Heat-resistant plastic deep groove ball bearings in pellet stoves

Profile

What was needed?
Ball bearing for the drive mechanism that works consistently despite adverse environment

Requirements:
High temperature resistance, functionality despite small installation space

Industry:
Furniture construction / industrial design

Success for the customer:
Plastic ball bearings guarantee long-term smooth operation and minimise downtimes.

Thanks to a mechanical drive unit, the Gravity pellet stove enables wood pellets to be transported into the combustion chamber without electricity. In addition to its current-free function, it is adjustable in three stages, can be stopped immediately without completely burning the pellets. With an efficiency of 80%, it is the first stove in its class to work according to this innovative system.

Problem

Both metallic and various polymer plain bearings did not convince in tests of "Erwin Koppe - Keramische Heizgeräte GmbH". Metallic ball bearings not only seized too fast, but were too loud in operation. Alternative tests with polymer plain bearings led to excessive coefficients of friction, so that these were also discarded. The problem was to find a component that keeps the complete mechanism running despite very small installation space and is also durable, temperature-resistant and insensitive to dirt.

Solution

Two lubrication-free plastic ball bearings made of the material xirodur A500 are used in the mechanical drive unit. They ensure that the wood pellets are fed to the combustion chamber via a roller. The biggest advantage lies in the high temperature resistance of the ball bearing material. Short-term temperatures of up to 150°C are possible without any problems and since there are no lubricating greases/oils, nothing can stick inside the shaft. The plastic ball bearings from igus thus always guarantee the required smooth operation.