Project 1: A Pully drive system used in washing machine is designed based on flat belt as in Figure.1/a. The tension in the pully is 115 N when it is stationary. The flat and V-belt type as well as the geometry specifications (Diameters and lap angle) are shown in Figure.2. The speed of rotation N is 1400 rpm and the coefficients of friction is u = 0.25 Flat Belt V-Belt (а) (b) Figure.1: Flat vs V-belt pully drive section lap angle - 480 mm 0= 160 %3D D,-240 mm Figure.2: Pully drive system specifications HT Page 5 of 10 الحسين التقنية Al Hussein Technical 1. Find the initial tension in each side 2. Find the power transmitted on the smaller wheel 3. Discuss the initial tension requirements/calculations to convert the system to the operation of a V-belt drive, if the included angle of V-section B = 15° (assume same u ), in your discussion compare the critical tension ration for both type and the transmitted power values.

A 2:1 speed reduction drive (Fig Q4) between two parallel shafts at 1200 mm centre distance is being provided by a V-belt of mass 0.5 kg/m. The diameter of the driving pulley is 200 mm and the driving shaft rotates at 900 rev/min. The driven pulley is 400 mm diameter. The angle of the pulley grooves is 40°, and the coefficient of friction between belt and pulleys is 0.35. If the maximum beit tension is 400 N determine: (i) The linear belt speed and the centripetal tension due to that belt speed. (ii) The angle of lap on each pulley (iii) The maximum power that may be transmitted Ø200 1200 Ø400

10 kN FIGURE P5-36 In Problem 5-36, if a force P= 400 N is required to resist the 10-kN force. determine the coefficient of static friction between the rope and the shafts. 5-37