There is no spring pressure on the clutch assembly parts. So there is no friction between the driving members and driven members.
离合器主动件、从动件上没有弹簧作用力，因此主动件和从动件之间也没有摩擦力。
2
Assembly method for the Optic is designed and the solution for problem about positioning and aligning of the contact coupling and trapped friction which affect the figure are put forward.
Between the light the light source seat and the protecting window, is set low friction coefficient material to make light source assembly slide smoothly.