The coupling is mainly the connection between the screw rod and the motor, which is one of the important parts in the linear module. The main purpose is to make the center lines of the driving shaft and the driven shaft in the same straight line when the motor is working, which is related to whether the linear sliding table can operate normally and ensure the precision. Therefore, the coupling is particularly important for the linear module with high-speed operation.

In the design of linear module, there is a allowable deviation value in the center of two shafts, which is also required for the installation of coupling. From the perspective of assembly, as long as the coupling can transmit torque safely and reliably, the larger the allowable deviation value in the center of two shafts, the easier to meet the requirements during installation. But from the point of view of quality, the smaller the deviation of the two axis center line, the more accurate the alignment, the better the operation of the linear sliding table, and the longer the service life.

When installing the coupling, we fix one end first. For example, after positioning the coupling on the main engine side, we adjust the other half coupling based on this to align it with the half coupling on the main engine side. Fix the dial indicator on the half coupling of the main engine side, the contact of the dial indicator contacts another half coupling, and rotate the coupling to align and adjust. Fix the dial indicator on the half coupling of the non main engine side, the contact of the dial indicator contacts the half coupling of the main engine side, and the alignment meter can be placed on the side of the main engine or the side of the transmission machine, mainly for the convenience of work. When centering, adjust the left and right values of the circumference = sum of the upper and lower values. Finally, the standard of alignment is that the centers of two pairs of wheels coincide, that is, the outer circles of the two pairs of wheels coincide, and the joint surfaces (end faces) of the two pairs of wheels are parallel (parallel lines of the two center lines).