PROBLEM TO BE SOLVED: To easily fit a wheel driving device which is fitted to a wheeled moving body, and drives and rotates its wheels, to the moving body.SOLUTION: A wheel driving device includes: a pendulum which has an arm part 23, a fulcrum part provided at one end of the arm part 23, and a weight 24 provided at the other end of the arm part 23； a drive part 21 which drives and rotates the pendulum around the fulcrum part； and a control part 25 which controls the driving and rotation by the drive part 21. The control part 25 when rotating wheels 13 so that the moving body (exemplified with a wheel chair 1) moves in its moving direction controls the drive part 21 so as to maintain the weight 24 on the side in the moving direction, thereby driving and rotating the wheels 13 by utilizing position energy of the pendulum.【課題】車輪付きの移動体に取り付け、その車輪を回転駆動させるための車輪駆動装置において、移動体への取り付けを容易にする。【解決手段】車輪駆動装置は、腕部２３、腕部２３の一端に設けた支点部、及び腕部２３の他端に設けた重し２４を有する振り子と、上記支点部を中心として上記振り子を回転駆動させる駆動部２１と、駆動部２１での回転駆動を制御する制御部２５と、を備える。制御部２５は、移動体（車椅子１で例示）が進行方向に進むように車輪１３を回転させる場合、進行方向側で重し２４を維持するように駆動部２１を制御することにより、振り子の位置エネルギーを利用して車輪１３を回転駆動させる。【選択図】図４Ａ
