Patent ID: 8505378

Claim:
A flowmeter for measuring flow of a fluid, of the type where the fluid flow is directed into rotation movement for measurement, the flowmeter comprising: a housing having an inlet, an outlet, and a measuring chamber between the inlet and outlet, the measuring chamber having a diameter larger than that of the inlet; a blade section between the inlet and the measuring chamber, the blade section comprising: a cylindrical part near the measuring chamber and having a cylindrical inner wall, an expanding part between the cylindrical part and the inlet, and spiral blades which extend from the expanding part to the housing, for imparting the rotational movement to the fluid when the fluid enters the measuring chamber; and a ball positioned in the measuring chamber such that the rotational movement of the fluid moves the ball in a circular motion around the measuring chamber for measuring the flow of the fluid; wherein, measured in the axial direction, the length of the expanding part of the blade section is larger than the length of the cylindrical part of the blade section.