| 摘要 |
A screw pump is provided to utilize an introduction space part rotating once from a starting point as a space part for a transfer object to increase the volume of a working fluid to be transferred. A pair of screw type rotors(20,30) are engaged with each other. A housing contains the rotors. The housing has an introduction port(17) for introducing a working fluid into the housing and a discharge port(15) for discharging the working fluid out of the housing. The rotors have introduction openings(27,37) formed at a rotor section of the introduction port, and unequal lead parts where a lead angle changes toward the discharge port from the introduction port. The introduction port and the introduction openings are connected to introduce the working fluid. An introduction space part(P) changes volume according to rotation of the rotors and communication between the introduction space part and the introduction port is interrupted to form a sealed transfer space part(S) at the outlet, wherein the state of forming the transfer space part is a starting point of one rotation of the rotors. The introduction space part is a space part executing volume change reaching the maximum volume before one rotation from the starting point. The volume of the transfer space part is less than the maximum volume of the introduction space part by setting of the lead angle of the unequal lead parts. A sealing body covers a part of the introduction openings and seals the introduction space part in state of exceeding the volume of the transfer space part.
|
