rpm. contact between the belt and pulley is 144°, the coefficient of friction between belt and pulley is 0.15 and the safe working stress of the belt is 2.1 Mpa. Determine the belt tension ratio, neglecting the effect of centrifugal force. A. 2.41 В. 2.44 С. 1.458 D. 4.12

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.

A flat belt is required to transmit 35 kw from a pulley of 1.5 m effective diameter running at 300 rpm. The angle of contact spread over 11/24 of the circumference and the coefficient of friction between pulley and belt 0.3. Determine width of belt required. It is given that the belt thickness is 10mm, density of its material is 1.1Mg/m and the related permissible working stress is 2.5 Mpa.

Q2 / A belt drive consist of two V- belts in parallel, on grooved pulleys of the same size. The angle of the groove is 30. The cross - section area of each belt is 750 mm and u is 0.12. The density of the belt material is 1.2 Mg/m and the maximum safe stress in the material is 7 MN/m. Answer the following questions 1- The centrifugal tension in belts is . (a) increases power transmitted (b) decreases power transmitted (c) have no effect on power transmitted (d) increases power transmitted up to a certain speed and then decreases 2- The power that can be transmitted between pulleys of 300 mm diameter rotating at 1500 r.p.m is .. 3- The shaft speed in r.p.m at which the power transmitted would be a maximum 4- When two pulleys are connected by means of an open belt drive, then both the pulleys will rotate is opposite directions. (true or falls) 5- The length of V- belt drive are usually used for .. (a) long drives (b) short drives (c) long and short drives (d) none of these.