outflow port for the fluid to be measured; a first inflow path extending in the axial direction formed in the main body casing so as to be continuous with the inflow port for the fluid to be measured, the first inflow path being parallel to the first outflow path in the main body casing; a second outflow path extending in an orthogonal direction to the axial direction formed in the main body casing so as to be continuous with the first outflow path; a second inflow path extending in the orthogonal direction so as to be continuous with the first inflow path and parallel to the second outflow path formed in the main body casing; one pressure difference detection connecting path formed in the main body casing, one end of which is open to the first inflow path at a position between a continuation center position of the first inflow path and the second inflow path and the inflow port for the fluid to be measured, and which extends so as not to overlap the second inflow path; another pressure difference detection connecting path formed in the main body casing, one end of which is open to the first outflow path at a position farther away from the outflow port for the fluid to be measured with respect to a continuation center position of the first outflow path and the second outflow path, which extends so as not to overlap the second outflow path, and which is parallel to the one pressure difference detection connecting path; and a pressure difference detecting portion formed in the main body casing so as to be continuous with the other end of the one pressure difference detection connecting path and with the other end of the other pressure difference detection connecting path.