SCREW PUMP AND ROTOR FOR SCREW PUMP

摘要

The present invention provides a screw pump provided with a screw-shaped first rotor, and a screw-shaped second rotor having tooth spaces that engage with teeth of the first rotor. The first rotor has a first variable lead part, and the second rotor has a second variable lead part that engages with the first variable lead part. Two tooth surfaces that form a tooth of the first variable lead part and/or two tooth surfaces that form a tooth space of the second variable lead part are formed on the basis of tooth trace curves different from each other.