HMS072 9177550 Swing Motor Assembly for Hitachi ZX120 Excavator

Dealing with 12-ton upper carriage drift on steep side slopes, violent mechanical rebound shudder when centering the swing joystick, or gear oil leaking into your slewing ring grease tub on your Hitachi ZX120? The HMS072 9177550 Swing Motor assembly with planetary reduction gearbox by Tatan is engineered specifically for 12-ton heavy earthmoving excavators. Pre-assembled with wet multi-disc parking brakes, dual anti-reaction shock relief valves, and 20CrNiMo carburized planetary reduction gears, it locks holding torque at 29.4 MPa and restores smooth, precise slewing positioning with zero pipe alterations.

Need Pinion Tooth Count & Flange Pilot Verification?

Contact Senior Hydraulic Specialist Gavin for free swing drive matching & machine serial-number double-check:

What Equipment Owners & Hydraulic Mechanics Get from Tatan:

  • Stops 12-Ton Superstructure Drift: Spring-applied wet multi-disc parking brakes lock the excavator upper house rigidly on 30-degree slopes immediately upon joystick neutral return.
  • Smooth Anti-Reaction Cushioned Braking: Built-in dual anti-rebound shock relief valves absorb rotational kinetic inertia, preventing gear tooth shear during rapid back-and-forth trench backfilling.
  • 100% Direct Bolt-On for ZX120: Precision CNC-machined mounting flange, output pinion shaft, and port threads align directly with Hitachi 9177550 chassis lines right out of the crate.
  • Zero Gear Oil Contamination: Upgraded lower shaft mechanical face seals retain SAE 80W-90 gear lubricant and lock out slurry, dirt, and wash-down water from the planetary carrier.
  • Automated Test-Bench Certified: Full-load holding torque, 29.4 MPa relief cracking pressure, and casing drain flow rates 100% verified before crate packaging.
  • Backed by a 12-Month Warranty: Zero MOQ (1 PC accepted) with fast 3-7 day global air express or sea container freight options.

Description

HMS072 9177550 Swing Motor Assembly Overview

The HMS072 9177550 Swing Motor assembly manufactured by Tatan is an integrated dual-axial piston hydraulic drive with heavy-duty multi-stage planetary reduction gearing belonging to our Swing Motor Assembly classification. Engineered specifically for Hitachi ZX120, ZX120-1, ZX120-3, and ZX135US 12-ton crawler excavators, replacing your worn swing drive with a Tatan complete assembly eliminates superstructure drifting on slopes, prevents sudden hydraulic stopping shocks, and cures internal casing bypass across demanding civil excavation applications.

Operating under direct pressure flow from the machine’s main hydraulic pump and routed through the main control valve assembly, this swing device incorporates carburized alloy sun and planet gears, a hydraulic-release parking brake pack, and dual anti-rebound cushion valves, ensuring 100% direct bolt-on installation with turntable frames and chassis pilot lines.

⚠️ Pinion Shaft & Flange Verification: Hitachi ZX120 series excavators feature specific swing pinion tooth profiles and mounting pilot diameters. Please send your original motor nameplate photo or count your output pinion teeth to Gavin for free verification before dispatch.

Key Attributes & Technical Parameters for HMS072 9177550 Swing Motor

Product CategorySwing Motor AssemblyWarranty1 Year / 12 Months
Specific Valve ModelHitachi / Kayaba HMS072 / HMS072AG-2UABrand NameTatan
Compatible EquipmentHitachi ZX120 | ZX120-1 | ZX120-3 | ZX135USOEM Part Number9177550 / 9196961 / 9188270
Matched Engine SeriesIsuzu 4BG1T / 4JJ1X Diesel Engine (72 kW)Place of OriginGuangdong, China
Max Relief Pressure29.4 MPa (294 bar / 4264 PSI Cushion Relief)Brake Release Pressure3.9 MPa (39 bar Pilot Hydraulic Line)
Spool Precision SpecMicro-Lapped Valve Plate < 0.003 mmQuality Status100% Brand New Motor & Gearbox Unit
Machinery Test ReportProvided (100% Bench Holding Tested)Video Outgoing-InspectionProvided Before Shipping
Gear Oil SpecSAE 80W-90 / SAE 85W-140 EPPackagingExport Wooden Box Packaging

Excavator Hydraulic Drives & Swing Machinery Inventory

Tatan maintains extensive factory inventory of complete integrated swing devices, planetary reduction gearboxes, hydraulic piston motors, and replacement internal rotating groups for earthmoving machinery:

Tatan Hydraulic Swing Motors Pumps Valves and Undercarriage Drives for Hitachi Komatsu Caterpillar Excavators

