ME1001-BASIC MECHANICAL
ENGINEERING
SYLLABUS
UNIT I– MACHINE ELEMENTS– I
(5 hours)
Springs: Helical and leaf springs – Springs in series and parallel.
Cams: Types of cams and followers – Cam profile.
UNIT II- MACHINE ELEMENTS– II
(5 hours)
Power Transmission: Gears (terminology, spur, helical and bevel gears,
gear trains). Belt drives (types). Chain drives. Simple Problems.
UNIT III- ENERGY
(10 hours)
Sources: Renewable and non-renewable (various types, characteristics,
advantages/disadvantages).
Power Generation: External and internal combustion engines – Hydro,
thermal and nuclear power plants (layouts, element/component description,
advantages, disadvantages, applications). Simple Problems.
SYLLABUS
UNIT IV - MANUFACTURING PROCESSES - I
(5
hours)
Sheet Metal Work: Introduction – Equipments – Tools and
accessories – Various processes (applications, advantages /
disadvantages).
Welding: Types – Equipments – Tools and accessories –
Techniques employed -applications, advantages / disadvantages –
Gas cutting – Brazing and soldering.
UNIT V - MANUFACTURING PROCESSES– II
(5 hours)
Lathe Practice: Types - Description of main components – Cutting
tools – Work holding devices – Basic operations. Simple Problems.
Drilling Practice: Introduction – Types – Description – Tools.
Simple Problems.
MACHINE ELEMENTS - I
CHAPTER -1
SPRINGS
• A spring is an elastic body, which deflects under load
and recover to its original shape upon release of the
load.
• It is also resilient member which stores energy once
deflected and releases the same as it recovers to its
original shape.
APPLICATIONS OF SPRINGS
1. Applying forces and controlling motions, as found
in brakes and clutches.
2. Measuring force, as in the case of spring balance. Ex
weighing machine (Analogue).
3. Storing energy, as in the case of clock springs &
springs used in toys.
4. Reduce the effect of shock loading, as in the case of
vehicle suspension ring.
5. Changing the vibration characteristics of machine
mounted on foundation beds.
CLASSIFICATION OF SPRINGS
1. Helical tension and compression spring:
•
•
•
The helical springs are made up of a wire coiled
in the form of a helix and are primarily intended
for compressive or tensile loads.
The cross-section of the wire from which the
spring is made may be circular, square or
rectangular.
Helical compression springs have applications to
resist applied compression forces
CLASSIFICATION OF SPRINGS
• The major stresses produced in helical springs are
shear stresses due to twisting. The load applied is
parallel to or along the axis of the spring.
CLASSIFICATION OF SPRINGS
Helical compression spring
CLASSIFICATION OF SPRINGS
2. Helical torsion springs:
• The principal stress
induced are tensile and
compressive due to
bending.
• These are similar to the
helical tension and
compression springs.
• In these springs, the load is
subjected to torsion about
its axis.
CLASSIFICATION OF SPRINGS
Helical torsion springs
CLASSIFICATION OF SPRINGS
3. Spiral Springs:
• The principal stress
induced are tensile and
compressive due to
bending.
•
•
These are made of flat strip,
wound in the form of spiral.
This is subjected to torsion
about its axis.
CLASSIFICATION OF SPRINGS
Spiral Spring
CLASSIFICATION OF SPRINGS
4. Leaf or laminated Springs :
• The principal stresses are tensile and compressive de
to bending.
• These are made of flat strips of varying lengths ,
clamped together.
• These may be cantilever, semi-elliptic or full elliptic
in form.
CLASSIFICATION OF SPRINGS
Leaf Springs
CLASSIFICATION OF SPRINGS
5. Belleville springs:
• The principal stress are
tensile and compressive de to
bending.
• These are made in the form
of coned discs which may be
stacked so as to give the
required spring loaddeflection characteristics.
CLASSIFICATION OF SPRINGS
Belleville springs
MATERIALS OF SPRINGS
• Commonly from alloy steels, High carbon
steel (0.7 – 1 % C) or carbon alloy steel.
• The most common spring steels are music
wire, oil tempered wire, silicon, Chrome
vanadium.
• Stainless steel, Spring brass, Phosphor bronze,
monel & titanium are used for corrosion
resistance spring.
TERMINOLOGY IN SPRINGS
TERMINOLOGY IN SPRINGS
• Solid Length :When the compression spring is
compressed until the coils come in contact with each
other, then the spring is said to be solid. The solid
length of a spring is the product of total number of coils
and the diameter of the wire.
Solid length, L s = n x d
Where, n = number of coils
• Free Length (Lo) : The free length of a compression
spring is the length of the spring in the free or
unloaded condition.
Free length, Lo = Solid Length + Maximum Compression
deflection + Clearance between adjacent coils (1mm).
TERMINOLOGY IN SPRINGS
• Spring Index (C): The ratio of mean coil diameter to
wire diameter. A low index indicates a tightly wound
spring (a relatively large wire size wound around a
relatively small diameter mandrel giving a high rate).
C=d/D
• Spring rate(K): The Spring rate is defined as the force
required to produce unit deflection of the spring. It can
also be said as stiffness or spring constant.
K =F/
Where F is the load applied,
is the deflection of the spring.
TERMINOLOGY IN SPRINGS
• Pitch (P) : The distance from center to center
of the wire in adjacent active coils. The pitch
of the coil is defined as the axial distance
between adjacent coils in uncompressed
state.
P = Free length / (n-1)
SPRING COMBINATIONS
• Parallel arrangement: In parallel the spring are
arranged side by side. The deflection in spring
combination is equal to individual spring.
Ke = K1 + K2 + ...... + Kn
SPRING COMBINATIONS
• Series Arrangement: When the spring are
arranged in series, the total deflection of the
spring combination is equal to sum of the
deflection of individual springs.
1/ Ke = 1/ K1 + 1/ K2 +... + 1/ Kn
CAM
• CAM is a device used to convert one simple
motion such as rotation to any other motion.
• A CAM mechanism consist of two moving
elements, the cam and the follower which is
mounted on the frame.