A multiple vee-belt drive is required to transmit 4 kW. The smaller pulley has of the system has a diameter 150 mm and rotates at 200 rev/min. The grove angle is 40° and the coefficient of friction between the belt and pulley is 0·3. (a) If the maximum tension in any one belt is limited to 800 N and the angle of lap is 135°, determine the number of belts required.  (b) Determine also, the initial pre-tension required in the belt.

4.) A flat belt makes contact with an 16 in. diameter pulley through half its circumference. If the coefficient of friction is 0.45 , and a torque of300ft−bsis to be transmitted, calculate the belt tensions. (please type answer not write by hend)

In an engine governor of the Porter type, the upper and lower arms are 200 mm and 250 mm respectively and pivoted on the axis of rotation. The mass of the central load is 15 kg, the mass of each ball is 2 kg and friction of the sleeve together with the resistance of the operating gear is equal to a load of 24 N at the sleeve. If the limiting inclinations of the upper arms to the vertical are 30° and 40°, find, taking friction into account, range of speed of the governor.

In an open flat belt drive, a pulley of 800 mm diameter runs at 300 r.p.m. The coefficient of friction between the belt and the pulley is 0.25, the angle of lap is 170° and the maximum tension in the belt is 2000 N. The power transmitted is:   10.5 kW 9.4 kW 8.9 kW 7.6 kW None of the mentioned 13.1 kW

4.) A flat belt makes contact with an 18 in. diameter pulley through half its circumference. If the coefficient of friction is 0.45, and a torque of 350 ft-lbs is to be transmitted, calculate the belt tensions.

A multi-disk clutch consists of two steel disks with one bronze disk. Theinner and outer diameters of the contacting surfaces are 200 and 250 mmrespectively. The coefficient of friction is 0.1 and the maximum pressurebetween the contacting surfaces is limited to 0.4 N/mm2. Assuming uniformwear theory, calculate the required force to engage the clutch and the powertransmitting capacity at 720 rpm

The ratio of tension on the tight side to that of the slack ride in a flat belt drive is (a) proportional to the product of coefficient of friction and lap angle (b) an exponential function of the product of coefficient of friction and lap angle (c) proportional to lap angle (d) proportional to the coefficient of friction

2. A square threaded screw of mean diameter 25 mm and pitch of thread 6 mm is utilised to lift a weight of 10 kN by a horizontal force applied at the circumference of the screw. Find the magnitude of the [Ans. 966 N] force if the coefficient of friction between the nut and screw is 0.02. A bolt with a squore threaded screw has mean diameter of 25 mm and a nitch of 23 mm It carries an

The band brake of Fig. is used to control the rotation of a drum. The coefficient of friction between the belt and the 36° V-pulley is 0.15, and the weight of the han- dle is 15 N. If a force of 200 N is aPplied to the end of the handle, determine the maximum torque for which no mo- tion occurs if the torque is applied Counterclockwise. 150 mm T 200 N 60 150 mmi 675 mm 75 mm

Problem 8 Another Gear Two disks are connected to one another with a belt as shown. Both disks have mass m but the larger one has radius 4R and the smaller has radius R. The larger disk is powered by a motor that produces a constant torque, To, in the counter- clockwise direction. (a) By using the rotational equivalent of Newton's laws on the larger disk show that the difference in the tension at the top with the tension at the bottom is: Tto - Thot 1 4R (TO - 2m Ra), where a is the linear accleration of the elt. (b) Do the same (find Ttop - Tbot) with the smaller disk. (c) Use your two expressions to find the gular acceleration of the smaller disk. You answer should have m, R, and To in it only. (Careful, the sr aller disk does not have the same angular acceleration as the larger one).