The design of plastic gears: the plastic gear has the advantages of light weight, low modulus of elasticity, the characteristics, the same manufacturing accuracy than steel and cast iron gear transmission noise is small, therefore, in recent years in the machinery and electronics industry has been more and more widely applied, the transmission mechanism is mainly used in precision and strength requirements are not too high. Commonly used plastic with nylon, polycarbonate, polyoxymethylene and Jufeng etc.. In order to make the plastic gear to injection molding process, ensure the spoke, spoke with corresponding thickness, do the following: 1 the size of each part of the gear rim width t of at least 3 times the whole tooth to. 2 plate thickness of H1 should be equal to or less than the width thickness H. H2 3 hub thickness should be greater than or equal to the tooth section thickness H, and equivalent to the diameter of the shaft hole D; 4 hub diameter minimum D1 should be 1.5-3 times the diameter of the shaft hole of D.
  It should also pay attention to, in order to reduce effect of plastic gear corner stress concentration and forming stress, should try to avoid sudden changes in cross-sectional area size or sharp corners, as far as possible to increase the surface contact or turning round and arc radius; at the same time, the stress to avoid the assembly, shaft and the hole should as far as possible not by interference fit, and the pin hole with the form or half moon.
  For the thin-walled gears, uneven wall thickness can cause gear skew, which adopts the structure of wheel rim without no can well improve the situation. But if there is a big hole on the web, because the hole in the molding cooling is rarely shrink to the center, the gear skew.