Investigation of the Drag Losses of Wet Clutches at Dip Lubrication
2022-01-0788
03/29/2022
- Event
- Content
- Wet running multi-plate clutches and brakes are important components of modern automotive and industrial powertrains. In the open stage, drag losses occur due to fluid shearing. This subsequently can lead to a perceptible reduction in the overall drivetrain efficiency. Depending on the application and requirements, injection or dip lubrication is used. For the first one there is already a deep fundamental understanding existing, whereas the latter was not extensively investigated so far. This contribution gives a detailed insight in the experimental research of the drag losses of wet running multi-plate clutches at dip lubrication. In a base study the flow conditions and origins of the drag torque generation were investigated. Built on this, the effects of operating and geometry parameters such as oil viscosity and level, clearance, groove design, disk size and number of gaps on the drag loss characteristic were determined based on a full-factorial testing. The paper further explains the setup of the drag loss test rig LK-4 used. An important outcome of this contribution is the development of a systematic testing procedure to accurately acquire the drag torque. Through the demonstration of the reproducibility of the test results, in fact, it was confirmed that the scientific outcomes are not expected to alter over time. Moreover, the developed evaluation methodology is described in detail. This research investigates a wide size range of friction disks and steel plates of serial production parts from automotive and industrial applications in order, not only to characterize the phenomenon and the trends for a specific dimension, but also to compare the behavior within different sizes.
- Citation
- Pointner-Gabriel, L., Forleo, C., Voelkel, K., Pflaum, H. et al., "Investigation of the Drag Losses of Wet Clutches at Dip Lubrication," SAE Technical Paper 2022-01-0788, 2022, .