Bosch Rexroth A7VO bent-axis hydraulic pump for Schwing Concrete pump truck 10155091 10155094 10155096 10166689 10169465 10174799

The A7VO is a variable-displacement, bent-axis axial piston pump built by Bosch Rexroth's mobile hydraulics division. It's part of the same broad family as the A4VG and A6VM units you'll find in excavators and wheel loaders, but the A7VO variant is specifically engineered for closed-circuit, high-pressure duty cycles — exactly the kind of load reversal you get when a concrete pump truck alternates between the two sides of an S-valve, pushing material through the delivery line in short, forceful strokes.

How the A7VO Fits Into a Schwing Pump Truck's Hydraulic System

A Schwing truck-mounted concrete pump has, broadly, three interconnected hydraulic circuits: the boom circuit, the agitator circuit, and the main pumping (delivery) circuit. The A7VO's job is almost always in that third one — the circuit that actually pushes concrete.

The Closed-Loop Delivery Circuit

The main pumping cylinders on a Schwing unit work in tandem — while one hydraulic cylinder drives its concrete piston forward, the other retracts, and then the S-valve swings to switch which cylinder is delivering material into the boom. The A7VO, paired with a second variable pump on the opposite bank, drives this reciprocating action through a closed hydraulic loop, with a smaller charge pump keeping the low-pressure side of the loop topped off and cooled.

Load-Sensing and Output Control

Most Schwing installations pair the A7VO with a load-sensing (LS) control or an electro-proportional control (EP), depending on the truck generation and control system (Schwing's own electronic control packages, sometimes integrated with the Rexroth controller). This lets the pump automatically adjust displacement based on the resistance it's feeling in the line — critical when concrete consistency changes mid-pour, or when the boom is pumping at a steep vertical angle and needs more pressure to overcome the head of material in the pipe.

Key Specifications and Configuration Considerations

Every A7VO ships in several frame sizes (commonly seen across the field in roughly the 55, 80, 107, 160, 200, and larger displacement classes, measured in cm³/rev), and Schwing specifies the frame size and control type based on the boom pump's rated output and maximum concrete pressure class.

When you're troubleshooting or sourcing a replacement, the details that actually matter are:

Frame size/displacement (cm³ per revolution) — must match the original unit; this is not a "close enough" part

Control type — hydraulic remote control, electro-hydraulic (EP), load-sensing (LS), or a DA/DR combination valve setup

Shaft configuration and spline — must match the coupling to the transfer case or PTO

Rotation direction — clockwise or counter-clockwise as viewed from the shaft end

Charge pump and relief valve settings — often a Rexroth gear pump bolted to the back of the A7VO, and it has its own pressure rating

A mismatch on any one of these — a technician grabbing "an A7VO off the shelf" without checking the full model code — is one of the most common causes of a rebuilt or replacement pump underperforming or failing prematurely on a Schwing unit.

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Q1: How long does an A7VO pump typically last on a concrete pump truck?

A1: Service life varies widely with duty cycle, oil cleanliness, and maintenance discipline. Trucks with disciplined filtration and oil-change practices routinely get many thousands of hours out of a pump before a rebuild is needed, while poor oil maintenance can cut that life dramatically. There's no single universal number — hour-based inspection intervals from Schwing's service manual are a better guide than a rule of thumb.

Q2: What's the single earliest warning sign that an A7VO is starting to fail?

A2: Rising case drain flow and a slow upward trend in hydraulic oil temperature, often noticeable before any drop in pumping performance, are obvious to the operator.

Q3: What is the price and delivery time of the A7VO hydraulic pump for the Schwing Concrete pump truck?

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

Q4: How to purchase an A7VO hydraulic pump for the Schwing Concrete pump truck?

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