Belt Friction Example (courtesy of Prof. James W. Phillips)
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At a processing plant,
sheet steel is pulled horizontally from a supply roll of weight, W, and radius, R, after which it
passes 90o over a fixed cylinder C as shown below. Find the force, P, required for this
operation. The coefficient of
friction, μ, has the same value at point
A, point B, and the curved
surface around the fixed cylinder, C. |
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Strategy: Construct a FBD of the roll of sheet steel and use the relation for a belt sliding on a fixed cylinder. Then write the equations of equilibrium and supplement them with appropriate relations from friction for conditions of sliding. Solution: Equations of equilibrium: + ↑∑ Fy = 0 NA + FB ˗ W = 0 + → ∑ Fx = 0 FA ˗ NB + P e μβ = 0 CCW ∑ MO = 0 FA R + FB R ˗ P R e μβ = 0 Click here to continue with this example. |
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