With the application of servo motorsstepper motorsintelligent motors and ball screws in machine tool and automation, flexible couplings are widely used as a device to transfer torque and protect motors and lead screws. However, most people do not know how to apply the coupling. Cases of unreasonable selection and the incorrect installation often occur, resulting in more and more coupling are damaged. As a result of the unexpected shutdown, to the production of the loss is also greater. Combined with MOONS’ coupling products, this paper introduces how to select and install a coupling.

# A.    Choose steps

• Calculate the torque(Ta) applied to the coupling

Ta (Nm) =P (Kw)*9550/N (rpm)

Remark: P: the output power of the driving motor that stepper motors reference to holding torque, AC motors reference to rated torque, servo motors reference to max torque.

N: the working speed.

• Calculate the compensating torque (Td) applied on the coupling.

Td=Ta * K,

Remark:  K is the safety factor (K=1.2 ~ 1.5)

According to the compensation torque value, check the coupling selection data, as long as the maximum torque capacity of the coupling is greater than Td is ok.

3, Refer to the coupling size table, according to the drive shaft diameter, select the appropriate size of the coupling.

# B. Installation of coupling

When the coupling is strongly impacted, the assembly results will be affected, so professional steps are required to install it. Product damage may occur during installation, please handle with care.

Installation steps are as follows：

• Loosen clamp screw, clean shaft surface and inner hole of coupling.
• When installing couplings, do not apply external force on elastic parts such as compression and traction. Please note that sometimes excessive compression force may be applied to the coupling after installation.
• When the locking screw is loose, it is necessary to confirm whether the coupling can move easily along the axial direction and rotation direction. If it cannot move, please readjust the concentricity of the axis again.
• After confirming that there is no axial force on the coupling, start locking screws.