描述

Rexroth A7VO Hydraulic Pump A7VO28 A7VO55 A7VO80 A7VO107 A7VO160 Variable Displacement Piston Pump

Higher Pressure at Lower Input Speeds

Since the pistons follow the rotating group more naturally, the A7VO80 delivers steady output even below 500 rpm. For operators running PTO‑driven attachments off a diesel engine at idle, this means useful hydraulic power without needing to raise engine speed.

Superior Suction Performance
The bent‑axis layout provides a straighter flow path into the cylinder bores. As a result, the A7VO80 tolerates inlet vacuum down to 0.4 bar absolute without cavitation damage – a vital feature for cold starts or when the reservoir is mounted unfavourably.

Key Technical Specifications of the A7VO80
Before ordering, confirm these baseline values:

• Displacement: 80 cm³/rev (adjustable from zero to maximum)
• Max pressure: 400 bar peak / 350 bar continuous
• Speed range: up to 3000 rpm (control‑type dependent)
• Rotation: bidirectional as standard
• Weight: roughly 40 kg dry

Practical Control Options
Rexroth provides modular regulators; these three are the most frequently chosen for the A7VO80.

1. DA – Speed‑Sensitive Control
No wiring or proportional valves required. Pump flow rises and falls directly with input shaft speed – ideal for winch drums and wheel‑loader traction drives.

2. EP – Electric Proportional Control
A 4‑20 mA or 0‑10 V command signal varies displacement. This is the go‑to for precision mixer drums or conveyor feeders where gentle acceleration is essential.

3. HW – Hydraulic Manual Control
A pilot pressure signal moves the yoke mechanically. Dependable for straightforward open‑loop jobs like agricultural spreaders.

Common Failure Points (and How to Prevent Them)
Even a rugged pump has vulnerabilities. Here is what typically shortens the A7VO80’s life.

• Contaminated case drain – The bent‑axis design relies on case‑drain oil for lubrication. If the return filter goes into bypass, particles gouge the piston slippers. Remedy: Fit a 10‑µm absolute filter on the case‑drain line – not only on the main return.
• Incorrect mechanical stop adjustment – The displacement‑limiting screw is factory‑set. Twisting it to “gain more flow” often over‑strokes the rotating assembly, causing timing‑plate galling. Remedy: Never alter the max‑volume stop without a flowmeter and pressure gauge.
• Aeration whine – A high‑pitched crackling noise is never normal. The suction port requires positive head pressure (at least 0.8 bar absolute). Remedy: Elevate the tank or install a charge pump.

Installation Best Practices for Extended Life
Fitting this pump is not like mounting a gear pump.

1. Flexible coupling alignment – Angular misalignment exceeding 0.5° will ruin the shaft seal within 200 hours. Use a laser alignment tool.
2. Housing drain – Always route a separate case‑drain line back to the tank, terminating above oil level. Daisy‑chaining drains with other components creates backpressure over 2 bar, which unseats the shaft seal.
3. Startup priming – Fill the housing through the top port before the first start. Running dry for even 10 seconds scuffs the bronze timing plate.