Patent ID: 8459974

Claim:
A six-blade biaxial rotary positive-displacement pump comprising: a casing formed with a suction port and a discharge port, a pair of rotors accommodated in the casing and having rotor shafts rotatably mounted on housings fixed to opposed ends of the casing, respectively, wherein: each rotor is formed with six blades extending radially equiangularly about the rotor shaft; each blade is formed so as to have a constant thickness in a rotational direction of each rotor; and each blade has a curved convex apex and a curved concave valley between an adjacent blade, and a distance between the apex and the valley is set so as to range from three to five times larger than the thickness of each blade, and three chambers are defined by up to four blades simultaneously closed and the inner surface of the casing between the suction port side and the discharge port side.