LINE OF ACTION #TOM #GEAR

Due to the special design of the tooth shape of an involute gear (rolling a straight line on a circle), the intersection of two involutes rolling off each other describes a straight line. This situation occurs when two gears are meshing. The involute tooth flanks then slide along a straight line (black line in the animation below). This straight line is also referred to as the line of action or line of engagement. This line of action corresponds in principle to the rolling line for the construction of the involute tooth flanks.