Starter Drive Pinion Bevel Geometry to Prevent Gear Jamming

The patent applies different bevel configurations to different regions of the tooth end face. The active flank bevel has varying width along the active flank, with greater reduction near the head and less near the root, creating local quality variations that optimize engagement while preserving strength where needed.

The patent extends the bevel concept from simple end face chamfers to three-dimensional bevels that vary in width along the flank length. This adds a dimensional aspect to the bevel geometry, allowing progressive tooth reduction that prevents simultaneous contact of multiple tooth pairs while maintaining structural integrity.

The active flank bevel width varies along the active flank, with the greatest reduction occurring near the tooth head where engagement initiation occurs, and progressively less reduction toward the root where strength is critical. This local quality differentiation optimizes engagement while preserving structural strength.

The bevel applies partial action by selectively reducing material only in regions where it serves the engagement function, rather than uniformly across the entire tooth. The varying bevel width ensures sufficient inclination for engagement facilitation while avoiding excessive material removal that would compromise strength.

The active flank bevel width varies systematically along the active flank length, creating local quality differences that prevent simultaneous contact of multiple tooth pairs. This graduated reduction is more effective than uniform bevels while remaining manufacturable through standard machining processes.

The bevel geometry is designed to pre-condition the tooth engagement by creating a progressive reduction that guides the engagement sequence. The varying width ensures that contact occurs progressively from one tooth pair to the next, preventing simultaneous contact before the engagement process even begins.