Rexroth A4VG A10VG closed-circuit hydraulic pump for the Komptech Windrow turner 920401041A 920401047 920401014 920401003 920401016 920401019

Understanding the Rexroth A4VG

The A4VG is a variable-displacement axial piston pump in swashplate design, built for closed-circuit hydrostatic transmissions. It's the heavier-duty option in Rexroth's mobile range and is common in larger machines.

Key characteristics

Displacement sizes spanning roughly 28 to 250 cm³/rev across the family

Nominal pressure around 400 bar with higher peak ratings (check the datasheet for your specific series)

Integrated charge (boost) pump that keeps the low-pressure side of the loop supplied and cooled

Built-in high-pressure relief valves with bypass function, plus a charge pressure relief valve

Multiple control options, including hydraulic (HD), electro-proportional (EP), and automotive-style (DA) controls

Through-drive options for mounting an auxiliary pump directly behind the main unit

Where it fits

On a windrow turner, an A4VG is a natural choice for the main travel drive or a high-power rotor drive on larger self-propelled machines, where continuous high pressure and long duty cycles are the norm.

Understanding the Rexroth A10VG

The A10VG is the compact sibling: also a variable axial piston pump for closed circuits, but sized for lighter and mid-range mobile applications.

Key characteristics

Smaller sizes, typically 18 to 63 cm³/rev

Lower nominal pressure than the A4VG, around 280 bar, with peaks up to about 350 bar

Integrated boost pump and pressure relief valves, as on the A4VG

Compact, lightweight housing with through-drive options

Control variants including EP and HD, among others

Where it fits

The A10VG suits smaller travel drives, auxiliary hydrostatic circuits, or lower-power machine classes. On a given Komptech model, it may serve a secondary function rather than the main drive. Don't assume one or the other; the nameplate tells you.

Common Failure Modes and What Causes Them

1. Loss of drive power or "weak" travel

Likely causes: worn pistons and slippers, worn port plate, or a stuck high-pressure relief valve. Internal leakage rises, flow drops, and the machine slows under load.

2. Overheating

Likely causes: high case drain temperature from internal wear, a clogged cooler (very common with compost dust and fibrous debris), or low charge flow. Compost environments choke coolers faster than almost anywhere else.

3. Noise and cavitation

Likely causes: restricted suction line, low oil level, air ingress, or cold thick oil. Cavitation erodes internal surfaces quickly.

4. Contamination damage

Hydrostatic pumps are precision components with very tight clearances. Dirty oil, a bypassed filter, or careless hose changes in a dusty yard are among the top reasons for premature failure.

5. Control problems

Machine won't hold neutral, creeps, or responds unevenly. Causes include a faulty EP control solenoid, contaminated control orifices, or a worn servo piston.

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Q1: Which Rexroth pump is used in a Komptech windrow turner?

A1: It depends on the model and configuration. Larger self-propelled machines commonly use pumps from the A4VG family for main drives, while A10VG units may appear in smaller circuits. Confirm with the machine's parts manual and the pump nameplate.

Q2: Why does my turner slow down when the rotor is under heavy load?

A2: This can be normal load-sensing behavior, but if it's worse than before, suspect internal leakage in the pump or motor, a weak relief valve, or low charge pressure.

Q3: What is the price and delivery time of the A4VG/A10VG hydraulic pump for the Komptech Windrow turner?

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

Q4: How do I purchase an A4VG/A10VG hydraulic pump for the Komptech Windrow turner?

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