The document discusses the basics of hydraulics including definitions, classifications, formulas, Pascal's law, and the multiplication of forces. It explains how pressure is transmitted undiminished through confined liquids according to Pascal's law. Bramah's press and the law of conservation of energy are also summarized. Practical uses of hydraulics like linear and rotary power transmission are mentioned. The advantages of hydraulics include speed, direction, and force control as well as overload protection. The document concludes by covering topics like how pressure is created, parallel vs series flow paths, principles of flow measurement, laminar vs turbulent flow, and pressure drops due to friction.

2. BASICS OF HYDRAULICS
1) DEFINITIONS
1.1) HYDRAULICS BASIC
DEFINITIONS
1.2) CLASSIFICATION
&
1.2.1) HYDROSTATICS FORMULAE
1.2.2) HYDRODYNAMICS
1.3) FORCE , PRESSURE , AREA
1.4) PASCAL’S LAW
2) MULTIPLICATION OF FORCES
2.1) BRAMAH’S PRESS
2.2) LAW OF CONSERVATION OF ENERGY
3) HYDRAULIC POWER TRANSMISSION
USES OF
3.1) LINEAR ACTUATOR HYDRAULICS
3.2) ROTARY ACTUATOR

3. BASICS OF HYDRAULICS
4) ADVANTAGES OF HYDRAULICS
4.1) SPEED CONTROL
4.2) DIRECTION CONTROL
4.3) FORCE CONTROL
4.4) OVERLOAD PROTECTION ADVANTAGES
OF
4.5) COMPACTNESS
HYDRAULICS
5) HOW PRESSURE IS CREATED
PRACTICAL
DETAILS IN
HYDRAULICS

4.  HYDRAULICS
HYDRO AULUS
( meaning Water ) ( meaning Pipe )
HYDRAULICS :
Work done by fluids in pipes.
H y d r a u lic s is C la s s ife d a s
H Y D R O S T A T IC S H Y D R O D Y N A M IC S

5. HYDROSTATICS
HYDROSTATICS
Eg.:- FORCE
F1
F1 = 1 Kg
A1 = 1 Cm2
P = F1 = 1 Kg
A1 1 Cm2 AREA
A1
= 1 Kg / Cm2
( Same Pressure P )
A2 = 10 Cm2
F2 = P x A2
= 1 x 10 FORCE AREA
F2 A2
= 10 Kg

6. HYDRODYNAMICS
LIQUID AT
HIGH VELOCITY
NOZZLE
TURBINE

7.  IN ORDER TO DETERMINE THE TOTAL FORCE EXERTED
ON A SURFACE WE NEED TO KNOW THE PRESSURE OR
FORCE PER UNIT AREA.
 PRESSURE = FORCE FORCE IN → KILOGRAMS ( Kg )
AREA AREA IN → SQ. CM ( Cm2 )
PRESSURE IN → KILOGRAM / SQ.CM
(Kg / Cm2 )
P = F
A
 FORCE = PRESSURE x AREA
 F
THE ATMOSPHERIC AIR EXERTS UNIFORM PRESSURE
ALL ROUND. THIS PRESSURE IS APPROX. 1 Kg / Cm2 AND
IS DENOTED AS 1 BAR ( BAROMETER ) P A

8. PRESSURE APPLIED ON A CONFINED FLUID IS
TRANSMITTED UNDIMINISHED IN ALL DIRECTIONS AND
ACTS WITH EQUAL FORCE ON EQUAL AREAS AND AT
RIGHT ANGLES TO THEM.
 PRESSURE APPLIED ON A  FRENCH SCIENTIST
PASCAL DISCOVERED
CONFINED FLUID
THIS LAW IN THE
IS TRANSMITTED
17th CENTURY.
 UNDIMINISHED
 IN ALL DIRECTIONS • RELATES TO
USE OF CONFINED FLUID
 ACTS WITH EQUAL IN
FORCE ON EQUAL AREAS ♦ TRANSMITTING
AND POWER
♦ MODIFYING
 AT RIGHT ANGLES TO MOTION
THEM ♦ MULTIPLYING
FORCE.

