1. Fluid Power Control

2. Module:03 ~ Hydraulic SYSTEM COMPONENTS
FLUID POWER
Module:03 ~ Hydraulic SYSTEM COMPONENTS
Sources of Hydraulic Power
Construction and working of pumps – Variable displacement pumps
Actuators:
Hydraulic cylinders, performing linear motion
Hydraulic motors, performing continuous rotary motion
Hydraulic rotary actuators, performing limited angular
Control Components:
Direction control valve
Flow control valves
Electrical control -- solenoid valves. Relays, Accumulators and Intensifiers.

3. It performs useful work.
Hydraulic ACTUATORS
FLUID POWER
Actuators
ENERGY OF
FLUID
MECHANICAL
ENERGY
It performs useful work.

4. Linear actuator: For linear actuation (hydraulic cylinders).
Hydraulic ACTUATORS
FLUID POWER
CLASSIFICATION:
Linear actuator: For linear actuation (hydraulic cylinders).
2. Rotary actuator: For rotary actuation
(hydraulic motor).

5. Linear actuator: Hydraulic Cylinders Barrel Base / Cap Head
Hydraulic ACTUATORS
FLUID POWER
Linear actuator:
Hydraulic Cylinders
TERMINOLOGY:
Barrel
Base / Cap
Head
Piston / Rod
Seal Gland
Tie Rod
Ports
ROD END
BLANK END
TYPES:
Single-acting cylinders.
Double-acting cylinders.

6. Retraction is done either by gravity or by a spring.
Hydraulic ACTUATORS
FLUID POWER
Linear actuator:
Hydraulic Cylinders ~ single acting
Graphic Symbol implies how a component operates / functions without showing any of its constructional details.
It facilitates circuit analysis.
It helps in trouble-shooting.
Retraction is done either by gravity or by a spring.

7. It makes cylinder more productive.
Hydraulic ACTUATORS
FLUID POWER
Linear actuator:
Hydraulic Cylinders ~ double acting
TYPES:
Piston rod on one side
Piston rod on both side.
It makes cylinder more productive.

8. Cylinder Cushion Hydraulic ACTUATORS
FLUID POWER
Cylinder Cushion
To prevent shock due to stopping loads at the end of the piston stroke.
When the cylinder piston is actuated, the fluid enters the cylinder port and flows through the little check valve.
At the end of retraction stroke, an exhaust fluid is forced to go through an adjustable needle valve that is set to control the escaping fluid at a given rate.

9. Cylinder Cushion :: Graphical Representation
Hydraulic ACTUATORS
FLUID POWER
Cylinder Cushion :: Graphical Representation

10. Cylinder Force, & Velocity
Hydraulic ACTUATORS
FLUID POWER
Cylinder Force, & Velocity
Extension Stroke:
VELOCITY FORCE

11. Cylinder Force, & Velocity
Hydraulic ACTUATORS
FLUID POWER
Cylinder Force, & Velocity
Retraction Stroke:
VELOCITY FORCE
ret
ret

12. Hydraulic ACTUATORS
FLUID POWER
… and Power

13. Hydraulic ACTUATORS
FLUID POWER
Exercise: 01
A cylinder is required to move a 10 kN load 150 mm in 0.5 s. What is the output power?
What cylinder size is required to achieve the above speed in a system with a flow rate of 60 LPM?
Answer: 3 kW, 65 mm

14. Hydraulic ACTUATORS
FLUID POWER
Exercise: 02
An 8 cm diameter hydraulic cylinder has a 4 cm diameter rod. If the cylinder receives flow at 100 LPM and 12 MPa, find the (a) extension and retraction speeds and (b) extension and retraction load carrying capacities.
Answer: m/s , m/s , kN, kN

15. Hydraulic ACTUATORS
FLUID POWER
Exercise: 03
A cylinder with a bore of 150 mm and a piston rod diameter of 105 mm, has to extend with a speed of 7 m/s, pressure applied is 150 bar. Calculate
(a) The flow rate in LPS of oil to extend the cylinder
(b) The flow rate in LPS from annulus side to extend the cylinder.
(c) The retract speed in m/s using (a).
(d) The flow rate from full bore end on retract.
Answer: LPS, 63 LPS, m/s, LPS

16. Vertical Piston-Cylinder to lift a load:
Hydraulic ACTUATORS
FLUID POWER
Hydraulic Cylinder carrying a load:
Vertical Piston-Cylinder to lift a load:

