Yen Hung-sen, who has made important breakthroughs in the area of variable pitch lead screw mechanics, remarks that China has led the world with many of its mechanical developments: the pulley, gear wheel, roller bearing, and chain drive were all used first in China.
在變導螺桿上有世界性突破研究成果的顏鴻森表示，中國在機械發展上，有許多領先世界的成就。像是滑輪、齒輪、滾柱軸承、鍊條等，都是中國最早使用的。