Bosch Rexroth A7VO55 Conical Plunger Hydraulic Pump

A7VO55 is a Conical Plunger Hydraulic Pump.

Three Concrete Benefits of the Conical Design

1.Lower Bearing Stress: The resulting internal forces create better load distribution on the drive shaft bearings. In field tests, A7VO55 units often outlast comparable flat-swashplate pumps by 1.5x in high-vibration environments like excavators and pile drivers.

2.Cold-Start Reliability: Conical pistons tolerate higher viscosity oil during cold starts. Example: A forestry crane in Northern Canada at -20°C fired up without cavitation damage—something a standard pump wouldn't survive repeatedly.

3.Compact Power Density: The A7VO55 delivers 55 cc/rev displacement in a housing smaller than many 45 cc pumps. For OEMs designing tight engine compartments, every inch matters.

Control Options: Matching the Pump to Your Logic

Rexroth offers several hydraulic and electric controls for the A7VO55. Choose based on your system architecture:

DR (Pressure Compensator): Constant pressure control. Ideal for power units running multiple actuators.

LR (Load Sensing + Pressure Cut-off): Best for fuel-efficient mobile machines. The pump only delivers flow when demanded.

HD (Hydraulic Remote Control): For joystick-operated equipment like cranes or drill rigs.

EP (Electric Proportional): Connect directly to a PLC or CAN bus. Enables pump displacement control without a pilot oil line.

Pro tip: If your system already has a separate pilot oil supply (e.g., 20–30 bar), the HD control offers the fastest response time—under 100 ms from neutral to full displacement.

Maintenance & Failure Prevention (From Field Data)

The A7VO55 is robust, but it has two common failure modes. Here’s how to avoid them:

1.Shaft Seal Leakage

Cause: Restricted case drain line (pressure exceeds 2 bar absolute).

Fix: Ensure the case drain line runs directly to tank, with no valves or filters. Use a hose one size larger than the outlet port.

2.Conical Piston Scoring

Cause: Water-contaminated oil leading to micro-pitting.

Fix: Maintain ISO 4406 cleanliness code 18/16/13 or better. Use a beta-10 filter (ß10 ≥ 75). Sample oil every 1,000 hours in wet environments.

For more information on the A7VO55 hydraulic pump, please visit https://www.baolilaihydraulic.com/product/.

Specifications

Selection Table

Q1:My pump is noisy at low rpm (<800). Is that normal?

A1:No. Conical piston pumps are quieter than swashplate designs. You likely have aeration (suction line leak) or viscosity that’s too high (>500 cSt). Check inlet vacuum—it should remain under 0.8 bar absolute.

Q2:Can I retrofit an A7VO55 into an old machine that had a different brand?

A2:Often yes, but you’ll need a mounting flange adapter (SAE or ISO) and a shaft coupling to match your existing prime mover. The control valve interface may also require custom pilot lines.

Q3:How to purchase an A7VO55 hydraulic pump?

A3:You can visit https://www.baolilaihydraulic.com/contact/ to contact us and purchase our products through various methods.

Q4:What is the price and delivery time of the A7VO55 hydraulic pump?

A4:The specific price and delivery time will be provided based on the specific model you provide.