Micro tooth surface topography of face-milled hypoid gears

•A kinematic model of the face-milling process of hypoid gears is developed.•The micro tooth surface topography in hobbed hypoid gears is determined.•Generated and sinusoidal roughness is introduced.•By optimal manufacture drastic reduction in the roughness is obtained.

An accurate kinematic model of the face-milling process of hypoid gears has been developed in order to compute the micro tooth surface topography, generated by successive cuts of the head-cutter cutting edges, as they come into contact with the gear blank. The instantaneous gear tooth surface point has been determined at each point on each active cutting edge and from this it has been possible to predict the tooth surface roughness experienced during the machining process. The paper presents a description of the theoretical gear cutting model and the method to calculate the generated roughness of gear tooth flank. The effectiveness of the presented method is demonstrated by using a hypoid gear example.