AC /DC fans life report

Ball bearing: the model is generally indicated in B; several small steel beads in the bearing rotate around the shaft in the form of rolling friction, so the friction is less without oil leakage. 

Features: long life, suitable for high speed fan

sleeve bearing The model is generally expressed in S; using sliding friction sleeve, the blade shaft uses lubricating oil as lubricant and drag reducer in the sleeve simplicity, but the lubricating oil will evaporate and cause wear, so the life is shorter than the ball 

Features: resistant to external force impact, low noise