The manufacturing precision requirements for gears are quite high.

The selection of processing benchmarks for gears often varies due to differences in the structural shapes of the gears. For shaft gears, positioning is mainly done using vertex holes; for hollow shafts, after drilling the central hole, positioning is done using the inclined surfaces of the holes at both ends; when the hole diameter is large, a cone plug is used. Vertex positioning has high precision and can achieve benchmark coincidence and unification. For hole gears, two common positioning and clamping methods are often used during tooth surface processing. 1. Inner hole and end face positioning: This positioning method uses the inner hole of the workpiece to determine the positioning location, and the end face serves as the axial positioning benchmark, with clamping done against the end face. This allows the positioning benchmark, design benchmark, assembly benchmark, and measurement benchmark to coincide, resulting in high positioning accuracy, making it suitable for mass production. However, this method requires high precision in the manufacturing of the fixture. To improve gear precision and reduce tooth surface roughness, methods such as grinding or polishing can be employed. However, for gears that have already been processed and lack grinding allowance, using conventional grinding agents can be time-consuming and labor-intensive with not very obvious results. Therefore, a new process using CRONEX special grinding materials is adopted. For reducer gears, EP6 CRONEX abrasives are used for grinding. During grinding, the process starts with low-speed no-load grinding, followed by accelerated pressure grinding (controlling pressure through load control). After grinding, the tooth surface roughness is reduced from the original 2.25μm to 0.25μm. The Chinese gear industry is mainly composed of three parts: industrial gears, vehicle gears, and gear equipment. Among them, vehicle gears account for 60% of the market share; industrial gears consist of general industrial, specialized, and special gears, with market shares of 18%, 12%, and 8%, respectively; gear equipment accounts for 2% of the market share. The gear industry should improve industry concentration through market competition and integration, forming a number of large, medium, and small enterprises with assets of several billion, 500 million, and 100 million yuan; through the design and development of products with independent intellectual property rights, a group of leading enterprises in vehicle transmission systems (gearboxes, drive axle assemblies) should be formed, integrating the capabilities and resources of the gear industry through the supporting capabilities of leading enterprises; achieving specialized and networked support, forming a large number of distinctive processes, distinctive products, and well-known enterprises with rapid response capabilities; and through technological transformation, realizing the transformation of modern gear manufacturing enterprises.

Gear