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

Abstract

Wet clutch is a widely used machine element in the agricultural machines be-cause 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 ag-ricultural 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, pres-sure, 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, offer less costly trial-and-error in the design and tune-up of future systems.

An improved adaptive position tracking strategy for automatic shift actuator with uncertain parameters

“…According to different design principles, different clutch architectures have been devised such as friction clutch 2 , 3 , Electro mechanically clutch taking motor as power source 4 , 5 , hydraulic or electro hydraulic clutch 6 , 7 and electro pneumatic clutch 8 , 9 . To realize clutch engagement or disengagement control, clutch chamber pressure, transmission torque and clutch piston displacement are the mostly used control modes.…”

Research on clutch position control based on backstepping method for small-sized tractors

“…Hydraulic manipulator or electro hydraulic manipulator is an alternative drive form for the automatic mechanical transmission system not only used on the wheeled agricultural tractors but also on the heavy-duty automobile vehicles. 6 – 9 Moreover, electro pneumatic driven clutch actuators are also used for the shift gear control in heavy-duty vehicles. 10 , 11 To track the desired clutch engagement point, clutch piston displacement, clutch chamber pressure and transmission shaft torque are the mostly used control modes.…”