Mini rotary air motor is maintenance-free

The motor employs a simple rotary design in which air pressure acting directly on self-mating rotors drives an output shaft through a simple gear train. The company's sales and marketing manager Nick Eliot told Eureka: "The rotors are manufactured to a very fine tolerance so that they can turn within the housing without contacting it. This provides a sufficiently good air seal, yet there is virtually no frictional loss." Eliot said the motors rely on an airborne oil mist to keep all moving components lubricated. "This allows the air motor to be used at any altitude including with the output shaft vertically up or down, which is a major advantage we have over conventional piston air motors." The design of the motor also allows either two or three rotor configuration, with the gear train maintaining synchronisation between shafts. The company's range of standard rotary lobe air motors covers outputs from 1kW to 55kW, with torque ratings between 3Nm and 400Nm and geared ratios up to 2000:1. The motors are suitable for a wide range of applications, including mining and drilling, hoisting, winching, paper mill machinery, pumping, hauling and mixing. Rotair's motor, the M42, is available through Rotair's UK agent, Motair. DP Pointers * The motor has a diameter of just 42mm * The rotors are made to very fine tolerances which provides a good enough air seal and there is virtually no frictional loss * An airborne mist provides lubrication for all moving parts