9. PASCAL’S LAW
FORCE F1
SMALL AREA
A1
PRESSURE
P = F1
P
A1
F2 = P x A2
LARGE AREA
A2
FORCE F2

10. BRAMAH’S PRESS
THIS
HYDRAULIC LEVERAGE PRESSURE
SUPPORTS A
WT OF 100 Kg
10 Kg ON A IF AREA IS
1Cm2 100 kg 10 Cm2
10 AREA PRESSURE
kg DEVELOPED
1Cm2 THROUGHOUT 10 Cm2
IS 10 Kg / Cm2
INPUT THE FORCES ARE PROPORTIONAL OUTPUT
TO THE PISTON AREAS
10 Kg = 100 Kg
1 Cm2 10 Cm2
MECHANICAL LEVERAGE WILL
BALANCE
A LOAD 100 Kg A LOAD OF
10 Kg OF 10 Kg 100 Kg
HERE HERE
10 1

11. LAW OF CONSERVATION OF ENERGY
MOVING THE SMALL PISTON 10 Cm OF LIQUID WILL
10 Cm DISPLACES MOVE LARGER PISTON
1 Cm2 x 10 Cm = 10 Cm3 OF LIQUID ONLY 1Cm.
10 Cm2 x 1 Cm = 10 Cm3
10 Q=Axh 100 kg
1 Cm
kg
1Cm2 10 Cm2
10 Cm
WORK DONE = FORCE x DISTANCE MOVED
W=Fxd
W=Fxd W=Fxd
= 10 Kg x 10 Cm = 100 Kg x 1 Cm
= 100 Kg-Cm = 100 Kg-Cm
 ENERGY CAN NEITHER BE CREATED NOR DESTROYED.
 WHAT IS GAINED BY FORCE IS SACRIFICED IN THE
DISTANCE MOVED.

12. HYDRAULIC POWER TRANSMISSION
LINEAR ACTUATOR
PUMP LOAD
PISTON & ROD
TO RESERVOIR
ROTARY ACTUATOR
HYDRO MOTOR
PUMP

13. ADVANTAGES OF HYDRAULICS
 SPEED CONTROL
PISTON MOVES
MAXIMUM SPEED “X” Cm IN 1 min.
THIS VOL.
(No speed control ) 10 lpm IS 10 Lts.
Q=AxV PUMP
Q  Flow
(Cm3/min)
A  Area
FLOW
( Cm2 ) CONTROL
VALVE
10 lpm
V  Velocity
(Speed control ) PUMP 5 lpm
(Cm/ min )
RELIEF
VALVE
ACTUATOR GETS ONLY
5 LPM AND TRAVELS
“X/2” Cm IN ONE MIN.

14. ADVANTAGES OF HYDRAULICS
 HYDRAULIC DRIVES ARE REVERSIBLE
DIRECTION CONTROL
PUMP RELIEF
VALVE
DIRECTIONAL THE CYLINDER
ROD EXTENDS
VALVE
RELIEF
PUMP VALVE
DIRECTIONAL THE CYLINDER
VALVE ROD RETRACTS

15. ADVANTAGES OF HYDRAULICS
 OVER LOAD PROTECTION
 RELIEF VALVE PROTECTS THE SYSTEM BY MAINTAINING
THE SYSTEM SET PRESSURE.
 ANY INCREASE IN PRESSURE IN SYSTEM IS RELEAVED
TO TANK . ( MOMENTARILY DIVERTING FLOW TO THE
TANK. )
 THUS OVERLOAD PROTECTION IS ACHIEVED.

16. PRESSURE HEAD
PUMP INLET LOCATIONS
PRESSURE HERE IS
OIL LEVEL ABOVE PUMP 0.85 x 100 gm / Cm2
CHARGES INLET 100 Cm = 0.085 Kg / Cm2
PUMP
INLET OUTLET
INLET OUTLET
PUMP
OIL LEVEL BELOW PUMP
REQUIRES VACUUM TO
“LIFT “ OIL 100 Cm THERE MUST BE A VACUUM
EQUIVALENT TO
0.085 Kg / Cm2 TO LIFT THE
OIL
PUMP MECHANISM CREATES
THE LOWER PRESSURE
CONDITION.

