Timepiece movement fitted with an electromagnetic transducer

A timepiece movement comprising an electromagnetic transducer formed by a stator and a rotor, the stator comprising at least one coil with a central axis that is parallel to the axis of rotation of the rotor, the rotor comprising a central shaft, two magnetic plates that are mounted on the central shaft and at least one magnet that is mounted on one of the two magnetic plates so as to be located between these two magnetic plates, said at least one coil lying in a general plane, located between the two magnetic plates, axially remote from said at least one magnet, the rotor and said at least one coil being configured so that said at least one coil is located at least partially in a circular space which is defined by the rotor between its two magnetic plates from its central shaft to its periphery and which is left free by this rotor, said central shaft comprising a pinion which engages with a wheel of the timepiece movement;

• wherein said stator is configured so as to leave an angular sector of said circular space free, the aperture angle of which is selected to allow said wheel to penetrate radially into said circular space up to said central shaft while remaining in this angular sector;
• wherein said pinion is arranged between the two magnetic plates and has at least one useful portion located between two geometric planes defining said circular space about said axis of rotation;
• and wherein said wheel is partially arranged between the two magnetic plates, in said angular sector of the circular space, so as to engage with said pinion.