Bosch Rexroth A10VO85 variable displacement hydraulic pump

The A10VO85 is a swashplate-design, variable displacement axial piston pump built for closed-circuit and open-circuit hydraulic systems. "A10VO" identifies the series — an axial piston unit with a variable swashplate, rated for a nominal pressure around 280 bar and peak pressures up to roughly 350 bar, depending on the exact control and size variant. The "85" denotes the geometric displacement: approximately 85 cm³ per revolution.

How the Swashplate Mechanism Works

The Core Operating Principle

Inside the A10VO85, a cylinder barrel houses a set of pistons arranged parallel to the drive shaft. As the shaft rotates, the pistons ride against a swashplate set at an angle. That angle determines the piston stroke length — and stroke length is what determines displacement.

Swashplate at maximum angle → full piston stroke → maximum flow output

Swashplate near zero angle → minimal piston stroke → flow drops toward zero

Swashplate reversed (on closed-circuit variants) → flow direction reverses

This is fundamentally different from a fixed-displacement gear or vane pump, where the only way to change flow is to change shaft speed. With the A10VO85, the prime mover can run at a constant speed while the pump itself adjusts output on the fly.

Control Options That Shape Real-World Behavior

The control type bolted to the back of the pump is really what defines how it behaves in a given machine:

DR (pressure control): Holds system pressure at a set value; flow drops automatically as pressure approaches the setpoint.

DFR (pressure and flow control): Adds a flow-limiting function on top of pressure control — common in injection molding and press applications.

EO / EO-LR (electric proportional control): Lets a PLC or controller command displacement electronically, useful where flow needs to track a changing process variable.

HD (hydraulic displacement control): Remote hydraulic signal adjusts swashplate angle, often used in load-sensing circuits.

Typical Applications

The A10VO85 earns its keep in systems where load demand changes constantly and energy efficiency actually matters. A few concrete examples:

Mobile and Construction Equipment

On excavators, wheel loaders, and similar machines, implement circuits rarely need full flow all the time — a bucket curl needs different flow than a boom lift. A variable pump like the A10VO85 lets the engine deliver only the flow the current function needs, cutting fuel consumption and heat generation compared to a fixed-displacement setup with a bypass valve.

Plastics and Rubber Processing

Injection molding machines cycle through phases — clamp, inject, hold, cool — each demanding a different flow and pressure profile. A DFR-controlled A10VO85 can taper flow precisely during the pack-and-hold phase, which is exactly why this pump family is so common on hydraulic injection molding presses.

Machine Tools and Industrial Presses

Stamping presses and clamping systems often need high force at low speed during the work stroke and rapid approach/retract otherwise. The pump's ability to modulate displacement in real time avoids the energy losses of throttling excess flow across a relief valve.

Agricultural Machinery

Combine harvesters and large sprayers use variable pumps like the A10VO85 to run multiple hydraulic functions — steering, header lift, fan drives — off a shared power source without one function starving another.

Installation and Maintenance Considerations

Fluid Cleanliness Is Non-Negotiable

Axial piston pumps run tight piston-to-bore clearances. Contamination is the single biggest killer of A10VO85 pumps in the field. Rexroth typically specifies a cleanliness target around ISO 4406 18/16/13 or better, achieved through proper filtration (commonly 10-micron or finer return-line filtration).

Case Drain Monitoring

Because the case drain line carries internal leakage flow out of the pump housing, its flow rate is one of the best early-warning indicators of wear. A gradual increase in case drain flow — measured with a simple flow meter during routine PM — often signals piston or valve plate wear well before a catastrophic failure shows up.

Priming and Start-Up

Like most piston pumps, the A10VO85 is not fully self-priming from a dead-dry state indefinitely — the inlet needs to be flooded or gravity-fed, and the case should be pre-filled with clean oil before first start to avoid dry-running the piston shoes and slippers.

Common Failure Symptoms

Rising case drain temperature or flow → wear in pistons, cylinder barrel, or valve plate

Loss of pressure at the swashplate control → control spool contamination or seal failure

Cavitation noise at start-up → inadequate inlet conditioning or suction line restriction

Erratic flow response → sticking control valve or degraded control oil

For more information on the A10VO85 hydraulic pump, please visit https://www.baolilaihydraulic.com/product/.

Specifications

Selection Table

Q1: Is the A10VO85 compatible with load-sensing systems?

A1: Yes. With the appropriate control option (typically an LS or HD-type control), the A10VO85 integrates into load-sensing circuits, adjusting displacement to match the highest pressure demand signal from the actuators it feeds.

Q2: How much flow does the A10VO85 actually produce?

A2: Roughly speaking, multiply the displacement (85 cm³) by shaft speed, then account for volumetric efficiency (typically 90–95% when in good condition). At 1,800 rpm, that lands in the range of 140–150 L/min at full stroke, tapering down as the swashplate angle reduces.

Q3: How to purchase an A10VO85 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 A10VO85 hydraulic pump?

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