OPEN FLEXIBLE-LINK DRIVE MECHANISM WITH PULLEYS ROTATING IN OPPOSITE DIRECTIONS

Pulleys 1 and 2 of radius R rotate about fixed axes A and B. Pulleys 3 of radius r rotate about fixed axes C and D. Flexible link 4 runs over pulleys 1, 2 and 3. The transmission ratio from pulley 1 to pulley 2 is i₁₂=ω₁/ω₂=n₁/n₂=-1 where ω₁, ω₂, n₁ and n₂ are the angular velocities and speeds (in rpm) of pulleys 1 and 2. Thus pulleys 1 and 2 rotate in opposite directions. The length of link 4 is …