17. Horizontal Piston-Cylinder to displace a load:
Hydraulic ACTUATORS
FLUID POWER
Hydraulic Cylinder carrying a load:
Horizontal Piston-Cylinder to displace a load:

18. Inclined Piston-Cylinder to displace a load:
Hydraulic ACTUATORS
FLUID POWER
Hydraulic Cylinder carrying a load:
Inclined Piston-Cylinder to displace a load:

19. Hydraulic Cylinder carrying a load:
Hydraulic ACTUATORS
FLUID POWER
Hydraulic Cylinder carrying a load:
Exercise: 04
A 6000 N weight is to be lifted upward in a vertical direction for the system shown in Figure. Find the cylinder force required to
(a) Move the weight at a constant velocity of 1.75 m/s.
(b) Accelerate the weight from zero velocity to 1.75 m/s in 0.5 s.

20. Hydraulic Cylinder carrying a load:
Hydraulic ACTUATORS
FLUID POWER
Hydraulic Cylinder carrying a load:
Exercise: 05
A N weight is to be lowered by a vertical cylinder as shown in the figure. The cylinder has a 75 mm diameter piston and 50 mm diameter rod. The weight is to decelerate from 100 m/min to a stop in 0.5 s. Determine the required pressure in the rod end of the cylinder during the deceleration motion.

21. It permits versatility in anchoring of cylinders.
Hydraulic ACTUATORS
FLUID POWER
Linear actuator:
Hydraulic Cylinders ~ mountings
It permits versatility in anchoring of cylinders.

22. Hydraulic Cylinders ~ mountings
Hydraulic ACTUATORS
FLUID POWER
Linear actuator:
Hydraulic Cylinders ~ mountings
Things which controls the choice of right mountings:
The specific application out of the wide varieties.
The force applied is tensile or compressive.
The bucking load.
Alignment of the rod with the resistive load.

23. Hydraulic Cylinders ~ mountings
Hydraulic ACTUATORS
FLUID POWER
Hydraulic Cylinders ~ mountings
Piston Rod Buckling:
Euler’s formula states that:
L is the free (equivalent) buckling length (cm) depending on –
The method of fixing the cylinder and piston rod.
The maximum distance between the fixing points, that is, when the cylinder fully extended.

24. Hydraulic Cylinders ~ mountings
Hydraulic ACTUATORS
FLUID POWER
Linear actuator:
Hydraulic Cylinders ~ mountings
Types of Mountings:
1. Foot mounting
2. Rod-end flange or front flange mounting
3. Rear flange, back flange or head-end flange mounting
Trunnion mounting
Clevis Mounting

25. Hydraulic Cylinders ~ mountings
Hydraulic ACTUATORS
FLUID POWER
Linear actuator:
Hydraulic Cylinders ~ mountings
Tie Rods
The head / cap are connected to the body (barrel) by means of threading, bolts, or tie rod.

26. Hydraulic Cylinders ~ mountings
Hydraulic ACTUATORS
FLUID POWER
Linear actuator:
Hydraulic Cylinders ~ mountings
LUGS
FLANGES
Used when the cylinder is loaded mainly by thrust force (tension or compression)

27. Hydraulic Cylinders ~ mountings - TRUNNION
Hydraulic ACTUATORS
FLUID POWER
Linear actuator:
Hydraulic Cylinders ~ mountings - TRUNNION
It  is a cylindrical protrusion used as a mounting and/or pivoting point. It is one part of a rotating join where a shaft (the Trunnion) is inserted into (and turns inside) a full or partial cylinder.

28. Riverine Lock Gate; Trunnion Mounted Hydraulic Cylinders
FLUID POWER
Hydraulic ACTUATORS
Linear actuator:
Hydraulic Cylinders ~ mountings
Riverine Lock Gate; Trunnion Mounted Hydraulic Cylinders
TRUNNION: It allows angular movement of the cylinder.

29. It is a fastener system consisting of a clevis, clevis pin & tang.
Hydraulic ACTUATORS
FLUID POWER
Linear actuator:
Hydraulic Cylinders ~ mountings - CLEVIS
It  is a fastener system consisting of a clevis, clevis pin & tang.
The combination of a simple clevis fitted with a pin is commonly called a shackle.

