Pneumatic motor
Pneumatic motors generally convert the compressed-air energy to mechanical work through either linear or rotary motion.
[4] The vanes are extended to the housing walls using springs, cam action, or air pressure, depending on the motor design.
Air is pumped through the motor input which pushes on the vanes creating the rotational motion of the central shaft.
Rotation speeds can vary between 100 and 25,000 rpm depending on several factors which include the amount of air pressure at the motor inlet and the diameter of the housing.
[2] One application for vane-type air motors is to start large industrial diesel or natural gas engines.
Stored energy in the form of compressed air, nitrogen or natural gas enters the sealed motor chamber and exerts pressure against the vanes of a rotor.
Reduction gears create high torque levels with the lower amounts of energy input.
Air turbines spin the burr in high-speed dental handpieces, at speeds over 180,000 rpm, but with limited torque.
[8] At the same time it was experimentally shown that efficiency of a motor can be increased by the usage of anti-friction additives to the lubricating oil.
Though little is known about the first recorded compressed-air vehicle, it is said that the Frenchmen Andraud and Tessie of Motay ran a car powered by a pneumatic motor on a test track in Chaillot, France, on 9 July 1840.
[12] The first successful application of the pneumatic motor in transportation was the Mekarski system air engine used in locomotives.
Compressed-air engines were used in trams and shunters, and eventually found a successful niche in mining locomotives, although in the end they were replaced by electric trains, underground.
[14] Over the years designs increased in complexity, resulting in a triple expansion engine with air-to-air reheaters between each stage.
The Energine Corporation was a South Korean company that claimed to deliver fully assembled cars running on a hybrid compressed air and electric engine.
[17] EngineAir, an Australian company, is making a rotary engine powered by compressed air, called The Di Pietro motor.
People should note that, meantime, the team has recognized the physical impossibility to use on-board stored compressed air due to its poor energy capacity and the thermal losses resulting from the expansion of the gas.
These days, using the patent pending 'K'Air Generator', converted to work as a compressed-gas motor, the project should be launched in 2010, thanks to a North American group of investors, but for the purpose of developing first a green energy power system.
It has been reported in 2008 that Indian car manufacturer Tata was looking at an MDI compressed-air engine as an option on its low priced Nano automobiles.
[25] Armando Regusci's version of the air engine couples the transmission system directly to the wheel, and has variable torque from zero to the maximum, enhancing efficiency.
[27][28] Milton M. Conger in 1881 patented and supposedly built a motor that ran on compressed air or steam using a flexible tubing which will form a wedge-shaped or inclined wall or abutment in the rear of the tangential bearing of the wheel, and propel it with greater or less speed according to the pressure of the propelling medium.
