a magnetic gear train formed of a first wheel and a second wheel, the first wheel being provided with N first alternating magnetic poles which are circularly arranged and define a first magnetic toothing, N being an integer being 3 or greater, the second wheel being provided with teeth made of ferromagnetic material or with second alternating and circularly arranged magnetic poles, said teeth or said second magnetic poles defining a second magnetic toothing which has a magnetic coupling with the first magnetic toothing such that, when one of the first or second wheels is driven in rotation, said one of the first or second wheels rotates, via the magnetic coupling, over a geometric circle centered on the other of the first or second wheels and linked to said other of the first or second wheels;

a ferromagnetic element or a set of ferromagnetic elements arranged, relative to the first wheel, so as to offset at least most of a magnetic disturbance torque to which said first wheel is subjected, resulting from said magnetic coupling, said magnetic disturbance torque having a periodic variation in intensity according to an angular position of the first wheel relative to a reference half-axis starting from the central axis of the first wheel and intercepting the central axis of the second wheel.