6E Series Excavator Hydraulic Piston Pump 6E-3137 6E-3136 6E-3139 for Machinery Motor Grader 120H 120K 140H 160H 160K

1. Technical parameters
As a dedicated main pump for Caterpillar’s medium-sized excavators, its parameters are adapted to the continuous operation requirements of medium and high pressure. The core indicators are as follows:
Pressure specification: Rated working pressure 31.5MPa, maximum pressure up to 35MPa (short-term overload allowable value), suitable for heavy-load working conditions such as excavator excavation and crushing.
Flow rate and displacement: The displacement is approximately 120mL/rev. At a rated speed of 2000r/min, the theoretical flow rate is about 240L/min. The actual output flow rate fluctuates between 225 and 235L/min due to volumetric efficiency fluctuations.
Efficiency performance: Volumetric efficiency ≥93%, total efficiency ≥87%, and energy loss under continuous high-voltage output is 5%-8% lower than the industry average.
Medium and environment compatibility: Compatible with Caterpillar’s special anti-wear hydraulic oil (ISO VG 46), with a working temperature range of -20 ℃ to 85℃, it can adapt to cold region start-up and high-temperature outdoor operation scenarios.
Drive and installation: It adopts involute splined shaft connection, with a rated input power of approximately 110kW. The flange installation dimensions comply with the standard interfaces of the Caterpillar 320 series excavators. Original factory replacement does not require modification of the installation base.2. Product features and advantages
Core features
Swash plate plunger structure: It adopts Caterpillar’s patented swash plate design. The fit clearance between the plunger and the cylinder block is ≤0.015mm. Under high pressure, the leakage is reduced by 60% compared with gear pumps.
High-strength material configuration: The pump body is made of ductile iron (tensile strength ≥450MPa), and the surface of the swash plate is sprayed with tungsten carbide coating (thickness 0.15mm), which enhances the wear resistance by three times.
Multi-stage filtration protection: The oil inlet integrates a 15μm filter screen, combined with a 5μm fine filter layer inside the pump. The anti-pollution grade reaches ISO 4406 19/17/14, suitable for dusty dense working conditions.
Integrated control module: Equipped with a built-in pressure shut-off valve and flow compensator, it can be directly connected to the main control system of the excavator to achieve load-sensitive control.
Outstanding advantages
Extremely reliable: The core components have passed 3,000 hours of continuous load testing without failure, and the actual service life generally reaches 12,000 to 15,000 hours, which is more than twice that of ordinary domestic pumps.
Remarkable energy-saving effect: The load-sensitive design can automatically adjust the output flow according to the operation requirements, saving 20%-25% energy compared with the fixed displacement pump and reducing the fuel consumption of the excavator.
High maintenance convenience: It adopts a modular structure. Vulnerable parts such as plungers and distribution plates can be replaced separately. The single maintenance time can be controlled within 3 hours, which is 40% shorter than similar products.
Excellent impact resistance: Under impact load conditions such as breakers, pressure fluctuations can be controlled within ±1MPa, and the failure rate is 40% lower than the industry average.

3. Usage functions
The power core of the hydraulic system: It converts the mechanical energy of the engine into hydraulic energy to provide high-pressure oil sources for the actuator mechanisms such as the excavator’s mobile arm, boom, and bucket.
Load sensitive regulation: By using a pressure compensator to sense load changes in real time, the output flow is automatically adjusted to avoid energy waste caused by “a big horse pulling a small cart”.
System safety protection: The set pressure of the pressure shut-off valve is precisely matched with the rated pressure of the excavator’s hydraulic system. In case of overpressure, it can quickly unload within 0.1 seconds to protect the oil cylinder and oil pipe.
Multi-action coordinated control: In conjunction with the Caterpillar PC-E3 controller, it can achieve the compound actions of boom lifting and bucket digging, increasing the operation efficiency by 15%.

4. Product detail description
Model attribute: “6E” is the series code of Caterpillar medium hydraulic pump, and “3137” is the specific accessory number, belonging to the category of Genuine Cat Parts.
Physical specifications: Length × width × height approximately 420×260×210mm, weight 28kg (including installation accessories), compact volume suitable for the layout of the excavator engine compartment.
Interface configuration: The diameter of the oil inlet is φ65mm, and the diameter of the oil outlet is φ50mm. It adopts SAE flange connection, and the sealing surface is spherical structure, which improves the sealing reliability by 20% under high pressure.
Quality Certification: Passed the ISO 9001 quality system certification and the original factory installation test of Caterpillar. Each pump is equipped with a unique QR code, allowing for the traceability of production batches and quality inspection information.
Packaging and storage: Vacuum anti-rust packaging + cushioning foam is adopted, with a high-strength plywood box on the outside. The storage validity period can reach 2 years (unopened).

5. Applicable machines and scenarios
Applicable machines
Caterpillar’s main models: excavators 320C, 320D, 323D, 325C, loaders 950H, etc., are the original factory standard main pumps for these models.
Compatible alternative scenarios: After parameter matching, it can be used for the refurbishment of second-hand equipment of the same power level from Caterpillar, the replacement of faulty pumps, and the power system upgrade of some domestic excavators.
Applicable scenarios
Mining site: Suitable for heavy-duty excavation operations of iron ore, coal, etc. The high-pressure output feature can drive large buckets to work efficiently, and the anti-pollution design can cope with dusty environments.
Construction site: It is used for earthwork excavation and foundation treatment, and can operate stably in muddy and impurity conditions to ensure the continuous operation of excavators.
Municipal engineering operations: In scenarios such as road construction and demolition and crushing, it ADAPTS to frequent starts and stops as well as impact loads, reducing the frequency of equipment maintenance.
Port handling scenarios: Container and bulk cargo grasping and transshipment operations, precise flow control enables stepless adjustment of operation speed.

6. Relevant models
Direct replacement models of the same series: 6E-3138 (flow-enhanced version, compatible with 325D), 6E-3136 (small displacement version, used for 318C), 6E-3140 (high-pressure version, rated pressure 35MPa).
Structural derivative models: 6E-3137-2S (dual pump structure), 6E-3137-L (with cooling module), meeting the requirements of multiple circuits and high-temperature environments.
After-sales replacement models: CT-3137 (imitating the original factory parameters) and SD-6E3137 (high cost-performance model) launched by domestic manufacturers, with prices ranging from 50% to 60% of the original factory. The compatibility needs to be verified through actual testing.