Drum-shaped gear couplings need to be subjected to high-frequency quenching and tempering treatment, because the high-frequency treatment needs to be carried out at a higher temperature, it will be heated and deformed.The tolerance of the shaft hole will become a negative tolerance due to thermal expansion and contraction.Therefore, the high-frequency treatment of the coupling is heated to the specified temperature in the heating furnace, and the temperature of the workpiece is detected.Take out the coupling and turn it over and put it in the furnace to continue heating.For example, use firewood to heat large couplings.After 2 to 3 hours, the measuring rod repeatedly measures the aperture until the measuring rod with a large size can freely enter the coupling hole, and the heating is finished.Lift out the coupling and install the striker, climbing or other kit tools.Correct the position so that the coupling hole is vertical (for vertical assembly) or horizontal (for horizontal assembly), and clean the coupling hole so that the inner hole is free of debris.Hang the coupling close to the shaft; once again check with the measuring rod whether the inner hole size has the required assembly clearance, if the measuring rod can pass, the assembly can be carried out.Apply engine oil evenly on the mating surface of the shaft.

　　The annealing treatment of the drum gear coupling is mainly for the secondary heating treatment process for the hardness of the material that does not meet the specified requirements. The purpose is to ensure that the hardness of the gear coupling reaches the specified standard hardness.This process is mainly used in many types of drum-shaped gear couplings; the following points should be paid attention to when the drum-shaped gear coupling is annealed:

　　(1) Stress: due to the difference in heating between the inside and outside of the metal, the expansion is uneven and internal stress is generated, which is called thermal stress.If the temperature is too high during annealing to cause graphite cross-section, it will not be easy to cut and cause overheating and deformation during quenching.Decarburization causes soft spots on the surface of the workpiece, reducing the hardness, wear resistance and fatigue strength of the surface;

　　(2) Decarburization of drum gear coupling: Decarburization refers to the phenomenon that all or part of the carbon on the steel surface is burned off;

　　(4) Overheating and overburning: Overheating refers to the growth of coarse grains after the steel exceeds the allowable temperature during heating;

　　(5) Hard and brittle mesh carbide of the coupling;

　　What happens if the drum gear coupling is heated for too long? The heating of the elastic coupling forging will cause the workpiece to crack during heating, which will cause the workpiece to crack and be scrapped after turning.If band-shaped carbides appear on the surface of the elastic coupling, the hardness and structure after quenching and tempering will be uneven, and it will be easily deformed. This is also a defect of the band-shaped structure of pearlite and ferrite along the processing deformation direction. .However, if the annealing is underheated or the temperature is low, the pearlite will not be globalized, and it will not be conducive to cutting and subsequent heat treatment.There is no cure for a fever.Failure to remove beryllium oxide will affect turning processing.Overburning refers to the phenomenon of metal oxide or partial melting due to too long heating time and too high temperature.