ST. ALOYSIUS INSTITUTE OF TECHNOLOGY, JABALPUR
MACHINE COMPONENT DESIGN (ME-504)
TUTORIAL UNIT-II
Q1. A shaft is supported on bearings A and B, 800 mm between centers. A 20° straight tooth spur
gear having 600 mm pitch diameter, is located 200 mm to the right of the left hand bearing A,
and a 700 mm diameter pulley is mounted 250 mm towards the left of bearing B. The gear is
driven by a pinion with a downward tangential force while a pulley drives a horizontal belt
having 180° angle of wrap. The pulley also serves as a flywheel and weighs 200N. The belt
tension is 3000N and the tension ratio is 3:1. Determine the maximum bending moment and the
necessary shaft diameter if the allowable shear stress of the material is 40MPa.
Q2. A steel solid shaft transmitting 15KW at 200 rpm is supported on two bearings 750 mm
apart and has two gears keyed to it. The pinion having 30 teeth of 5 mm module is located
100mm to the left of the right hand bearings and delivers power horizontally to the right. The
gear having 100 teeth of 5 mm module is located 150 mm to the right of the left hand bearing
and received power in a vertical direction from below. Using an allowable stress of 54MPa in
shear, determine the diameter of the shaft.
Q3. A mild steel shaft transmits 20KW at 200 rpm. It carries a central load of 900 and is simply
supported between the bearings 2.5m apart. Determine the size of the shaft, if the allowable shear
stress is 42MPa and the maximum tensile or compressive stress is not to exceed 56MPa. What
size of the shaft will be required, if it is subjected to gradually applied loads.
Q4. A hollow shaft is subjected to a maximum torque of 1.5KN-m and a maximum bending
moment of 3KN-m. it is subjected at the same time to an axial load of 10KN. Assume that the
load is applied gradually and the ratio of the inner diameter to the outer diameter is 0.5. if the
outer diameter of the shaft is 80 mm find the shear stress induced in the shaft.
Q5. A hollow steel shaft is to transmit 20KW at 300 rpm. The loading is such that the maximum
bending moment is 1000N-m, the maximum torsion moment is 500N-m and axial compressive
load is 15KN. The shaft is supported on rigid bearing 1.5m apart. The maximum permissible
shear stress on the shaft is 40MPa. The inside diameter is 0.8 times the outside diameter. The
load is cyclic in nature and applied with shock. The values for the shock factor are Kt=1.5 and
Km=1.6.
Q6. Compare the weight, strength and stiffness of a hollow shaft of the same external diameter as
that of solid shaft. The inside diameter of the hollow shaft is being half the external diameter.
Both the shaft has the same material and length.
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Asst. Prof. PremKushwaha (SAIT)|MECHANICAL DEPARTMENT
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ST. ALOYSIUS INSTITUTE OF TECHNOLOGY, JABALPUR
MACHINE COMPONENT DESIGN (ME-504)
ASSIGNMENT UNIT-II
Q1. A shaft running at 400rpm transmits 10KW. Assuming allowable shear stress in the shaft as
40MPa, find the diameter of the shaft.
Q2. A hollow shaft for a rotary compressor is to be designed to transmit a maximum torque of
4750N-m. The shear stress in the shaft is limited to 50MPa. Determine the inside and outside
diameter of the shaft, if the ratio of the inside to the outside diameter is 0.4.
Q3. A cylindrical shaft made of steel of yield strength 700MPa is subjected to static loads
consisting of a bending moment of 10KN-m and a torsional moment of 30KN-m. Determine the
diameter of the shaft using two different theories of failure and assuming a factor of safety of 2.
Q4. A line shaft rotating at 200rpm is to transmit 20KW. The allowable shear stress for the
material of the shaft is 42MPa. If the shaft carries a central load of 900N and is simply supported
between bearing 3meter apart, determine the diameter of the shaft. The maximum tensile or
compressive strength is not to exceed 56MPa.
Q5. The problem is shown in the given figure. A pulley drive is transmitting power to a pinion,
which in turn is transmitting power to some other machine element. Pulley and pinion diameters
are 400mm and 200mm respectively. Shaft has to be designed for minor to heavy shock.
Q6. A shaft subjected to a torque of 4KN-m carries a bending moment of 1.5KN-m in vertical
plane and 2KN-m in horizontal plane at a section. Determine its diameter and check for factor of
safety. The determination of property in tension of the material of steel is quite reliable. The
calculation of bending moment and torque is accurate. The shaft will be ground finished and heat
treated to ultimate tensile strength of 700MPa with uniform micro structure.
Q7. A section of a shaft is subjected to a bending moment of 1.5KN-m and a torque of 0.5KN-m.
It is proposed to check the design of shaft for three different steels having ultimate tensile
strengths of 400, 700 and 1000MPa. Find the diameter of the shaft at this section for each steel
and check for factor of safety of 2, assuming that a key slot of end milled type exists at the
section.
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Asst. Prof. PremKushwaha (SAIT)|MECHANICAL DEPARTMENT
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ST. ALOYSIUS INSTITUTE OF TECHNOLOGY, JABALPUR
Q8. Design a solid shaft of length 1m, carrying a load of 5 KN at the center and is simply
supported as shown in figure. The maximum shaft deflection is 1mm. E=200GPa.
Q9. Two 400mm diameter pulleys are keyed to a simply supported shaft 500mm apart. Each
pulley is 100mm from its support and has horizontal belts, tension ratio being 2.5. if the shear
stress is to be limited to 80MPa while transmitting 45KW at 900rpm, find the shaft diameter if it
is to be used for the input-output belts being on the same or opposite sides.
Q10. A machine shaft supported on bearings having their centers 750mm apart, transmitted
185KW at 600rpm. A gear of 200mm and 20° tooth profile is located 250mm to the right of left
hand bearing and a 450mm diameter pulley is mounted at 200mm to right of right hand bearing.
The gear is driven by a pinion with a downward tangential force while the pulley drives a
horizontal belt having 180°angle of contact. The pulley weighs 1000N and tension ratio is 3. Find
the diameter of the shaft, if the allowable shear stress of the material is 63MPa.
Q11. The engine of a ship develops 440KW and transmits the power by a horizontal propeller
shaft which runs at 120rpm. It is proposed to design a hollow shaft with inner diameter as 0.6 of
the outer diameter. Considering torsion alone, calculate the diameter of the propeller shaft if
stress in the material is not to exceed 63MPa and also the angular twist over length of 2.5m is not
to be more than 1°. The modulus of rigidity of the shaft material is 80GPa.
Q12. The internal diameter of a hollow shaft is 2/3rd of its external diameter. Compare the
strength and stiffness of the shaft with that of a solid shaft of the same material.
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Asst. Prof. PremKushwaha (SAIT)|MECHANICAL DEPARTMENT
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