The functions of shaft loading and gear units
The Atlas Copco Air Motor catalogue contains curves giving maximum shaft loads for working lives of 10 million turns. The curves in the catalogue indicate the maximum permitted combination of radial and axial load.
The use of gear units
Air motors operate at high speeds and although they can be controlled over a wide speed range, the output characteristics are not always suitable for the application. To achieve the required output an appropriate gear unit can be selected. The planetary and helical gear units used by Atlas Copco have a high level of efficiency that can be assumed to be 100%. Evidently, while the torque/speed relationship undergoes a considerable change, the power output remains virtually unchanged. The torque is increased and the speed is reduced proportional to the gear ratio.