A keyless locking assembly is a friction-type fastening device: tapered faces convert the clamping force of the bolts into surface pressure on the inside and outside diameters, locking the shaft and the hub together. The shaft and hub (pulley, gear, sprocket, etc.) are assembled simply by tightening the bolts.
Because there is none of the play that occurs with a parallel key, it is especially effective where the drive reverses repeatedly. It can also carry thrust loads that a key cannot.
As installation only requires tightening the bolts, it can be fitted where a keyway and hub could not be aligned.
No keyway machining of the shaft and hub and no fitting work at assembly are needed, which reduces total cost.
