Radialtätning till Retarder
This thesis has the overall objective to develop the optimum sealing system between the retarder and transmission. Today, there is a pressure-relief and two radial seals separation between the retarder and transmission. It has been found that carbon residue formation may occur between retarder axle and seal lips with, in some cases, leakage as a result.We have in this thesis tried to explain the phenomenon of carbon residue, how it is formed and why it can be seen just on the seals? A rig test was conducted where we show how friction, speed, transmission temperature and mitigation phases of the retarder affects temperatures in the sealing environment. Factors affecting the coke structure are reported, together with proposals for measures that provide a mitigating seal environment. The material is PTFE, which is standard in the seals today; we believe meets all requirements for the sealing material.The final recommendation is a tripartite cooperation between Scania, a petroleum company and an additive manufacturer where the different base oils and additive tested as multi-factorial experiments to identify what gives the best results. On transmission side we recommend to ensure a constant oil flow to the seal.