The invention includes a pair of bottom frame components, a riding mechanism and a pair of pivot components.The bottom frame component, the riding mechanism and the pivot component are connected with each other and can move relatively； the riding mechanism is provided with a front support part and a rear support part.When the riding mechanism carries the user and forms the combination, it has a center of gravity. When the riding mechanism and the pivot assembly are rotated and tilted, the front support system generates a front arc moving track, and the rear support system generates a back arc moving track. The front arc moving track and the back arc moving track form an instantaneous turning center, and the distance between the instantaneous turning center and the center of gravity is less than 5. A centimeter.Therefore, the case has the advantages of the wheelchair device that can be turned and tilted in a labor-saving way and the mechanical structure that can also achieve the labor-saving effect.本發明係包括一對底框組件、一乘坐機構及一對樞接組件。底框組件、乘坐機構及樞接組件之間相互連接並可相對移動；乘坐機構設一前支撐部及一後支撐部。乘坐機構承載使用者並構成組合體時，係具有一重心，並當乘坐機構與樞接組件被旋轉傾斜時，前支撐部係產生一前圓弧移動軌跡，且後支撐部係產生一後圓弧移動軌跡，前圓弧移動軌跡與後圓弧移動軌跡係形成一瞬時轉動中心，瞬時轉動中心與重心之距離係小於5公分。故，本案兼具輪椅裝置可省力轉動傾斜與機械式結構同樣達到省力效果等優點。
