Micro-Geometry Sign Conventions

1. Active Flanks

The active flank is used in the contact life calculations and also in the Gear Micro-Geometry Analysis Module. It is automatically selected from the mounting direction and rotational direction. The 8 possible cases are detailed below.

2. Micro-Geometry Modifications

2.1 Display of Modifications

The modifications to the gear flanks (i.e. tip and root relief) are relative to the gear's local Z-axis.

The 2D displays show modification relative to the gear's local Z-axis.

The 3D displays show modification and results relative to the shaft's Z-axis.

2.2 Sign and Direction of Modifications

Positions along Involute and Lead

The specified values of all modifications are at the evaluation limits except end relief which is at the ends of the face width.

Sign of Modifications

All positive input values of Relief, Barrelling, Crowning and End Relief in the dialog boxes indicate material removed.

Sign of Lead Slope

A positive value of lead slope indicates material removed at the (bottom end) of the face width. Top end of the face width remains unchanged.

A negative value of lead slope indicates material removed at the (top end) of the face width. The bottom end remains unchanged.

Sign of Involute Slope

A positive value of involute slope indicates :-

Material removed at the lower region (Start of Active Profile, SAP). Upper region (End of Active Profile, EAP) remains unchanged.

A negative value of involute slope indicates :-

Material removed at the upper region (EAP). Lower region (SAP) remains unchanged.