A screw conveyor hanger bearing is commonly used in screw conveyors over about 12-14 feet. It is a friction, also called a plain, bearing used to support the coupling shaft and the ends of multiple screws. The bearings are available in a verity of materials, with wood and hard iron being the most popular. In addition to these materials various plastics and bronze are available. Each material has advantages and disadvantages, but in the end each one is a maintenance item that will have to be inspected as part of the preventative maintenance process and eventually replaced. (Click here for hanger bearings)
Since there are not many parameters to choosing a hanger bearing there are only a few pieces of information you need to know. The questions and diagrams below will help you narrow down you selection and choose the correct one.
- What style of hanger do you have? There are many types of hangers used in screw conveyors and they are all designated by sometime of numbering system. Luckily, all the CEMA (xxxxxx What is CEMA) manufacturers use the same numbering system. The most popular hangers are the 220, 226, 216, and 230 styles. The 220 and 226 use the same bearing as do the 216 and 230. See the images to tell which one you have. The main difference is the 216 uses a horseshoe shaped body bar and the 226 uses a more narrow straight body bar design.
- What shaft size do you have? The hanger bearing is sized based on the shaft size. The shaft size can be determined by measuring the shaft OD or the bearing ID. The bearings come in standard CEMA shaft sizes (1 1/2”, 2”, 2 7/16”, 3 7/16”) Keep in mind, if the bearing is badly worn the bearing ID and shaft OD may not be the original size.
- What hanger bearing material do I need? The chart below will help you select the best material for your applications. Just keep in mind, wood and hard iron are the most popular and therefor the easiest to source.
- If you have a style 216 or 230, what is the body bar width? Annoyingly, CEMA never could come to an agreement on the width of the body bar for the 216, 230 hanger bearing. This means different manufacturers have different widths. From what we can tell Martin, KWS and Conveyors Inc use the same 2” wide body bar with the “B” dimension on the 216 chart below being 2 ¼”