Product Overview
The PERMCO P7600 / P5100 / P3100 Series are heavy-duty high-pressure external gear pumps manufactured by PERMCO USA, covering large, medium, and small displacement ranges to comprehensively address the hydraulic system requirements of construction machinery, road machinery, and special-purpose vehicles.
As direct OEM replacement solutions, these products are manufactured to strict OEM technical standards, ensuring 100% interchangeability with existing hydraulic systems. Every unit undergoes 100% simulated duty-cycle testing to validate volumetric efficiency, thermal performance, and seal integrity under rated load conditions—ensuring reliable operation in heavy-load, high-dust, and high-temperature environments.
Technical Specifications
P7600 Series (Large Displacement, Roller Bearing)
Series Type: Large-frame roller bearing gear pump/motor
Displacement Range: 33.1 – 198.8 ml/r (2.02 – 12.10 in³/r)
Rated Pressure: 21 MPa (3,000 PSI)
Maximum Pressure: 25 MPa (3,625 PSI)
Peak Pressure: 28 MPa (4,060 PSI)
Maximum Speed: 2,400 RPM
Minimum Speed: 600 RPM
Gear Width Range: 1/2″ – 3″
Bearing Type: Needle roller bearing (pressure-controlled, US patent)
Port Standard: SAE standard flange interface
Housing Material: High-strength cast iron
Operating Temperature: -30°C to +90°C
P5100 Series (Medium Displacement, Roller Bearing)
Series Type: Medium-frame roller bearing gear pump/motor
Displacement Range: 21.1 – 105.4 ml/r (1.28 – 6.43 in³/r)
Rated Pressure: 21 MPa (3,000 PSI)
Maximum Pressure: 25 MPa (3,625 PSI)
Peak Pressure: 28 MPa (4,060 PSI)
Maximum Speed: 2,400 RPM
Minimum Speed: 600 RPM
Gear Width Range: 1/2″ – 2-1/2″
Bearing Type: Needle roller bearing
Port Standard: SAE standard flange interface
Housing Material: High-strength cast iron
Operating Temperature: -30°C to +90°C
P3100 Series (Small Displacement, Roller Bearing)
Series Type: Small-frame roller bearing gear pump/motor
Displacement Range: 16.4 – 65.5 ml/r (1.00 – 4.00 in³/r)
Rated Pressure: 21 MPa (3,000 PSI)
Maximum Pressure: 25 MPa (3,625 PSI)
Peak Pressure: 28 MPa (4,060 PSI)
Maximum Speed: 2,400 RPM
Minimum Speed: 600 RPM
Gear Width Range: 1/2″ – 2″
Bearing Type: Needle roller bearing
Port Standard: SAE standard flange interface
Housing Material: High-strength cast iron
Operating Temperature: -30°C to +90°C
P124 / P197 / P257 / P360 Series (Bushing Bearing)
Series Type: Bushing (sleeve) bearing gear pump/motor
Displacement Range: 2 – 180 ml/r
Rated Pressure: 21 – 28 MPa
Maximum Pressure: 25 – 32 MPa
Maximum Speed: 2,400 – 3,000 RPM (model dependent)
Bearing Type: Sleeve/bushing bearing
Port Standard: SAE standard flange interface
Key Technical Advantages
1. US Patent Pressure-Controlled Roller Bearing Technology (P7600/P5100/P3100 Series)
The P7600/P5100/P3100 series feature PERMCO’s proprietary US-patented pressure-controlled roller bearing technology, which actively manages bearing clearance through hydraulic pressure—extending service life by 30% compared to conventional designs. This design is particularly critical under high-load, high-speed operating conditions, effectively reducing bearing wear rates and extending maintenance intervals.
2. Advanced Side Plate Design with Secondary Sealing Technology
These series incorporate PERMCO’s patented secondary sealing structure and specially surface-treated side plates. This configuration achieves optimal axial clearance control through automatic hydraulic compensation, significantly improving volumetric efficiency while minimizing internal leakage. The specialized surface treatment of the side plates delivers exceptional wear and pressure resistance—a design protected by both US and Chinese patents.
3. Full SAE Standard Interface – 100% Drop-In Interchangeability
All PERMCO gear pumps and motors feature SAE standard flange and shaft configurations. The P7600, P5100, and P3100 series—as well as different displacement variants within each series—share identical mounting dimensions. End users can achieve direct drop-in replacement without any modifications, significantly reducing equipment downtime.
4. Precision Dry Assembly Process with Strict Cleanliness Control
PERMCO products are manufactured using a proprietary dry assembly process in a rigorously clean assembly environment. This process ensures that internal components remain free from contaminant ingress during assembly, guaranteeing long-term precision and reliability of gear pairs, bearings, and seals. Every unit undergoes comprehensive performance testing prior to shipment.
5. Ultra-Wide Displacement Coverage with Flexible Multiple Pump Configurations
The P7600, P5100, and P3100 series collectively offer displacement coverage from 16.4 ml/r to 198.8 ml/r, addressing flow requirements ranging from compact loaders to large-scale mining equipment. Products can be configured as single pumps or multiple pumps (tandem/parallel combinations) per customer requirements, enabling compact hydraulic system layouts with multiple pump stages in a single assembly.
Application Areas
PERMCO P7600/P5100/P3100 series gear pumps and motors are widely deployed across the following heavy equipment categories:
Wheel Loaders: Wheel loaders, underground mining loaders
Road Rollers: Vibratory rollers, static rollers
Bulldozers: Track-type bulldozers, swamp bulldozers
Motor Graders: Self-propelled graders
Cranes & Truck Cranes: Truck-mounted cranes, crawler cranes, loader cranes
Forklifts: Heavy-duty forklifts, container handlers
Oilfield Equipment: Drilling rigs, workover rigs
Mining Equipment: Shearer loaders, roadheaders
Special Purpose Vehicles: Dump trucks, refuse trucks, concrete mixer trucks
Expert Maintenance Tips
1. Correct Model Selection – Distinguishing P Series from M Series
In PERMCO product nomenclature, “P” prefix denotes Pump, while “M” prefix denotes Motor. The internal configurations differ and these are not interchangeable. Always verify whether your equipment requires a pump or a motor before selection.
2. Verify Rotation Direction
Confirm the rotation direction of the original pump/motor on your equipment before installation. PERMCO gear pumps support bi-directional rotation, but the specific inlet/outlet port configuration is rotation-dependent. Select the appropriate port layout based on the original equipment’s rotation direction.
3. Prime the Pump Before First Start
Fill the pump cavity with clean hydraulic fluid through the suction port prior to initial startup. Dry-starting will cause rapid wear to gears and bearings under unlubricated conditions, potentially leading to catastrophic pump failure.
4. Maintain Fluid Cleanliness
Although PERMCO gear pumps offer high tolerance to fluid quality variations, for optimal service life we recommend a minimum filtration level of ISO 4406 19/17/14 or NAS 1638 Class 8. Regularly inspect filter elements to prevent particles larger than 10μm from accelerating gear and bearing wear.
5. Monitor Operating Temperature
The normal operating temperature range for these pumps is -30°C to +90°C. Keep housing surface temperature below 90°C and system oil temperature within the 15–65°C range. If temperatures exceed these limits, inspect the cooling system or fluid viscosity.
6. Periodic Torque Check on Mounting Bolts
Given the common use of these pumps in high-vibration equipment, we recommend checking mounting bolt and flange bolt torque every 500 operating hours to prevent loosening-induced leakage or misalignment.
