IMPROVEMENT OF NONCIRCULAR GEAR AND NONCIRCULAR GEAR- TYPE FLOWMETER USING IT

摘要

PROBLEM TO BE SOLVED: To reduce a metering error in a small flow-rate region by reducing the leak amount of a tooth tip gap.;SOLUTION: A noncircular gear in an oval gear-type flowmeter is formed of a continuous curve wherein its major axis parts are formed of arcs of r=a/(1-b), its minor axis parts are formed of arcs of r=a/(1+b) and parts between them are connected by oval curves of r=a/[1-b cos (πθ/θ0)] (0≤θ≤θ0) [where (a) represents a similarity factor and (b) represents a flatness degree]. Thereby, the number of teeth of a gear coming into contact with the inner wall surface of a metering chamber is increased, the leakage amount of a tooth tip gap is reduced, and a metering error can be reduced.;COPYRIGHT: (C)2000,JPO