Supported Excavator Machinery Brands & Swing Drive Lineup

In addition to Hitachi crawler excavators, Tatan manufactures and supplies replacement swing hydraulic motors, planetary reduction gears, and slewing rings across global equipment brands:

Tatan Compatible Excavator Machinery Brands Display Hitachi Komatsu Kobelco Caterpillar Volvo Doosan

Application Scenarios & Buyer Value

When replacing your 12-ton excavator slewing unit with our HMS072 9177550 Swing Motor, machine operators and fleet managers secure measurable field reliability:

Application ScenarioValue Delivered to Buyer
Hitachi ZX120 Motor Replacement1:1 direct bolt-on installation eliminates carriage creep on side slopes and restores sharp boom swing acceleration.
Heavy Equipment Repair WorkshopsAvoids the complex labor of shimming internal brake friction discs; installs as a factory-tested complete reduction unit.
Quarry & Civil Earthmoving FleetsBuilt-in anti-reaction cushion valves protect swing gearbox teeth from fatigue fracture during rapid back-and-forth trench backfilling.
Machinery Parts StockistsHigh-demand 12-ton swing motor inventory packaged in solid export wooden crates ready for immediate global dispatch.

HMS072 9177550 Swing Motor Diagnostic & Troubleshooting Guide

Use this technical guide to diagnose common swing motor and reduction gearbox symptoms on Hitachi ZX120 series crawler excavators:

Hydraulic Fault SymptomTechnical Cause AnalysisTatan Factory-Grade Solution
1. Superstructure creeps or drifts when parked on side inclineMechanical parking brake friction discs glazed or brake release piston seal leaking pilot fluid into casing.Replace with Tatan 9177550 complete swing motor assembly fitted with factory pre-seated wet multi-disc brake pack.
2. Violent shudder / clunking when releasing swing joystickAnti-reaction check valve poppet contamination or cushion relief valve spring fatigue failing to absorb 12-ton inertia rebound.Clean relief valve cartridges, reset 29.4 MPa relief pressure, or install new Tatan pre-calibrated swing drive assembly.
3. Weak slewing acceleration and motor casing temperature > 80°CMicro-scoring across bronze valve plate and cylinder barrel face allowing high-pressure fluid to bypass into case drain.Install Tatan new swing motor with micro-lapped bimetal valve plates (< 0.003 mm tolerance); flush hydraulic lines.
4. Gear oil leaking downward into swing bearing grease tubLower output shaft mechanical face seal or radial lip seal failure caused by dirt ingress or wire wrapping around pinion.Replace complete reduction unit to prevent dry friction wear and tooth fracture in the planetary gear carrier.

Transport Packaging & Certified Quality Assurance

Precision hydraulic motors and gearboxes require absolute shock protection. Every Tatan unit is sealed and packaged in solid export timber crates:

Global shipping supported by multiple logistics companies DHL FedEx UPS Sea Air Freight
Tatan Quality Assurance ISO9001 CE Qualification Certificates

✈️ Express Air Courier

Partnered with DHL, FedEx, and UPS for 3-7 day priority delivery worldwide.

🚢 Sea Cargo Freight

LCL and FCL container ocean freight for bulk equipment parts replenishment.

📦 Export Wooden Crates

Solid fumigated timber cases lined with thick shockproof foam to prevent transit damage.

HMS072 9177550 Swing Motor FAQ & Related Categories

Q1: Is this HMS072 9177550 Swing Motor compatible with Hitachi ZX120 excavators?
A: Yes. The HMS072 9177550 / 9196961 swing drive is the direct factory replacement for Hitachi ZX120, ZX120-1, ZX120-3, and ZX135US excavators. Send your original motor nameplate photo to Gavin for precise pinion tooth confirmation.
Q2: Does this unit include both the hydraulic motor and reduction gearbox?
A: Yes. Tatan supplies 100% complete turnkey assemblies, including the HMS072 hydraulic piston motor, integrated parking brake pack, cushion relief valves, and planetary reduction gearbox ready to mount.
Q3: What are the primary OEM part numbers for this Hitachi ZX120 swing motor?
A: Common cross-reference part numbers include 9177550, 9196961, 9188270, and 9262018.

Get Wholesale Factory Quote for HMS072 9177550 Swing Motor

Looking for direct factory pricing, stock availability, or technical advice for Hitachi ZX120 swing motors? Contact senior engineer Gavin now!

💡 Fast Quote: Send your machine serial number or old swing motor photos for a 100% accurate match within 10 minutes!

* Note: Wholesale Reference Price Starts From $300.00. Please contact Gavin for a final customized quote.

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