Many situations which call for a motoror gearhead to be mounted into a hollow bore, such as in belt drive linearactuators, require that a stub shaft be mounted into the bore so that the motoror gearhead can be coupled to it. Thismethod of mounting can take up a large amount of space and add unnecessaryhardware to the bill of materials.

The model EK7 from R+W Coupling Technology addresses these issueswith an expanding shaft. These precision couplings allow the installer to slidethe male portion of the coupling into the driven bore, and with the tighteningof a single screw cause the shaft to expand into the bore for a high-strength,backlash-free connection. Internal to the expanding shaft is a cone, which whentightened into the shaft, forces the outer portion of the shaft to spread andcreate the frictional connection to the bore.

Standard EK7 couplings are availablein eight sizes with English or metric expanding shafts ranging from 10 - 80 mm(0.394 - 3.150 inch). Torques range from 9 - 2,150 Nm (79.65 - 19,027 inch-lb)though some specially made couplings can transmit up to 4,000 Nm. Threedifferent Shore hardnesses allow the designer to select the correct amount offlexibility, vibration damping or stiffness depending on their performancerequirements.

R+W's Expanding Shaft Coupling EK7_A