ME6503 - DESIGN OF MACHINE ELEMENTS UNIT - V NOTES

R.M.K COLLEGE OF ENGG AND TECH / AQ / R2013/ ME6503 / V / MECH / JUNE 2016 – NOV 2016
ME6503 – DESIGN OF MACHINE ELEMENTS QUESTION BANK by ASHOK KUMAR.R (AP / Mech) 87
UNIT – V – BEARINGS
PART – A
5.1) Classify the types of bearings. [AU, May / Jun – 2014]
5.2) What is cooling stress? [AU, April / May – 2010]
5.3) What is meant by hydrodynamic lubrication? [AU, May / Jun – 2016]
5.4) What are journal bearings? Give a classification of these bearings.
5.5) What is meant by journal bearing? [AU, May / Jun – 2013, 2014, 2016]
5.6) What is full journal bearing? [AU, Nov / Dec – 2015]
5.7) For a journal bearing the maximum operating temperature must be less than 80°C.
Why? [AU, Nov / Dec - 2010]
5.8) What is meant by square journal bearing? [AU, Nov / Dec – 2015]
5.9) What are the properties required for bearing material?
5.10) What are the factors to be considered while selecting a type of bearing?
5.11) Write a short note on the lubricants used in sliding contact bearing.
5.12) Differentiate clearly between sliding contact and rolling contact bearing.
[AU, Nov / Dec –2012]
5.13) Define anti friction bearings. [AU, May / Jun - 2012]
5.14) Give an example for anti-friction bearing. [AU, Nov / Dec – 2015]
5.15) What do you mean by life of an individual bearing? [AU, May / Jun – 2013, 2016]
5.16) What is meant by life of anti-friction bearings? [AU, Nov / Dec – 2008, 2013]
5.17) Why ball bearings are called antifriction bearing? [AU, April / May – 2011]
5.18) Write a short note on classifications and different types of antifriction bearings.
[AU, Nov / Dec –2011]
5.19) Name the materials used for sliding contact bearings [AU, April / May – 2011]
5.20) Classify the sliding contact bearings according to the thickness of layer of the
lubrication between the bearing and the journal. [AU, May / Jun - 2012]
5.21) What are the loads to be considered for designing a ball bearing?
5.22) Explain the term dynamic load carrying capacities of rolling contact bearing.
[AU, Nov / Dec –2012]
5.23) What is meant by Sommerfield number?

5.24) What is Sommerfield number? State its importance in the design of journal
bearing? [AU, Apr / May – 2015]
5.25) Define static Capacity of Bearing [AU, Nov / Dec –2014]
5.26) What are the various types of radial ball bearings? [AU, May / Jun - 2012]
5.27) State the advantage of thrust ball bearing. [AU, Nov / Dec - 2009]
5.28) State the disadvantage of thrust ball bearing. [AU, Nov / Dec - 2009]
5.29) What is quill bearing [AU, April / May – 2010]
5.30) What is self-aligning ball bearing? Statue its unique feature.
[AU, Apr / May – 2015]
5.31) What are the advantages of Rolling Contact Bearings over Sliding Contact
Bearings? [AU, May / Jun – 2016]
5.32) List any 4 advantages of rolling contact over sliding contact bearing.
[AU, May / June – 2009]
5.33) In what way the backling strength differed from compressive strength?
5.34) What is meant by self-acting bearing?
5.35) Write the differences between hydrostatic and hydrodynamic bearing.
5.36) In hydrodynamic bearing, what are factors which influence the formation of
wedge fluid film? [AU, Nov / Dec –2014]
5.37) List the basic assumptions used in the theory of hydrodynamic lubrication.
[AU, Nov / Dec –2011]
5.38) What are the essential requirements in an end face seal? [AU, Nov / Dec –2013]
PART – B
5.39) List the types of lubrication used in journal bearing and their characteristics.
[AU, May / June – 2009]
5.40) Enumerate the detail steps involved in the selection of bearings from the
manufacturer’s catalogue. [AU, Apr / May – 2015]
5.41) Design a journal bearing for a centrifugal pump to the following specifications.
Diameter of the journal = 75 mm
Speed of the journal = 1140 mm
Load on each journal = 11,500 N [AU, Nov / Dec – 2004]
5.42) Design a journal bearing for a centrifugal pump with the following data:

