A kind of multi-step method for measuring pitch deviation of a gear

The inspection of a gear's pitch deviation is one of the most important tests on gears. The specifications of gears are usually assessed using gear measuring instruments or coordinate measuring machines. The National Metrology Institute of Japan and the Physikalisch-Technische Bundesanstalt proposed the closure technique for measuring gear pitch deviation, which can eliminate the systematic errors in pitch measurement, and can also be used for calibrating pitch standards. The reference to a closure technique-a kind of multi-step method for measuring pitch deviation-is introduced, of which the measurement process is relatively simple, and systematic errors can also be eliminated. Two gears' pitch deviations were measured by adopting the closure technique and multi-step method, respectively. The result shows that the multi-step method can also be used for highly accurate measurements of pitch deviation.