This is an animation of epicyclic gearing or planetary gearing. The reference I referred to is here:bl.ocks.org/mbostock/1353700　　　　　 This animation is implemented by attributeName="transform" function of SMIL.
行星，齒輪
animation、attributeName="transform"、epicyclic、gear、gearing、planetary、remix 230261、SMIL、type="rotate"、yamachem
動畫、的attributeName =“改造”、行星、齒輪、傳動裝置、行星、混音230261、SMILE、類型=“旋轉”、Yamache米
資料來源：openclipart ( https://openclipart.org/ )