The surface roughness of the shaft has the following effects on the noise and vibration of the parallel axis FA47-48-0.55KW reducer:
Affects friction and wear: The greater the roughness of the shaft surface, the more microscopic protrusions. When the reducer is running, the effective contact area between the shaft and the mating parts such as bearings and gears is small, the pressure increases, and the friction resistance increases. This will intensify wear between mating components, causing the gap between components to gradually increase, causing vibration and noise. For example, when the shaft surface roughness value is high, after operating for a period of time, the matching gap between the bearing and the shaft journal may become larger due to wear, causing the shaft to shake during operation, resulting in vibration and noise.
Inducing stress concentration: There are microscopic defects such as knife marks on the rough shaft surface, and stress concentration is easily generated at the roots of these defects. When the reducer is working, the shaft is subjected to alternating load, and fatigue cracks are easily caused at the concentration of stress. As the cracks spread, local stiffness of the shaft will change, which will in turn cause vibration and noise. Moreover, fatigue cracks develop to a certain extent may lead to shaft fracture and affect the normal operation of the reducer.
Interference lubrication effect: The roughness of the shaft surface is too high, making it difficult for the lubricating oil to form a uniform oil film on the surface. On the one hand, the lubrication effect will be worse, the friction between the components will be increased, and vibration and noise will be caused; on the other hand, the uneven oil film distribution will cause local pressure changes and will also cause vibration. For example, in a high-speed reducer, if the roughness of the shaft surface is not suitable, the lubricating oil film is prone to rupture, causing the shaft to come into direct contact with the mating member, causing friction noise and vibration.
Influence aerodynamic effects: When the reducer is running at high speed, the microscopic raised parts of the rough shaft surface will produce an aerodynamic effect. Air flows on the shaft surface and creates additional noise, similar to the effect of aircraft wing surface roughness on aerodynamic noise.
