Rexroth A8VO160 Variable-displacement axial piston hydraulic pump

The A8VO160 is a variable-displacement axial piston pump built around a swashplate design, engineered by Bosch Rexroth for open-circuit hydraulic systems in mobile and industrial machinery. The "160" in the model name refers to its geometric displacement of roughly 160 cm³ per revolution — the maximum volume of fluid the pump can move with each shaft rotation before the swashplate angle is reduced.

Unlike a fixed-displacement gear or vane pump, the A8VO160 can change how much oil it delivers per revolution without changing shaft speed. That's the entire point of the "VO" designation: Variable, Open circuit.

The A8VO160 is a popular middle-to-upper displacement choice because it delivers enough flow for large main pump duty on excavators and similar equipment while still fitting a compact housing envelope compared to the largest units in the series.

How the A8VO160 Works

The Swashplate Principle

Inside the pump housing sits a cylinder block with a series of pistons arranged in a circle, parallel to the drive shaft — hence "axial piston." As the shaft turns, the pistons ride against an angled swashplate. That angle forces each piston to slide in and out of its bore, drawing in fluid on one side of the block and expelling it on the other.

The key mechanism: changing the swashplate angle changes piston stroke length, which changes displacement per revolution — all without touching shaft speed. Tilt the plate to zero and the pump produces (theoretically) no flow even while spinning at full speed; tilt it to maximum and you get full rated displacement.

Displacement Control Options

The A8VO160 is available with several control types, chosen based on the machine's control philosophy:

DA (hydraulic remote control) — flow adjusted by an external pilot pressure signal

LA (load-sensing control) — the pump automatically adjusts displacement to match load pressure and flow demand, improving efficiency

EP (electro-proportional control) — an electronic signal from the machine's controller sets displacement directly, common on modern excavators with electrohydraulic systems

DR (pressure control) — limits maximum system pressure by de-stroking the pump

Load-sensing (LS) and electro-proportional (EP) variants are the most common on current-generation excavators because they let the machine's ECU coordinate multiple pumps and functions simultaneously — critical for smooth multi-function operation (boom, arm, swing, and travel moving together).

Typical Applications

The A8VO160 is most often found as a main hydraulic pump on:

Crawler excavators in the mid-to-large size class (commonly cited examples include Volvo EC950F-class machines)

Wheel loaders requiring high flow for lift/tilt and steering circuits

Asphalt pavers and road construction equipment

Cranes and material handlers needing precise, load-sensing flow control

Industrial presses and test rigs where variable flow under high pressure improves energy efficiency versus a throttled fixed-displacement system

Example: Excavator Main Pump Duty

On a large excavator, the A8VO160 typically works as one of two (or more) main pumps in a tandem or split-flow arrangement, each feeding a bank of control valves. As the operator moves joysticks, the machine's controller reads pilot pressure or electrical signals and commands the pump's LS or EP control to de-stroke or up-stroke the swashplate in real time — delivering exactly the flow the current combination of functions needs, rather than dumping excess flow over a relief valve. This is the mechanism behind the fuel-efficiency gains modern excavators advertise over older fixed-displacement designs.

Example: Load-Sensing Response

Imagine an operator curling the bucket while simultaneously swinging the upper structure. Demand on the pump spikes as two functions draw flow at once. A load-sensing A8VO160 detects the pressure drop across the meter-in orifice and strokes the swashplate up almost instantly, maintaining a nearly constant pressure margin so both functions move smoothly instead of one starving the other.

Common Failure Modes and Wear Points

Piston and Slipper Wear

The piston/slipper interface rides on a thin hydrodynamic oil film against the swashplate. Contamination, oil starvation, or cavitation erodes this film over time, leading to slipper scoring and eventual displacement loss or internal leakage.

Valve Plate Scoring

The valve plate manages the transition between suction and discharge as the cylinder block rotates. Score marks here — often from contamination or a momentary loss of lubrication — show up as reduced volumetric efficiency and a whining or knocking noise under load.

Servo/Control Piston Sticking

On LA and EP variants, the small servo piston that positions the swashplate can stick due to varnish buildup or contaminated control oil, causing sluggish or erratic flow response — often misdiagnosed as an electrical fault on EP units when it's actually a mechanical or fluid cleanliness issue.

Shaft Seal Leakage

As with any rotating hydraulic component, the case drain shaft seal is a common leak point, particularly after long service intervals or when case drain pressure exceeds the seal's rating due to a restricted return line.

For more information on the A8VO160 hydraulic pump, please visit https://www.baolilaihydraulic.com/product/.

Specifications

Selection Table

Q1: What machines commonly use the A8VO160?

A1: It's most commonly specified as a main pump on mid-to-large crawler excavators, wheel loaders, pavers, and similar mobile equipment, often in tandem with a second pump of matching or different displacement.

Q2: What causes most A8VO160 failures?

A2: Contamination is the single most common root cause — piston/slipper and valve plate wear accelerate dramatically when system cleanliness falls below the ISO 4406 targets Rexroth specifies for this pump class.

Q3:How to purchase an A8VO160 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 A8VO160 hydraulic pump?

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