Q3-a/ What are the characteristics of material which used for lining friction surfaces of a clutch? (5Marks) b/ An engine developing 45 kW at 1000 r.p.m. is fitted with a cone clutch built inside the flywheel. The cone has a face angle of 12.5° and a maximum mean diameter of 500 mm. The coefficient of friction is 0.2. The normal pressure on the clutch face is not to exceed (0.1 N/mm2). Determine: 1. The face width required, and 2. The axial spring force necessary to engage the clutch Answer question 4 or 5 (15 Marks) 15 Q4/ The areas of the turning moment diagram for one revolution of a multi-cylinder engine with reference to the mean turning moment, below and above the line, are - 32, + 408,-267, +333,-310, +226,- 374, + 260 and 244 mm². The scale for abscissa and ordinate are: 1 mm = 2.4° and 1 mm = 650 N-m respectively. The mean speed is 300 r.p.m. with a percentage speed fluctuation of± 1.5%. If the hoop stress in the material of the rim is not to exceed 5.6 MPa, determine the suitable diameter and cross-section for the flywheel, assuming that the width is equal to 4 times the thickness. The density of the material may be taken as 7200 kg/m³. Neglect the effect of the boss and arms. (10 Marks) Q5: /A truck has a gross vehicle weight of 89026 N. engine displacement is 10 m, power 77.3kW at governed speed, of 2400 r.p.m. maximum torque, 345.8 Nm at 1400r.p.m. Rear axle ratio 6.166: 1. And the overall gear ratio 9.9:1 drive line losses amount to 10.7kW at 2400r.p.m and 6.3 kW at 1400 r.p.m. effective wheel diameter 0.950 m, frontal area of truck 2.4mx 2.9m calculate the grades which the vehicle can climb in fourth gear in still air conditions. (i) (ii) At governed engine speed; and At speed of maximum torque, in the equation. (10 Marks) ***Best of Luck *** UNIVERSITY OF BABYLON Examiner Dr. Dhyai .H. Aljashaami Head of Department: Dr. Dhyai .H. Aljashaami