Flankenwinkel

Flankenwinkel, or flank angle, is a term used in engineering to describe the orientation of a flank surface relative to a chosen reference plane. It is most commonly encountered in gear technology, where the flank (the Zahnflanke) is the surface of a gear tooth that comes into contact with the mating tooth. The Flankenwinkel thus characterizes how steep or sloped the tooth flank is and influences meshing behavior, load distribution, and noise generation.

Geometrically, the Flankenwinkel is defined with respect to a reference such as the gear axis, the base circle, or the pitch plane. In involute gear geometry the tooth flank approximates an involute curve; as a result, the angle between the flank and a reference line changes along the flank, and engineers may specify a nominal or mean flank angle at a reference circle.

Practical measurement uses gear measurement machines, optical or tactile probes, and gear tooth templates. Tolerances on the Flankenwinkel are specified to ensure proper contact ratio and to avoid interference under load.

Outside gear technology the term can also appear in other mechanical contexts to denote the angle of a flank surface, for example on blades, cam followers, or bevel components, always referring to the orientation of the flank surface relative to a reference.

Since standards and field practices differ between industries and languages, the exact definition of Flankenwinkel can vary. When precision is required, the term should be defined by the relevant standard or technical drawing.