Three Gears or Pulleys Force Calculations and Equations
Use the following equation to determine the lifting force of the selected gear or pulley arrangement . A, B, C and D are the pitch circles of gears or pulleys.
F = [ W x r x r1 x r2 ]/[ R x R1 x R2 ]
W = [ F x R x R1 x R2 ]/[ r x r1 x r2 ]
W = Unknown weight (lbs, N)
Let the pitch diameters of gears A, B, C and D be 30, 28, 12 and 10 inches, respectively.
Then the force F required to lift a weight W of 2000 pounds, friction being neglected, is: 95 lbs
1 lbs = 4.4482216 Newtons