Diameter of the journal = 150 mm
Load on bearing = 40 kN
Speed of journal = 900 rpm.
[AU, Nov / Dec – 2007, 2015, May / Jun – 2014]
5.43) A journal bearing is to be designed for a centrifugal pump for the following data:
Load on the journal = 12kN
Diameter of the journal = 75mm
Speed = 1440 rpm
Atmospheric temperature of the oil = 16 ˚C
Operating temperature of the oil = 60˚C
Absolute viscosity of the oil at 60˚C = 0.23kg/m-s
Give a systematic design of the bearing [AU, May / Jun - 2012]
5.44) Design a full journal bearing for the following specification D = 75mm: W =
3500N; L = 75mm; N = 400rpm. The minimum oil film thickness ho = 0.02mm.
Determine (i) viscosity of oil (ii) coefficient of friction (iii) heat generated (iv)
amount of oil pumped to the bearing (v) Amount of end leakage (vi) temperature rise
in oil
5.45) A 100 mm diameter full journal bearing supports a Radial load of 5000N. The
bearing is 100 mm long and the shaft operates at 400 rpm. Assume permissible
minimum film thickness of 0.025mm and diametral clearance of 0.152mm. Using
Raimondi and Boyd curves, determine a) viscosity of a suitable oil b) hgc) hdd)
amount of oil pumped through bearings e) amount of oil to be supplied to bearings
f) temperature rise of the oil flowing through the bearings ho = 0.025 C = diametral
clearance = 0.152 mm
5.46) A full journal bearing of 50mm diameter and 100 mm long has a bearing pressure
of 1.4 N/mm2
. The speed of the journal is 900 rpm and the ratio of journal diameter
to the diametral clearance is 1000. The bearing is lubricated with oil whose absolute
viscosity at the operating temperature of 75 0
C may be taken as 0.011 kg/ms. The
room temperature is 350
C. Find the i) amount of artificial cooling required and ii)
mass of lubricating oil required, if the difference between the outlet and inlet

temperature of the oil is 10o
C. Take specific heat of the oil as 1850 J/kg/C o
.
[AU, Nov / Dec – 2012]
5.47) A full journal bearing of 50 mm diameter and 100 mm long has a bearing pressure
1.4N/mm2
. The speed of the journal is 900 rpm and the ratio of journal diameter to
the diametral clearance is 1000. The bearing is lubricated with oil whose absolute
viscosity of the operating temperature is 35o
C. Find the
(i) The amount of artificial cooling required and
(ii)The mass of lubricating oil required if the difference between the outlet and
inlet temperature of oil is 10o
C. Take specific heat of oil as 1850 J/kg/o
C.
[AU, Nov / Dec – 2008, 2015]
5.48) Design a journal bearing for a centrifugal pump from the following data:
Load on the journal = 20 kN, speed of the journal = 900 rpm, type of oil is SAE
10 for which the absolute viscosity at 550
C = 0.017 N/m-s; ambient temperature
of oil = 15.50
C, maximum bearing pressure for the pump = 1.5 N/mm2
. Calculate
the mass of the lubricating oil required for artificial cooling, if the rise of
temperature of oil be limited 100
C. Heat dissipation co-efficient = 1232 W/m2
/0
C.
[AU, May / June – 2007, 2016, Nov / Dec –2011, 2013]
5.49) Design a journal bearing for 12 MW, 1000 rpm steam turbine, which is supported
by two bearings. Take the atmospheric temperature as 16ºC and operating
temperature of oil as 60°C. Assume viscosity of oil as 23 Ns/m2
.
[AU, May / Jun – 2013, 2016]
5.50) A 50 mm diameter journal bearing rotates at 1500 rpm, L/D = 1, radial
clearance is 0.05 mm, minimum film thickness = 0.01 mm. Calculate the maximum
radial load that the journal bearing can carry and still operate under hydrodynamic
condition. For this load, calculate power lost in friction and increase in the oil
temperature. Assume Hg = Hd. Absolute viscosity = 20*103
Pas, Sp. Gravity of oil
0.8, Sp. Heat of oil 2.1 kJ/kg°C. [AU, Nov / Dec –2014]
5.51) A wall bracket supports a Plummer block for 80mm diameter shaft. The length
of bearing is 120 mm. The cap of bearing is fastened by means of four bolts, two on
each side of the shaft. The cap is to withstand a load of 16.5 KN. The distance
between the center line of the bolt is 150 mm. Determine the thickness of the bearing
cap and the diameter of the bolts. Assume safe stress in tension for the material of

