Product Overview
The GPY-3R, GPY-4R, GPY-5.8R, GPY-6R, and GPY-7R are representative models of the SHIMADZU GPY series high-pressure external gear pumps. The GPY series is a key product line in Shimadzu’s gear pump portfolio, offering displacements from 2.98 to 11.55 cc/rev, with maximum operating pressures of 20.6 MPa (approx. 206 bar) and peak pressures of 22.6 MPa (approx. 230 bar).
The GPY series gear pumps feature high-precision gears and high-strength aluminum alloy housings, delivering high efficiency, high reliability, light weight, compact construction, and low noise. The series is a compact fixed-displacement external gear pump, commonly used in hydraulic power units, industrial machinery, and mobile equipment.
The GPY series can be configured as double pumps and is widely used in construction machinery, building machinery, agricultural machinery, textile machinery, mining machinery, lifting and transport machinery.
Engineered as a direct OEM-replacement solution for SHIMADZU original products, these models fully comply with Shimadzu original design standards and JIS mounting interface specifications, offering 100% direct interchangeability with OEM pumps. Every unit undergoes 100% workload simulation testing prior to shipment, rigorously validating pressure retention, volumetric efficiency, and internal leakage performance to meet or exceed OEM standards.
Model Code Breakdown (Bulleted List) :
GPY — Series: SHIMADZU GPY High-Pressure Gear Pump
3 / 4 / 5.8 / 6 / 7 — Displacement code: Theoretical output flow (cc/rev)
R — Rotation direction: R = Clockwise (viewed from shaft end)
Technical Specifications
GPY Series General Specifications
Series: SHIMADZU GPY High-Pressure External Gear Pump
Displacement Range: 2.98 – 11.55 cc/rev
Rated Pressure: 20.6 MPa (approx. 206 bar / 210 kgf/cm²)
Peak Pressure: 22.6 MPa (approx. 230 bar)
Mounting Flange: JIS 4-bolt flange
Rotation Direction: R = Clockwise / L = Counter-Clockwise (viewed from shaft end)
Recommended Media: Hydraulic oil
Operating Temperature Range: 30 – 90℃
GPY-3R Specifications
Model: GPY-3R
Theoretical Displacement: 2.98 cc/rev
Rated Pressure: 20.6 MPa (approx. 206 bar)
Peak Pressure: 22.6 MPa (approx. 230 bar)
Minimum Speed: 700 r/min
Maximum Speed: 3000 r/min
Weight: 1.2 kg
GPY-4R Specifications
Model: GPY-4R
Theoretical Displacement: 4.09 cc/rev
Rated Pressure: 20.6 MPa (approx. 206 bar)
Peak Pressure: 22.6 MPa (approx. 230 bar)
Minimum Speed: 500 r/min
Maximum Speed: 3000 r/min
GPY-5.8R Specifications
Model: GPY-5.8R
Theoretical Displacement: 5.77 cc/rev
Rated Pressure: 20.6 MPa (approx. 206 bar)
Peak Pressure: 22.6 MPa (approx. 230 bar)
Minimum Speed: 500 r/min
Maximum Speed: 3000 r/min
GPY-6R Specifications
Model: GPY-6R
Theoretical Displacement: Approx. 6.0 cc/rev
Rated Pressure: 20.6 MPa (approx. 206 bar)
Peak Pressure: 22.6 MPa (approx. 230 bar)
Minimum Speed: 500 r/min
Maximum Speed: 3000 r/min
GPY-7R Specifications
Model: GPY-7R
Theoretical Displacement: 7.07 cc/rev
Rated Pressure: 20.6 MPa (approx. 206 bar)
Peak Pressure: 22.6 MPa (approx. 230 bar)
Minimum Speed: 500 r/min
Maximum Speed: 3000 r/min
Key Technical Advantages
1. High Efficiency & High Reliability
The GPY series features high-precision gears with precise and detailed structural design, delivering high volumetric efficiency and high mechanical efficiency. Advanced casting processes ensure stable and reliable performance. The high-strength aluminum alloy body with multiple high-strength fastening bolts provides excellent sealing, leak resistance, and high-pressure durability.
