the stationary support in a machine or power tool that supports and drives a revolving part (as a chuck or the spindle on a lathe)
详细解释
head.stock n.（名词）A nonmoving part of a machine or power tool that supports a revolving part, such as the spindle of a lathe.头座：机器或动力工具上用于安装旋转部件的不能移动的部分，如车床的转轴