the cap, which is cast- iron, as 15 MPa and for bolts as 35 MPa. Also check the
deflection of the bearing cap taking E = 110 KN/mm2
.
5.52) A footstep bearing supports a shaft of 150 mm diameter, which is counter board
at the end with a hole diameter of 50mm. If the bearing pressure is limited to 0.8
N/mm2
and the speed is 100rpm, find the i) load to be supported ii) power lost in
friction and iii) heat generated at the bearing . Assume co-efficient of friction =
0.015.
5.53) Select a suitable deep groove ball bearing for supporting a radial load of 10KN
and an axial load of 3 KN for a life of 4000 hrs at 800 rpm. Select from series 63.
Calculate the expected life of the selected bearing.
[AU, Nov / Dec - 2012, May / Jun – 2013, 2016]
5.54) The following data is given for a 3600
hydrodynamic bearing.
[AU, April / May – 2010]
Journal diameter = 100 mm
Bearing length = 100 mm
Radial load = 50 KN
Journal speed = 1440 rpm
Radial clearance = 0.12 mm
Viscosity of the lubricant = 16 cP.
Calculate the i) minimum film thickness ii) co-efficient of friction iii) power
lost in friction
5.55) Explain in detail rolling contact bearing failure – causes and remedies.
[AU, Nov / Dec - 2009]
5.56) A ball bearing is operated on work cycle consisting of three parts – a Radial load
of 3000 N at 1440 rpm for one quarter cycle, a Radial load of 5000 N at 720 rpm for
one half cycle, and Radial load of 2500 N at 1440 rpm for the remaining cycle. The
expected life of bearing is 10,000 hr. Calculate the dynamic load carrying capacity
of the bearing. [AU, Nov / Dec - 2009]
5.57) The load on the journal bearing is 150 kN due to turbine shaft of 300 mm diameter
running at 1800 rpm. Determine the following.

