a) The plates of a multi-plate clutch have the outer and inner diameters 200 mm and...

  

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a) The plates of a multi-plate clutch have the outer and inner diameters 200 mm and 120 mm respectively. The clutch is required to transmit 12.5 kW at 1250 rev/min. The maximum axial thrust in this case is 1100 N. i) Using the uniform wear theory, calculate the required number of pairs of surfaces in contact. The plates are both made from tempered steel with a friction coefficient of 0.35 when in contact. ii) Using the result from 3 a) i), recalculate the actual axial thrust required to transmit the same power at the same speed. (1 mark) b) The pulley and the V-belt shown in the left side of figure 3(b) below have the following parameters: - the angle of lap is 170° - the coefficient of friction is 0.17 a section through the V-belt that fits into the pulley's groove is shown on the right side of Figure 4a and has the dimensions w = 22 mm, h = 18 mm, b = 11 mm - the V-belt mass is 0.7 kg/m maximum belt tension is limited to 2100 N. D (4 marks) 170- W Figure 3(b) i) Allowing for centrifugal tension, calculate the belt speed at which the maximum power will be transmitted by the pulley. (3 marks) ii) Using the result from 3 b) i), calculate the power in kW transmitted at this speed. (2 marks) a) The plates of a multi-plate clutch have the outer and inner diameters 200 mm and 120 mm respectively. The clutch is required to transmit 12.5 kW at 1250 rev/min. The maximum axial thrust in this case is 1100 N. i) Using the uniform wear theory, calculate the required number of pairs of surfaces in contact. The plates are both made from tempered steel with a friction coefficient of 0.35 when in contact. ii) Using the result from 3 a) i), recalculate the actual axial thrust required to transmit the same power at the same speed. (1 mark) b) The pulley and the V-belt shown in the left side of figure 3(b) below have the following parameters: - the angle of lap is 170° - the coefficient of friction is 0.17 a section through the V-belt that fits into the pulley's groove is shown on the right side of Figure 4a and has the dimensions w = 22 mm, h = 18 mm, b = 11 mm - the V-belt mass is 0.7 kg/m maximum belt tension is limited to 2100 N. D (4 marks) 170- W Figure 3(b) i) Allowing for centrifugal tension, calculate the belt speed at which the maximum power will be transmitted by the pulley. (3 marks) ii) Using the result from 3 b) i), calculate the power in kW transmitted at this speed. (2 marks)

Answer rating: 100% (QA)

a i To calculate the required number of pairs of surfaces in contact for the multiplate clutch we can use the uniform wear theory The formula for calc... View the full answer