Total No. of Questions : 8] SEAT No.
:
PB-3909 [Total No. of Pages : 4
[6262]-174
T.E. (Automation and Robotics)
DESIGN OF ROBOT ELEMENTS
(2019 Pattern) (Semester - I) (302521)
Time : 2½ Hours] [Max. Marks : 70
Instructions to the candidates :
1) Answer Q.1 or Q.2, Q.3 or Q.4, Q.5 or Q.6, Q.7 or Q.8.
2) Draw neat labeled diagrams wherever necessary.
3) Figures to the right side indicate full marks.
4) Use of non programmable electronic calculator is permitted.
5) Assume Suitable/Standard data if necessary.
Q1) a) The layout of an intermediate shaft of a gear box supporting two spur gears
B and C is shown in Figure. The shaft is mounted on two bearings
A and D. The pitch circle diameters of gears B and C are 900 and 600 mm
respectively. The material of the shaft is steel FeE 580 (Sut = 770 and
Syt = 580 N/mm2). The factors kb and kt of ASME code are 1.5 and 2.0
respectively. Determine the shaft diameter using the ASME code. Assume
that the gears are connected to the shaft by means of keys. [13]
b) Explain design of shaft design using ASME code. [5]
OR
P.T.O.
Q2) a) The following data is given for a V-belt drive connecting a 20 kW motor
to a compressor. The centre distance between pulleys is 1 m and the
dimensions of the cross-section of the belt are given in Figure. The density
of the composite belt is 0.97 g/cc and the allowable tension per belt is
850 N. How many belts are required for this application? [11]
b) Derive equations of V-belt for analysis of tensions in the belt. [7]
Q3) a) Write a note on remote compliance center design with neat labelled
diagram. [8]
b) Write basic design process of gripper. [9]
OR
Q4) a) Write a note on using tools as end effectors. [9]
b) What do you mean by payload in the design of robots. Explain payload
force analysis with neat diagram and mathematical equations. [8]
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Q5) a) A 3 × 3 Gear box is transmitting a power of 10 KW. Choose the best ray
diagram based on minimum summation of shaft diameters made of same
material with permissible shear stress of 36 N/mm2. Use GP ratio of 1.26
and Lowest speed N1 = 100 RPM. [10]
b) Write a note on general recommendation for developing the gearing
diagram. Explain with suitable example. [8]
OR
Q6) Design a nine-speed gear box having Nmin 100 rpm and Nmax = 630 rpm.
Assume motor speed 1400 rpm. The design should include structural diagram,
ray diagram, speed chart, gearing diagram and number of teeth of the gear.
(Gearing diagram is not essential) [18]
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Q7) a) In a particular application, the radial load acting on a ball bearing is 5 kN
and the expected life for 90% of the bearings is 8000 h. Calculate the
dynamic load carrying capacity of the bearing, when the shaft rotates at
1450 rpm. [5]
b) Explain in details equivalent bearing load in rolling contact bearing. [5]
c) A single-row deep groove ball bearing is subjected to a 30 second work
cycle that consists of the following two parts: The static and dynamic
load capacities of the ball bearing are 50 and 68 kN respectively. Calculate
the expected life of the bearing in hours. [7]
Refer table for values of X and Y factors as follows :
OR
Q8) a) Derive Petroff’s Equation for sliding contact bearing. [7]
b) The following data is given for a 360° hydrodynamic bearing: radial
load = 3.2 kN journal speed = 1490 rpm journal diameter = 50 mm bearing
length = 50 mm radial clearance = 0.05 mm viscosity of lubricant = 25 cP
Assuming that the total heat generated in the bearing is carried by the total
oil flow in the bearing, calculate (i) coefficient of friction (ii) power lost in
friction, (iii) minimum oil film thickness (iv) flow requirement in
litres/min; and (v) temperature rise. [10]
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