Product Overview
The PGH Series Internal Gear Pumps are high-performance fixed-displacement internal gear pumps from Bosch Rexroth, a global leader in drive and control technologies. The PGH series is renowned for high efficiency, low noise, low pulsation, and long service life, widely used in industrial hydraulics, die casting machinery, injection molding machines, metallurgical equipment, and machine tools.
The PGH series features gap-compensated internal gear pump design with fixed displacement, delivering exceptionally high volumetric efficiency. The pump mainly consists of a mounting flange, housing, cover with through-drive, pinion shaft, internal gear, plain bearings, and axial washers.
PGH5-3X series: Frame size 5, displacements from 63 to 250 cm³/rev
PGH4-3X series: Frame size 4, displacements from 20 to 50 cm³/rev
PGH3-2X series: Frame size 3, component series 2X, displacements from 5 to 16 cm³/rev
Model Code System (based on Bosch Rexroth PGH series designation rules):
PG: Internal gear pump
H: High pressure pump
Frame size (3/4/5) : Series and specification
-2X / -3X: Component series
Numbers after slash (e.g., 011, 040, 080) : Displacement (cm³/rev)
R / L: Rotation direction – R = clockwise, L = counter-clockwise
E / R: Shaft end – E = cylindrical with key (ISO 3019-2), R = geared (ISO 3019-1)
07 / 11: Mounting flange and port specification
VU2: Seal configuration – FKM seals
PGH5-3X/080RR11VU2 model code breakdown:
PGH5-3X: PGH series frame size 5, component series 3X
080: Displacement – 81.4 cm³/rev
R: Rotation direction – Clockwise
R: Shaft end – Geared (ISO 3019-1)
11: Mounting flange and port specification
VU2: FKM seals
PGH4-3X/040RE11VU2 model code breakdown:
PGH4-3X: PGH series frame size 4, component series 3X
040: Displacement – 40.1 cm³/rev
R: Rotation direction – Clockwise
E: Shaft end – Cylindrical with key (ISO 3019-2)
11: Mounting flange and port specification
VU2: FKM seals
PGH3-2X/011RE07VU2 model code breakdown:
PGH3-2X: PGH series frame size 3, component series 2X
011: Displacement – approx. 11 cm³/rev
R: Rotation direction – Clockwise
E: Shaft end – Cylindrical with key (ISO 3019-2)
07: Mounting flange and port specification
VU2: FKM seals
We specialize in the R&D and manufacturing of high-pressure pumps, motors, and valve groups. All PGH series models offer 100% direct interchangeability with original Bosch Rexroth PGH series pumps of the same model—no modification required. Every unit undergoes 100% simulated load testing before shipment, ensuring performance validation under real-world operating conditions.
Technical Specifications
PGH Series General Specifications:
Brand Series: Bosch Rexroth PGH Series
Pump Type: Gap-compensated internal gear pump (fixed displacement)
Body Material: Cast iron housing
Bearings: Plain bearings (hydrodynamic lubrication)
Seal Material: VU2 = FKM seals
Fluid Media: HLP, HEES, HFDU, and other hydraulic fluids
Mounting Flange: ISO 3019-1 / ISO 3019-2 compliant
Rotation Direction: Clockwise (R designation)
PGH5-3X/080RR11VU2 Specifications：
Displacement: 81.4 cm³/rev
Continuous Operating Pressure: 315 bar
Peak Pressure: 350 bar
Maximum Speed: 3000 rpm
Minimum Speed: 200 rpm
Rated Flow (@ 1450 rpm, 10 bar, 30 mm²/s): 116.9 L/min
Maximum Flow: 240 L/min
Weight: Approx. 43.5 kg
Mounting Flange: SAE J744 152-2 (SAE D)
Shaft End: Geared 25-4, 15T 16/32 DP, ISO 3019-1
Pressure Port Rating: 6000 psi
Suction Port Rating: 3000 psi
Fluid Temperature Range: -10°C to +80°C
Viscosity Range: 10 to 300 mm²/s
PGH4-3X/040RE11VU2 Specifications：
Displacement: 40.1 cm³/rev
Continuous Operating Pressure: 315 bar
Peak Pressure: 350 bar
Maximum Flow: 120 L/min
Weight: Approx. 16.56 kg
Shaft End: Cylindrical Ø25 mm with key, ISO 3019-2
Frame Size: 4
Mounting Flange: 4-hole flange, ISO 3019-2
PGH3-2X/011RE07VU2 Specifications：
Displacement: Approx. 11 cm³/rev
Continuous Operating Pressure: 315 bar
Peak Pressure: 350 bar
Flow Rate: 33 L/min
Frame Size: 3
Component Series: 2X
Shaft End: Cylindrical Ø20 mm with key, ISO 3019-2
Rotation Direction: Clockwise
Body Material: Cast iron housing
Note: Specifications above are based on Bosch Rexroth PGH series official technical data. Different configuration codes correspond to different shaft types, flange specifications, and seal materials. Refer to the pump nameplate for exact specifications.
Key Technical Advantages
1. Gap-Compensated Design – Maintains High Volumetric Efficiency Throughout Service Life
The PGH series features axial and radial clearance automatic compensation. Axial compensation uses pressure fields to balance axial washers, achieving perfect sealing with low mechanical losses. Radial compensation elements (segment, segment support, seal rolls) separate suction and pressure zones with automatic clearance adjustment. This design ensures consistently high volumetric efficiency throughout the entire operating life.
