Bosch Rexroth A4VG variable hydraulic pump for the ROPA harvester 274152 274153 274169 274185 274189

The A4VG is a variable displacement axial piston pump in swashplate design, made for closed-circuit hydrostatic transmissions. Flow is proportional to drive speed and displacement, and it can be varied infinitely as the swashplate angle goes from zero to its maximum. Flow direction also changes smoothly as the swashplate passes through neutral.

Why It Fits a ROPA Harvester

What the job demands

Beet harvesting punishes a travel drive in three ways:

1. High tractive effort at very low speed. A loaded machine in wet soil needs torque at a crawl, and high system pressure and fine displacement control are what deliver it.

2. Slope and stability. The Panther, for example, uses two swing axles and four stabilization cylinders to cut machine sway and hold better on side slopes. The drive has to work with that chassis and not fight it.

3. Long, hot days. The pump shares a cooling package with everything else, and it can't be allowed to cook the oil.

Maintenance and Troubleshooting

Keep the oil clean

Contamination is the leading killer of piston pumps. Rexroth's guidance for Series 40 is a cleanliness level of at least 20/18/15 per ISO 4406, and 19/17/14 when viscosity drops below 10 cSt at the drain port. In a dusty beet field, breathers, filter changes, and clean refilling practice matter more than almost anything else. The A4VG is also unsuitable for HFA, HFB and HFC fluids.

Watch heat and case drain

Rising case-drain flow is one of the best indicators of internal wear. Measure it on a warm machine with a proper flow meter, and compare against the datasheet or OEM specification. Overheating is usually a system issue (blocked cooler, weak fan drive, low oil level), not a pump defect.

Protect the shaft seal

Shaft seal life shortens with more frequent pressure peaks and higher mean differential pressure, and the case pressure must be higher than ambient pressure at the seal. Kinked case-drain lines and blocked return filters are classic seal killers.

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Q1: Is the A4VG an open- or closed-circuit pump?

A1: Closed-circuit. It's designed for hydrostatic transmissions where oil circulates between the pump and motor.

Q2: What causes premature failure?

A2: Mostly contamination, overheating, cavitation, and poor case drainage. Actual mechanical defects are far less common.

Q3: What is the price and delivery time of the A4VG hydraulic pump for the ROPA harvester?

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 hydraulic pump for the ROPA harvester?

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