K.

RAMAKRISHNAN COLLEGE OF TECHNOLOGY

SAMAYAPURAM, TRICHY – 621 112.

DEPARTMENT OF MECHANICAL ENGINEERING

YEAR/SEM III/VI SECTION EXAM MODEL –

SUBJECT CODE & NAME: C309 & ME8651 & DESIGN OF TRANSMISSION SYSTEMS
Course Outcomes:
CO1 Understand the design process and select the proper belt and chain drive.
CO2 Design and Select the proper spur and parallel axis gear drives
CO3 Design the bevel and worm gear and calculate the forces on the gears
CO4 Design the multi speed gear boxes
CO5 Design the cams, clutches and brakes.
Level K1 K2 K3 K4 K5 K6 Total
REMEMBER UNDERSTAND APPLY ANALYSE EVALUATE CREATE
Mark
6 2 2 19 17 54 100
Allotment

PART-A (10*2=20) Marks Mapping

1. Define slip in a flat belt drive 2 C309.1/k1
2. Describe the stresses induced in wire ropes? 2 C309.1/k2
3. Explain undercutting in gears. 2 C309.2/k5
4. Differentiate Spur and helical gear 2 C309.2/k4
5. Show when do you prefer worm and worm wheel drive? 2 C309.3/k3
6. Differentiate between the spiral bevel gears and hypnoid gears. 2 C309.3/k4
7. Define gear box 2 C309.4/k1
8. Explain the basic rules to be followed for optimum gear box 2 C309.4/k1
9. Integrate the importance of pressure angle in CAM design. 2 C309.5/k6
10. Explain the function of a clutch 2 C309.5/k4
PART-B(5*13=65)
11. a) Design a V-belt drive and calculate the actual belt tension and average
stress for the following data. Driven pulley diameter, D= 500 mm, driver 13 C309.1/K6
pulley diameter, d=150 mm, center distance C=925 mm, speed n 1 = 1000
rpm, n2 = 300 rpm and power, P = 7.5kW.
(OR)
b) A roller chain drive is used between a driver shaft running at 1440rpm and a
driven shaft running approximately at 720rpm. The power transmitted is
15KW. The drive is to be used for 2 shifts/day with 8hours/shift. The center 13 C309.1/K6
distance is approximately 1000mm and the chain tension can be adjusted by
moving the motor in the rails. Design the drive.
12. a) Design a pair of straight spur gear drive for a stone crusher, the gears are
made of C40 steel. The pinion is to transmit 30 KW at 1200 rpm. The gear 13 C309.2/K6
ratio is 3. The gear is to work 8 hours/day 6days in a week for 3 years.
(OR)
b) Design a helical gear to transmit 15 KW at 1440 rpm to the following
specification. Speed reduction is 3, Pressure angle is 20 0and helix angle is
15 degree. The material for both the gears is C45 steel. Allowable static 13 C309.2/K6
stress is 180 N/mm2, Surface endurance limit is 800 N/mm2 and Young’s
Modulus of material is 2 x 105 N/mm2.
13. a) A Pair of bevel gears is to be used to transmit 14KW from a pinion rotating 13 C309.3/K6
 at 400rpm to a gear mounted on shaft running at 200rpm. The axes of the
two shafts are at 90°. Design the pair of bevel gears.
(OR)
b) Design a bevel gear drive, to transmit 10 KW power at 1440 rpm. Gear ratio
is 3, and life of gears 10,000 hrs. Pinion and gear are made of C45 steel and 13 C309.3/K6
minimum number of teeth as 20.
14. a) Design 12 speed gear box for a minimum speed of 160 rpm and a maximum
speed of 2000 rpm. The input speed of motor is 1600 rpm. Draw the speed 13 C309.4/K6
diagram, kinematic diagram and indicate the number of teeth on each gear.
(OR)
b) Select speeds for an 18 speeds gear box for a minimum speed of 35 rpm and
maximum speed 650 rpm. Draw speed diagram and a kinematic 7 C309.4/K6
arrangement of the gear box showing the number of teeth in all the gears.
15. a)i) A single plate sketch, effective on both sides, is required to transmit 25KW
at 3000 rpm. Determine the outer and inner diameter of frictional surfaces if
the coefficient of friction is 0.25, ratio of diameter is 1.25 and the maximum 7 C309.5/K4
pressure is not to exceed 0.1 N/mm2. Determine (i) the face width required
and (ii) the axial spring force necessary to engage the clutch.
ii) An engine developing 45kW at 1000 rpm id fitted with a cone clutch built
inside the fly wheel. The cone has a face angle of 12.5 degree and a
maximum mean diameter of 500 mm. The coefficient of friction is 0.2. The 6 C309.5/K4
normal pressure on the clutch face is not exceeded 0.1N/mm 2. Determine
(i) The face width required (ii) the axial spring force necessary to engage
the clutch. (OR)
b) In a winch, the rope supports a load W and is wound round a barrel 450 mm
diameter. A differential band brake acts on a drum 800 mm diameter which
is keyed to the same shaft as the barrel. The two ends of the bands are
attached to pins on opposite sides of the fulcrum of the brake lever and at 13 C309.5/K4
distances of 25 mm and 100 mm from the fulcrum. The angle of lap of the
brake band is 250° and the coefficient of friction is 0.25. What is the
maximum load W which can be supported by the brake when a force of 750
N is applied to the lever at a distance of 3000 mm from the fulcrum?
PART-C(1*15=15)
16 a) A work shop crank carries a load of 30KN using wire ropes and a hook. The
hook weighs 15KN. Diameter of the rope drum is 30 times the diameter of
the rope. The load is lifted with an acceralation of 1m/s2. Find the diameter 15 C309.1/K5
of the rope. FS = 6, Er =80KN/mm2, σu = 180KN/mm2, cross section of
the rope =0.4 x (Dia. of the rope) 2.

b)i) A double shoe brake, as shown in Fig., is capable of absorbing a torque of

1400 N-m. The diameter of the brake drum is 350 mm and the angle of
contact for each shoe is 100°. If the coefficient of friction between the brake
drum and lining is 0.4 ; find 1. the spring force necessary to set the brake ;
and 2. The width of the brake shoes, if the bearing pressure on the lining
material is not to exceed 0.3 N/mm2.

15 C309.5/K5

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