Patent ID: 8403656

Claim:
A rotary displacement pump, comprising: a stator; a rotor including a shaft portion and a radially protruding web having a configuration of an undulatory disk; a scraper comprising a single-piece solid body having an engagement slot of predetermined radial height and predetermined axial width, the engagement slot being between oppositely facing surfaces on the scraper body that engage opposite sides of the protruding web of said rotor; said stator including a generally cup shaped first member and a generally cup shaped second member, and defining a circumferential wall that encircles said radially protruding web of said rotor; said scraper being arranged within said stator, supported to be retained in a circumferential direction and to allow a reciprocating movement in a substantially axial direction; said stator together with said scraper defining an inlet chamber, having an inlet port, of said pump, an outlet chamber, having an outlet port, of said pump, and a channel extending from said inlet chamber to said outlet chamber, said scraper forming a partition between said inlet chamber and said outlet chamber, and said web of said rotor being rotatable through said inlet chamber, said channel, said outlet chamber and said slot of said scraper.