Modeling, Simulation and Validation of a Tractor Wet Clutch Controlled by Proportional Valve


International Journal of Automotive Science and Technology, vol.5, no.1, pp.8-18, 2021 (Peer-Reviewed Journal) identifier


Wet clutch is a widely used machine element in agricultural machines because it allows the transmission of high torque with a more user-friendly turn on/off. In this article, the control of a wet clutch pack using a proportional valve in the power take-off unit is investigated. A wet clutch package is implemented on the transmission direct PTO shaft and actuate the power take-off unit of an agricultural tractor. A one-dimensional mathematical model of the wet clutch and the electro-hydraulic control system was developed. Several actuation cases were simulated, and responses of all circuit elements were evaluated. Based on these predictions, test procedures with out-put torque values 300 and 600 N-m were set at 1.900 rpm unloaded engine speed. Variables, including speed, pressure, and temperature, were recorded in the experiments. The test and simulation results were compared. The clutch pressure increase was 10% under-predicted while the mainline pressure drop was 1% over-predicted. The proposed 1-D model can be further improved indeed. Yet, the acceptable agreement between the model and tests, offers less costly trial-and-error in the design and tune-up of future systems.