Answer Happy

Q1 A single stage helical gearbox as shown in Figure Q1 is pulling a crate with an acceleration of 1.5 m/s2. The rope is attached to a 1.2 m diameter drum. Since the gearbox was not properly maintained and running with less lubricant, the gear box efficiency, 7 has dropped to 70 percent. Table below show details arrangement: Descriptions Weight of crate Number of teeth at motor shaft gear Number of teeth at drum shaft gear Inertia of motor shaft Inertia of drum shaft Specifications 200 kg 20 200 1.5 kgm? 125 kgm? Using the coefficient of friction, u =0.3 between crate and floor, Calculate the required torque by the motor to accelerate the crate at 1.5 m/s2. (15 marks) (ii) Calculate the motor power P, when motor rotation is 1800 rpm. (3 marks) (iii) What will happen to the motor if the rope is broken. (2 marks) a= 1.5 m/s2 Drum Gearbox Motor