2. High-Strength Aluminum Housing – Lightweight & High Strength
The pump body is manufactured from high-strength cast aluminum alloy, delivering lightweight design without compromising structural integrity. The aluminum body with high-precision molding design ensures low-noise operation.
3. High-Pressure Capability
Rated pressure of 20.6 MPa (approx. 206 bar) with peak pressures of 22.6 MPa (approx. 230 bar) . High-performance, high-wear-resistance bearings perform reliably under high-pressure and high-speed conditions.
4. Flexible Configuration & Combination Capability
The GPY series supports both clockwise (R) and counter-clockwise (L) rotation directions. The series can be configured as double pumps to meet the oil supply requirements of multi-circuit hydraulic systems.
5. Wide Speed Range – Strong Adaptability
Speed range of 500 – 3000 r/min. Minimum speeds of 500–700 r/min and maximum speeds of 3000 r/min accommodate various prime mover conditions from low-speed to high-speed drives.
6. Broad Application Fields
The GPY series is widely used in automobiles, construction machinery, building machinery, textile machinery, mining machinery, lifting and transport machinery, and agricultural machinery.
7. 100% Factory Tested & Direct Interchangeability
Every unit undergoes 100% workload simulation testing prior to shipment, covering pressure retention verification, internal leakage detection, and flow validation. Fully compliant with SHIMADZU original design standards and JIS mounting interface specifications, with flange dimensions, shaft specifications, and mounting interfaces identical to OEM pumps—direct drop-in replacement with zero modifications required.
Application Areas
The GPY series gear pumps are widely used in the hydraulic systems of the following equipment:
Construction Machinery: Various construction equipment hydraulic systems
Building Machinery: Building equipment hydraulic systems
Agricultural Machinery: Tractors, combine harvesters, and agricultural equipment
Textile Machinery: Textile equipment hydraulic systems
Mining Machinery: Mining equipment hydraulic systems
Lifting & Transport Machinery: Cranes, lift platforms
Hydraulic Power Units (HPU): Core power elements for industrial hydraulic stations
Machine Tools & Automation Equipment
Material Handling & Lifting Equipment
Expert Maintenance Tips
1. Model Confirmation
GPY-3R (2.98 cc/rev), GPY-4R (4.09 cc/rev), GPY-5.8R (5.77 cc/rev), GPY-6R (approx. 6.0 cc/rev), and GPY-7R (7.07 cc/rev) have different displacements. Before installation, confirm the correct displacement based on system flow requirements and verify the complete model code on the pump nameplate.
2. Rotation Direction Confirmation
Suffix “R” indicates clockwise rotation (viewed from shaft end), “L” indicates counter-clockwise rotation. Before installation, always verify that the PTO rotation direction of the host machine matches the pump’s rotation direction—incorrect rotation will result in pump failure to prime and may cause severe damage to gears and bearings within a short period.
3. Installation Precautions
Thoroughly clean the JIS 4-bolt flange and shaft mating surfaces before installation to ensure no debris remains
Use SHIMADZU-specified torque values for mounting bolts—avoid over-tightening which may cause distortion of the aluminum housing
Ensure correct connection of inlet and outlet ports—the inlet line must have no restrictions or sharp bends
Clean the inside of piping with high-pressure oil before installation to prevent hard particles from entering
4. First Start-Up and Bleeding
Before first start-up, must fill the pump with hydraulic oil through the inlet port—never start dry
After start-up, run at low speed with no load for 2–3 minutes to ensure complete air evacuation from the system
Check for abnormal noise or leakage—aluminum housing pumps are particularly sensitive to cavitation
5. Fluid and Filtration
Use high-quality anti-wear hydraulic oil compliant with standards
Maintain operating temperature within 30 – 90℃
Maintain system oil cleanliness to ISO 4406 18/15 or better
Regularly replace return line filters to prevent contaminants from entering the pump
6. Periodic Maintenance
Check mounting bolt torque every 1,000 operating hours
Regularly monitor system operating pressure—not to exceed 20.6 MPa rated pressure (22.6 MPa peak)
Regularly inspect shaft seals to prevent leakage
If flow output decreases, noise levels increase abnormally, or system temperature rises excessively, inspect and replace worn components promptly
