SK120‑5 Hydraulic Main Pump for Kobelco SK120‑5 12‑ton Medium‑small Excavator spare parts

Short Description:

The Kobelco SK120‑5 hydraulic main pump is an original K3V series negative‑flow dual‑variable piston pump, the core hydraulic power source matched for Kobelco SK120‑5 12‑ton medium‑small excavator. Precisely calibrated for negative‑flow control hydraulic system, it perfectly matches the engine power‑torque curve of SK120‑5, converting mechanical rotational power into high‑pressure hydraulic energy. It supplies stable pressurized oil flow for boom, arm, bucket, travel and swing hydraulic actuators. Optimized for earth‑moving project, foundation excavation, municipal construction and material‑loading conditions, this main pump delivers stable power output, sensitive response and reliable negative‑flow regulation, adapting to long‑time continuous medium‑intensity construction scenarios.

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description

Genuine Kobelco SK120‑5 main pump adopts mature dual‑piston variable displacement structure, equipped with negative‑flow control valve group, LS load‑sensing valve, servo piston assembly and built‑in boost pump. Driven by engine output power, the pump adjusts displacement in real‑time according to negative‑flow feedback signal to realize power matching between engine and hydraulic circuit. Core plunger‑barrel pairs, valve‑plate and slipper components adopt super‑precision grinding and surface quenching hardening treatment, reducing internal leakage and friction loss under cyclic load impact. High‑strength cast pump housing resists construction‑site vibration and pressure shock. Every finished pump passes factory full‑pressure impulse test, displacement calibration and long‑cycle endurance inspection. Compared with older‑generation pump assemblies, SK120‑5 main pump features stable negative‑flow response, good anti‑contamination performance and convenient field adjustment, effectively improving typical faults such as weak digging force, slow movement response and excessive system heat generation for medium‑small‑tonnage excavators.

product parameters

Brand: KOBELCO Genuine Original

Model: SK120‑5

Product Name: Negative‑Flow Control Dual‑Variable Piston Hydraulic Main Pump Assembly

Applicable Equipment: Kobelco SK120‑5 12‑ton Medium‑small Excavator

Structural Type: Dual‑piston variable displacement pump, negative‑flow hydraulic control system, mechanical‑hydraulic feedback regulation

Core Structure: High‑strength cast pump housing, hardened plunger‑cylinder assembly, wear‑resistant valve‑plate & slipper, negative‑flow control valve group, LS load‑sensing valve, servo piston unit, built‑in charge pump, high‑pressure ageing‑resistant sealing group

Main Material: High‑strength alloy cast housing, carburized hardened alloy plunger, high‑precision valve‑plate, composite high‑pressure sealing parts

Core Function: Convert mechanical energy to high‑pressure hydraulic energy, variable displacement adjustment, negative‑flow power matching, overload pressure limiting protection, hydraulic energy supply for whole‑machine actuators

Working Characteristics: Mechanical‑hydraulic feedback, sensitive negative‑flow response, stable displacement regulation, good anti‑pollution performance, convenient pressure‑flow onsite adjustment

Working Condition Adaptation: Earth‑moving construction, foundation excavation, municipal engineering, material loading, long‑duration medium‑load cyclic operation

Matching Parts: SK120‑5 negative‑flow main control valve, hydraulic cylinder group, travel & swing motor, PPC pilot valve, high‑pressure hydraulic pipeline and filter elements

advantages

Exclusive negative‑flow system calibration for SK120‑5, perfect power matching with original engine and main control valve, delivering stable hydraulic power under earth‑moving and light‑loading working conditions.
Combined negative‑flow feedback and LS load‑sensing control dynamically adjusts pump displacement according to actual load, reducing unnecessary power loss and improving fuel‑saving performance.
Hardened precision plunger‑cylinder and slipper‑valve‑plate assemblies minimize internal leakage, maintaining stable output performance after long‑time continuous medium‑intensity site operation.
Built‑in charge pump supplies stable pilot oil source, ensuring reliable pilot operation under variable load conditions.
Heavy‑duty cast pump housing withstands frequent pressure impact and construction‑site vibration, enhancing reliability under complex municipal and earth‑work environments.
Modular internal control‑valve layout supports partial component replacement, lowering spare‑parts cost and on‑site maintenance difficulty for 12‑ton medium‑small machines.
Original mounting dimensions support one‑to‑one direct replacement without modification, shortening equipment downtime for overhaul and reconstruction.

maintenance & replacement tips

Inspect pump mounting bolts, pilot‑port connector and oil‑port sealing surfaces regularly to eliminate oil‑leak risks caused by long‑term construction‑site vibration and mechanical impact.
Replace hydraulic oil and filter elements strictly following Kobelco official maintenance cycles, to prevent hard granular impurities from scratching precision plunger‑barrel pairs and degrading main‑pump performance.
Adopt qualified high‑cleanliness hydraulic oil, to avoid internal component sticking and negative‑flow signal disorder triggered by oil contamination and deterioration.
Periodically test main‑system pressure, pump output displacement and negative‑flow feedback response status, ensuring the hydraulic main pump runs within the rated pressure range of SK120‑5.
Avoid persistent full‑load overpressure operation and frequent violent impact, to slow fatigue wear of internal precision hydraulic components.
Replace genuine Kobelco SK120‑5 hydraulic main pump timely once faults including insufficient digging power, slow actuator response, obvious internal leakage and system high‑temperature occur, so as to restore full‑machine hydraulic power performance.

warehouse

We have built four spare parts warehouses in Xuzhou, Jining, Kunshan and Changsha to provide customers from all over the world with a variety of high-quality spare parts. We can basically ship self-provided spare parts within three days after confirming the order. If the spare parts need to be adjusted or processed, they will be shipped within 7-30 days.