WPDS135 - 30 - B As a worm gear reducer, its worm gear is mostly made of tin bronze and its worm is mostly made of alloy nitride steel. This type of reducer itself has obvious sliding friction and is prone to heat generation. Excessive operating temperature will cause chain damage to the worm gear, and will also cause problems with peripheral components, further aggravating the damage to the worm gear, as follows:
Lubrication failure causes serious wear of the tooth surface : rising temperature will cause the viscosity of the special lubricating oil for worm gears to drop significantly, and the thickness of the oil film will become thinner or even ruptured. The metal meshing surfaces of the worm gear and worm cannot be effectively isolated, resulting in boundary friction or even dry friction. At the same time, high temperatures will accelerate the oxidation of lubricating oil and generate sediments such as sludge and colloid. These impurities will cause abrasive wear when mixed into the meshing surface, resulting in a large number of scratches and pitting on the tooth surface. For every 10°C increase in oil temperature, the oxidation rate of lubricating oil will be approximately doubled, and the wear rate will also increase sharply.
The tooth surface is prone to sticking and seizure : high temperature will soften the surface metal of the tin bronze worm gear, and although the worm is made of alloy steel, its hardness will also decrease to a certain extent at high temperatures. At this time, the friction coefficient of the meshing surface will increase significantly, and the softened metal will easily stick to each other under heavy load conditions. If the high temperature continues, the adhesion will be torn along with the transmission, causing adhesive wear. In severe cases, the tooth surface will bite, and even cause the worm gear to get stuck, causing the equipment to suddenly stop and malfunction.
Early fatigue spalling on the tooth surface : Long-term high temperature environment will reduce the mechanical properties of the worm gear material. For example, the toughness of the worm gear copper alloy decreases and the surface hardness of the worm gear attenuates. When the worm gear meshes, the tooth surface will bear repeated contact stress. High temperature will amplify the destructive effect of this stress. Tiny fatigue cracks will first appear on the tooth surface, and then the cracks will gradually expand, eventually leading to pitting and spalling of the tooth surface metal, which will greatly reduce the stability of the transmission and may also cause abnormal vibration.
Deterioration of meshing accuracy aggravates eccentric load wear : The thermal expansion coefficient of the worm gear and the worm is different. The thermal expansion coefficient of the worm gear is about 1/2 of that of the worm. There is a difference in the degree of thermal deformation between the two at high temperatures, which will cause the original precise axis line to shift and the meshing gap to abnormally change. This makes the contact area smaller during meshing and local stress is concentrated, which will not only produce obvious abnormal noise, but also cause the local tooth surface to wear much faster than other parts, causing problems such as eccentric wear and tooth chewing, which will further damage the transmission structure of the worm gear.
The associated damaged seals indirectly aggravate pollution and wear : the oil seals, gaskets, etc. of the reducer are mostly made of rubber. High temperatures will cause them to rapidly age, harden, and lose elasticity, leading to seal failure. External dust, water vapor and other impurities will enter the inside of the casing through the sealing gap and mix into the lubricating oil. After these impurities enter the worm gear meshing surface, they will further aggravate abrasive wear. At the same time, water vapor may also interact with high temperature to cause slight rust on the worm surface. Corrosion spots may also appear on the worm gear copper alloy, doubly damaging the worm gear tooth surface.
