On the spot, we measured the diamet

On the spot, we measured the diameter of tooth top circle Da = 138, measured the common normal size, wk = 2 = 37.085, wk = 3 = 60.715. The measured value minus the calculated value of mapping parameters Δ wk = 3 = -0.086, which is considered to be caused by the design and manufacturing errors of gears. In the process of precision gear manufacturing, the measured tooth top circle size is only used as the process benchmark, not as the measurement benchmark, and the external circle size is not strictly required in the process of manufacturing, so we will not consider it. With the steel ball method, the measurement data measured by everyone in the measurement process is completely consistent, without any dispute.