29. A hydraulic hose is a high-pressure, synthetic
rubber, thermoplastic or Teflon reinforced hose
that carries fluid to transmit force within hydraulic
machinery
3.Hydraulic hose
29
39. • Positive displacement
pump (Gear Pump): a
specific amount of fluid
passes through the pump
for each rotation
• Centrifugal pump (Vane
Pump): no specific
amount of fluid flow per
rotation; flow depends on
speed of blades
39
43. • Displacement relates to how the output of the pump reacts to
system loads
– Non-positive-displacement pumps produce flow variations
due to internal slippage.
– Positive-displacement pumps produce a
constant output per cycle
43
44. • A non-positive-displacement pump has large
internal clearances
– Allows fluid slippage in the pump
– Results in varying flow output as system load varies
44
45. Key Feature of a V-Displacement
Pump
• Fixed Displacement Pump
–A fixed volume of fluids
will be provided in each
revolution
Variable Displacement
Pump
_The volume of supplying
fluids may be change
based on demands
45
71. If the pump is the heart of a hydraulic system then
the valve is the brain.
Valves are used to perform a large variety of
governing and controlling functions.
Valves
Function:
• pressure control valves
• flow control valves
• check valves (non-return valves)
• directional control valves
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73. Form:
a) Spherical
b) c) d) e) Conical
f) Plate
g) Spool valve
Poppet
valve
Aspects of classification
73
74. Flow valvesBasics:
The velocity of hydraulic cylinders can be influenced by the flow rate.
This can be done by an adjustable pump or by a flow rate control valve.
The flow rate is changed by changing an orifice surface area or by changing the
pressure difference on a resistance or dividing the flow rate.
Advantages of flow valves
are:
simplicity
safe operation
good dynamic behaviour
precision
Disadvantage:
the relatively high energy losses
Types:
Restrictor valves (throttle valves)
Flow control valves
Flow dividing valves
74
143. ACTUATORS
Hydraulic actuators convert the fluid power
from the pump into mechanical work.
A hydraulic cylinder is a linear actuator.
A hydraulic motor is a rotary actuator.
143
153. HYDRAULIC MOTORS
The function of hydraulic motors is the
opposite of hydraulic pumps:
Pump
It draws in oil and displaces it, converting mechanical force
into fluid force.
Motor
Oil under pressure is forced in and spilled out, converting
fluid force into mechanical force.
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