# HFN9 Friction of Belts Apparatus

The apparatus consists of a wall mounted pulley with a loaded belt. The pulley is made of aluminium and has two machined grooves to suit a flat, vee belt, and a rope. Each belt fits into its respective groove during testing.

For a given belt tension and angle of lap, a turning moment can be applied by adding weights to the pulley drive hanger. The idea is to determine the torque which just causes the pulley to turn, and so to find the ratio of the belt tensions. This enables the belt tension equation to be verified and the coefficient of friction to be determined.

The angle of lap can be easily varied by placing one end of each belt at different angular positions on the wall bracket. A removable pin and bar are used to enable the various angular positions to be achieved.

• Observes the relationship between the tensions in the two sides of a belt; assesses the differences between vee, rope and flat belts; determines coefficient of friction between pulley and the three belt sections; investigate the effect of angle of lap.
• The wall mounted apparatus consists of a pulley, 3 belts and 2 load hangers. Pulley graduated in 15 degree intervals.
• The aluminium alloy pulley of approx. 150mm diameter has machined grooves to suit the three belts.
• The three belts are vee, rope and flat.
• An Instruction manual for student and lecturer provided.
• Set of weights
• 2 year warranty
• To observe the relationship between the tensions in the two sides of a belt
• To assess the differences between Vee, rope, and flat belts
• To determine the coefficient of friction between the pulley and belt for the belt sections
• To investigate the effect of angle of lap