guided-answer 2 ship june 2010

8/6/2019 Guided-Answer 2 Ship June 2010

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Suez Canal University Production Engng & Mechanical Design DeptFaculty of Engineering Theory & Machine Design ( Code : PRD 217 )Port Said Total Allowed Time : 3 Hours2 nd Year (Ship Building Dept ) Allowed Time For Machine Design : 90 minutes

Final Exam June 2010

Answer All the questions and assume any missing data you find it necessary to completeyour answer

The quality of the needed drawing has a direct influence in the evaluation of the question

mark

Question No. 1 30 Marks

A 5 tilting pad bearing is required to support a shaft 0.125 m diameter carrying a steady load of 2 kNduring running . the shaft rotates in one direction at 120 rev/s . It is required that the bearing be designed

for an oil viscosity grade No. 68 entering at 50 C o. with viscosity index of 95. The lubricant is suppliedin the form of flooded feed The Start up load of 200 N is to be expected . The inner diameter is 0.14 m.

Bearing misalignment is expected to be minimal with inlet temperature of 50 Co

. and the drain

temperature Tout and the pad feed temperature Tf are assumed to be 70 C

o

) .N.B.

The Vogels Eqn. Constants are as follows :

K= 5.95804x10-5

, B= 894.233 , = 106.5863

S1 = 0.45 , S2= 1.4 , C = 1.7x106 j/m3 K , k = 0.08x10-6 m2 / s , = 1

It is required topresent a full design of that bearing. Draw a neat sketch showing thegeneral layout and the configuration of the final design of the off set pads thrust bearing .


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Design and draw a neat sketch of a knuckle joint for a tie rod of a circular section to sustain amaximum pull of 70 kN. The ultimate strength of the material of the rod against tearing is 420MPa. The ultimate tensile and shearing strength of the pin material are 510 MPa and 396 MParespectively. Determine the tie rod section and pin section. Take factor of safety= 6

Present a neat sketch of the assembled joint indicating the important dimensions. The stressesdeveloped in the various members have to be checked before finalizing the design . ( The Finalneat Drawing of the joint has a direct effect on the evaluation of the total marks)

The permissible tensile stress for the rod material,


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An eccentrically loaded lap riveted joint is to be designed for a steel bracket as shown inthe Fig..The bracket plate is 25 mm thick. All rivets are to be of the same size. Load on thebracket, P = 50 kN ; rivet spacing, C = 100 mm; load arm, e = 400 mm. Permissible shearstress is 65 MPa and crushing stress is 120 MPa. Determine the size of the rivets to be usedfor the joint .

Standard Sizes of Power Transmission Shafts

The standard sizes of transmission shafts are :

25 mm to 60 mm with 5 mm steps; 60 mm to 110 mm with 10 mm steps ; 110 mm to 140 mm with15 mm steps ; and 140 mm to 500 mm with 20 mm steps.

The standard length of the shafts are 5 m, 6 m and 7 m.


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Solution.

Given : t= 25 mm ; P= 50 kN = 50 103 N ; e= 400 mm ; n= 7 ; = 65 MPa = 65 N/mm2 ;c= 120 MPa = 120 N/mm2


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guided-answer 2 ship june 2010

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