Requirements for coupling assembly:          

The overall coupling is divided into two categories: rigidity and flexibility. 

For rigid couplings, the two sides of the shaft to be connected are required to have high coaxiality and rotation accuracy, and there should be no interference in the axial direction. Check whether the matching size is appropriate before assembly, and try to assemble unilateral components by pressing instead of knocking Then connect them together; for flexible couplings, larger errors are allowed (including shaft eccentricity, angle, and axial position), but must be within the compensation capability of the selected coupling.          

Method of finding the right           

When the coupling is aligned, the coaxiality (radial displacement or radial clearance) and parallelism (angular displacement or axial clearance) are mainly measured. There are four methods according to the different tools used in the measurement.          

 1. Use a square ruler to measure the coaxiality (radial displacement) of the coupling, and use a plane gauge and a wedge gap gauge to measure the coupling           

This method is simple and widely used, but the accuracy is not high. It is generally used for low-speed or medium-speed operation equipment with low requirements.Measure the longitudinal displacement of the coupling with a straightedge and feeler gauge, and measure the angular displacement of the coupling with each wedge gauge of a plane gauge.     

2. Directly use dial indicator, feeler gauge and center card to measure the coaxiality and parallelism of the coupling.

The method of adjustment: It is usually achieved by adding or subtracting the spacers under the feet of the active machine (motor) in the vertical direction or moving the position of the active machine in the horizontal direction.

The assembly method of the coupling on the shaft

    The assembly of the coupling on the shaft is one of the keys to the installation of the coupling.Couplings and shafts are mostly fitted with interference fits. The connection is divided into keyed and non-keyed connections. The shaft hole of the coupling is divided into two forms: cylindrical shaft hole and tapered shaft hole.The assembly methods include static press-in method, dynamic press-in method, temperature difference assembly method and hydraulic assembly method.           

1. Static pressure method           

This method uses clamps, jacks, manual or motorized presses according to the size of the required press-in force during assembly. The static press-in method is generally used for tapered shaft holes.Because the static press-in method is restricted by the pressure machine, it is difficult to apply a large force when the interference is large.At the same time, the uneven small peaks on the mating surface between the coupling and the shaft will be cut off during the press-in process, causing the mating surface to be damaged.Therefore, this method is generally not widely used.

2. Power press-in method    

This method refers to the use of impact tools or machinery to complete the assembly process, and is generally used in situations where the coupling and shaft fit is transitional or has little interference.The assembly site usually uses a hand hammer to knock in. The method is to put a wooden block or other soft material on the end face of the hub as a buffer, and rely on the impact force of the hand hammer to knock the coupling in.This method has the risk of local damage to couplings made of brittle materials such as cast iron, quenched steel, and cast alloys, and should not be used.This method will also damage the mating surface, so it is often used for the assembly of low-speed and small couplings.           

3. Temperature difference assembly method          

The coupling is heated to expand by heating or the end of the shaft is cold and contracted by cooling, so that the wheel coupling can be easily mounted on the shaft.This method has more advantages than static press-in method and dynamic press-in method. For wheels made of brittle materials, the temperature difference assembly method is very suitable.The temperature difference assembly method mostly uses the heating method, and the cooling method uses more