PUMPS

1
PUMPS
2
Used to create flow

• Converts mechanical energy into hydraulic energy
• Heart of hydraulic system

3
Positive Displacement Pump

• Piston pump, Gear pump, Vane pump
• Cyclic in nature
• Pumping is done by trapping a liquid in a pumping
  chamber
• Volume changes during pumping cycle
• Large pressure low flow rate
• As fluid moves volume increases and finally
  reduces
• Pulsations in output

4
Positive Displacement Pump

• Volume of fluid pumped depends on no. of cycles
  per unit time
• Without restriction on downstream pump transfer
  very small amount of fluid
• Positive pressure is created only when a
  restriction is encounter
• Fluid enters and leaves pump at same velocity
  hydrostatic power generators

5
Advantages of PDP

• Generates very high pressure (up to 400 bars)
• Small size and high P/W ratio
• High volumetric efficiency

6
Disadvantages of PDP

• More no. of moving parts so high cost
• Maintenance cost
• Less reliable

7
Non-Positive Displacement Pump

• Centrifugal pump, propeller pump
• Continuous flow
• Flow is created due to inertia imparted by the
  impeller on fluid
• Low pressure high volume
• Fluid moves against system resistance
• Impeller imparts kinetic energy to fluid
  hydro-kinetic power generators

8
Non-Positive Displacement Pump

• Centrifugal pump- rotational inertia
• Propeller pump- translation inertia
• Volume of fluid pumped depends on the speed of
  rotation system resistance
• Inlet and outlet passages are connected so not
  self priming
• Installed below fluid level

9
Advantages of NPDP

• Low cost
• Less maintenance
• Silent operation
• Pulsation free output
• High reliability

10
PD pump classification
11
Advantages of rotary over reciprocating

• High P/W ratio
• Direct coupling to electric motor

12
GEAR PUMP
13
GEAR PUMP

• Construction
• Working
• Problem with trapped Oil
• Axial Seal
• Radial Seal
• Duo Pump

14
Construction
15
GEAR pump

• Manufacturing requirement
• 0.025 mm dia clearance
• 20 involute teeth
• 11 to 15 no.of teeth
• Multi gear pump
• Herringbone Gear Pump
• Internal Gear Pump