R+W developed the ZA high torque series with tapered bushings for improved shaft holding ability.
The shafting systems not only compensate for lateral and angular shaft misalignments like other high torque couplings, but they can absorb axial movement as well.
For this reason, special shorter versions have been made available for replacement of double disc pack type couplings.
These line shafting assemblies consist of two hydroformed stainless steel bellows, which allow for the misalignment compensation with zero backlash and high torsional stiffness. Between the two bellows is a precision cut-to-length tube exhibiting a high straightness and lateral rigidity, allowing for very smooth operation even at higher speeds. The connection between the bellows and tubing is safeguarded by a set of gimbals on each end of the shafting assembly. These gimbals transfer the weight of the tubing onto the coupling hubs, protecting the bellows from bearing its lateral load. Installation is simplified by the flanged connection between the tube and the bellows, allowing for lateral mounting.
Due to the lateral stiffness of the tubing, these shafts can span distances from 0.24 to 3 meters (9.5 in. to 10 ft) without a center support and can transmit torques from 1500 to 4000 Nm (13,275 to 35,400 in. lbs.). Bore diameters are available in English or metric dimensions and span a range from 35-100mm (1.375-3.99 in.).
Special balancing and a low mass moment of inertia allow the coupling to reach speeds of up to 8000 rpm.