Differences between sleeve, Hydraulic and ball bearings on fans

There are three common types of bearings: ball bearing, hydraulic bearing, and sleeve bearing.

Sleeve bearing

Sleeve bearing is made of porous metal that can absorb and retain lubricating oil. The lubricant filled between the blade shaft and sleeve acts as a drag reducer. Generally, the lifetime of sleeve bearing is 8000-10000 hours. It is suitable for a fan with medium or low speed.

Advantages: low price, low noise, suitable for intermittent use.

Disadvantages: high wear rate, short service life.

Ball bearing

Ball bearing has the characteristics of rolling friction by metal beads,  small contact surface, and small friction coefficient. Lifetime is improved because the friction of bearing surfaces is reduced. As none oil leak, it is suitable for products that are often operated in different angles and directions.

Advantages: Long service life, suitable for the fans with higher rotation speed.

Disadvantages:  high price, high noise level caused by rolling of metal beads.

Hydraulic bearing

Hydraulic bearing has larger oil storage space than sleeve bearing, and has a unique oil supply circuit of loop type. As its bottom is sealed completely, the lifetime is longer than that of sleeve bearing. It is suitable for high, medium, and low-speed fans. The average life of hydraulic bearings is 40000-50000 hours.

Advantages: low noise, longer life than sleeve bearing.

Disadvantages: more expensive than sleeve type.