AP300/63 D 287-S Bucher Gear Pump 63cc 220 bar

Product Overview

The AP300/63 D 287-S, AP300/63 S 287-S, along with the AP300/27/31/38/45/53/63/75/93 series, are high-performance external gear pumps from the Swiss manufacturer BUCHER Hydraulics. Headquartered in Switzerland, BUCHER Hydraulics is a globally recognized manufacturer of hydraulic components, with the AP series renowned for its compact design, high efficiency, and long service life.

The AP300 series belongs to Group 3 (large frame) with displacements ranging from 27.0 to 93.0 cc/rev. This series features a high-strength aluminum housing that delivers excellent heat dissipation and significant weight reduction. The pump body is made of high-strength extruded aluminum alloy, while the front cover (which also serves as the mounting flange) and rear cover are made of cast iron.

The AP300 series incorporates optimized hydraulic compensation design. Through meticulous CAD design of gear teeth and balancing areas, careful selection of high-performance materials, rigorously controlled heat treatments, and increasingly tight coupling tolerances, the series achieves high operating pressures, excellent volumetric and mechanical efficiency, and lower operating noise levels. The AP series supports single, double, and triple pump configurations.

Interchangeability: The AP300 series is manufactured to exacting BUCHER original design standards. Mounting flange, shaft type, port dimensions, and rotation direction are fully compliant with genuine BUCHER specifications, enabling 100% drop-in replacement without any system modification.

Technical Specifications 

AP300/63 Series (D 287-S / S 287-S)

• Brand: BUCHER Hydraulics (Switzerland)

• Series: AP300

• Group: Group 3 (large frame)

• Displacement: 63.0 cm³/rev

• Continuous operating pressure: 180 bar (2600 psi)

• Maximum continuous pressure: 210 bar (3000 psi)

• Peak pressure: 240 bar (3400 psi)

• Minimum speed: 550 rpm

• Maximum speed: 2,500 – 3,000 rpm

• Rotation: D = Right-hand (clockwise) / S = Left-hand (counter-clockwise)

• Seal code: 287-S = Standard NBR

• Housing material: High-strength aluminum alloy

• Front cover / Rear cover material: Cast iron

• Gear material: High-strength steel alloy

• Bearings: Balancing bushings (bearing and axial/radial thrust balancing functions)

• Media compatibility: Mineral-based hydraulic oils (ISO/DIN compliant)

• Recommended viscosity range: 20 – 120 mm²/s (cSt), maximum 700 mm²/s

• Operating temperature range (NBR seals): -15°C to +80°C

• Recommended filtration: Return line ≤ 25 μm

• Country of origin: Italy / Switzerland

AP300 Series Displacement Model Specifications 

• AP300/27: 27.0 cm³/rev, continuous 220 bar, max. continuous 250 bar, peak 280 bar, max. speed 3500 rpm, min. speed 600 rpm

• AP300/31: 31.0 cm³/rev, continuous 220 bar, max. continuous 250 bar, peak 280 bar, max. speed 3500 rpm, min. speed 600 rpm

• AP300/38: 38.0 cm³/rev, continuous 220 bar, max. continuous 250 bar, peak 280 bar, max. speed 3000 rpm, min. speed 600 rpm

• AP300/45: 45.0 cm³/rev, continuous 200 bar, max. continuous 230 bar, peak 260 bar, max. speed 3000 rpm, min. speed 600 rpm

• AP300/53: 53.0 cm³/rev, continuous 200 bar, max. continuous 230 bar, peak 260 bar, max. speed 3000 rpm, min. speed 600 rpm

• AP300/63: 63.0 cm³/rev, continuous 180 bar, max. continuous 210 bar, peak 240 bar, max. speed 3000 rpm, min. speed 550 rpm

• AP300/75: 75.0 cm³/rev, continuous 170 bar, max. continuous 190 bar, peak 220 bar, max. speed 2500 rpm, min. speed 550 rpm

• AP300/93: 93.0 cm³/rev, continuous 150 bar, max. continuous 170 bar, peak 200 bar, max. speed 2500 rpm, min. speed 500 rpm

Data compiled from BUCHER official technical documentation

Model Code Breakdown

• AP300: Series code (Group 3 external gear pump)

• /63: Displacement (63.0 cm³/rev)

• D: Rotation (D = Right-hand/clockwise; S = Left-hand/counter-clockwise)

• 287-S: Seal and configuration code (Standard NBR)

Key Technical Advantages

1. Optimized Hydraulic Compensation for High Overall Efficiency

The AP300 series features optimized hydraulic compensation design. The balancing bushings serve dual purposes – acting as bearings for the gears and balancing axial and radial thrust in proportion to changes in operating pressure. Precision CAD-designed gear tooth profiles and carefully calculated balancing areas effectively minimize internal leakage.

