2. Module 1
•Introduction to fluid power:
-Classification of fluid power systems
- Basic components, symbols & circuits of a hydraulic and
pneumatic system,
-Properties of fluids
•Hydraulic fluids and fluid handling components:
-Fluid for hydraulic systems
-Hydraulic fluid reservoirs
- Hydraulic seals
- Filters
-Strainers
3. •The fluid power systems are power transmitting assemblies
employing the pressurized liquid or a pressurized gas to transmit
energy from an energy generating source to energy usable area
especially in a cold condition.
•It is a technology which deals with generation, control and
transmission of power using pressurized fluid.
•Popularity of fluid power system in industries because:
-Ability to multiply the force or a pressure is possible
-Flexibility to change the direction very quickly,
- Very precise movements and occupies a less space as
compared to other two power transmission elements.
What is Fluid power systems?
4. •Fluid power is called hydraulics when the fluid is a liquid and is called
pneumatics when the fluid is a gas.
•Thus fluid power is the general term used for both hydraulics and
pneumatics.
•Hydraulic systems use liquids such as petroleum oils, synthetic oils, and
water.
Types of fluid systems: (i) fluid transport (ii) fluid power.
•Fluid transport systems – To deliver a fluid from one location to another to
accomplish some useful purpose.
•Example: pumping stations for pumping water to homes
•Fluid power systems are designed specifically to perform work.
•The work is accomplished by a pressurized fluid.
•A fluid cylinder produces a force resulting in linear motion, whereas a
fluid motor produces a torque resulting in rotary motion.
•Thus in a fluid power system, cylinders and motors (which are also called
actuators)..
5.
6.
7.
8.
9. Governing laws
9
e) Continuity
b) Pascals’s law
g) Bernoulli
equation
f) Flow resistance
a) Hydrostatic pressure c) Transmission of power
d) Transmission of
pressure
10. MULTIPLICATION OF FORCE (PASCAL’S LAW)
•Pressure applied to a confined fluid is transmitted undiminished in all directions
throughout the fluid and acts perpendicular to the surfaces in contact with the fluid.
Px=Py=Pz
11. As shown, a downward input force F1 is applied to
the small-diameter piston 1, which has an area
A1.This produces an oil pressure p1 at the bottom
of piston 1.This pressure is transmitted through the
oil to the large-diameter piston 2, which has an area
A2.The pressure p2 at piston 2 pushes up on the
piston to create an output force F2.
•By Pascal’s law, p1 p2. Since pressure equals
force divided by area, we have
•Thus, a force multiplication occurs from the input to the output of the jack if the
output piston area is greater than the input piston area.
•The force multiplication ratio F2/F1 equals the piston area ratio A2/A1.
12. •The cylindrical volume of oil displaced by the input piston equals the cylindrical
volume displaced by the output piston:
It should be noted that in a real hydraulic jack, friction between the piston and
cylindrical bore surface will produce frictional energy losses. This causes the
actual output energy to be less than the input energy.
Thus the above equation states that the energy input to the hydraulic jack equals
the energy output from the jack.