30. Hydraulic Cylinders ~ mountings - CLEVIS
Hydraulic ACTUATORS
FLUID POWER
Linear actuator:
Hydraulic Cylinders ~ mountings - CLEVIS

31. Hydraulic Cylinders ~ mountings
Hydraulic ACTUATORS
FLUID POWER
Hydraulic Cylinders ~ mountings
Piston Rod Buckling:
Euler’s formula states that:
L is the free (equivalent) buckling length (cm) depending on –
The method of fixing the cylinder and piston rod.
The maximum distance between the fixing points, that is, when the cylinder fully extended.

32. Leq = l Leq = 2l Leq = l Leq = l/2
Hydraulic ACTUATORS
FLUID POWER
Hydraulic Cylinders ~ mountings
Piston Rod Buckling:
Leq = l
Leq = 2l
Leq = l
Leq = l/2
Center trunnion mounted, Load guided pivoted.
Rear pivot and Load guided & pivoted.
One end rigidly fixed, free load.
One end rigidly fixed, load is guided.

34. Application of cylinder through mechanical linkage
Hydraulic ACTUATORS
FLUID POWER
Application of cylinder through mechanical linkage

35. Application of cylinder through mechanical linkage
Hydraulic ACTUATORS
FLUID POWER
Application of cylinder through mechanical linkage
First class lever

36. Application of cylinder through mechanical linkage
Hydraulic ACTUATORS
FLUID POWER
Application of cylinder through mechanical linkage
Mechanics of cylinder loading used in first-class lever systems
Note 1: If L1> L2, the cylinder force is less than the load force and the cylinder stroke is greater than the load stroke.
Note 2: If the inclination of cylinder is less than 10o,its effect can be ignored in equation

37. Application of cylinder through mechanical linkage
Hydraulic ACTUATORS
FLUID POWER
Application of cylinder through mechanical linkage
Second class lever

38. Hydraulic ACTUATORS Application of cylinder through mechanical linkage
FLUID POWER
Application of cylinder through mechanical linkage
Mechanics of cylinder loading used in second-class lever systems
Note 1: Comparison with the first-class lever. Second-class lever requires smaller cylinder force, a smaller size (lesser diameter) cylinder can be used.
Note 2: Compared to the first-class lever, the second-class lever also results in a smaller load stroke for a given cylinder stroke.

39. Application of cylinder through mechanical linkage
Hydraulic ACTUATORS
FLUID POWER
Application of cylinder through mechanical linkage
Third class lever

40. Hydraulic ACTUATORS Application of cylinder through mechanical linkage
FLUID POWER
Application of cylinder through mechanical linkage
Mechanics of cylinder loading used in third-class lever systems
Note 1: In a third-class lever system, cylinder force is greater than load force.
Note 2: Reason of using this lever system is to produce larger load stroke than cylinder stroke at the expense of a larger cylinder diameter.

41. Exercise: 06 Hydraulic ACTUATORS
FLUID POWER
Exercise: 06
For the system given in figure, determine the force required to drive a 1000 N load.
Answer: 1250 N

42. Exercise: 07 Hydraulic ACTUATORS
FLUID POWER
Exercise: 07
For the crane system, determine the hydraulic cylinder force required to lift a 2000 N load.
Answer: 6600 N

43. Four positive positions with two cylinders
Hydraulic ACTUATORS
FLUID POWER
Application of cylinder through mechanical linkage
Four positive positions with two cylinders

44. Toggle: ..\video\Spring toggle mechanism 8.mp4
Hydraulic ACTUATORS
FLUID POWER
Application of cylinder through mechanical linkage
Toggle: ..\video\Spring toggle mechanism 8.mp4

45. Rack moving perpendicularly to the cylinder
Hydraulic ACTUATORS
FLUID POWER
Application of cylinder through mechanical linkage
Rack moving perpendicularly to the cylinder

46. Motion transfer to a distant port
Hydraulic ACTUATORS
FLUID POWER
Application of cylinder through mechanical linkage
Motion transfer to a distant port

47. Fast rotary motion using steep screw nut
Hydraulic ACTUATORS
FLUID POWER
Application of cylinder through mechanical linkage
Fast rotary motion using steep screw nut

48. Application of cylinder through mechanical linkage
Hydraulic ACTUATORS
FLUID POWER
Application of cylinder through mechanical linkage
A single-sprocket wheel produces rotation in the plane of motion

49. Application of cylinder through mechanical linkage
Hydraulic ACTUATORS
FLUID POWER
Application of cylinder through mechanical linkage
A double-sprocket wheel produces more nearly continuous rotational motion

50. Application of cylinder through mechanical linkage
Hydraulic ACTUATORS
FLUID POWER
Application of cylinder through mechanical linkage
TRAMMEL PLATE