Patent ID: 7751746

Claim:
A driving device for driving a rotary body, comprising: a driving-force source that outputs a rotational driving force; a rotary-body driving-force transmitting mechanism that transmits the driving force of the driving-force source to the rotary body; a rotary inertial body for dampening a velocity fluctuation in rotation velocity of the rotary body; and a rotary-inertial-body driving-force transmitting mechanism that transmits the driving force of the driving-force source to the rotary inertial body; wherein the rotary-body driving-force transmitting mechanism includes a down-shift unit that shifts down the driving force of the driving-force source and transmits a down-shifted driving force to the rotary body, the rotary-inertial-body driving-force transmitting mechanism includes an up-shift unit that shifts up the down-shifted driving force and transmits an up-shifted driving force to the rotary inertial body, the rotary inertial body, the down-shift unit, and the up-shift unit are arranged coaxially with a rotation axis of the rotary body, the up-shift unit includes a sun axis arranged coaxially with the rotation axis of the rotary body and is coupled to the rotary body, a carrier that includes a plurality of satellite shafts arranged equidistant along a circumferential direction of a circle that is coaxial with the sun axis, a plurality of satellite wheels respectively arranged on the satellite shafts, each of the satellite wheels rotating around its corresponding satellite shaft, and an inscribed ring in which the satellite wheels are inscribed, the satellite wheels being in pressure contact with the sun axis and the inscribed ring, and the rotation axis of the rotary body coupled to the inscribed ring, so that the down-shifted driving force is transmitted to the inscribed ring, which drives in turn the satellite wheels and the sun axis, shifting up the down-shifted driving force, thus transmitting the up-shifted driving force to the rotary inertial body.