Browning Sheaves, Bushings & Overall Belt Drive FAQ

1. Do you have someone I can talk to on problem drives?
   Yes, contact the EPT Application Engineering department. They will assist you in trouble shooting problem drives or designing a new drive. Phone 800-626-2093; Fax 606-564-2079
2. What is the most common cause of V-belt drive failure?
   The most common cause for failure of properly designed drives is premature belt failure due to under tensioned belts. The belts slip on the sheaves causing friction. Heat from this friction causes the belt to be hard and brittle failure is not far behind.
3. How often should I replace my sheaves?
   Use a groove gage or small metal ruler to check sheave groove for wear. If the sheave is dished out more than 1/32 inch the sheave should be replaced. Depending on the drive ratio and drive maintenance you may replace the belt 2 or 3 times before replacing the sheaves.
4. Is it OK to use never seize when installing my bushing?
   No, Browning recommends cleaning the bushing, shaft and sheave of all lubricants. Never seize will act as a lubricant. This could allow you to over torque the bolts and fracture the hub.
5. Do I align variable pitch sheave the same way as fixed pitch sheaves?
   No, on variable pitch sheaves we must align the center flange on sheaves with an even number of grooves or the center belt on sheaves with an odd number of grooves. This will allow the belt misalignment to be divided equally between the grooves.
6. Where should I locate my sheaves on the shaft?
   You should always locate your sheaves as close to the bearing as possible. By installing your sheave near the bearing you reduce the load and extend the life of the bearing.
7. What is the maximum misalignment capability of a V-Belt?
   You should align your belt drive as close as possible for maximum belt life. The maximum misalignment is the angle at which the belt enters the sheave. This angle is a result of both angular and parallel offset misalignment. For wrapped belts the angle is 2 degrees. For raw edge notched the angle is 1/2 degree. The maximum misalignment in inches would be .0349 x the center distance for a wrapped belt. The maximum misalignment for a raw edge notched would be .0087 x the center distance.
8. Is it normal for my belt to run on the bottom of the sheave groove?
   No, your belt should never run on the bottom of the groove. If the belt is running in the bottom of the sheave groove, check the groove for wear. Another problem that would cause the belt to bottom out would be a mismatched groove and belt section.
9. What causes flanges to break on variable pitch sheaves?
   Misalignment of the driver and driven sheave. Replace sheave and align by the center groove(s).
10. Why are variable sheaves so hard to adjust after they have been installed a couple of years?
    Fretting corrosion (drive allowed to operate at one speed over a period of time). Disassemble, clean, lubricated, and then reassemble.