Suez Canal University
Production Engng & Mechanical Design Dept
Faculty of Engineering
Theory & Machine Design ( Code : PRD 217 )
Port Said
Allowed Time : 3 Hours
2 nd Year (Ship Building Dept )
Exam Date : May 30 , 2009
Final Exam May 2009
§ Answer All the questions and assume any missing data you find it necessary to complete your answer
§ The quality of the needed drawing has a direct influence in the evaluation of the question mark
Question No. 1 25 Marks
1 – An Uni-directional 7 pads thrust bearing is required to support a load of 10 Kn. The Start up load of 200 N is to be expected . The shaft diameter to be 0.04 m and the bearing has to operate at max. Speed of 170 rev/s . The lubricant available to the bearing is a mineral oil grade 46 ( ISO VG 46 ) with viscosity index of 95 . The Bearing outside diameter can be considered as 0.15 m. and the inner diameter is 0.045 m. Bearing misalignment is expected to be minimal . The lubricant is supplied in the form of flooded feed with inlet temperature of 50 C o . and a housing outlet temperature ( pad feed temperature Tf is 65 C o ) .
N.B.
The Vogel’s Equation Constant are :
K = 8.9527x10-5 , B = 808.5279 , q = 93.054
S1 = 0.12 , S2= 1.4 , ρC = 1.7x106 j/m3 K , k = 0.08x10-6 m2 / s , α = 1
It is required to present a full design of that bearing. Draw a neat sketch showing the general layout and the configuration of the final design of the off –set pads thrust bearing .
Question No. 2 25 Marks
screw jack is to lift a load of 80 kN through a height of 400 mm. The elastic strength of screw material in tension and compression is 200 MPa and in shear 120 MPa. The material for nut is phosphor-bronze for which the elastic limit may be taken as 100 MPa in tension, 90 MPa in compression and 80 MPa in shear. The bearing pressure between the nut and the screw is not to exceed 18 N/mm2.
Design and draw the screw jack. The design should include the design of
1.screw, 2. nut, 3. handle and cup, and 4. body.
Question No3 20 Marks
Design and draw a neat sketch of a knuckle joint to transmit 150 kN. The design stresses may be taken as 75 MPa in tension, 60 MPa in shear and 150 MPa in compression.
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