Shedding machine for a loom and shedding assembly for a loom comprising a group of such machines

A shedding machine for actuating a heald frame of a loom according to a stroke in reciprocating translation according to a frame axis, the shedding machine comprising:

• a rotary electric motor, comprising:
• a housing, centered on a main axis of the rotary electric motor and configured to be integral with a machine frame of the loom,
• a stator, integral with the housing,
• a rotor, arranged in the stator and comprising a cylindrical part, centered on the main axis and comprising an outer peripheral wall,
• a first bearing, arranged in a first plane, perpendicular to the main axis, on a front side of the rotary electric motor, and
• a second bearing, arranged in a second plane, perpendicular to the main axis, at a rear side of the rotary electric motor, the first bearing and the second bearing guiding the rotor in rotation relative to the stator about the main axis;
• a crank, integral with the rotor and comprising a crank pin defining an eccentric axis, parallel to the main axis and distant from the main axis by an eccentric center distance;
• a drive lever, which is configured to pivot about a first lever axis relative to the machine frame, to actuate the heald frame, the first lever axis being fixed relative to, and parallel to, the main axis;
• and
• a drive connecting rod, comprising:
• a first end, coupled to the crank pin and being pivotable about the eccentric axis relative to the crank pin, and
• a second end, coupled to the drive lever and being pivotable about a second lever axis relative to the drive lever, the second lever axis being parallel to the first lever axis;
• wherein:
• the stator comprises:
• winding laminations, surrounding the main axis and extending radially between an outer stator diameter and an inner stator diameter centered on the main axis, the winding laminations forming winding teeth distributed around the main axis, directed toward the main axis and delimiting between them stator slots, which extend parallel to the main axis, and
• electrical windings, each electrical winding being wound around a plurality of the winding teeth and being received in the stator slots;
• and
• the rotor comprises:
• a rotor shaft, centered on the main axis, surrounded by the cylindrical part of the rotor and being integral with the cylindrical part of the rotor and the crank, and
• permanent magnets, arranged on the outer peripheral wall of the cylindrical part and being distributed about the main axis, each permanent magnet comprising a respective outer surface, the outer surfaces facing the winding teeth and being on a rotor circle, centered on the main axis and defining a rotor diameter;
• and
• a ratio of the outer stator diameter relative to a length of the cylindrical part, measured parallel to the main axis without passing the permanent magnets, is between 2.0 and 4.0.