When the vertical turret decline, due to friction hinder its decline, the screw on helical screw nut under the physiognomy contact screw nut in the space below.
The initial contact of helical gear teeth is a point, which changes into a line as the teeth come into more engagement.
斜齿轮轮齿的初始接触是一点，当齿进入更多的啮合时，它就变成线。
3
The mesh stiffness of a pair of helical gears is calculated by substituting the variance of the contact line length for the variance of the instantaneous mesh stiffness.