Code No: 53207/MT
M.Tech. II-Semester Examinations, July/August-2006.
Time: 3 hours Max. Marks: 60
Answer any FIVE questions
All questions carry equal marks
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1.a) How the contact surface topography and finish affect the friction and wear characteristics of materials?
b) How the lubricants reduce the friction and wear characteristics of the parts in contact?
2.a) Differentiate between rolling and sliding contact bearings and explain the parameters to be considered in the selection.
b) What is the need of pre-loading? Explain with sketches various methods of pre-loading the bearings?
3.a) Derive Reynold’s equation for hydro-dynamic journal bearing.
b) Describe Raimondi and Boyd solution for hydrodynamic thrust bearings.
4.a) Differentiate between the hydrodynamic and hydro-static bearings mentioning their performance, advantages and applications.
b) Describe the design procedure for hydrostatic thrust bearings.
5.a) Describe the advantages and limitations of porous bearings over rolling contact bearings and explain their characteristics.
b) What are the various materials used for porous bearings and explain the method of manufacture of porous bearings?
6.a) What are the various properties to be considered in the selection of lubricants for a particular application and explain the importance of additives?
b) Describe the fields of application of different oils, greases ad solid lubricants mentioning their relative advantages.
7.a) Explain various metallic and non-metallic seals used in practice.
b) Sketch ad explain the applications of lip seals, packed gland seals, soft piston seals.
8.a) What are the various methods used in the analysis of failure of sliding contact bearings?
b) How the soap and ferrography methods are employed in the wear analysis of the sliding and rolling contact parts?