- What is the difference between a fixed displacement pump and a variable displacement pump?
HAWE Hydraulik variable displacement pump
The displacement of a pump is defined by the volume of fluid that the gears, vanes or pistons will pump in one rotation. If a pump has a capacity of 30 cm3, it should treat 30 ml of fluid in one rotation.
- With a fixed displacement pump, it is impossible to vary the amount of fluid at each rotation.
- With a variable displacement pump, it is possible to set the amount of fluid pumped at each rotation.
The main advantage of being able to vary the displacement of a pump is to save energy when the circuit does not require the pump’s maximum power.
Piston and vane pumps are available in fixed and variable displacement versions. Gear pumps are only available with fixed displacement.