FLUID POWER DRIVES

Which among the following pumps have a definite amount of discharge?

• Positive displacement pumps

• Non-positive displacement pumps

• Self-priming pumps

• Jet pumps

Pumps used in hydraulic applications are

• Positive displacement pumps

• Variable displacement pumps

• Fixed displacement pumps

• All the above

Volumetric efficiency is the ratio of

• Theoretical flow rate to actual flow rate

• Actual flow rate to theoretical flow rate

• Actual fluid power to pump input power

• None of the above

Which of the following is a hydrodynamic pump?

• Vane pump

• Gear pump

• Centrifugal pump

• Piston pump

What causes suction of fluid into the gear pump?

• when pressure drops during disengagement of teeth at the suction side

• when pressure increases during disengagement of teeth at the suction side

• when pressure drops during engagement of teeth at the suction side

• when pressure increases during engagement of teeth at the suction side

Variable displacement pumps used in hydraulic applications can

1. have variable flow rate

2. consume less energy

3. be operated with high accuracy for slow and rapid motion

4. generate more heat

• 1 and 2

• 3 and 4

• 1, 2 and 3

• All the above

Which type of displacement is observed in gear pumps?

• Only variable displacement

• Only fixed displacement

• Both fixed and variable displacement

• None of the above

What prevents the leakage of oil inside an unbalanced vane pump?

• Vanes

• Screw

• Cylindrical rotor

• Difference between pressure of inlet and outlet

Which among the following are not the main selection criteria for selection of hydraulic pumps?

• Discharge

• Pressure

• Speed

• Weight

Which force causes vanes to come out of the rotor slots?

• Centripetal force

• Centrifugal force

• Friction force

• None of the above