Sealing of Dry Particles with Grease-Filled Non-Contacting Sealing Systems

There is no wear and no friction with non-contacting sealing systems. Because of this, there is in principle no lifetime-limit. However, this does not apply for grease-filled labyrinth seals. To seal against particles, the grease inside the gaps of the seal has to bind pollution particles and the grease-filled gap must be opened. If the surfaces of the grease layers in the gaps are saturated with particles, further particles penetrating the sealing system can no longer be bound. The seal must then be relubricated. Based on the actual state of the art, this work shows the latest results of experiments to enable designers to unerringly develop non-contacting sealing systems with grease-filled gaps to seal dry particles with reliable function. To that end, a lot of experiments were done to expand existing design guidelines. Additionally, new operating instruction were found to ensure permanent operation. A possibility to reduce the complexity of the sealing system is presented at the end of the present work.