IBMMAE – 3- Machine Elements
1
Belt transmission of a drilling machine
On a small drilling machine 0.75 HP (1HP= 736W), the rotation speed of the drill is changed by selecting the appropriate stages for the belt (see below)
1. The output rotation speeds are 495, 790, 1250 rpm, deduce the diameters of pulley 2.
2. Determine the minimum setting tension T0_MIN for transmitting the power.
3. Then, rounds T0_MIN towards the upper hundred (of newton) T0, determine the tensions t and T in the slack and tight spans, when the belt is mounted on stage 1. The friction coefficient f=0.2.
4. Determine the relative sliding angle.
D13 = 120 mm, stage 3
D12 = 90 mm, stage 2
D11 = 60 mm, stage 1
a = 300 mm
1 2
Input 1500 rpm Output