RexrothPGH4 Series 25cc Fixed Displacement Internal Gear Pump for Open Circuit Industrial Hydraulic System

Key Features

1. Fixed displacement internal gear pump, gap compensation design

2. Displacement:25 cc/rev, for open hydraulic circuit

3. Max working pressure: 350 bar (35MPa)

4. Low flow pulsation, ultra-low running noise

5. High volumetric efficiency even under low speed & low viscosity

6. Wide applicable viscosity and speed range

7. Modular structure, combinable with other pumps

8. FKM fluoro rubber seals, good medium compatibility

Technical Parameters

Specification:

Application Scenarios

· Injection molding machine / Plastic processing machinery

· Hydraulic press & automated forging machine

· Foundry & casting equipment

· CNC machine tools

· Hydraulic power unit, accumulator charging system

· General heavy-duty stationary industrial hydraulic drive

Competitive Advantage:

1. This Rexroth PGH4-21/025RE11VU2 is an internal gear pump with optimized gear profile. It delivers low flow pulsation and low noise with stable pressure output, perfectly suited for industrial hydraulic equipment such as CNC machine tools and injection molding machines that require strict vibration and noise control.
2. It has a compact layout with reliable radial and axial compensation design. It maintains high volumetric efficiency and low internal leakage under high pressure. Stable continuous operation supports non-stop running of hydraulic power units and reduces downtime.
3. Standard mounting flange and port dimensions bring excellent interchangeability. The PGH4 series has a large installed base and easily accessible spare parts. Simple disassembly and replacement make it a preferred quiet hydraulic power source for industrial retrofit and spare part replacement.

The Analysis For Rexroth PGH4-21 Gear Pump Common Breakdown:

1. Insufficient pump flow and difficulty building system pressure. It is usually caused by excessive internal leakage from worn gears and side plates, or high suction resistance from blocked suction filters. It leads to weak feed movement of machine tools and slow pressure build-up of injection molding machines.
2. Sharply increased noise and vibration during operation. Common causes include contaminated hydraulic oil, air entering the suction line or worn bearings. Excessive vibration and noise impair machining accuracy and accelerate wear of internal precision components.
3. Severe overheating of the pump housing. It mainly results from enlarged internal clearance due to wear, high return back pressure or improper oil viscosity. Accumulated heat speeds up seal aging and worsens internal leakage, shortening the service life of the gear pump.