The timepiece mechanism comprises a rotating wheel set, a support element, a pivoting member mounted on the support element and magnetic return means for returning one portion of the pivoting member against a surface of the rotating wheel set. The return means comprise a first magnet carried by the pivoting member and a second magnet carried by the support element. The first and second magnets are arranged such that, in normal operation, the interaction of their respective magnetic fields generates a magnetic force oriented to return said pivoting member portion towards said rotating wheel surface. At least one of the first and second magnets is arranged to permit reversal of its polarity, preferably with the aid of a tool, and thereby of the direction of the magnetic force acting on the pivoting member, said magnetic force then tending to move said pivoting member portion away from said rotating wheel set surface, which makes it easy to handle the various elements of the timepiece mechanism.

A mechanism (1) including a magnetic gear (2) including a first wheel (6B) and a second wheel (6C) provided with a first magnetic toothing (10) and a second magnetic toothing (12) respectively. The first and second magnetic toothings are respectively formed by first and second teeth made of a soft ferromagnetic material; and the magnetic gear (2) further includes a third wheel (6A) arranged between the first and second wheels (6B, 6C) and provided with a third magnetic toothing (8) formed by permanent magnetic poles, in particular by bipolar magnets. In general, the first wheel is a drive wheel, whereas the second wheel is driven into order to carry out a function or transmit a torque. The third intermediate wheel is preferably mounted such that it can rotate freely.