Magnetic modulation gear and gear motor

A magnetic modulation gear comprising:

• a plurality of outer pole magnets arranged in a circumferential direction;
• a rotor that includes a plurality of magnetic pole pieces arranged in the circumferential direction on an inner side in a radial direction with respect to the plurality of outer pole magnets;
• a plurality of inner pole magnets arranged in the circumferential direction on an inner side in the radial direction with respect to the plurality of magnetic pole pieces;
• and
• one or a plurality of bearings that support the rotor to be rotatable relative to the outer pole magnets or the inner pole magnets,
• wherein the one or plurality of bearings include at least one one-side bearing that is located on one side in an axial direction with respect to the plurality of magnetic pole pieces, and
• a first bearing closest to the magnetic pole pieces, of the at least one one-side bearing, is disposed within a region outward in the radial direction with respect to inner peripheral ends of the plurality of outer pole magnets, or within a region inward in the radial direction with respect to outer peripheral ends of the plurality of inner pole magnets.