When the coupling is overloaded, the reaction process is faster, and the coupling detents or the power input end disconnects with the output end more quickly. This type of safety coupling is known for its excellent detachable performance and relatively small red areas in the performance curve. A specially developed disc spring with special spring characteristics is designed to stabilize the safe coupling adjustment range and reduce the power input and output residual friction torque when the coupling is off. Its working characteristic is not according to the ordinary characteristic curve, but has its own unique working characteristic curve. As with all other safety couplings that require control using inductive proximity switches or end-point switches, the switch travel of this switch ring is monitored. In order to ensure reliable operation even when contaminated by dirt, the control stroke of the switch ring should be as large as possible. Safety couplings that work according to the ball-ratchet principle work according to the release torque in most cases. In the case of high dynamic performance, the influence of resonant frequency should also be considered in addition, and the magnitude of resonant frequency should be calculated, because the torsional stiffness also has an important influence on dynamic balance. Fast and correct coupling design depends on the rated torque or detaching torque. When the torque transmitted by the driveline reaches the rated value, the coupling will play a safety protection role, making the power input and output of the driveline disconnected. Detaching torque is the torque normally applied to the drive system to input the real torque. In addition, taking into account the acceleration torque and other influencing factors, the integrated safety factor used in practical applications is 1.5. Safety couplings can be selected according to this.

Couplings are mainly used to connect the driving shafts of various mechanisms. Due to different mechanical equipment, the functions of various couplings are slightly different. For example, on a forklift, the couplings are used to transfer the power between the transmission and the driving axle. Forklifts below 3T generally adopt a rigid connection structure due to the short longitudinal dimensions of the transmission system, that is, the engine, clutch, transmission, coupling housing-drive axle are all connected by bolts, that is, from the engine to the drive axle is a rigid whole, and in the middle of the rigid whole, a gear coupling is adopted. Forklifts above 5T generally adopt universal joints because of the long longitudinal dimensions of the transmission system. A drive axle that transmits power through a coupling to a forklift.