The QD design provides for both conventional (flange outboard) and reverses (flange inboard) mounting configurations. The original sheave and pulley mounting system developed to facilitate installation and replacement of components.
The main difference in the two is that the QD style bushing has a flange around the outside diameter, while the taper lock bushing has straight sides on the OD which is meant to mount flush. Many people refer to both types as a “taper lock” because they both use the tapered wedging action to lock to the shaft. The taper bushing, with its straight sides, uses a set screw to drive the bushing into the bore of the component being installed (sheave, sprocket, etc.). Be careful when installing these screws. The holes with threads on the bushing are for removal only. Also be aware that the appearance of a flange on the outside of the bushing doesn’t necessarily mean it’s a QD style. Split Taper bushing also has a flange, and the two are not interchangeable. The QD style has a split that continues through the flange.
The Steel QD (Quick Disconnect) Type bushing offers flexible and easy installation while providing exceptional holding power. QD Bushings are used thought out the industry offering convenience and design flexibility. They are precision machined of quality Steel and are installed by tightening several cap screws. This draws the bushing into the taper bore of the product which compresses the bore of the bushing. QD bushings are easily removed by using the cap screws as jack-screws.
Double drilled holes are furnished in QD Bushings permitting mounting of product in the conventional or reverse positions. This allows cap screws to be installed through product hub or bushing flanges whichever is most convenient. Significant benefits in installation, cap screws are always inserted from the outside where they are easily accessible.