2. Hydrodynamic and Hydrostatic Bearings – Stable Operation at Low Speeds and Viscosities
The pinion shaft is supported by hydrodynamically lubricated plain bearings, while the internal gear is hydrostatically mounted in the housing. The sealing gap compensation feature ensures stable operation even at low speeds and low viscosities.
3. Involute Gear System – Low-Noise and Low-Pulsation Operation
The gear tooth system features involute tooth profiles with a large meshing length, effectively reducing flow and pressure pulsation. This design guarantees low-noise and low-pulsation operation.
4. Cast Iron Housing with High-Strength Construction – Withstands Heavy-Duty Industrial Applications
The PGH series features cast iron housing with robust, durable construction. With peak pressures up to 350 barand optimization for variable-speed drives, the pump is suitable for fatigue-resistant drives that require high power and endure numerous load cycles.
5. Optimized for Variable-Speed Drives – No Load Cycle Limitations
The PGH series is optimized for variable-speed drives. The gap-compensated design maintains high efficiency throughout its operational lifespan without load cycle limitations. The pump can be combined with other hydraulic pumps such as axial piston pumps or vane pumps for versatile system integration.
6. Broad Media Compatibility
The PGH series comes standard with FKM seals, compatible with a wide range of hydraulic fluids including HLP mineral oils, HEES synthetic esters, and HFDU polyurethanes. It operates across a wide fluid temperature range of -10°C to +80°C.
7. Wide Speed Range – Flexible Adaptation to Various Drives
The PGH series covers a speed range from 200 rpm to 3000 rpm, allowing slow positioning or high-cycle duty. This wide speed range enables flexible adaptation to various drive motors and variable-speed drive systems.
Application Areas
PGH5-3X/080RR11VU2 (Large Displacement, Frame Size 5):
Die Casting Machines—injection and clamping hydraulic systems
Injection Molding Machines—clamping and injection hydraulic systems
Automated Presses—press hydraulic systems
Accumulator Charging Systems—accumulator charging operations
Plastic Processing Machinery—extruders, molding machines hydraulic systems
PGH4-3X/040RE11VU2 (Medium Displacement, Frame Size 4):
Industrial Hydraulic Systems—hydraulic transmission and control for various industrial equipment
Machine Tools—hydraulic systems for machining centers, lathes
Metallurgical Equipment—hydraulic systems for the metallurgy industry
PGH3-2X/011RE07VU2 (Small Displacement, Frame Size 3):
Machine Tools—hydraulic systems for precision machine tools
Mining Machinery—hydraulic systems for mining equipment
Construction Machinery—hydraulic systems for small construction equipment
Metallurgical Equipment—hydraulic systems for the metallurgy industry
Expert Maintenance Tips
Model Code Verification (verify each element):
PGH series model codes contain critical information. Before selection and installation, confirm the following:
PG: Internal gear pump.
H: High pressure pump.
Frame size (3/4/5) : Series and specification – 3 is smallest, 5 is largest.
-2X / -3X: Component series – 2X for PGH3, 3X for PGH4 and PGH5.
Displacement numbers (e.g., 011, 040, 080) : Displacement (cm³/rev).
Rotation direction (R/L) : R = clockwise, L = counter-clockwise.
Shaft end (E/R) : E = cylindrical with key (ISO 3019-2), R = geared (ISO 3019-1).
07 / 11: Mounting flange and port specification.
VU2: FKM seals.
Verify Rotation Direction:
Confirm that the drive shaft rotation matches the direction code in the model – “R” indicates clockwise, “L” indicates counter-clockwise. Incorrect rotation will prevent pressure build-up and may damage internal gears and bearings.
Mounting Flange and Drive Shaft Matching:
PGH series offers two shaft end types:
E-type: Cylindrical with key, ISO 3019-2
R-type: Geared, ISO 3019-1
Verify that the equipment-side shaft type matches the pump configuration before installation. Mounting flanges conform to ISO 3019-1 (2-hole) or ISO 3019-2 (4-hole) standards.
Suction Line and Fluid Requirements:
PGH series recommends hydraulic fluids meeting ISO/DIN standards (HLP, HEES, HFDU, etc.). Ensure the suction line is properly sealed with no air leaks and the suction filter is not clogged. Viscosity should be maintained within 10 to 300 mm²/s. Fluid temperature should be maintained within -10°C to +80°C.
First-Start Priming Procedure:
After new pump installation or system overhaul, ensure the pump cavity is filled with oil before first start. Jog the pump at low speed and low pressure until the pump body is fully filled with oil and air is purged, then gradually increase to rated speed and working pressure. The PGH series uses plain bearings—running the pump dry will cause irreversible damage to bearings and gears. Repairs on PGH series internal gear pumps may only be performed by the manufacturer or their authorized dealers.
Oil Cleanliness and Regular Maintenance:
Replace hydraulic oil and return filters every 1,000 operating hours or per equipment manufacturer recommendations. Regularly monitor pump body temperature—if it consistently exceeds +80°C, inspect the system cooling. Listen for abnormal noise or vibration during operation; if detected, shut down and troubleshoot immediately.
