Theory and Design of Machine Elements
ME 603

Lecturer   :   3                                                                                          Year   :   III
Tutorial     :   1                                                                                          Part    :   I
Practical   :   2
Course Objective:
After completion of this course, the students will be able to:
·         Select proper mechanisms and analyze it for agricultural machines.
·         Carry out simple design or modify the existing design for product development or repair and maintenance work.
·         Know how the failure can take place on components of agricultural machines.
·         Select the most appropriate machine elements by catalogue/data book references.
1.       Mechanism                                                                                                   [4 hours]
        1.1  Introduction of mechanism
        1.2  Mechanism configuration, Link, pair and chain
        1.3  Degree of freedom of mechanism
        1.4  Inversion of mechanism – single slider crank mechanism
2.       Kinematic Analysis of Mechanism                                                            [8 hours]
2.1      General plane motion representation
2.2      Relative motion velocity analysis – Velocity polygons
2.3      Velocity of any point on the link or outside the link [offset point]
2.4      Velocity and angular velocity of different links
2.5      Velocity and angular velocity diagrams of quadratic cycle chain and slider crank mechanism
2.6      Velocity of rubbing at pin joints
2.7      Instantaneous centers of velocity and Kennedy’s theorem
2.8      Instantaneous center method to find out velocity of any link on quadratic cycle         chain
2.9      Acceleration diagrams of quadratic cycle chain and slider crank mechanism
2.10    Centripetal, tangential and coriolis components of acceleration of a link
3.       Fundamentals of Machine Design                                                            [6 hours]
3.1  Introduction to engineering design and design process
3.2  Material properties and selection of material in m\ c design
3.3  Theories of failures
3.4  Endurance limit of materials
3.5  Factors affecting fatigue strength
3.6  Stress concentration effects
3.7  Fatigue failure curves
3.8  Factors of safety and basis for safety factor
3.9  Use of data hand book for safety factor, design codes [ISI and ISO codes]
4.       Shaft, Axle, Keys and Shaft Couplings                                                      [5 hours]
        4.1  Functions application, type and material
        4.2  combined bending and torsion effects
        4.3  Power and torque considerations
        4.4  Fatigue strength stress concentration and keyways effect
        4.5  Critical speed of shaft  
        4.6  Design of keys     
        4.7  Design of couplings
5.       Journal Bearing                                                                                            [6 hours]
        5.1  Types, application and material
        5.2  Journal bearing terminology
        5.3  Hydrodynamic theory of lubrication of rotating journal
        5.4  Viscosity, petroff’s law, bearing characteristic numbers
        5.5  Operating pressure load and heat balance of bearing
        5.6  Design procedure
6.       Ball and Roller Bearing                                                                               [5 hours]
        6.1  Construction and types of ball bearing
        6.2  Design for variable loads and axial load
        6.3  Operating capacity of rolling element bearing
        6.4  Bearing load, life and reliability relationship
        6.5  Selection of bearings, lubrication, mounting and enclosure
7.       Gears                                                                                                             [6 hours]
        7.1  Classification of gears and gear terminology
        7.2  Gear tooth profiles – Cycloidal and Involute
        7.3  Angle of obliquity
        7.4  Causes of gear tooth failure
        7.5  Design of spur gear considering static, dynamic and wear tooth load
        7.6  Helical, Bevel and Worm gear characteristic requirements for design
8.       Clutch and Brake                                                                                         [5 hours]
        8.1  Purpose, Type, Working principle and application of clutch
        8.2  Design steps for friction clutch – Multidisc and cone clutch
        8.3  Design basis of uniform wear and uniform pressure assumption
        8.4  Purpose, Type, Working principle and application of brake
        8.5  Design procedure for block brake
        8.6  Friction material and heat dissipation
        8.7  Operation system and control system
               

Practical:
1.       Pro-active learning approach: Each student will carry out a research project. S/he should write 4-8 pages summary on her/his topic and deliver it taking 10-15 minute time. The sample topic may be one of the following:
a)       Design for manufacturing
b)       Material selection for gear
c)       Design for assembly
d)       Optimal design
e)       Value engineering
f)        Patenting
g)       Bench marking
2.       Undertaking Design project: One team of the student will be 2 to 3 in number and it will complete a design project of a product on:
a)                   A gravel conveyor
b)                   A garage door opener
c)                   A lifting device
d)                   A maze planter
e)                   A sprinkler
f)                    A mechanical jack to lift and lower the load
3.       Live field project: Mechanical design related industrial problems as an assignment.

Tutorial:
1.       Problem solving on related topics.
2.       Old questions of TU examination will be the base for tutorial classes.
3.       Number of numerical examples in each chapter should be solved in the classes according to the weight-age given for TU final examination.
4.       Preference is to be given for applied type of questions that includes synthesis and analysis of real problem of machine design.



Evaluation Scheme:
The questions will cover all the chapters of the syllabus. The evaluation scheme will be as indicated in the table below

Chapter
Hours
Mark Distribution*
1
4
8
2
8
12
3
6
12
4
5
8
5
6
12
6
5
8
7
6
12
8
5
8
Total
45
80
*There may be minor variation in marks distribution. 


References:
1.       Theory of Machine and Mechanisms by J. E. Shigley and J. J. Uicker, Jr. McGraw Hill Publication, 1980.
2.       Mechanisms and Dynamics of Machinery, Fourth Edition by H. H. Mabie and C. F. Reinholtz, Wiley Publication.
Source: Department of Agricultural Engineering
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