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An electric motor drives a machine through a speed reducing gear of ratio 9:1. The motor armature, with its shaft and gear wheel, has moment of inertia 0.6 kg-m2. The rotating part of the driven machine has moment of inertia 45 kg-m2. The driven machine has resisting torque of 100 N-m and the efficiency of reduction gear is 95%. Find the power which the motor must develop to drive the machine at a uniform speed of 160 r.p.m.

Correct Answer: 1764 W
Given : G = 9; IA = 0.6 kg-m2 ; IB = 45 kg-m2; TB = 100 N-m; η = 95% = 0.95; N = 160 r.p.m. ; N1 = 0 ; N2 = 60 r.p.m. TA = 30 N-m We know that the power which the motor must develop, P = 2πN TB/60× η = 2π × 160 × 100/60 x 0.95 = 1764 W

A torsional system with discs of moment of inertia $${I_1}$$ and $${I_2}$$ as shown in the below figure, is gear driven such that the ratio of speed of shaft B to shaft A is 'G'. Neglecting the inertia of gears, the equivalent inertia of disc on shaft B at the speed of shaft A is equal to
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1st gear - 4.3 : 1
2nd gear - 3.00 : 1
3rd gear - 2.71 : 1
4th gear - 1 : 1
Final drive reduction is 5.0 : 1
The overall reduction when the vehicle is driven in 2nd gear is

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A double universal joint is used to connect two shafts in the same plane. The intermediate shaft is inclined at an angle of 20° to the driving shaft as well as the driven shaft. Find the maximum speed of the driven shaft if the driving shaft has a constant speed of 500 r.p.m.

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A main shaft is running at 250 rpm and machine spindle is to be driven directly from the main shaft to tum at 25 rpm. If the diameter of pulley fitted on machine spindle is 20 em, what would be the diameter of pulley fitted on main shaft?

A double universal joint is used to connect two shafts in the same plane. The intermediate shaft is inclined at an angle of 20° to the driving shaft as well as the driven shaft. Find the maximum speed of the intermediate shaft if the driving shaft has a constant speed of 500 r.p.m.