In 1817, another British Roberts adopted with round 4 wheel mechanism and back to changespindlespeed.
1817年，另一位英国人罗伯茨采用了四级带轮和背轮机构来改变主轴转速。
2
This apparatus is enable to change the rotational speed of the pump in a wide range, to heat recirculating water and to load both axial and radial forces on the pump spindle.
该装置的特点是调速范围大，工作介质温度高，可以同时对泵轴进行径向和轴向加载。
3
A speed-raising tool holder which is drived by special traction agent is developed. Speed of tools can be raised8thimes without any change of the construction and spindlespeed of machine.