Gear oil pump QX Series QX43-025R138

2. Product Description

The quality QX43-025R138 Internal Gear Oil Pump is engineered by Hengmeisi – a leading China manufacturer and factory direct supplier, designed to be a drop-in replacement for the original Bucher QX43 series gear pump. This model delivers stable 250bar continuous pressure, 97.5% volumetric efficiency, and ultra-low noise operation. With a rated displacement of 25 cm³/rev, the pump provides consistent low-pulsation flow, making it ideal for high-precision and high-pressure hydraulic applications. The robust construction and premium materials ensure long service life in harsh environments.

3. Product Advantages

3.1 Internal Gear Design vs. External Gear Pump Designs

Unlike traditional external gear pumps, the QX43-025R138 Internal Gear Oil Pump uses a precision internal gear profile. This eliminates gear meshing losses and side loads, enabling higher pressure capacity and efficiency. The balanced pressure distribution reduces wear and extends component life by over 30% compared to conventional pumps.

3.2 Premium Materials for Extreme Durability

Gear & Housing: High-strength alloy cast iron, surface hardened, for excellent wear and pressure resistance up to 250bar.

Shaft & Bearings: Hardened steel shaft with precision-ground bearings, supporting continuous operation up to 3000 r/min.

Seals: Imported high-pressure composite seals, rated -30℃ to +120℃, leak-free at maximum working pressure.

Service Life: Over 16,000 hours of reliable operation under rated conditions.

3.3 Built-In Contamination Control

An integrated anti-pollution filter protects the gears and variable mechanisms from hydraulic oil impurities. This feature is critical for long-term reliability in harsh industrial environments, reducing maintenance costs and downtime.

4. Model Code Explanation

The model code QX43-025R138 has a clear and intuitive coding logic, which is easy for purchasers to quickly identify product parameters without professional hydraulic knowledge:

QX: Internal gear oil pump series (core identifier, distinguishing from external gear pumps and vane pumps)

43: High-pressure high-efficiency series code, optimized for 250bar working range

025: Rated displacement of 25 cm³/rev, suitable for medium-to-high pressure hydraulic systems

R: Rotation direction (clockwise rotation)

138: Special port configuration and enhanced sealing variant, customized for industrial heavy-duty applications

5. Product Structure

Core Architecture: Precision Internal Gear StructureComposed of high-precision internal/external gear pair, high-strength cast iron housing, pressure balance plate, and integrated bearing assembly. The symmetrical gear design eliminates radial loads, reducing wear and improving efficiency.

Material Upgrades: Industrial-Grade Construction

Housing: High-strength cast iron with precision CNC machining, ensuring dimensional stability under high pressure and temperature.

Gears: Alloy steel with carburizing and quenching treatment, surface hardness up to HRC60, for excellent wear resistance.

Seals: Imported PTFE composite, high-pressure resistant up to 250 bar, temperature range -30℃ to +120℃.

Integrated Filtration & Protection: Built-In Contamination ResistanceOptimized inlet flow path reduces fluid turbulence and protects the gear pair from hydraulic oil impurities, minimizing wear in poor oil quality environments.

6. Application Scenarios

Plastic Machinery: High-precision injection molding machines, blow molding machines, and extruders

Metallurgical Machinery: High-pressure die-casting machines, continuous casting lines, and rolling mills

Industrial Hydraulic Systems: Machine tools, hydraulic presses, and test benches

Construction Equipment: Hydraulic power units and material handling machinery

Marine & Offshore Applications: Hydraulic power packs and deck machinery