Kiln maintenance typically focuses on the kiln itself, due to the huge stresses and heat involved – but few parts of a rotary kiln system take more abuse than the bearings and the bearing housings. The bearings have to deal with a huge amount of weight while keeping the kiln rotating smoothly for its heat profile to be optimized. Bearings and housings are also necessary for other aspects of the kiln system as well, such as the feed system its conveyor belts.
What are some of the most common types of bearing housings? These are ones we often see when doing maintenance and repairs on rotary kilns.
Five Common Types of Bearing Housings
1 – Split Plummer Block
Possibly the most common bearing housing type is the split plumber block, which is also sometimes called a pillow block. In these, the housing is split into two parts, upper and lower, which are held together with thick bolts. These are easy to mount and make maintenance easier through convenient access to the internals. You don’t have to disassemble the shaft to get at the housing or bearings.
2 – Non-Split Plummer Block
As the name suggests, non-split plummer blocks are similar in design to split blocks, but without the split. They’re a single solid piece instead. This improves stability for particularly heavy loads by removing any chance of the split or its holding bolts becoming a point of failure but loses the easy maintenance advantage.
3 – Flanged Housings
Flanged housings keep their attachment points perpendicular to the shaft axis and are typically slimmer than plummer blocks. This gives them an advantage in tight spaces, and are particularly useful with horizontal frames, although they are not as good at holding up against some angular forces.
4 – Take-Up Housings
These are typically only seen on conveyor belt systems and roller beds. They feature a yolk-shaped drawbar eye at the top or bottom, which is the main attachment point. These bearing housings are also useful for loads that act in different directions.
5 – Two-Bearing Housings
These are effectively two housings in one, creating a longer tube around the shaft, with four mounting points at the corners. They’re particularly effective in applications with an overhanging load that needs to be suspended from the top of the structure and are especially stable due to their design.