Rexroth A4VSO260 axial piston variable hydraulic pump

The A4VSO260 is a swashplate-design axial piston variable displacement pump manufactured by Bosch Rexroth, part of the A4VSO series that spans frame sizes roughly from 40 cm³/rev up to 1000 cm³/rev. The "260" designates a geometric displacement of 260 cm³ per revolution, placing it among the larger-mid-range units used for high-power, high-pressure hydraulic circuits.

How the A4VSO260 Works: The Engineering Behind It

The Swashplate Principle

Inside the A4VSO260, a cylinder barrel houses a set of pistons arranged parallel to the drive shaft — hence "axial piston." Each piston rides against a swashplate set at an adjustable angle. As the shaft rotates, the pistons are forced in and out of their bores, drawing hydraulic fluid in on one stroke and expelling it under pressure on the next.

The keyword is adjustable. Tilt the swashplate further, and the piston stroke lengthens, increasing displacement per revolution. Bring the swashplate toward zero angle and displacement drops toward zero — even while the shaft keeps turning at full speed. This is what makes it a variable pump rather than a fixed one: output flow can be changed independent of prime mover speed.

Why This Matters in a Real System

Think of a plastic injection molding machine. During the fill phase, the machine needs high flow to move the mold quickly. During pack and hold, it needs high pressure but very little flow. A fixed-displacement pump would waste enormous energy dumping excess flow over a relief valve during that hold phase. The A4VSO260's variable swashplate lets the control system throttle displacement down automatically once target pressure is reached — flow drops, pressure holds, and the prime mover isn't fighting a relief valve. That's a direct, measurable energy savings, which is why variable piston pumps replaced fixed gear and vane pumps in most mid-to-high power hydraulic power units decades ago.

Control Options — This Is Where Selection Gets Serious

The A4VSO260 isn't sold as one generic pump; the control type bolted to the back of it defines how displacement is actually commanded. Common variants include:

DR — Pressure control, the pump destrokes automatically as system pressure approaches the set point

DRG — Pressure and flow control combined, useful where both parameters need active limiting

EO / EP — Electric proportional control, displacement commanded by an analog or PWM signal, common in CNC and servo-adjacent systems

HD — Hydraulic displacement control, remote hydraulic signal sets swashplate angle

HM / HW — Manual and hand-wheel control for simpler, fixed-operating-point applications

LR2 / LRS — Load-sensing controls, matching pump output to actual downstream demand for further energy savings

Choosing the wrong control for the application is one of the most common and expensive mistakes in a hydraulic power unit design. A load-sensing (LR2) control on a system with wildly fluctuating multi-actuator demand behaves completely differently than a straight pressure-compensated (DR) control on a single-actuator press.

Technical Specifications Deep Dive

Displacement and Flow

At 260 cm³/rev and a typical rated speed near 1500 rpm, theoretical flow works out to roughly 390 L/min (actual delivered flow is slightly lower once you account for volumetric efficiency, typically in the 92–96% range for a pump in good condition).

Pressure Ratings

Nominal pressure: 350 bar — the pump's continuous-duty rating

Peak pressure: 400 bar — permissible for intermittent pressure spikes, not continuous operation

Running near peak pressure continuously will shorten bearing and piston/shoe interface life significantly. This is a common failure mode on presses where the relief valve setting creeps upward over time to compensate for cycle speed complaints.

Shaft, Mounting, and Drive

The A4VSO260 uses a splined shaft (standard per SAE or DIN specification depending on the ordering code) and an SAE four-bolt flange mount. It's typically direct-coupled to an electric motor via a bell housing, or used in a through-drive tandem/triple-pump arrangement where a second or third pump is stacked off the back for multi-circuit power units.

Case Drain and Cooling

Like all axial piston pumps, internal leakage across the piston/cylinder and shoe/swashplate interfaces is collected as case drain flow and routed to tank, often through a cooler. Case drain flow and temperature are two of the best early indicators of internal wear — a healthy A4VSO260 will run a relatively cool, stable case drain temperature; a rising case drain temperature under constant load is an early wear signal long before performance visibly drops.

For more information on the A4VSO260 hydraulic pump, please visit https://www.baolilaihydraulic.com/product/.

Specifications

Selection Table

Q1: Is the A4VSO1000 a fixed or variable-displacement pump?

A1: It's variable displacement. The swashplate angle can be adjusted — manually via a control valve, or automatically via pressure, flow, or electronic controls — to change output flow without changing shaft speed.

Q2: What industries typically use this pump?

A2: Heavy industrial and mobile applications with high flow demands: metal forming and forging presses, plastic injection molding, mining and construction equipment, marine and offshore machinery, and large central hydraulic power units.

Q3: What is the price and delivery time of the A4VSO260 hydraulic pump?

A3: The specific price and delivery time will be provided based on the specific model you provide.

Q4: How to purchase an A4VSO260 hydraulic pump?

A4: You can visit https://www.baolilaihydraulic.com/contact/ to contact us and purchase our products through various methods.