What You Need to Know about Taper-Lock Bushings
A taper-lock bushing gets its name from the 8 degree taper from one side to the next before it locks into place. This reduces the necessary length-thru-bore for any application. An internal screw holds the taper-lock bushing in place, providing a slimmer fit than a flanged bushing.
First, what not to do when installing a taper-lock bushing: Do not use apply any lubricant or anti-seize to any component. Either can cause the bushing to seat improperly, setting you and your machinery up for failure.
Now on to what to do. Start by thoroughly inspecting and cleaning everything you will be assembling: the bushing (inner and outer surfaces), the bore and the shaft.
Place the bushing into the sprocket or sheave, lining up the bushing’s non-threaded holes with the sprocket’s or sheave’s threaded holes. Put the screws into the threaded holes by hand and, with the assembly still only loosely fitted, install the shaft. If necessary to get everything squarely in place, you can use a rubber mallet and block to set the bushing. Then gradually tighten the screws, cycling from one to another, until you reach the rated torque for the size of your bushing and screws (it should go without saying that you have any necessary documentation in front of you this whole time).
Finally, protect the unit from contamination by filling the remaining holes with grease.
What are the main things to watch out for? As mentioned above, lubricating or applying anti-seize to the bushing is the absolute wrong way to start. Next, as ever, over-torquing the screws is an easy way to damage the bushing and the shaft, reducing inefficiency until inducing failure. Finally, be sure to alternate the screws when tightening them. This process ensures a uniform pressure across the entire unit, preventing a “pinch point” or “pressure point” that will snowball into a larger problem once in operation.
The experts at MDS know their way around bushings, taper-lock and otherwise. Let us know what question you have and we’ll help you find the right product for your needs.
