The following points should also be noted when installing the PU timing belt: ①When installing the PU timing belt, if the center distance between the two pulleys can be moved, the center distance of the pulley must be shortened, and the center distance must be reset after the synchronous belt is installed. If there is a tensioner, first relax the tensioner, then install the timing belt, and then install the tensioner. ② When installing the synchronous belt on the pulley, remember not to use excessive force or pry the synchronous belt with a screwdriver to prevent the tensile layer in the synchronous belt from causing unsightly breakage. When designing the pulley, it is better to choose the structure where the two shafts can move closer to each other. If the structure does not allow it, it is best to install the timing belt and the pulley together on the corresponding shaft. ③ Control proper initial tension. ④In the PU timing belt drive, the parallelism of the axis of the two pulleys is relatively high, otherwise the timing belt will run out of position during work, or even jump out of the pulley. Non-parallel axes will cause uneven pressure and cause early wear of the teeth. ⑤The rack supporting the pulley must have sufficient rigidity, otherwise the pulley will cause the two axes to be non-parallel when the combination lock is running