Bosch Rexroth A4VG series 40 closed-circuit hydraulic pump

The A4VG is a swashplate-design, variable displacement axial piston pump from Bosch Rexroth, intended for the hydrostatic drives of mobile and industrial machines.

Key characteristics at a glance

• Pump type: variable displacement axial piston, swashplate design
• Circuit type: closed circuit (flow returns directly from the motor to the pump inlet)
• Typical application: hydrostatic travel drives and, in some machines, hydrostatic auxiliary drives such as fans, augers and mixer drums
• Pressure class: high-pressure rating in the region of 400 bar nominal with higher peak capability, depending on size (verify in the data sheet)
• Size range: a broad span of displacements from compact to heavy-duty units
• Integrated features: a built-in charge (boost) pump, pressure relief valves, and options for a through drive to mount a second pump

Control Options Explained

Controls are where the A4VG family becomes genuinely flexible. The right control determines how the machine feels to the operator and how it integrates with your electronics. Typical options include the following, though availability depends on size and series, so check the current data sheet.

HD: hydraulic control, pilot-pressure related

A pilot pressure signal moves the swashplate in proportion to its value. It is simple, robust and well suited to machines with a hydraulic joystick or pedal system. If you want fewer electronics and straightforward serviceability, HD is a natural fit.

EP: electro-proportional control

An electric current to proportional solenoids sets the pump displacement. This is the preferred route when a machine controller handles traction control, speed limiting, or automated functions. It also makes it easier to tune ramp-up and ramp-down behavior in software.

DA: automotive (speed-related) control

The DA control makes displacement dependent on engine speed, so the machine behaves like a car: push the throttle and the machine accelerates, release it and engine braking is felt through the drive. A hydraulic inching valve usually accompanies it so the operator can precisely modulate travel speed independent of engine rpm. It is a classic choice for wheel loaders and telehandlers.

EZ: electric two-point control

A simple on/off solenoid selects between two displacements. This suits applications such as fan drives or simple two-speed functions where proportional control is unnecessary.

Manual or lever-operated options

Some variants provide mechanical lever control, used where an electrical or pilot system is not available or not desired.

Where the A4VG Series 40 Is Used

The A4VG earns its reputation in machines that need smooth, strong, controllable travel drive at a reasonable size and cost.

Real-world examples

Wheel loaders. A mid-size wheel loader running a DA-controlled A4VG feeds one or two hydraulic motors on the transmission. The operator gets stepless acceleration, strong breakout torque at low speed, and engine braking on downhill sections, all without a conventional gearbox.

Road rollers and compactors. These machines depend on slow, precise speed control and frequent direction reversals. An EP-controlled pump lets the machine controller hold a steady compaction speed and reverse smoothly at the end of each pass.

Compact track loaders and skid steers. Two pumps (often tandem-mounted through a through drive) each feed a track motor. Independent control of each side gives zero-radius turning and fine maneuverability.

Concrete mixers. A closed-circuit pump drives the drum motor, changing speed and direction for mixing, discharge and cleaning. The pump's response and smoothness reduce shock loads on the drum.

Street sweepers, forestry and agricultural equipment. Any machine needing a continuous, reversible power path from engine to wheels, tracks, brushes or augers is a candidate.

For more information on the A4VG hydraulic pump, please visit https://www.baolilaihydraulic.com/product/.

Specifications

Selection Table

Q1: What is the Bosch Rexroth A4VG series 40 used for?

A1: It is a variable displacement axial piston pump for closed-circuit hydrostatic drives, most commonly the travel drive in wheel loaders, rollers, telehandlers, compact track loaders, mixers, and similar mobile machines.

Q2: Should I repair or replace a worn pump?

A2: If wear is limited to the rotating group and the housing is sound, a professional rebuild with a proper test can be cost-effective. Severe housing damage or repeated failures may justify replacement. Request test-bench data either way.

Q3:How to purchase an A4VG 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 A4VG hydraulic pump?

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