Coupling, also called as coupler, is mainly used to connect transmission shafts of all parts. Due to the differences between mechanical equipment, function of all kinds of coupling is also different, for instance, coupling on the forklift is used to transfer power between the transmission and drive axle.

Because longitudinal size of drive train is short, forklifts below 3t usually apply rigid connection structure to connect, namely, from the engine to clutch, transmission, coupling shell and drive axle, all of them are connected by bolt coupling, which means it is a whole rigidity from the engine to the drive axle and in the central part it, gear coupling is adopted.

Because the longitudinal size of the transmission system is longer, forklifts over 5t generally apply universal joint, ensuring the power to be transmitted to the drive axle through the coupling.

Gear coupling is made up of two connecting plates, joined by inner gear and outer gear. Terminal pad with inner gear and outer gear connects with transmission and drive axle by spline or key.

a. When the spline on the gear tooth is damaged and fit clearance is over 0.4 mm, it should be replaced.

b. When gear coupling is in adjustment, coaxial degree of two axis should not be over 0.4 mm.

c. If slotting on the gear is damaged, the keyway is allowed to be expanded and changed. Or insert another system keyway from the original keyway 60 °.