Method for computational determination of the oil temperature in a clutch unit

A method for computational determination of the oil temperature in a clutch unit for a drive train of a motor vehicle, the clutch unit having a housing, a wet friction clutch disposed in the housing for controllable transmission of a torque from an input element to an output element of the clutch unit, oil for cooling the friction clutch disposed within the housing, and an actuator for actuating the friction clutch that is attached to the housing in a thermally conductive manner and has a temperature sensor for sensing a temperature of the actuator, the method comprising:

• determining a thermal input power to the clutch unit as a function of at least a speed of one of the input element and the output element of the clutch unit;
• determining a thermal output power of the clutch unit as a function of at least the actuator temperature;
• determining a difference between the thermal input power and the thermal output power;
• and
• determining the oil temperature as a function of the difference between the thermal input power and the thermal output power.