Actuators

1. Actuators
Supervisor:-
Dr. Jagadish Chandra Mohanta
Presented By:-
Anurag Chaudhary
Atul Kushwaha

2. Actuators are devices used to produce action or motion.
It is operated by a source of energy (mainly electrical signal,
air ,fluids) and converts that energy into motion.
Actuator is a mechanism by which a control system acts
upon environment.
Actuator’s output is usually Mechanical i.e. linear
displacement or velocity.
Actuation can be from few microns to few meters.

3. A
Signal
Amplification
Transducer
Control
Signal
Physical
Process
Unmodulate
Energy Source
Amplifier converts the (low power) control signal into a high
power signal .
Transducer converts the energy of the amplified control signal
into work

4. Main Attributes Of Actuators
 The size of operating forces and torques.
 The operating environment.
 Linear or rotational movement.
 The energy source.
 Speed of response and motion.
 The amount of movement needed.
 The degree of precision needed.
 The method of control and monitoring.

6.  Hydraulic actuator consists of cylinder or fluid motor that
uses hydraulic power to facilitate mechanical operation.
 Mechanical motion gives output in terms of linear, rotary or
oscillatory motion.
 Pump driven by prime mover (electric motor) creates flow of
fluid.

7.  Linear actuator (Hydraulic cylinder)-
 Provides motion in straight line.
 Linear displacement depends on stroke length.
 Usually referred to as cylinders, rams (single acting
cylinders) or jacks.
 Rotary actuators (Hydraulic motors)-
 Produces continuous rotational motion.
 Pump shaft is rotated to generate flow.
 Motor shaft is caused to rotate by fluid being forced into
driving chambers.
Types Of Hydraulic Actuator

8. Hydraulic jack.
Hydraulic brake.
Hydraulic ram.
Used as sensor.
Close loop velocity controlling.
Highly precise positioning for heavy loads.

9.  It converts high pressure energy of compressed air into
either linear or rotary motion.
 Quickly respond in operation.
Pneumatic Actuator

10. Mechanical linear actuators typically
operate by conversion of rotary motion
into linear motion.
Screw-jack
Wheel and axle
Cam

11.  Electric actuator is actuated by motor that converts electrical
energy into mechanical torque.
• Solenoid
• Electric motors
• DC servomotors
• AC motors
• Stepper motors
 Electric actuator consists of electric motor, speed reducer,
position limit mechanism and over torque protection
mechanism and position feedback device.

12. A solenoid is a coil wound into a tightly packed helix.
In physics, the term solenoid refers to a long, thin loop of wire,
and wrapped around a metallic core.
Which produces a magnetic field when an electric current
is passed through it.

13. Principle:
 Convert energy into linear motion.
 Magnetic coil and movable armature.
 Coil produce magnetic field that moves the armature.
Application:
Pneumatic valve.
Car door openers.

14.  Every motor works on the principle that when a current-
carrying conductor is placed in a magnetic field, it
experiences a mechanical force.
Working Principle Of Electric Motor

15. DC-Servomotor
Any electrical motor can be utilized as servo motor if it is
controlled by servomechanism. Likewise, if we control a DC
motor by means of servomechanism, it would be referred as DC
servo motor.

16. A.C. Motor
Stepper Motor
A stepper motor is an electromechanical device which converts
electrical pulses into discrete mechanical movements.

17.  Piezoelectric actuator is a device that makes use of the
inverse piezoelectric effect (generates mechanical energy
when subjected to electrical energy).
 Piezoelectric materials are: Quartz, Ceramics, PZT(lead
zirconate titanate).
Advantages:
Short response time.
Ability to create high forces.
Higher displacement accuracy.
High energy efficiency.
Disadvantage:
Have small strains. (0.1-.2%)
High supply voltage needed.(60-1000V)
 Large hysteresis.(actuator doesn’t go back to exactly where it
started).

18. Application
 Hand-blurring correction of
digital cameras.
 Ultra-precise mass-flow
controller.

19. Thermal/ Magnetic Actuator
 These Actuators are actuated by applying thermal or Magnetic
energy.
 These use shape memory materials (shape memory alloys
or magnetic shape-memory alloys).
 They tend to be compact, lightweight, economical and with high
power density.
 MEMS(Micro-Electro-Mechanical Systems) thermal
actuator where small amount of thermal expansion of one part of
the device translates to a large amount of deflection of the overall
device.
 A device is considered to be MEMS device if its size is between
0.1 µm and hundreds of micrometers.
 MEMS Magnetic Actuator is device that uses
microelectromechanical systems (MEMS) to convert an electric
current into a mechanical output.

20.  SMAActuator use SMAs(Shape Memory Alloys) that
contracts 4% or more when heated.
 Usually heat is precisely generated by electrical current.