(i) Length of the bearing if the allowable bearing pressure is 1.6 N/mm2
and
(ii) Amount of heat to be removed by the lubricant per minute if the bearing
temperature is 60o
C and viscosity of the oil at 60o
C is 0.02 kg/m-s and
the bearing clearance is 0.25 mm.
[AU, May / June – 2009, Nov / Dec –2011]
5.58) Design a journal bearing to support a load of 5000N at 720rpm using a hardened
steel journal and a bronze bracket babbit bearing. The bearing is lubricated by oil
rings. Room temp. is 25 C and oil temp. is 82C. Assume viscosity of oil as
25Centipoise.
5.59) Design a journal bearing for a centrifugal pump from the following data:
Load on the journal = 20000 N;
Speed of the journal = 900 rpm;
Type of oil is SAE 10, for which the absolute viscosity at 55° C = 0.017kg/m-s;
Ambient temperature of oil= 15.5° C;
Maximum bearing pressure for the pump = 1.5 N/mm2
.
[AU, April / May – 2011]
5.60) A journal bearing 150mm diameter and 300mm long carries a radial load of 9kN
at 1220rpm. The diametral clearance is 0.075mm. If 6kW is being lost in friction.
What is the viscosity of the oil used at given operating temperature?
[AU, Nov / Dec - 2012]
5.61) The load on a 100mm full hydrodynamic journal bearing is 9000N. Speed of the
journal is 320rpm. Let l/d = 1, C/d = .0011. The operating temp. is 65C and minimum
oil film thickness is 0.022m. Find (i) Select an oil (ii) Frictional loss (iii) Oil flow
(iv) Amount of leakage (v) Temperature rise of oil (vi) Max. oil pressure
5.62) Load on a hydrodynamic full journal bearing is 30kN. The diameter and speed of
the shaft are 150mm and 1200rpm respectively. Diametral clearance 0.2mm.
Sommerfield number is 0.631. L/D ration 1:1. Calculate temperature rise in oil,
quantity of oil, heat generated and type of oil required. [AU, Apr / May – 2015]
5.63) A bearing for an axial flow compressor is used to support a Radial load of 2500N
and a thrust load of 1500N. The service required for the bearing is 5years at the rate
of 40hours per week. The speed of the shaft is 1000rpm. Select suitable ball bearing
for the purpose. The diameter of shaft is 50mm.

5.64) Design a suitable ball bearing for an axial flow compressor to carry a radial load
of 2.5 kN and a thrust load of 1.3 kN. The service imposes a light shock with shock
factor 1.5 and bearing will be in use for 35 hours per week for 4 years. The speed of
shaft is 900 rpm and diameter of shaft is 45 mm. Assume X = 0.56 and Y= 1.4.
[AU, Nov / Dec – 2015]
5.65) Select a bearing for a 40 mm diameter shaft rotates at 400 rpm. Due to bevel gear
mounted on the shaft, the bearing will have to withstand a 5000 N radial load and a
3000 N thrust load. The life of the bearing expected to be at least 1000 hrs.
[AU, May / Jun – 2014]
5.66) Select a deep groove ball bearing it carry a radial load of 5kN and thrust load of
1.5kN. The diameter of the shaft is 130mm and rotates at 2500rpm. The expected
life of the bearing is 20,000 hrs.
5.67) Select a deep groove ball bearing from series 63 to take a radial load of 4kN and
axial load of 2kN. The speed of shaft 1000rpm. Life of bearing 10,000 hrs.
5.68) The Radial reaction on a bearing is 9000N. It also carries a thrust of 5000N. The
speed of the shaft is 1000rpm. The outer ring is stationary. Expected average life of
bearing is about 25000hrs. The load on bearing is smooth, the service is 8hrs/day.
(i) Select suitable roller bearing
(ii)What is the rated 90% life of selected bearing?
(iii) Compute the probability of selected bearing surviving 25000hrs
5.69) Select a suitable ball bearing to support the overhang counter shaft. The diameter
of the shaft is 60mm and speed 1000rpm. The bearing are to have 99% of reliability
corresponding to life of 10,000hrs. The baring is subjected to equivalent radial load
of 4kN and axial load of 2kN
5.70) A 6207 Radial bearing is to operate in the following cycle:
Radial load of 4500N at 150rpm for 30% of time
The inner ring rotates, loads are steady, what is the expected average life of
the bearing.

