Design of Bearings · Machine Design · GATE ME
Marks 1
1
For a ball bearing, the fatigue life in millions of revolutions is given by $L = \left(\frac{C}{P}\right)^n$, where $P$ is the constant applied load and $C$ is the basic dynamic load rating. Which one of the following statements is TRUE?
GATE ME 2024
2
A CNC worktable is driven in a linear direction by a lead screw connected directly to a stepper motor. The pitch of the lead screw is 5 mm. The stepper motor completes one full revolution upon receiving 600 pulses. If the worktable speed is 5 m/minute and there is no missed pulse, then the pulse rate being received by the stepper motor is
GATE ME 2022 Set 1
3
Which of the bearings given below SHOULD NOT be subjected to a thrust load?
GATE ME 2016 Set 3
4
Ball bearings are rated by a manufacturer for a life of $${10^6}$$ revolutions. The catalogue rating of a particular bearing is $$16$$ $$kN.$$ If the design load is $$2$$ $$kN,$$ the life of the bearing will be $$P \times {10^6}$$ revolutions, where $$P$$ is equal to ___________.
GATE ME 2014 Set 4
5
Which one of the following is criterion in the design of hydrodynamic journal bearings?
GATE ME 2005
6
The basic load rating of a ball bearing is
GATE ME 1998
7
To restore stable operating condition in a hydrodynamic journal bearing, when it encounters higher magnitude loads.
GATE ME 1997
8
In thick film hydrodynamic journal bearings, the coefficient of friction
GATE ME 1996
9
Spherical roller bearings are normally used
GATE ME 1992
10
Starting friction is low in
GATE ME 1992
11
Match the roling element bearings with the most appropriate loading condition
Bearing - type
(a)$$\,\,\,\,\,\,$$ Ball bearing
(b)$$\,\,\,\,\,\,$$ Roller bearing
(c)$$\,\,\,\,\,\,$$ Needle bearing
(d)$$\,\,\,\,\,\,$$ Taper roller bearing
Loading condition
(p)$$\,\,\,\,\,\,$$ Tangential load
(q)$$\,\,\,\,\,\,$$ Radial load
(r)$$\,\,\,\,\,\,$$ Heavy radial load with impact
(s)$$\,\,\,\,\,\,$$ Light radial load with space limitation
(t)$$\,\,\,\,\,\,$$ Heavy radial and axial load
(u)$$\,\,\,\,\,\,$$ Fatigue load
GATE ME 1991
12
If the load on a ball bearing is reduced to half, the life of the ball bearing will
GATE ME 1988
13
The expected life of a ball bearing subjected to a load of $$9800N$$ and working at $$1000RPM$$ is $$3000$$ hours. What is the expected life of the same bearing for a similar load of $$4900$$ $$N$$ and a speed of $$2000rpm$$
GATE ME 1987
Marks 2
1
For ball bearings, the fatigue life $$L$$ measured in number of revolutions and the radial load $$F$$ are related by $$F{L^{1/3}} = K,$$ where $$K$$ is a constant. It withstands a radial load of $$2$$ $$kN$$ for a life of $$540$$ million revolutions. The load (in $$kN$$) for a life of one million revolutions is ___________.
GATE ME 2015 Set 3
2
A hydrodynamic journal bearing is subject to $$2000$$ $$N$$ load at a rotational speed of $$2000$$ $$rpm.$$ Both bearing bore diameter and length are $$40mm.$$ If radial clearance is $$20\mu m$$ and bearing is lubricated with an oil having viscosity $$0.03$$ $$Pa.s,$$ the Sommerfeld number of the bearing is _______
GATE ME 2014 Set 1
3
Two identical ball bearings $$P$$ and $$Q$$ are operating at loads $$30kN$$ and $$45kN$$ respectively. The ratio of the life of bearing $$P$$ to the life of bearing $$Q$$ is
GATE ME 2011
4
A journal bearing has a shaft diameter of $$40mm$$ and a length of $$40mm.$$ The shaft is rotating at $$20$$ $$rad/s$$ and viscocity of the lubricant is $$20mPa.s.$$ The clearance is $$0.020mm.$$ The loss of the torque due to viscocity of the lubricant is approximately
GATE ME 2008
5
A natural feed journal bearing of diameter $$50mm$$ and length $$50mm$$ operating at $$20$$ revolutions/sec carries a load of $$2kN$$. The lubricant used has a viscosity of $$20mPa$$-$$s$$. The radial clearance is $$50\mu m.$$ The Sommerfeld number for the bearings is
GATE ME 2007
6
A ball bearing operating at a load $$F$$ has $$8000$$hours of life. The life of the bearing, in hours, when the load is doubled to $$2F$$ is
GATE ME 2007
7
The life of a ball bearing at a load of $$10$$ $$kN$$ is $$8000$$ hours. Its life in hours, if the load is increased to $$20$$ $$kN,$$ keeping all other conditions same, is
GATE ME 2000
8
The dynamic load capacity of $$6306$$ bearing is $$22KN.$$ The maximum radial load it can sustain to operate at $$600$$ $$rev/min,$$ for $$2000$$ hours is
GATE ME 1997
9
Match the following
List - $${\rm I}$$
(a)$$\,\,\,\,\,$$ Automobile wheel mounting on axle
(b)$$\,\,\,\,\,$$ High speed grinding spindle
(c)$$\,\,\,\,\,$$ $${\rm IC}$$ - Engine connecting rod
(d)$$\,\,\,\,\,$$ Leaf spring eye mounting
List - $${\rm I}$$
(a)$$\,\,\,\,\,$$ Automobile wheel mounting on axle
(b)$$\,\,\,\,\,$$ High speed grinding spindle
(c)$$\,\,\,\,\,$$ $${\rm IC}$$ - Engine connecting rod
(d)$$\,\,\,\,\,$$ Leaf spring eye mounting
List - $${\rm II}$$
1.$$\,\,\,\,\,$$ Magneto bearing
2.$$\,\,\,\,\,$$ Angular contact bearing
3.$$\,\,\,\,\,$$ Taper roller bearing
4.$$\,\,\,\,\,$$ Hydrodynamic journal bearing
5.$$\,\,\,\,\,$$ Sintered metal bearing
6.$$\,\,\,\,\,$$ Teflon/Nylon bush
GATE ME 1997