Significant new rotary engine design runs on compressed air

Engineair Pty Ltd (http://www.engineair.com.au/) was established in September 2000, with the objective to perform research and development on the innovative air motor design. In the first 2 years the company focused on developing prototype models to test the concept and understand the performance characteristics. Current development status shows performance and efficiency to be superior over state of the art air motor technology.

Engineair is now entering the commercialisation of its technology and is working on several fronts to prove the engine's capability. One of the first commercial applications will see the Engineair Rotary Air Engine applied in a commercial and outdoor environment by Melbourne-based CityWide which has replaced the petrol driven engine in one of its ParkCare garden maintenance vehicles (known as a 'gator').

The vehicle will be used on the company's City of Melbourne parks and garden maintenance contract. The project will run over 2004-05 enabling CityWide to test the vehicle under different environmental conditions.

Engineair has already successfully tested the powerplant in a roadgoing passenger car, a go-kart, a boat and as the power source for a utility vehicle for use in the Melbourne Fruit and Vegetable market, the latter project in conjunction with the Melbourne Market Authority.

The Di Pietro motor concept is based on a rotary piston. Different from existing rotary engines, the Di Pietro motor uses a simple cylindrical rotary piston (shaft driver) which rolls, without any friction, inside the cylindrical stator.

The space between stator and rotor is divided into six expansion chambers by pivoting dividers. These dividers follow the motion of the shaft driver as it rolls around the stator wall.

The cylindrical shaft driver, forced by the air pressure on its outer wall, moves eccentrically, thereby driving the motor shaft by means of two rolling elements mounted on bearings on the shaft.

The rolling motion of the shaft driver inside the stator is cushioned by a thin air film. Timing and duration of the air inlet and exhaust is governed by a slotted timer which is mounted on the output shaft and rotates with the same speed as the motor.

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