17. HOW PRESSURE IS DEVELOPED
NO PRESSURE
PUMP
NO RESTRICTION
RELIEF
VALVE
Set at 100
Kg/Cm2
PRESSURE
BUILDS UP
WITH RESTRICTION PUMP
RELIEF
VALVE
Set at 100
Kg/Cm2
PRESSURE BUILDS
UPTO RELIEF VALVE
SETTING (100 Kg / Cm2)
PUMP
CLOSING
RELIEF
VALVE
Set at 100 Kg/
Cm2

18. PARALLEL FLOW PATHS
10
THE OIL CAN CHOOSE
A
10 BAR OPENS VALVE A
3 PATHS
PUMP
B
20 BAR OPENS VALVE B
C
30 BAR OPENS VALVE C
IF FLOW IS BLOCKED
OIL TAKES THE BEYOND “ A”
PATH OF LEAST 20
RESISTANCE
OIL WILL FLOW
THRO “B” WHEN
PUMP PRESSURE
REACHES 20 BAR

19. SERIES RESISTANCE ADD PRESSURE
P1 = 0
A 0
10 BAR
P2 = ( P1 + 10 )
10
B = 0 + 10
20 BAR = 10 BAR
P3 = ( P2 + 20 )
C 30 = 10 + 20
30 BAR = 30 BAR
P = ( P3 + 30 )
PUMP
60 = 30 + 30
= 60 BAR

20. PRINCIPLES OF FLOW
♦ HOW FLOW IS MEASURED ?
 VELOCITY
 FLOW ( FLOW RATE )
♦ FLOW RATE AND SPEED
♦ FLOW AND PRESSURE DROP
♦ LAMINAR AND TURBULENT FLOW
♦ BERNOULLI’S PRINCIPLE
FLOW IS THE ACTION IN THE HYDRAULIC SYSTEM
THAT GIVES THE ACTUATOR ITS MOTION.
PRESSURE GIVES THE ACTUATOR ITS FORCE , BUT
FLOW IS ESSENTIAL TO CAUSE MOVEMENT.
FLOW IN THE HYDRAULIC SYSTEM IS CREATED BY THE
PUMP
PRESSURE INDICATES WORK LOAD.

21. VELOCITY : IS THE AVERAGE SPEED OF THE FLUID’S
PARTICLES PAST A GIVEN POINT
OR
THE AVERAGE DISTANCE THE PARTICLES
TRAVEL PER UNIT OF TIME.
Unit :m/Sec or m / min ( Metres / Sec or Metres/min )
FLOW RATE : IS THE VOLUME OF FLUID PASSING A POINT
IN A GIVEN TIME.
Unit: Cm3 / min or l / min ( cc / minute or litres / min )
SPEED OF AN ACTUATOR DEPENDES ON THE ACTUATOR
SIZE AND RATE OF FLOW INTO IT.
Q=AxV
FLOW IN Cm3 / min : AREA IN Cm 2 :
VELOCITY IN Cm / min

22. FLOW AND PRESSURE DROP
MAX. PRESSURE SUCEEDINGLY LOWER LEVEL OF LIQUID
HERE BECAUSE SHOWS PRESSURE IS REDUCED AT POINTS
OF THE HEAD OF DOWNSTREAM FROM SOURCE.
THE FLUID
PRESSURE
GRADIENT
FRICTION IN PIPE PRESSURE IS
DROPS PRESSURE ZERO HERE AS
THE FLUID
FLOWS OUT
UNRESTRICTED
DUE TO EFFECT OF FRICTION RECOMMENDED VELOCITY RANGES ARE :
1.) PUMP INLET LINE : 0.6 ~ 1.2 metres / Second
2.) WORKING LINE ( PR. LINES) : 2~6 metres / Second

23. NOR DOES A
GRADUAL
CHANGE IN
LAMINAR FLOW DIRECTION.
LOW VELOCITY FLOW IN A
STRAIGHT PIPE IS STREAMLINED.
THE FLUID PARTICLES MOVE
PARALLEL TO FLOW DIRECTION.
SO DOES AN ABRUPT
TURBULENT FLOW CHANGE IN DIRECTION.
AN ABRUPT
THE FLOW MAY START OUT CHANGE IN CROSS-
STREAMLINED. SECTION MAKES IT NON PARALLEL PATHS OF PARTICLES
TURBULENT. INCREASE RESISTANCE TO FLOW.