PTO drive for an agricultural or construction work vehicle and method for operating a PTO clutch serving as an overload clutch of a PTO drive

摘要

A PTO drive for a farm or construction work utility vehicle has a PTO clutch (3) via which one of an internal combustion engine (1) driven input shaft (2) with a drivingly connected to a PTO stub shaft (17) output shaft is coupled. The PTO clutch (3) is hydraulically actuated via a proportional valve in an engaged position and serves as an overload clutch on which by means of transducers and an electronic control unit when exceeding a limit value of a torque transmitted by this detectable slippage is determined. The occurrence of a slip via the electronic control unit (25) and the proportional valve (20) to an actuation of the PTO clutch (3) in its disengaged position. In order to avoid overloading and slippage leading to wear on the PTO clutch serving as an overload clutch in all operating states, a pressure p present in a hydraulic actuator (21) of the PTO clutch (3) is applied directly to it in its engaged position As proportional to the transmitted by means of the PTO clutch (3) torque Man, wherein via the electronic control unit (25) based on a characteristic of each transmittable torque, a corresponding pressure p, with which the PTO clutch (3) of the PTO drive is operated.