The piston pin bearings in heavy duty diesel engines are
Needle roller bearings
Tapered roller bearings
Spherical roller bearings
Cylindrical roller bearings
Correct Answer :
A. Needle roller bearings
Related Questions
The acme threads are usually found on
Spindles of bench vices
Railway carriage couplings
Feed mechanism of machine tools
Screw cutting lathes
The belt slip occurs due to
Heavy load
Loose belt
Driving pulley too small
Any one of the above
When a belt drive is transmitting maximum power,
Effective tension is equal to centrifugal tension
Effective tension is half of centrifugal tension
Driving tension on slack side is equal to centrifugal tension
Driving tension on tight side is twice the centrifugal tension
When a beam of rectangular cross-section of width b and depth d, is subjected to a shear force F, the maximum shear stress induced will be
F/bh
3F/2bh
2F/bh
4F/bh
Rankine's theory is used for
Brittle materials
Ductile materials
Elastic materials
Plastic materials
The pipe joint mostly used for pipes carrying water at low pressures is
Socket joint
Nipple joint
Union joint
Spigot and socket joint
The rated life of a bearing varies
Directly as load
Inversely as square of load
Inversely as cube of load
Inversely as fourth power of load
The size of a gear is usually specified by
Pressure angle
Pitch circle diameter
Circular pitch
Diametral pitch
If a material fails below its yield point, failure would be due to
Straining
Fatigue
Creep
Sudden loading
A tapered key which fits in a key-way in the hub and is flat on the shaft, is known as
Woodruff key
Feather key
Flat saddle key
Gib head key
When the screw in a mechanical screw jack rotates, the load kept on the top of it moves
Axially upwards
Axially downwards
Axially upwards or downwards
None of these
The suitable material for belt used in flour mill is
Leather
Rubber
Canvas or cotton duck
Balata gum
Which process will increase the fatigue duration of parts?
Finishing and polishing
Shotpeening
De-carburisation
Electroplating
The strap end of a connecting rod of steam engine is joined by
Gib of cotter joint
Sleeve and cotter joint
Spigot socket cotter joint
Knuckle joint
A locking device in which the bottom cylindrical portion is recessed to receive the tip of the locking set screw, is called
Ring nut
Castle nut
Sawn nut
Jam nut
The helix angle for double helical gears may be made up to
45°
60°
75°
90°
Tapered roller bearings can take
Axial load only
Both radial and axial loads and the ratio of these being greater than unity
Radial load only
Both radial and axial loads and the ratio of these being less than unity
According to I.B.R., when the thickness of boiler shell (t) is greater than 8 mm, then the diameter of rivet hole (d) is obtained by
Equating tearing resistance of the plate to the shearing resistance of the rivets
Equating tearing resistance of the plate to the crushing resistance of the rivets
Equating shearing resistance to the crushing resistance of the rivets
None of the above
In a multiple V-belt drive, when a single belt is damaged, it is preferable to change the complete set in order to
Reduce vibration
Reduce slip
Ensure uniform loading
Ensure proper alignment
A tap bolt
Has a head on one end and a nut fitted to the other
Has head at one end and other end fits into a tapped hole in the other part to be joined
Has both the ends threaded
Has pointed threads
Two helical springs of the same material and of equal circular crosssection, length and number of turns, but having radii 80 mm and 40 mm, kept concentrically (smaller radius spring within the larger radius spring), are compressed between two parallel planes with a load W. The inner spring will carry a load equal to
W/2
2W/3
W/9
8W/9
The bearings of medium series have capacity __________ over the light series.
10 to 20 %
20 to 30 %
30 to 40 %
40 to 50 %
Multiple threads are used to secure
Low efficiency
High efficiency
High load lifting capacity
High mechanical advantage
The permissible stress for carbon steel under static loading is generally taken as
2000-3000 kg/m²
3000-4000 kg/cm²
4000-4500 kg/cm²
7500-10,000 kg/cm²
A double fillet welded joint with parallel fillet weld of length l and leg s is subjected to a tensile force P. Assuming uniform stress distribution, the shear stress in the weld is given by
√2P/s.l
P/2.s.l
P/√2.s.l
2P/s.l
A spring is used to
Measure forces
Apply forces
Store energy
All of these
The centre distance between two meshing involute gears is equal to
(Sum of base circle radii)/cosφ
(Difference of base circle radii)/cosφ
(Sum of pitch circle radii)/cosφ
(Difference of pitch circle radii)/cosφ
Two shafts A and B under pure torsion are of identical length and identical weight and are made of the same material. The shaft A is solid and the shaft B is hollow. We can say that
Shaft B is better than shaft A
Shaft A is better than shaft B
Both the shafts are equally good
None of these
The contact ratio for gears is
Zero
Less than one
Greater than one
None of these
In helical gears, the distance between similar faces of adjacent teeth along a helix on the pitch cylinders normal to the teeth, is called
Normal pitch
Axial pitch
Diametral pitch
Module