Rexroth A4VBO swashplate variable displacement hydraulic pump

The A4VBO is an axial piston variable displacement pump built in swashplate design, manufactured by Bosch Rexroth for open-circuit hydrostatic drives.

Control Options: Where the A4VBO Sets Itself Apart

Raw hydraulic output is only half the story. What actually distinguishes the A4VBO in a specification meeting is its control flexibility, particularly on the electronic side.

HS5 Electro-Hydraulic Control

The HS5 control system pairs a proportional or servo valve with a position transducer, feeding continuous displacement feedback into Rexroth's control electronics (commonly VT-HPC-series controllers). This enables:

Electric displacement and pressure control — the operator or machine controller sets a target, and the pump tracks it in closed loop, independent of load fluctuations.

Torque limitation — the control actively caps torque draw, protecting the prime mover, coupling, and downstream drivetrain from overload events.

Load matching — output is trimmed to actual demand rather than run at full displacement and throttled downstream, which is where real efficiency gains show up on the utility bill.

HM2C Digital Control

For applications standardizing on Rexroth's digital electro-hydraulic control ecosystem, the HM2C option integrates a control valve with digital control logic, suited to machines already built around Rexroth's broader automation platform.

LR2 Mechanical Power Controller

Not every application needs — or can afford — full digital control. The LR2 is a mechanically adjustable power controller, giving a simpler, lower-cost path to power limitation for machines where electronic integration isn't justified.

Typical Applications

The A4VBO shows up wherever high pressure and controllable power delivery matter simultaneously:

Hydraulic presses and forming equipment — where peak force requirements push system pressure toward 450–500 bar

Injection molding machines — precise displacement control translates directly into repeatable shot control

Test rigs and simulation benches — closed-loop pressure and flow control lets engineers replicate demanding load cycles accurately

Heavy industrial mobile equipment — where power density per unit of pump weight and volume is a real constraint

Installation and Maintenance Considerations

A pump operating at 450–500 bar leaves less margin for error than a standard mid-pressure unit, so a few practices matter more here than they would elsewhere:

1. Respect the suction pressure window. Staying within the 5–30 bar absolute inlet range prevents cavitation on one end and seal or bearing overload on the other.

2. Verify control calibration after any electronics swap. Because the HS5's closed-loop behavior depends on accurate position-transducer feedback, a miscalibrated sensor can produce displacement errors that look like a mechanical fault but aren't.

3. Monitor case drain temperature and flow. At high pressure, internal leakage translates into more heat; case drain readings are an early warning system for wear before it becomes a failure.

4. Use Rexroth-specified fluid cleanliness targets. High-pressure axial piston pumps are far less tolerant of particulate contamination than lower-pressure gear or vane pumps — this is where most premature failures actually originate.

For more information on the A4VBO hydraulic pump, please visit https://www.baolilaihydraulic.com/product/.

Specifications

Selection Table

Q1: Is the A4VBO suitable for closed-circuit hydrostatic drives?

A1: No. It's purpose-built for open-circuit applications. Closed-circuit drive requirements are typically served by the A4VG or A4VSG series instead.

Q2: What sizes does the A4VBO come in?

A2: Four frame sizes: 71, 125, 250, and 450, referring to geometric displacement in cm³ per revolution.

Q3: How to purchase an A4VBO hydraulic pump?

A3: You can visit https://www.baolilaihydraulic.com/contact/ to contact us and purchase our products through various methods.

Q4: What is the price and delivery time of the A4VBO hydraulic pump?

A4:The specific price and delivery time will be provided based on the specific model you provide.