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.
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.