QUESTION 3
A four-ply open belt is 12 mm thick, 50 cm wide and has a density of 770 kg per cubic
metre. The belt is attached to a driving pulley that is 0,75 m in a diameter and rotates at
140 r/min. The angle of wrap between the belt and the pulley is 135 degrees and the
coefficient of friction is 0,27. The radius of the driven pulley is 0,9 m and the efficiency
of the system is 84%. The maximum allowable belt tension is 9 500 N/m.
Calculate:
3.1 The length of the belt if the distance between the two pulleys is 12 m
(2)
3.2 The mass of the belt
(3)
3.3 The speed (neglect the thickness of the belt)
(2)
3.4 The tight and slack tension of the belt, taking centrifugal force into account
(9)
3.5 The motor power when the system efficiency is 84%.
(4)
[20]