Two pulleys are used to transmit power between two shafts 1.95 m apart and connected by a parallel belt. The diameter of one pulley is 450 mm and the other is 200 mm. Calculate the length of the belt required and the angle of contact between the belt and each pulley.

Q1) A V-belt drive consists of three V-belts in parallel on grooved pulleys of the same size. The angle of groove is 30° and the coefficient of friction 0.12. The cross-sectional area of each belt is 800 mm² and the permissible safe stress in the material is 3 MPa. Calculate the power that can be transmitted between two pulleys 400 mm in diameter rotating at 960 rpm.

In an open-belt drive, two sheaves have diameters of 8 in and 16 in. If the center distance is 9 in, determine the length of belt (in) required

Two parallel shafts connected by a cross belt have the diameters of pulleys 40cm and 60cm respectively. The direction of rotation of the driven shaft is required to be reversed, by changing over to an open belt drive. State if the same belt can be used. If not, what is the remedy? Assume that the centre distance between the shaf is fixed at 6 metres.

A winch has a line speed of 4m/min and lifts a load of 10kN. What is the winch output power? Give your answer in Watts to 1 decimal place without units eg if you think it is 102.341W, simply type 102.3.

Belt drives have small pulleys 250 mm in diameter with a wrap angle of 120 degrees. The diameter of the large pulley is 500 mm. What is the distance between the axles of the two pulleys?

A system is being designed to lift objects with a cable. One end of the cable will be attached to the material while the other end will be permanently fixed to a drum (cylinder) so that as the drum is rotated the cable is wound around its outside surface. Two designs for a drum are being considered for use in the system. Design “A” calls for a solid aluminum pulley (paluminium = 2800 kg/m 3 ) while design “B” calls for a steel pulley (psteel = 8000 kg/m 3 ) that is hollow (it can be modeled as a 12 mm thick shell). Calculate the torque required to accelerate the pulley for Design B to reach 500 RPM in 4 seconds if the pulley is 500 mm wide. Assume constant

A fan is driven by a belt from a motor which runs at 880 rpm. A medium double ply leather belt 8 mm thick and 250 mm wide is used. The diameters of the motor pulley and the driven pulley are 350 mm and 1370 mm. The center distance is 1370 mm, and both pulleys are made of cast iron. Coefficient of friction of leather on cast iron is 0.35. The allowable stress for the belt is 2.4 MPa, which allows for the factor of safety and also for the fact that a double ply belt does not have double the capacity of a single ply belt. (A double ply belt has approximately 85% the capacity of a single ply belt of the same thickness.) The belt density p =970 kg/m^3. What is the power capacity? (Answer: 39.1 kW ) -0350 -1370

Homework 2 A pulley is driven by a flat belt, the angle of lap being 120º. The belt is 100 mm wide by 6 mm thick and density1000 kg/m3. If the coefficient of friction is 0.3 and the maximum stress in the belt is not to exceed 2 MPa, find the greatest power which the belt can transmit and the corresponding speed of the belt.

Power is transmitted between two shafts by a V-belt whose mass is 0.9 kg/m length. The maximum permissible tension in the belt is limited to 2.2 kN. The angle of lap is 170° and the groove angle 45°. If the coefficient of friction between the belt and pulleys is 0.17, find : 1. velocity of the belt for maximum power; and 2. power transmitted at this velocity. Note: Sketch the belt drive system for both parts and label the given data on it.