مخفض آلية الدوران Kawasaki M2X146B-CHB-10A-20 4330222 9148922 لـ حفارة Hitachi EX200-3 EX200-5 EX210H-5 EX210LC-5

Product Identification
Component: Complete Swing Drive Motor Assembly with Planetary Gearbox

Hydraulic Motor Model: Kawasaki M2X146B-CHB-10A-20 (M2X146 Series Architecture)

Motor Part number: 4330222
Gearbox Reducer Part number: 9148922

Machine Compatibility:

Hitachi EX200-3 / EX200LC-3

Hitachi EX200-5 / EX200LC-5

Hitachi EX210H-5 / EX210LC-5

Condition: High-Quality Premium Aftermarket New (Complete Drop-In Unit)

System Function: Provides high-torque rotary hydraulic force and multi-stage speed reduction to rotate the upper structure cabin on 20-ton class excavators.

2. Technical Specifications
Motor Type: Swash Plate Axial Piston Motor with Integrated Valve Casing

Gearbox Type: Heavy-Duty Multi-Stage Planetary Gear Swing Reducer Group

Built-In Valves: Includes integrated dual-cushion relief valves, anti-reverse valves, and dynamic parking brake delay mechanisms to eliminate rotational shock during sudden stops.

Structural Fit: Factory-standard mounting flange, pinion shaft pitch, and hydraulic port threads matching original Hitachi 200-series upper frame dimensions.

3. Critical Installation Requirements
Hydraulic Motor Housing Priming (Mandatory)
Before starting the engine or cycling the swing joystick, you must manually pre-fill the swing motor casing with clean hydraulic fluid through its highest available case drain port. Running an axial piston motor dry—even for a few seconds—will score the swash plate and cylinder block, causing immediate internal bypass and destruction.

Verify Case Drain Line Clearance
Thoroughly inspect the low-pressure case drain hose returning to the hydraulic reservoir. Ensure it is completely free of sharp bends, kinks, or collapsed internal walls. Any restriction in this return circuit creates excessive housing pressure, which will instantly blow out the motor's main shaft oil seal.

Slew Bearing Ring & Gearbox Oil Fill
Check that the lower planetary gear casing is filled to the proper level mark with heavy gear lube (typically SAE 80W-90 or SAE 90 gear oil) prior to operation. Apply a generous layer of heavy-duty lithium grease to the swing drive pinion gear and the main slew ring teeth upon mounting.

System Decontamination & Flushing
If replacing a unit that suffered catastrophic internal breakdown, you must flush the main control valve swing circuit lines, clean out the hydraulic reservoir, and inspect/replace return filters. Residual metallic contamination will rapidly score internal valve plates in the new drive.

4. Frequently Asked Questions (FAQ)
Q: Is the M2X146B-CHB-10A-20 motor and gearbox assembly a direct replacement for EX200-3 and EX200-5 models?
A: Yes. The Kawasaki M2X146 series is the standard framework utilized across Hitachi's 20-ton excavator fleet (including EX200-2, EX200-3, EX200-5, and EX210-5). The mounting bolt circle, output shaft drive pinion, and hydraulic porting align directly with factory connections.

Q: My EX200-5 swings smoothly, but drifting occurs when holding a load on a slope. Will replacing this assembly fix the issue?
A: Yes. Drifting, over-swinging, or failure to hold position when joysticks are in neutral usually indicates worn internal friction brake discs, leaking swing relief valves, or scored cylinder block wear plates inside the motor. Replacing the complete motor and reducer assembly restores factory holding torque.

Q: Is this assembly supplied with the gearbox attached?
A: Yes. This unit is shipped as a complete, pre-assembled combination including the upper Kawasaki M2X146 hydraulic motor block and the lower multi-stage planetary gearbox drive assembly.

5. Shipping & Logistics
Packaging: Thoroughly treated with rust-inhibiting anti-corrosion storage oil, fitted with heavy-duty plastic port plugs, and bolted securely inside an export-safe wooden crate.

Transit Time: Global express air freight via DHL/FedEx/UPS typically delivers within 3 to 7 business days directly to your workshop, or sea freight for non-urgent bulk logistics.