Product Overview
The GM5-5, GM5-6, GM5-8, GM5-10, GM5-12, GM5-16, GM5-20, GM5-25 series, along with specific models such as GM5-8-AE13S-20-L and GM5-5-AE13S-20-L, are high-pressure gear pumps/motors originating from the GM5 Series platform, developed under license from Parker Vickers technology. The series features a three-piece split housing design consisting of a front cover, center housing, and rear cover, with two DU bearings pressed into each cover.
The G5/GM5 Series gear pumps are external gear pumps featuring axial flexible compensation and radial hydraulic balance. The pressure plate serves as the primary component for radial and axial pressure compensation, reducing bearing loads and automatically adjusting gear axial clearance – effectively improving pump performance and operational reliability.
Key Interchangeability Advantage: Our GM5 series gear pumps are manufactured to strict Parker Vickers original design specifications, ensuring 100% direct interchangeability with original units. All mounting interfaces, flange dimensions, shaft configurations, and port positions are identical to the original product – no modifications required. Every pump undergoes 100% factory performance testing under simulated operating conditions (covering rated pressure, peak pressure, and full speed range performance curves), guaranteeing plug-and-play reliability with zero performance deviation.
Model Code Breakdown:
GM5 = Series: High Pressure Gear Pump/Motor
5 / 6 / 8 / 10 / 12 / 16 / 20 / 25 = Displacement code
A = Structure / mounting configuration code
E13 = Shaft type: Parallel keyed (E13S)
S = Port type: Metric thread
20 = Design number
L = Rotation direction: Left-hand (counter-clockwise) / R = Right-hand (clockwise)
Technical Specifications
GM5 Series – General Specifications
Product Series: GM5 Series High-Pressure External Gear Pump
Technology Source: Parker Vickers (USA)
Pump Type: External gear pump, three-piece split housing
Pressure Compensation: Axial flexible compensation + radial hydraulic balance
Bearings: DU bearings (two in each cover)
Maximum Operating Pressure: 25 MPa (250 bar)
Operating Temperature Range: 0 – 120℃
Recommended Fluid: Hydraulic oil
Maximum Speed: 4000 r/min
Material: Copper alloy
GM5-5 / GM5-5-AE13S-20-L
Displacement: 5.1 – 5.2 cm³/rev
Rated Pressure: 20 MPa
Maximum Speed: 4000 r/min
Theoretical Torque: 16.5 N·m
Weight: 1.9 kg
GM5-6
Displacement: 6.4 cm³/rev
Rated Pressure: 20 MPa
Maximum Speed: 4000 r/min
Theoretical Torque: 20.3 N·m
Weight: 2.0 kg
GM5-8 / GM5-8-AE13S-20-L
Displacement: 8.1 cm³/rev
Rated Pressure: 20 MPa
Maximum Speed: 3600 r/min
Theoretical Torque: 25.6 N·m
Weight: 2.2 kg
GM5-10
Displacement: 10.0 cm³/rev
Rated Pressure: 21 MPa
Maximum Speed: 3600 r/min
Theoretical Torque: 31.8 N·m
Weight: 2.3 kg
GM5-12
Displacement: 12.6 cm³/rev
Rated Pressure: 20 MPa
Maximum Speed: 3600 r/min
Theoretical Torque: 39.8 N·m
Weight: 2.6 kg
GM5-16
Displacement: 15.9 cm³/rev
Rated Pressure: 20 MPa
Maximum Speed: 3200 r/min
Theoretical Torque: 50.3 N·m
Weight: 3.1 kg
GM5-20
Displacement: 19.9 cm³/rev
Rated Pressure: 16 MPa
Maximum Speed: 2800 r/min
Theoretical Torque: 63.7 N·m
Weight: 3.4 kg
GM5-25
Displacement: 25.0 cm³/rev
Rated Pressure: 16 MPa
Maximum Speed: 2600 r/min
Theoretical Torque: 79.8 N·m
Weight: 3.7 kg
Key Technical Advantages
1. Axial Flexible Compensation and Radial Hydraulic Balance for High Efficiency
The GM5 Series features axial flexible compensation and radial hydraulic balance. The pressure plate serves as the primary component for radial and axial pressure compensation, reducing bearing loads and automatically adjusting gear axial clearance – effectively improving pump performance and operational reliability. This design significantly minimizes internal leakage, improves volumetric efficiency, and maintains stable flow output across all operating conditions.
