2. 1. Hydraulic accumulator
2. Hydraulic intensifier
3. Hydraulic press
4. Hydraulic crane
5. Hydraulic lift
6. Hydraulic ram
7. Hydraulic jack
8. Fluid coupling
9. Torque converter
Introduction
The function of this machine is to store the energy
and to transmit it through an incompressible fluid
like water or oil.
In this chapter following machine are discussed
4. Hydraulic accumulator
Which store or accumulate the energy of fluid under
pressure when it is not needed and supplies the energy
when need arises.
It works like a fly wheel of an engine, electric storage
batteries.
In descending position of ram no energy is required.
It takes a more time to put the machine in operation.
The stored energy is used to run hydraulic machine like
hydraulic crane, hydraulic lift, etc.
5. Differential Hydraulic accumulator
The main disadvantage of a simple
hydraulic accumulator is that heavy
weight are required on a ram to
store the fluid under very high
pressure.
6. Hydraulic Intensifier
For transforming hydraulic
power at low pressure into a
reduced volume at higher
pressure
Which is used for increasing the
intensity of pressure by utilizing
the energy of the large quantity
fluid.
7. Hydraulic Press
A hydraulic press is used to lift heavy load with the application of much
smaller force
It works on the basis of pascal’s principle.
10. Hydraulic Crane and Lift
The function of jigger is to
raise or lower a load.
The jigger can be used either
vertical, horizontal or
inclined position.
13. Hydraulic ram
Hydraulic ram is a hydraulic device which is used to lift
a small quantity of water to a greater height using the
energy of a large quantity of water available
comparatively at low heads.
The efficiency of the hydraulic ram depends upon
Losses in pipe
Losses in valve box
Ratio of length of supply pipe to delivery head (l/H), &
ratio of supply head to delivery head(h/H)
For optimum performance
l/H = 2.5
h/H = 5
15. Advantages
It has no moving parts. No lubrication is needed.
It does not need any external power.
Repair and maintenance cost is negligible.
Disadvantages
Wastage of water is high.
It makes a lots of noise.
17. Fluid Coupling
It is used to transmit the power and is combination of
a centrifugal pump and turbine, pump act as a driver
and turbine as a driven.
At full speed, the two shaft are supposed to be rotating
at the same speed, because of slip, driven shaft speed is
less about 2%.
Efficiency of the coupling is 98%.
19. Torque converter
In torque converter third component is added stator
between the pump impeller and turbine rotor.
The function of the runner is to change the direction of
flow.
The efficiency of the torque converter lies between the 85 to
87 %.
Torque converter gives the higher efficiency at the low speed
ratio as compared to fluid coupling. There is decrease in
efficiency when the speed ratio increases from 0.5 to 0.6
Use combination of torque converter and fluid coupling for
efficient performance over the full range of speed ratio. In
that case, as soon as the output torque becomes equal to the
input torque, the fixed guide vane(stator) start rotating and
combination start working in a fluid coupling.
