How to Check the Quality of Worms in Precision Parts Processing

In the processing of precision parts, worm gears are usually measured using a tooth thickness caliper to measure the normal indexing circle chord tooth thickness, or the pitch diameter three needle measurement method can also be used.

The method for measuring the chord tooth thickness of a worm indexing circle is to use a vertical ruler to determine the normal chord tooth height hnal of the indexing circle, and a horizontal ruler to measure the normal chord tooth thickness snl of the indexing circle. The calculation of hani and snl is shown in the table for the method of measuring the pitch diameter of the worm.

Method for measuring the pitch diameter of a worm. When measuring, place three equal diameter measuring rods into the corresponding slots of the worm, and use a common line micrometer to measure the distance between the measuring rods to verify the pitch diameter size of the worm. The diameter d0 of the measuring rod and the measurement distance M are generally determined by the technical data of the worm pattern. This measurement method has a sensitivity 3-4 times higher than tooth thickness caliper measurement.

Quality Analysis of Worm Milling Process: The accuracy of worm milling with disc type milling cutters on milling machines is relatively low. The main reason is that there is deviation between the tooth shape of the milling cutter and the tooth shape of the worm, and there is interference phenomenon during the processing of precision parts, which can also cause tooth shape errors, leading to milling quality problems and causes.