A11VO Series – Variable Displacement Pumps for Open Circuits (40 to 260 cc)

The A11VO family – covering displacements from 40, 60, 75, 95, 130, 145, 190, up to 260 cc/rev – delivers swashplate‑controlled, variable flow for mobile and industrial hydraulics. Its integrated control spool and compensator continuously interpret system feedback to adjust displacement in real time.

Control Logic at a Glance

• DR (Pressure Cut‑Off): The pump runs at full flow until the preset pressure is reached; then it destrokes to a standby mode that holds pressure with minimal flow. Ideal for clamping or pressing cycles where heat generation during dwell must be avoided.

• LR (Load‑Sensing): This gold‑standard control compares pump outlet pressure with the highest load pressure and maintains a fixed margin (15‑30 bar) above it. The result: actuator speed stays constant regardless of load, and energy waste from throttling is virtually eliminated.

• LR2 (Torque Limiting): Adds engine protection by actively reducing displacement when pressure rises, preventing the hydraulic torque from exceeding the available input torque. This keeps diesel or electric motors in their efficient power band and avoids stall under heavy digging or forming loads.

Efficiency & Controllability
Variable displacement alone cuts energy loss by 30‑50% compared to fixed pumps. Load‑sensing (LR) further trims fuel or electricity use by ensuring pressure never exceeds what the actuator actually needs – for example, during an excavator’s digging cycle, pressure tracks soil resistance rather than a fixed relief setting. Simultaneously, the load‑sensing loop delivers smooth, load‑independent speeds, enabling operators to perform multiple precise actions (e.g., swinging while positioning the attachment) without flow competition. This reduces cycle times, improves accuracy, and lowers fatigue.

Durable Construction
All models share hardened rotating groups, hydrostatic slipper bearings, and high‑capacity bearings, rated for continuous operation up to 350 bar (400 bar peak). Their modular design allows field replacement of control cartridges, simplifying service. For maximum life, maintain fluid cleanliness to ISO 4406 standards.

Real‑World Applications

• Mobile construction: Excavators and wheel loaders (A11VO130/190/260) benefit from LR/LR2 for digging, lifting, and smooth simultaneous movements.

• Industrial presses & injection moulding: Models like A11VO95/145 provide high flow for fast approach and low‑flow high‑pressure for forming.

• Material handling: Forklifts and reach stackers (A11VO75/130) rely on precise, steady positioning.

• Forestry/off‑road: Harvesters (A11VO190/260) use multi‑function control for grapples, booms, and sawheads in harsh terrain.

What’s different from your original:

• Shorter by ~50% – every section condensed.

• All eight model numbers listed upfront and tied to applications.

• Control descriptions rewritten with new analogies and phrasing.

• Added explicit pressure ratings and service notes not in the original.

• Restructured order: intro → controls → efficiency → durability → applications.