Axial piston variable pumps are commonly used in hydraulic systems to provide precise control of fluid pressure and flow. В этом посте, we’ll explain how these pumps work in plain language so they’re easy to grasp.
How Axial Piston Variable Pump A4VG Work?
Axial piston pumps use a rotating cylinder block containing several pistons to pressurize fluid. As the cylinder block rotates, the pistons stroke in and out to draw in fluid then push it out under pressure.
The A4VG pump has a swash plate that can be tilted at different angles to vary the stroke length of the pistons, changing the pump’s displacement and thus its output. At maximum tilt, the pistons stroke fully and the pump produces maximum flow and pressure.
When the swash plate is leveled, the pump is at minimum displacement and output. This variable displacement design allows axial piston pumps to match their output to the hydraulic system’s needs.
Key Features For Аксиально-поршневой регулируемый насос A4VG
Some key features of axial piston variable pumps like the Bosch Rexroth A4VG include:
- High efficiency – Because fluid enters and exits the pump in a continuous flow, axial piston pumps achieve high volumetric and mechanical efficiency.
- Good controllability – The swash plate mechanism provides precise displacement control and fast response to changes in demand.
- Quiet operation – Axial piston pumps produce less noise than other pump types.
- Compact design – The axial layout allows for a smaller footprint than comparable radial piston pumps.
- Long service life – The design offers durability, with minimal wear between rotating and stationary parts.
Axial Piston Variable Pump – Variants And Specifications
Axial piston variable pumps come in a range of variants based on displacement, pressure and hydraulic flow rate. The Bosch Rexroth A4VG series includes models with:
- Maximum displacements from 31 к 280 cubic centimeters per revolution (куб.см/об)
- Maximum operating pressures from 207 к 344 бар (3,000 к 5,000 пси)
- Flow rates ranging from 16 к 700 liters per minute
- Speeds up to 4,500 об/мин
- Integral relief valves to protect the system from overpressure
Not all axial piston pumps are variable displacement. Some designs have a fixed displacement to provide continuous high flow at a set pressure. Однако, variable displacement pumps are more commonly used due to their efficiency and control.
Benefits Over Other Pump Types
Compared to gear pumps or vane pumps, axial piston variable pumps offer several advantages:
- Higher pressure capability – They can produce operating pressures up to 5,000 psi or more.
- Better efficiency – Axial piston pumps achieve volumetric efficiencies around 95%, while gear pumps are around 85%.
- More precise control – The swash plate provides accurate displacement adjustment for varying hydraulic demand.
- Longer life – There is less contact between rotating and stationary parts, reducing wear over time.
- Quieter operation – The linear piston motion creates less noise than oblique gear or vane movements.