2. DU Bearings for Long Service Life and High Reliability
Two DU bearings are pressed into each of the front and rear covers. DU material is the ideal bearing material for gear pumps, offering excellent self-lubricating properties and wear resistance, significantly extending pump service life. Combined with the three-piece split housing design, service life under high-pressure, high-speed conditions is significantly extended.
3. Three-Piece Split Housing for Compact Lightweight Design
The GM5 Series features a three-piece split housing design consisting of a front cover, center housing, and rear cover with gears. The compact structure offers minimal size – the GM5-5 has a minimum height of just 84 mm and can be held in one hand. The lightweight design simplifies installation and reduces the load on host machinery – particularly critical for weight-sensitive mobile equipment applications.
4. Wide Displacement Coverage and Flexible Configuration
The GM5 Series offers eight displacement options from 5.1 to 25.0 cm³/rev (5/6/8/10/12/16/20/25). Multiple shaft types (parallel keyed E13, splined H15, etc.), port connections (metric thread S, BSP thread R, flange F, etc.), and rotation directions (left-hand L / right-hand R) are available. The extensive selection ensures precise matching to diverse application requirements.
5. High-Speed Performance for High-Speed Applications
The GM5 Series achieves maximum speeds up to 4000 r/min, maintaining low noise and low pulsation output with long service life even at high speeds. This characteristic makes it particularly suitable for high-speed hydraulic systems and compact space applications with demanding speed requirements.
Application Areas
Construction Equipment: Small loaders, excavator attachments
Agricultural Machinery: Tractors, harvesters, seeders, crop protection machinery
Material Handling Equipment: Forklifts, crane and material handling equipment
Municipal Vehicles: Street sweepers, cleaning vehicles, garbage trucks
Industrial Equipment: Plastics machinery, woodworking machinery, environmental equipment
Special Purpose Vehicles: Hydraulic systems for various special vehicles
Industrial Hydraulic Systems: Various industrial hydraulic power units
Expert Maintenance Tips
1. Model Confirmation and Selection
Complete GM5 series model should include: Series (GM5) + Displacement Code (5/6/8/10/12/16/20/25) + Structure Config (A) + Shaft Type (E13/H15, etc.) + Port Type (S/R/F, etc.) + Design Number (20) + Rotation Direction (L/R) .
E13 indicates parallel keyed shaft; S indicates metric thread ports; L indicates left-hand (counter-clockwise); R indicates right-hand (clockwise).
Pressure ratings vary by model: GM5-5/6/8/12/16: 20 MPa; GM5-10: 21 MPa; GM5-20/25: 16 MPa.
Verify system operating pressure, flow requirements, and rotation direction during selection.
2. Pre-Installation Checks
GM5 Series pumps have a fixed rotation direction (L = left-hand, R = right-hand) – verify matches system drive direction before installation.
Confirm mounting flange type and drive shaft specification (parallel keyed E13 or splined H15) precisely match system interface.
Confirm port connection type (metric thread S, BSP thread R, or flange F) precisely matches hydraulic fittings.
Never use hammer-driven installation – always use proper tools.
3. First Start-Up & Oil Priming
Prime the pump housing with clean hydraulic oil before first start-up; ensure suction line is fully filled – never run dry.
Operating temperature range: 0 – 120℃.
Maximum speed limits: GM5-5/6: 4000 r/min; GM5-8/10/12: 3600 r/min; GM5-16: 3200 r/min; GM5-20: 2800 r/min; GM5-25: 2600 r/min.
4. Filtration & Fluid Cleanliness
5. Operating Monitoring
Continuous operating pressure must not exceed the rated pressure for each model.
If abnormal noise or pressure fluctuation occurs, first check suction lines for leakage or blockage.
Regularly check torque on pump and piping connection bolts to prevent loosening from vibration.
