In the hoisting mechanism of a crane, the coupling cylinder between the output shaft of the reducer and the low-speed rotating drum often uses gear coupling discs, open gears, gear couplings, and a statically indeterminate with three bearings as the fulcrum. Shaft or statically determinate shaft with two bearings as fulcrum. Gear coupling discs are mostly used in small and medium lifting series, with compact structure, good grouping, complex shapes, time-consuming processing, and inconvenience for heavy lifting cranes. Open gear drive is mostly used for cranes with heavy lifting capacity (lifting capacity greater than 80T) to further reduce the speed and increase the distance between the motor and the drum. The structure is simple, the exposed gears are inconvenient to lubricate, the tooth surface is very easy to wear, and the gear fails. Fast, the use of gear couplings will increase the distance between the reel shafts and increase the weight of the mechanism; the connection type using statically indeterminate or super statically indeterminate shafts requires a long shaft, which can shorten the axial size of the reel. It is inconvenient to disassemble, and the reducer cannot be assembled and trial run separately. Each of these connection types has advantages and disadvantages.
Spherical roller coupling for crane drum is composed of outer cover, spherical roller, half coupling, inner cover, outer cover, etc., as shown in the figure. The half coupling is connected to the outer sleeve by spherical rollers distributed along the circumference. The spherical rollers are embedded in the hole between the half coupling and the outer sleeve to transmit torque and bear radial force. It can compensate the angular displacement between the output shaft of the reducer and the axis of the reel. Its mechanism is similar to that of an elastic pin gear coupling. When in use, the half coupling is sleeved on the output shaft of the reducer, and the outer sleeve is connected with the steel wire rope drum with high-strength bolts. Torque and radial load are transmitted between the half coupling and the outer sleeve through spherical rollers. The spherical roller coupling has the performance of compensating the relative displacement of the two shafts, compact structure, light weight, high reliability, convenient installation, and easy to arrange the mechanism on the crane trolley. It is suitable for the connection of the reducer of the crane hoisting mechanism and the reel and the connection of other similar mechanisms. It can be used to transmit torque and support radial load. The working temperature range is -25~80℃; the transmission nominal torque is 4000~800000N·m; the allowable radial force is 14500~450000N.