Abstract: An apparatus for pressurizing a fluid comprises a housing including a chamber and at least one vane positioned in the chamber and adapted to oscillate therein at any convenient speed to pressurize a fluid. A seal member is secured to the at least one vane for sealing between the at least one vane and the chamber. A propulsion apparatus is provided for oscillating the at least one vane and a counterweight device is operably secured to the propulsion apparatus. The counterweight device moves in opposition to the movement of the at least one vane to minimize the vibration produced in the housing by the oscillation of the at least one vane. A valve mechanism is secured to the housing and is in fluid communication with the chamber in the housing to control the movement of fluid into and out of the chamber.