Novel tooth profile of oil gas-water mixed transportation two-screw pump

The invention discloses a novel tooth profile curve of an oil gas-water mixed transportation two-screw pump. The novel tooth profile curve is composed of A, B, C, D, E, F, G and H on the cross sectionof a screw, wherein F is located on the pitch diameter R2 of a tooth surface, C, D and E are located on a root circle, and G, H and A are located on an addendum circle with the radius R3; a curve defined by A and B is an arc line with the radius R1 and is tangent to the addendum circle, a curve defined by B and C is a cycloidal envelope line with the arc line as the base line, a curve defined byG, H and A is an arc of the addendum circle, a curve defined by F and G is an involute line, and a curve defined by E and F is a cycloidal envelope line with the involute line FG as the base line; andthe radius R1 of the arc line and the radius R3 of the addendum circle meets the relation 0.03R3