Guidelines for preventing fatigue damage to gears in roller press reducers
1、 Optimize design and material heat treatment process
The inherent quality of gears is the basis for resisting fatigue damage. In the design and manufacturing stages, high-strength alloy steel (such as 20CrMnTiH, 18CrNiMo7-6 carburizing steel, or 42CrMo4 nitriding steel) should be prioritized, and advanced heat treatment processes such as deep carburizing, induction hardening, or laser surface strengthening should be used to achieve a tooth surface hardness of HRC 58-62 while maintaining core toughness. In addition, tooth profile modification (such as drum shape modification, chamfer modification) can be used to reduce meshing impact and tooth end stress concentration; Adopting helical gears or double circular arc gears to increase the length of the contact line and make the load distribution more uniform. For components such as internal gear rings that are prone to pitting corrosion, surface strengthening techniques such as nitriding and shot peening can be used to further enhance their fatigue resistance.
2、 Strictly control manufacturing accuracy and assembly quality
The precision of gear machining and assembly quality directly determine the meshing state. If the tooth profile error is large, the surface roughness is high, or the axis parallelism exceeds the tolerance during assembly, it will cause local contact stress overload and accelerate pitting corrosion. Therefore, it is necessary to improve the precision of gear machining by using gear grinding technology to control the tooth surface roughness within Ra ≤ 0.4 μ m, and improving the surface residual stress distribution through gear honing. In the installation process, it is necessary to accurately adjust the connection accuracy of the reducer base, motor and other matching components, strictly control the axial and radial runout, ensure that the contact rate of the tooth surface in the tooth height direction is ≥ 50% and the tooth length direction is ≥ 70%, and avoid excessive local stress caused by poor installation.
3、 Implement refined lubrication management
Lubrication is the "running blood" of gears, and oil film rupture or poor lubrication is the direct cause of pitting corrosion. Firstly, high-performance lubricants should be accurately matched according to the working conditions. It is recommended to use high viscosity extreme pressure (EP) gear oil containing anti-wear agents or synthetic lubricating oil with better high-temperature stability to ensure the formation of an effective oil film under heavy loads. Secondly, standardize lubrication management. After one month of operation of new equipment, low viscosity lubricating oil should be used to clean the internal plaster and iron filings; During daily operation, it is necessary to regularly check whether the lubrication station filter is clogged and the temperature difference between the inlet and outlet coolers (the inlet water temperature should be ≤ 30 ℃) to prevent excessive oil temperature from damaging the oil film. In addition, advanced lubrication devices can be explored to ensure sufficient lubrication between gears during the start-up of the gearbox, avoiding small scratches and pitting caused by dry friction or boundary lubrication.
