Variable-speed speed-up gear

A variable-speed speed-up gear comprising:

• an electric driving device that generates a rotational driving force;
• and
• a transmission device that changes the speed of the rotational driving force generated by the electric driving device and transmit the changed rotation driving force to a driving target,
• wherein the transmission device comprises:
• a sun gear that rotates about an axis;
• a sun gear shaft which is fixed to the sun gear and extends in an axial direction around the axis;
• a planetary gear that meshes with the sun gear, revolve around the axis and rotate about its own center line;
• an internal gear which has a plurality of teeth aligned annularly around the axis and meshes with the planetary gear;
• a planetary gear carrier which has a planetary gear carrier shaft extending in the axial direction around the axis and supports the planetary gear to revolve around the axis and to be rotatable around a center line of the planetary gear itself;
• and
• an internal gear carrier which has an internal gear carrier shaft extending in the axial direction around the axis and supports the internal gear to be rotatable about the axis,
• wherein the sun gear shaft acts as an output shaft connected to the driving target, the internal gear carrier shaft acts as a constant-speed input shaft, and the planetary gear carrier shaft acts as a variable-speed input shaft,
• wherein the electric driving device includes a constant-speed motor having a constant-speed rotor that rotates the constant-speed input shaft of the transmission device, and a variable-speed motor having a variable-speed rotor which is configured to rotate the variable-speed input shaft of the transmission device,
• wherein the variable-speed rotor and the planetary gear carrier shaft have a shaft insertion hole which is formed in a cylindrical shape around the axis and passes therethrough in the axial direction,
• wherein the constant-speed rotor is inserted through the shaft insertion hole, and
• wherein an inertia body is installed on the output shaft of the transmission device.