Patent ID: 7438535

Claim:
An ejector pump comprising: a flow path unit having formed therein a fluid discharge path leading to a fluid outlet; a nozzle body including a main fluid inlet port to which a main fluid is inputted, a nozzle which has a nozzle outlet from which a jet of the main fluid is emitted to the discharge path of said flow path unit and then discharged from the fluid outlet, and a main fluid flow path which has a length and communicates between the main fluid inlet port and the nozzle outlet of the nozzle, physical energy of the jet of the main fluid emitted from the nozzle serving to suck and direct a sub-fluid to the discharge path of said flow path unit, said nozzle body having a first sealing surface exposed to a portion of the main fluid flow path; a needle disposed coaxially within the main fluid flow path, said needle being slidable in a lengthwise direction of the main fluid flow path to change an open area of the nozzle outlet, said needle having a second sealing surface, when said needle is moved within the main fluid flow path and brings the second sealing surface thereof into abutment to the first sealing surface of said nozzle body, the main fluid flow path being closed; and a heater working to add thermal energy to the main fluid, said heater being disposed in a portion of said nozzle body which surrounds a location where the first sealing surface abuts the second sealing surface.