When the velocity (feedrate) is not constant, several problems can result.
当进给速度不恒定时，会造成许多问题。
2
Thread cutting. When performing thread cutting, the axial feed must be kept at a constantrate, which is dependent upon the rotational speed (RPM) of the workpiece.
在螺纹切削作业时，轴向进给必须保持恒定速率，这取决于工件的转速(rpm)。
3
The time constant and instantaneous efficiency of the feed-tube solar air heater were tested on the solar irradiance. The equation for instantaneous efficiency was obtained at the different flow rate.