2. High-Strength Aluminum Housing and Lightweight Design

The pump body is made of high-strength extruded aluminum alloy, while the front and rear covers are made of cast iron, delivering excellent structural integrity while effectively reducing pump weight. The aluminum material offers excellent thermal conductivity, rapidly dissipating operating heat.

3. Precision Gear Design and Long Service Life

AP300 series gears are manufactured from high-strength steel alloy, combined with careful selection of high-performance materials and rigorously controlled heat treatment processes. Optimized gear geometry and progressively tighter coupling tolerances achieve excellent technical specifications and long service life.

4. Modular Multi-Pump Design

The AP300 series supports single, double, and triple pump configurations. Tandem configurations enable multiple independent flow outputs to meet diverse flow and pressure requirements of complex hydraulic systems.

5. Wide Operating Temperature and Media Compatibility

NBR seals allow operating temperatures from -15°C to +80°C. For higher temperature applications, FKM (Viton) seals are available, extending the temperature range to -15°C to +120°C. Recommended viscosity range is 20 – 120 mm²/s, with maximum allowable up to 700 mm²/s.

6. Dedicated Front and Rear Cover Options

The AP300 series supports dedicated front covers to improve mechanical performance and service life under radial/axial loads, as well as dedicated back covers with integrated circuits for pressure and flow control.

Application Areas

• Tractors & Agricultural Machinery – Hydraulic lift and steering systems for large/medium tractors, combine harvesters

• Construction Machinery – Excavators, loaders, and other mobile equipment hydraulic systems

• Material Handling Equipment – Forklifts, lift trucks, lifting platforms

• Municipal Vehicles – Sweepers and other municipal vehicles

• Industrial Hydraulic Systems – Machine tools, presses, and other stationary industrial equipment

• Front Loaders – Loader hydraulic systems

• Hydraulic Cranes – Lifting and hoisting equipment hydraulic systems

Expert Maintenance Tips

1. Fluid Cleanliness Management

AP300 series gear pumps are sensitive to fluid contamination. Recommended fluid cleanliness: ISO 4406 19/17/14 or higher. Install a suction filter with minimum 100 μm filtration and a return line filter with ≤ 25 μm filtration.

2. Fluid Viscosity & Temperature Control

Mineral-based hydraulic oils conforming to ISO/DIN standards are recommended. Operating viscosity should be maintained within 20 – 120 mm²/s, with maximum allowable up to 700 mm²/s. Optimal operating temperature: 40 – 60°C. AP300 series NBR seals allow operating temperatures from -15°C to +80°C. For higher temperature applications, FKM seals are available, extending the range to -15°C to +120°C. For cold starts, ensure fluid temperature is above -10°C to prevent cavitation.

3. Suction Conditions

Ensure suction lines are properly sealed to prevent air ingress. Absolute suction pressure must be ≥ 0.75 bar (11 PSI). Suction line diameter should be sufficiently large and line length kept as short as possible to minimize suction resistance.

4. Rotation Direction Verification

Always verify the pump rotation direction indicator before start-up (D = right-hand/clockwise; S = left-hand/counter-clockwise). Start with jog operation to confirm correct rotation, then gradually load to operating pressure.

5. Alignment During Installation

Ensure concentricity between pump shaft and drive motor shaft does not exceed 0.05 mm, with angular misalignment within 0.5°. Flexible couplings are recommended to compensate for minor misalignment. Flange installation requires proper bolt torque according to specifications.

6. First Start-Up and Bleeding

Before initial start-up, pre-lubricate the pump by filling clean hydraulic oil through the housing ports. After start-up, run the pump in no-load operation for a few seconds to ensure sufficient lubrication. The pump must be bled before building up system pressure. Never allow the pump to run without oil.

7. Periodic Maintenance

Replace hydraulic oil and filters every 2,000 operating hours or annually. Regularly monitor pump body temperature (surface temperature should not exceed 80°C) and listen for abnormal noise increases, which may indicate internal wear or cavitation.