During pellet production, a customer discovered that the pellet mill's roller stopped rotating and became overheated. After inspection by after-sales engineers, they discovered that the cause was damage to the pellet mill's roller bearing. Many people are unclear about when the roller shell broke down, and what exactly causes the roller shells to break down.

1. Foreign matter contamination

The pellet mill's operating environment is dusty. When some fine dust enters the high-speed roller shell housing, corrosive particles can wear components, while conductive particles can interfere with current flow. Accumulation of particles can clog the roller's perimeter, accelerating overheating. Contamination can also occur due to factors such as opening the roller shells packaging too early before use, installing the roller in an unclean working environment, or contaminating the working medium.

2. Poor Lubrication: Poor lubrication is one of the main causes of roller shell damage. The main causes include: failure to add grease in a timely manner or not adding it properly, improper grease selection, incorrect lubrication method, etc., which can cause the roller to burn out due to lack of oil.

3. Improper Installation
Using brute force during installation, such as hitting the roller shells directly with a hammer, is the most damaging and the main cause of deformation. Improper installation, deviations, or failure to properly seat the roller shells can result in insufficient roller shells play, causing the inner and outer rings to rotate at different points, resulting in misalignment.

4. Fatigue Damage
Fatigue damage is a common cause of roller shells failure. The main causes include prolonged overload, lack of timely maintenance, and aging of equipment parts. Furthermore, if the ring die experiences material discharge difficulties or die blockage, the temperature inside the die cavity can rise rapidly, causing vibrations in the die body and potentially burning the rollers and spindle bearings.

5. Improper selection or poor quality.

The fit between the roller's inner diameter and the shaft, and between the outer diameter and the housing, is crucial. If the fit is too loose, the mating surfaces will experience relative sliding, a phenomenon known as creep. Once creep occurs, it can wear out the mating surfaces, damaging the shaft or housing. Furthermore, wear particles can penetrate the roller's interior, causing heat, vibration, or bearing breakage.

When selecting a pressure roller shell, you should use qualified and high-quality products from regular manufacturers, and pay attention to the maximum speed and load capacity of the pressure roller shell. Do not use it at excessive speed or overload!

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