Bosch Rexroth A10VG63 closed circuit variabel hydraulic pump

The A10VG63 is a swashplate-type axial piston variable displacement pump, engineered specifically for closed-circuit hydrostatic transmissions. "Closed circuit" here means the pump and the motor(s) it drives are connected in a loop — oil returns from the motor directly back to the pump's low-pressure side rather than draining to a reservoir — with a small boost (charge) pump topping off losses and providing control oil.

How the A10VG63 Works

Swashplate Design and Variable Displacement

Like other axial piston pumps in its class, the A10VG63 uses a rotating cylinder block with pistons arranged parallel to the drive shaft. A swashplate — mounted at an adjustable angle — forces the pistons to stroke in and out as the block rotates, drawing in and discharging hydraulic fluid. The genius of the variable-displacement design is that the swivel angle of the swashplate directly controls output flow: at zero angle, output is zero even while the shaft keeps turning; as the angle increases, flow rises smoothly up to the maximum.

Because the swashplate can pivot through the neutral position and into the opposite angle, the pump doesn't just modulate flow — it reverses it. That's what allows a single A10VG63 to drive a hydraulic motor forward, through neutral, and into reverse without any directional valving, which is exactly what a hydrostatic drivetrain needs.

Closed-Circuit Architecture and the Integrated Boost Pump

In an open circuit, a pump pulls from a tank and a valve routes flow to the actuator. In a closed circuit, the pump's two working ports (A and B) connect straight to the motor's ports, and flow just changes direction between them depending on which way the swashplate is swung. Because there's no tank in that loop to make up for internal leakage, the A10VG63 carries an integrated boost (charge) pump that continuously replenishes the low-pressure side and supplies the pilot oil that operates the swashplate control.

Two high-pressure relief valves sit on the A and B ports. They protect the pump and motor from pressure spikes, and — cleverly — they also double as boost/anti-cavitation valves, refilling the low-pressure side of the loop during rapid direction changes or overrunning loads.

Control Options

One of the reasons the A10VG63 shows up in so many different machines is the breadth of control heads Rexroth offers on the same base pump:

MD — mechanical pivot control (smaller frame sizes only)

HD — hydraulic control, pilot-pressure related

HW — hydraulic control via mechanical servo lever

DG — direct-operated hydraulic control

DA — speed-related (automotive-style) control, which generates pilot pressure proportional to engine speed for anti-stall, load-sensing behavior

EP — electric control with proportional solenoids, ideal for electrohydraulic and BODAS-based systems

EZ — electric two-position (on/off) switching control

This modularity means an OEM can spec the same core pump for a joystick-controlled skid steer, a foot-pedal-operated combine, or an electronically managed forestry machine, just by changing the control cartridge.

Where the A10VG63 Is Used

Because it's a closed-circuit pump with a wide displacement range and robust pressure rating, the A10VG63 tends to show up wherever a machine needs a hydrostatic travel or working drive rather than a simple hydraulic actuator.

Example 1: Agricultural Machinery

Combine harvesters and self-propelled sprayers often use an A10VG63 as the primary travel drive pump, paired with a hydrostatic motor at the wheels or tracks. The DA (speed-related) control is especially common here, because it lets the engine's speed automatically govern how much power goes to propulsion versus the header or other implements — protecting the engine from stalling under combined load.

Example 2: Forestry and Logging Equipment

Feller-bunchers, forwarders, and log skidders need high torque at low speed to move through rough terrain, plus the ability to reverse direction constantly. The A10VG63's closed-loop design and reversible flow make it a natural fit for track or wheel drive circuits on this kind of equipment.

Example 3: Cranes and Mobile Lifting Equipment

On mobile cranes, the A10VG63 frequently drives slewing or travel functions where smooth, proportional, reversible control is critical — a sudden direction change on a loaded crane isn't something you want a valve bank handling on its own.

Example 4: Marine Propulsion and Winches

The pump's sealed, closed-loop nature also suits marine applications like propulsion drives and hydraulic winches, where contamination control and consistent charge pressure matter for reliability in a harsh operating environment.

Installation and Maintenance Considerations

A few practical points that matter more than people expect when they're specifying or servicing an A10VG63:

Fluid cleanliness is non-negotiable. Rexroth specifies ISO 4406 cleanliness class 20/18/15 as a minimum, tightening to 19/17/14 at high fluid temperatures. Axial piston pumps have tight internal clearances between pistons, cylinder bores, and the swashplate — contamination is the single biggest killer of service life.

Viscosity window matters as much as oil grade. The optimal operating viscosity is 16–36 mm²/s; going outside that range, especially during cold starts, accelerates wear even with the "right" oil in the tank.

Boost pressure and case drain pressure need monitoring. Because the boost pump feeds both the loop and the control system, low boost pressure shows up as sluggish or erratic control response before it shows up as anything more obvious.

Installation position affects air bleeding and filling. Rexroth documents specific below-tank and above-tank mounting positions, each with a defined bleed and fill port — getting this wrong on commissioning is a common source of early cavitation damage.

Mind the maximum case drain pressure on the shaft seal. Sustained case pressure above the recommended limit shortens shaft seal life significantly, and it's an easy thing to overlook when a return line is undersized or partially restricted.

For more information on the A10VG63 hydraulic pump, please visit https://www.baolilaihydraulic.com/product/.

Specifications

Selection Table

Q1: What control types are available on the A10VG63?

A1: The A10VG63 (size 63) supports HD, HW, DG, DA, EP, and EZ control heads — everything except the MD mechanical pivot control, which is reserved for the smallest frame size (18) in the series. This lets the same base pump serve mechanical, hydraulic, and electronic control architectures.

Q2: What hydraulic fluid should be used with the A10VG63?

A2: Rexroth specifies mineral oils conforming to DIN 51524 as the standard fluid, with other fluid types (HFD or environmentally acceptable fluids) usable only within the limitations described in Rexroth's separate fluid data sheets. The pump is explicitly not suited to HFA, HFB, or HFC fluids.

Q3: How to purchase an A10VG63 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 A10VG63 hydraulic pump?

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