The transmission characteristics of the coal mining scraper conveyor are low speed and heavy load, impact resistance, small size, but poor lubrication and heat dissipation. In order to obtain high-performance gear transmission devices, it is necessary to continuously improve the design level and manufacturing level of products.
To improve the design level, we must first improve the design methods. Using advanced design technology. At present, some companies have developed gear tooth profile design calculation software based on load and deformation. In gear design, high displacement is used to perform finite element analysis of tooth root bending stress. The shape of tooth root transition curve is improved to make the gear under full load. The meshing state has been greatly improved and the contact strength has been improved. The load analysis of the planetary gear transmission mechanism using elastic mechanics and the finite element method has made the load-sharing structure more scientific and reasonable. And oil film status. The adoption of the above-mentioned advanced gear transmission design technology makes the gear design reach a high technical index.
Coal mining scraper conveyor gears are mostly made of surface-hardened high-grade low-carbon alloy steel materials. The hardening processes are: carburizing, nitriding and surface quenching. With the increase of gear transmission power and the relative decrease of volume, the contact stress on the tooth surface and the bending stress on the tooth root increase significantly. The intergranular impurities (molecular sulfur, phosphorus, nitrogen, etc.) of gear materials often become the source of fatigue crack initiation. At present, the major international coal mining scraper conveyor manufacturers widely use low-carbon high-quality multi-alloy gear steel smelted in a vacuum electric furnace. The gear heat treatment adopts computer measurement and control atmosphere carburizing equipment, strictly monitors the temperature and carbon potential in the furnace, and controls the thickness of the carburizing layer on the gear surface, the carbon content gradient and the metallographic structure. The main parts of the gear device are manufactured by a CNC machining center, and the machining accuracy has been greatly improved. The gear manufacturing accuracy of some foreign companies has reached the level of 6-6-5 of the Chinese GBlO0095-88 "Involute Gear Processing Precision" standard.