5.71) The Radial load on a roller bearing varies as follows. A load of 50KN is acting
20% of time at 500rpm and a load of 40KN is acting 50% of time at 600rpm. In the
remaining time, the load is varying from 40KN to 10KN linearly at 700rpm. Select
a roller bearing from N22 series for a life of at least 4000hrs. The operating
temperature is 175C.
5.72) A single row deep ball bearing is subjected to a Radial force of 8kN and the thrust
force of 3kN. The shaft rotates at 1200rpm. The expected life of the bearing is
20,000hr. The minimum acceptable diameter of the shaft is 75mm. Select a suitable
ball bearing [AU, April / May – 2010]
5.73) A single row deep groove ball bearing No.6002 is subjected to an axial thrust load
of 1000N and a Radial load of 2200N. Find the expected life that 50% of the bearings
will complete under this condition [AU, Nov / Dec - 2010]
5.74) Select a single row deep groove ball bearing for a radial load of 4000 N and an
axial load of 5000 N, operating at a speed of 1600 rpm for an average life of 5 years
at 10 hours per day. Assume uniform and steady load. [AU, Nov / Dec – 2015]
5.75) Select a single row deep groove ball bearing for a radial load of 4000 N and an
axial load of 5000 N, operating at a speed of 1600 rpm for an average life of 5 years
at 10 hours per day. Assume uniform and steady load. Take 300 working days per
year. [AU, May / Jun – 2016]
5.76) A ball bearing is operated on both cycle consisting of three parts. A radial load of
3kN at 1440rpm for one fourth of cycle. A radial load of 5kN at 720rpm for half
cycle, a radial load of 2500N at 1440rpm for the remaining cycle. The life of the
bearing is 10,000hrs. Calculate the dynamic load carrying capacity and also find the
specification of the bearing.
5.77) For 6307 ball bearing , the load varies as follows:
S.NO
RADIAL
LOAD (N)
AXIAL LOAD
(N)
CYCLE TIME
RATIO
SPEED (Rpm)
1 6300 3000 0.5 400
2 7500 - 0.3 650

3 4000 1000 0.2 900
The inner ring rotates, loads are steady, what is the expected average life of the
bearing.
5.78) Find the rated load of a deep groove ball bearing for the following load cycle.
S.NO RADIAL LOAD (N) AXIAL LOAD (N) % OF TIME
1 3000 1000 15
2 3500 1000 20
3 3500 10 30
4 500 2000 35
Also find the 90% life of ball bearing if bearing used is 6207 with dynamic capacity
19620 N [AU, Nov / Dec –2014]
5.79) In a deep groove ball bearing (6306) is to operate at 1600rpm and carries 8KN
Radial load and 6KN thrust load. Determine the rating life of the bearing.
5.80) Select a suitable ball bearing for a drilling machine spindle of diameter 40mm
rotating at 300rpm. It is subjected to a Radial load of 2000N and axial load of 1000N.
It is to work for 45 hours a week for one year.
5.81) A 30BC03 deep groove ball bearing is to operate at 1600rpm and carries 8KN
Radial load and 6KN thrust load. The bearing is subjected to light shock load.
Determine the rating life of the bearing.
5.82) Select a suitable deep groove ball bearing for the following data, Radial load of
7500N and axial load of 4500N. Speed is 2000rpm. L10 = 4.9*108
r
5.83) Select a suitable Conrad – type deep groove ball bearings for the following data,
the radial load 7500N and axial load is 4500N, the shaft speed is 2000rpm, the L10
life required is 4.9*108
revolutions; the inner of the bearing rotates.
[AU, May / Jun – 2012]
5.84) Select a deep groove ball bearing for a radial load of 4000N and axial load of
5000N operating at a speed of 160rpm for an average life of 5 years at 10 hours per
day. Assume uniform and steady load. [AU, Nov / Dec - 2012]

5.85) In a deep groove ball bearing , diameter is 40mm, Speed is 400rpm, Radial load
of 5000N and axial load of 3000N, Life is 1000hrs. Calculate Dynamic capacity of
the bearing

ME6503 - DESIGN OF MACHINE ELEMENTS UNIT - V NOTES

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to ME6503 - DESIGN OF MACHINE ELEMENTS UNIT - V NOTES

Similar to ME6503 - DESIGN OF MACHINE ELEMENTS UNIT - V NOTES (20)

More from ASHOK KUMAR RAJENDRAN

More from ASHOK KUMAR RAJENDRAN (20)

Recently uploaded

Recently uploaded (20)

ME6503 - DESIGN OF MACHINE ELEMENTS UNIT - V NOTES