Rexroth A11VO open-circuit hydraulic pump for the Putzmeister Road equipment 267391002 273978008 274262001 448039

The A11VO is a variable-displacement axial piston pump built by Bosch Rexroth, designed specifically for open-circuit hydraulic systems. "Open circuit" means the pump draws oil from a reservoir (tank), pushes it through the system to do work, and returns it to the same tank — as opposed to a closed-circuit design where fluid recirculates in a sealed loop between pump and motor. Open-circuit pumps like the A11VO are the standard choice anywhere a machine needs to power several different hydraulic functions from one source: travel, boom movement, agitator drives, outriggers, and more.

Core Design and Working Principle

The A11VO uses a swashplate design. A rotating cylinder block houses a set of pistons that reciprocate as the block turns against an angled swashplate. Tilt that swashplate, and you change how far each piston travels — which changes displacement, and therefore flow. At zero swashplate angle, the pump produces no flow even while spinning. Tilt it to maximum, and you get full rated flow. This is what lets one pump feed a hydraulic system whose demand is constantly changing, without needing to touch engine speed.

Key technical characteristics of the A11VO series worth knowing:

Displacement range: available in sizes from roughly 40 to 260 cm³ per revolution, covering a wide span of machine classes

Nominal pressure: 350 bar, with a peak pressure rating of 400 bar

Flow control: proportional to both drive speed and swashplate angle, adjustable continuously between zero and maximum displacement

Priming: self-priming as standard, with the option of tank pressurization or a built-in charge pump for higher-speed operation

Through-drive capability: up to 100% through-drive, allowing a second pump (gear or axial piston) to be mounted in tandem off the same drive

Control Options

Where the A11VO earns its keep is in the range of control types available, since different machine functions need to respond to different signals:

Power control (LR): limits the pump's power draw so it never exceeds what the engine can deliver, protecting against stalling under heavy load

Pressure control (DR): holds a set pressure, reducing flow automatically as system pressure rises

Hydraulic (pilot-pressure) control (HD): swashplate angle follows an external pilot pressure signal, useful for remote or joystick-based control

Electric proportional control (EP): a solenoid varies displacement in response to an electrical command, which is increasingly common as machines add electronic control systems

Why Putzmeister Road Equipment Relies on the A11VO

Putzmeister built its reputation on concrete pumps and placing booms, and that same engineering lineage carries into its road and construction-support equipment — truck-mounted pumps, stationary pumps, and mobile units used on paving and infrastructure jobs. These machines share a common demand: multiple hydraulic circuits, all needing independent, load-sensitive control, all running off one engine.

Matching Pump Behavior to Machine Demands

Think about everything happening on a working concrete pump during a pour. The main pumping cylinders need high flow at high pressure. The boom needs precise, low-flow movement for placement accuracy. The agitator needs a steady, moderate flow almost continuously. All of that load shifts second to second. A fixed-displacement pump can't respond to that; it would either starve the boom of precision or waste horsepower running full-tilt when nothing needs it. The A11VO's variable-displacement, power-limited design is exactly the tool for that job — it delivers flow on demand and steps back when demand drops, protecting the engine and improving fuel efficiency in the process.

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Q1: How often should the pump's hydraulic fluid be checked or changed on road equipment?

A1: This varies by manufacturer and duty cycle, but as a general rule, fluid condition (contamination and moisture content) matters more than a fixed calendar interval for piston pumps. Heavy-duty road and concrete equipment typically warrants more frequent oil analysis than light-duty machinery, given the dust and thermal cycling involved.

Q2: Is a "lazy" or sluggish response always a sign that the pump needs replacing?

A2: No. Sluggish displacement response is frequently a control-side issue — a sticking servo piston, low charge pressure, or a control valve problem — rather than pump wear. It's worth ruling those out before condemning the pump itself.

Q3: What is the price and delivery time of the A11VO hydraulic pump for the Putzmeister Road equipment？

A3: The specific price and delivery time will depend on the equipment model or specific product model you provide.

Q4: How to purchase an A11VO hydraulic pump for the Putzmeister Road equipment?

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