To provide a compact electric speed change gear 1 including a first rotary machine M1 constituting a magnetic modulation motor and a second rotary machine M2 constituting a general magnetic motor.

A first rotary machine M1 includes a first armature 14 having a three-phase winding wire 22 of a pole logarithm m, a permanent magnet forming the pole of a poke logarithm n, a first field magnet 15 disposed between permanent magnets arranged in a circumferential direction and having a soft magnetic body on an entire circumference to cover the armature side front surface of the permanent magnet, and a magnetic modulator 16 having m+n segment poles. The first field magnet 15 is disposed between the first armature 14 and the magnetic modulator 16, and the first field magnet 15 is connected to a first rotary shaft 2. A second rotary machine M2 includes a second armature 18 having a three-phase winding wire 30 wound thereon, and a second field magnet 19 forming a plurality of magnetic poles in the circumferential direction. The second field magnet 19 is connected to a second rotary shaft 3 via a second rotor disk 20, and mechanically connected to the magnetic modulator 16 of the first rotary machine M1.