Timepiece movement comprising a device for equalising a motor torque

Timepiece movement including a mechanism, a spring barrel for driving the mechanism, and an equalization device connected to the spring barrel. The spring barrel includes a drum and a motor spring to exert a driving torque which is variable as a function of the degree of winding-up of the motor spring. The equalization device is driven by the spring barrel and exerts an auxiliary torque which varies as a function of the degree of winding-up of the motor spring to counter variations in the motor torque. The equalization device includes a first and second magnetic elements being displaced from each other by exerting a magnetic force which varies as a function of the relative position of the first and second magnetic elements and produces the auxiliary torque.