A simple cloth tape measure can be used to measure belt size. It’s also important to remember that belts of different sizes should not be interchanged.
You can also use a mathematical equation to calculate the length of the belt. First, you will need to know the values of the following:
- The pitch diameter of the driving sheave (pD)
- The pitch diameter of the driven sheave (pd)
- The distance between the driving and the driven shafts
You can then take the pD and multiply by 3.14, divide by 2, and add to the pd multiplied by 3.14 again and divided by 2, then add 2 times the distance between the driving and driven shafts: this will also give you the belt length.
A couple tools you will want to have on hand when checking belts and sheaves:
- a belt and sheave gauge set (an invaluable tool when measuring proper belt and sheave size, as well as sheave wear)
- a belt tensioning gauge (used to push down on the belt and provide amount of give)
Remember, in order to avoid:
- Decreased belt life
- Increased vibration and noise
- Increased heat
- Axial loading of bearings
- Decreased sheave life
You will want to ensure that your belt and sheave are aligned correctly. An easy-to-use tool you can utilize for this purpose is the Belt Hog from VibrAlign. With the Belt Hog, there is no need to remove belts, and one person can quickly and accurately check the alignment.
Some other things to remember when it comes to belts and sheaves:
- Never “roll” belts on—this can cause damage to the belt and sheave
- Always check sheave grooves for wear
- Ensure proper ventilation—belts are often subject to overheating so it’s important to make sure the heat is drawn away from the belt and sheave
- Recheck belt tension again after the belt has been broken in
In our next blog in this series we will go over pump maintenance and overhaul. Be sure to look for that post!