basic mechanical engineering POWER POINT (PPT)

2.  TOPIC
 INTRODUCTION
 METHODS OF DRIVES
 BEARING CLASSIFICATIONS
 POWER TRANSMISSION ELEMENTS

3.  The Electricity is Main Source of power for machinery .The
Electricity or Electrical energy is converted to rotational energy by
means of an electric motor , various forms of energy like motion,as
per requriment in process.
 1. High speed of the prime movers can be reduced and torque is
increased by drive which is requriment of machines.
 2. By help of drives driven member gets member gets
variablespeed when the speed of prime mover is constant.
 3. Several machines may run by one prime movers.
 4. The machine should not be coupled directly to thr prime mover
shaft due to consideration of saftey,convenience and maintenance.

4. Machine may be driven by any
one of the following two methods
1. Individual Drive
2. Group Drive

5.  1. Individual drive : In this drive each machine
has its own electric motor and starter. The
motor is directly coupled with machine shaft by
help of belt,chain,gear or variable speed
transmission system.
 It is used in area where requires over head
crane servies and with machines that are likely
to be moved frequently.

6.  2. Group Drive
when one prime mover or motor is used for the
number of machine tools on
common shaft then the drive is called as group
drive . it is also sometimes called as line shaft
drive

7.  The main shaft runs from one end to other end
of the shop and it drives by very powerful motor.
 This Main Shaft drives another shaft called
counter shaft . counter shaft drives the machine
shafts.
 Counter shaft for starting stopping the machine
shaft.
 The motor is placed either on the floor or
mounted overhead.

8.  A bearing is machine element that constrain
relative motion to only desired motion and
reduce the friction of moving parts.

9. Rolling elements bearing
Jewel bearing
Fluid bearing
Magnetic bearing
Flexure bearing

10.  1.Ball bearing
 2. Roller bearing
 3. Tapered bearing

11.  Ball bearing
 Roller bearing
 Tapered roller bearing
• It support the large
radial and large thrust.
• It used in vehicle
transmission , car
hubs.

12.  It is small in size it is generally used in small
machine like watch.

13.  Fluid bearing support their load using a thin
layers of gas or liquid.
 Bearing are used in high load high speed
and precision.

14.  Magnetic bearing support moving parte without
physical parts contact due to magnetic fields.
 1. In which contain very low friction.
 2. it is ability to run without and lubrication.
 It works in vacuum.
 Used in motors , turbines , and generators.

15.  Flexure which is engineered to be compliant
in one or more angular degree of freedom.
 Many flexure bearing are made of a single
part.