Patent ID: 7299894

Claim:
An acoustic fluid machine comprising: an acoustic resonator having an internal resonant cavity having a larger-diameter base and a smaller-diameter upper end; a suction chamber located on the upper end of the acoustic resonator and having an inlet and a sucking hole communicating with the resonant cavity: a discharge chamber located on the upper end of the resonant cavity-and having an outlet and a discharge hole communicating with the resonant cavity; a valve device including: a sucking check valve device located with the sucking hole to permit a gas to be drawn into the resonant cavity, and a discharge check valve device located with the discharge hole to permit the gas to be drawn from the resonant cavity; a piston in the base of the resonant cavity, the piston having an upper concave spherical surface having a radius of defined by a straight line connecting a center of the upper end of the resonant cavity and a center of the upper surface of the piston wherein a center of the spherical surface coincides with the center of the upper end of the resonant cavity such that distances between the upper end of the resonant cavity and the upper surface of the piston are substantially constant over the whole concave spherical surface of the piston; and an actuator connected to the piston to reciprocate the piston continuously axially at high speed with a very small amplitude to cause a corresponding succession of waves of increased and decreased pressure amplitude to travel from the piston to the upper part of the resonant chamber so that the gas is sucked into the resonant cavity via the sucking hole and discharged via the discharge hole by virtue of pressure fluctuations within the resonant cavity.