This download link is referred from the post: JNTUA M.Tech 1st Sem last 10 year 2010-2020 Previous Question Papers (JNTU Anantapur)
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Code: 9D15106a
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M.Tech I Semester Supplementary Examinations August/September 2018
TRIBOLOGY
(Machine Design)
(For students admitted in 2013, 2014, 2015 & 2016 only)
Time: 3 hours
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Max. Marks: 60
Answer any FIVE questions
All questions carry equal marks
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- (a) What are skewness and kurtosis of rough surfaces? Explain with schematic sketches.
- (b) What are auto covariance and autocorrelation functions?
- (a) Outline the considerations that govern the following aspects of the performance of rolling-element bearings: (i) Load capacity. (ii) Rotational speed. (iii) Life. (iv) Lubrication requirements.
- (b) A shaft rotating at constant speed is subjected to variable load. The bearings supporting the shaft are subjected to stationary equivalent radial load of 3 kN for 10 per cent of time, 2 kN for 20 percent of time, 1 kN for 30 per cent of time and no load for remaining time of cycle. If the total life expected for the bearing is 20 x 10º revolutions at 95 percent reliability, calculate dynamic load rating of the ball bearing.
- (a) Derive the one dimensional Reynolds equation for long bearing approximation.
- (b) Derive the bearing parameters from the general Reynolds equation.
- (a) Derive the relation for lubricant flow of flat circular hydrostatic pad bearing.
- (b) What are aerostatic bearings? List its advantages.
- (a) What do you understand by sintered bearings? What are its applications?
- (b) What are the advantages of PTFE bearings? What do you understand by self-lubricated bearings?
- (a) Differentiate between lubricant and lubrication. Explain how MoS2 act as good solid lubricant.
- (b) What are additives? How it contributes in lubrication?
- (a) List the different types of seals and its applications.
- (b) Discuss the importance of Seal face materials and their significant properties.
- (a) Tabulate service failures and its causes of bearings.
- (b) List the common contaminants and its possible sources.
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This download link is referred from the post: JNTUA M.Tech 1st Sem last 10 year 2010-2020 Previous Question Papers (JNTU Anantapur)