This Technical Report is applicable to enclosed speed reducers and increasers for industrial applications, where the designs include spur, helical, herringbone or double helical gears and their combination in single or multistage drives.

This Technical Report provides a method by which gear drive designs can be compared and selected. It is not intended to assure performance of assembled gear drive systems. It is intended for use by experienced gear designers capable of selecting reasonable values for the factors, based on performance knowledge of similar designs and the effects of such items as lubrication, deflection, manufacturing tolerances, metallurgy, residual stress and system dynamics. It is not intended for use by the engineering public at large.

Maintaining an acceptable temperature in the oil sump of an enclosed gear drive is critical to the life of the gear drive. Therefore, this Technical Report for enclosed gear drives considers not only the mechanical rating but also the thermal rating.

The rating methods and influences identified in this Technical Report are limited to enclosed drives of single and multiple stage designs where the pitch line velocities do not exceed 35 m/s and pinion speeds do not exceed 4 500 r/min. In this Technical Report, gear teeth rating is covered only as limited by tooth root bending and contact pressure.

This Technical Report does not cover the design and application of epicyclic drives. It is beyond the scope of this Technical Report to present a detailed analysis of efficiency.

Annexes A to F can be used to make a more detailed analysis of certain rating factors.