1) During grinding, the feed rate is large, the grinding speed is fast, and the tooth surface temperature is too high. The grinder coolant cools it, forming re quenching, resulting in tooth surface cracks. Solution: determine the appropriate feed rate, grinding speed and grinding depth for gear grinding according to different materials and different allowances.
2) The allowance for gear processing shall be reasonable, and the machining process route shall be correctly arranged. During the heat treatment of gear wall thickness or wall thickness, the inner hole of the gear will shrink and swell. For the gear with keyway, the inner diameter will expand in the direction of keyway to form an ellipse. Solution: quenching and tempering first, and then finishing the inner diameter and key insertion can reduce the gear deformation.
The above is the crystallization of ZHY gear senior engineer team’s long-term hard research on heat treatment technology and personal experience in front-line production workshop. It is also the experience summary of gear heat treatment based on the combination of theory and practice. Now the surface quenching of carburized gear is changed to overall quenching, the mechanical performance of gear is improved, the quality of heat treatment is stable, and the qualified rate is more than 98%. Dozens of kinds and tens of thousands of gears have been treated, and good results have been achieved. The products are sold to major coal mines in China and exported abroad, and the economic benefits have been significantly improved. Practice has proved that the above preventive measures and solutions are very effective and feasible.