When it comes to industrial fans, bearings are extremely important. It is critical to select the right fan bearings and maintain them for improved performance and increase equipment longevity.
Hydrodynamic Fan Bearings
Water-cooled hydrodynamic fan bearings are being used more and more in large-scale industrial fans, especially in applications with extreme environments. We’re talking about pulp and paper plants, oil refineries, cement and power generation.
First, it helps to understand there are different types of fans. All will fall into one of two categories:
- Forced Draft (FD) – Fans that handle ambient air
- Induced Draft (ID) – Fans that handle hot process gasses
For large industrial fans, hydrodynamic bearings generally prove to be more effective and efficient over time than their standard counterparts. Standard rolling element bearings use balls or rollers to separate the inner and outer races. They can wear out more quickly when used in such extreme environments.
How Hydrodynamic Bearings Work
Hydrodynamic bearings, on the other hand, use a sliding motion between the bearing surface and the shaft. As the shaft turns, a thin film of oil forms in the clearance area between the two surfaces. This completely separates the shaft and the bearing, which in theory provides an infinite lifespan as long as you maintain the quality and quantity of the lubricant.
The oil film is generated by a combination of shaft surface speed, load and oil viscosity as heat is generated through operation. The circulating oil lubrication and water cooling properties helps prevent overheating.
Benefits of Hydrodynamic Fan Bearings
High-grade steel or cast iron are used in the two main components of a hydrodynamic bearing (the housing and the liner) for added durability. Other benefits of hydrodynamic bearings include:
- Improved damping
- Increased stiffness
- Reduced vibration
- Shock absorption in the presence of minor rotor unbalance
Unplanned shutdowns with industrial fans can be very expensive, so the bearings used are crucial. Careful monitoring and maintenance are also recommended to ensure that the lubrication is always proper and the bearings are performing as desired. With the right equipment, configuration and maintenance, water-cooled hydrodynamic bearings can essentially run forever and minimize downtime with industrial fans.
To learn more about hydrodynamic bearings, industrial fans, and expert help with installation and maintenance, contact Cortech today.