Mechanical Face Seals: Test Rig Development and Analysis of the Frictional Behaviour

Abstract: Mechanical face seals, MFS, are important machine components in the heavyduty-vehicle industry which generate a high frictional power loss. In order to lower these losses an investigation has to be performed on the frictional behavior of the MFS. A physical test rig allows an evaluation of existing seals and new concepts to compare their performances. Prior to this project, a test rig for MFS had been partially designed and manufactured by a group of students within a design project at KTH. This report presents the continuation of this work. A solid background study was performed in which the best testing equipment and theoretical models in the literature to characterize MFS were reviewed. The design and manufacturing of the test rig prototype has been completed and most importantly, it has been validated, achieving an acceptable assessment of repeatability. Tests have been planned and executed to assess the repeatability of the test rig and to study the effect of different parameters: speed, preload, eccentricity and angular misalignment. A theoretical loss model was performed which gave discrepant results for studies with mixed lubrication, making a comparison with the experiments impracticable. Further work has to be done to evaluate the applicability of the proposed model. In addition, a valuable Matlab tool has been developed and packaged to facilitate processing data of the test rig for future users.