1. Basic requirements for gear accuracy

It has been proved by practice that the gear accuracy must be controlled at gb10995-887 ~ 8 level, the linear speed is higher than 20 m / s gear, and the tooth pitch limit deviation, ring gear radial runout tolerance and tooth direction tolerance must be stable to reach 7 level accuracy. In the case of Grade 7 precision gear, the shuttle should be reversed at the tooth part and the root boss should be strictly prevented.

2. Control the quality of raw materials

High quality raw materials are the prerequisite for the production of high-quality products. No matter which way is adopted, the raw materials must go through strict chemical composition inspection, grain size measurement and purity assessment after arriving at the factory. Its purpose is to adjust the deformation of heat treatment in time and improve the quality of tooth profile processing.

3. Prevent heat treatment deformation

After rough machining, the gear blank is made into precision forging and normalized or tempered to achieve: (1) soften the steel parts for machining; (2) eliminate residual stress; (3) refine the grains and improve the structure to improve the mechanical properties of the steel; (4) make organizational preparation for the treatment. It should be noted that in the normalizing or tempering treatment, it is necessary to keep the furnace temperature uniform, and use the working position apparatus to make the workpiece evenly heated and cooled. It is strictly prohibited to stack them together. Ensure the accuracy of the gear blank according to the design requirements. . gear cutting processing measures: the purchased gear cutting tools must be inspected and meet the requirements of Class AA. After the grinding of gear cutting tool, it is necessary to check the radial property of the front edge of the tool, the difference between adjacent circumferential joints of the chip holding groove, the large accumulated error of the circumferential joints of the chip holding groove, and the parallelism between the front of the tooth and the axis of the inner hole.