PURPOSE: To reduce deformative stresses in a blade of a fluid compressor in such a construction, that a piston with a spiral blade fitted in a spiral groove reducing its pitch from the suction side toward the discharge gradually is fitted in a cylinder, by specifying the relationship between the inner dia. of cylinder and the effective length of piston.
CONSTITUTION: A stator 15 of an electromotive element 13 is fixed to the inner surface of side peripheries of an enclosed case 12, and a cylinder 17 is fitted on a rotor 16 arranged inside thereof, therein the two ends are supported rotatably by bearings 18, 19, which are provided with a suction hole 26 and a discharge hole 28, respectively. A piston 20 is fitted in this cylinder 17 eccentrically in an amount (e). This piston 20 is provided at its periphery with a spiral groove 23 reducing its pitch gradually from the suction toward discharge side, and a spiral blade 24 is fitted in this groove 23 in such a way that it can advance and retreat freely. Therein the relation as expressed by D≥L shall be met, where D is inner dia. of cylinder 17, and L is effective length of piston 20.
HONMA HISANORI
FUJIWARA HISAYOSHI
