ناقل الحركة النهائي travel motor 21W-60-41201 لـ حفارة صغيرة Komatsu PC78US-6 PC78UU-6 PC78MR-6

OEM Final Drive Travel Motor for Komatsu PC78US-6 PC78UU-6 PC78MR-6 | Part No. 21W-60-41201

1. Product Overview
The 21W-60-41201 is a heavy-duty integrated hydraulic transmission designed for 7-ton to 8-ton class excavators. It features a high-efficiency axial piston motor paired with a multi-stage planetary reduction gearbox. Given that the PC78 series often operates in tight urban spaces, this drive is engineered for high-precision tracking and superior tractive effort to manage the machine's substantial counterweight and lifting capacity.

2. Comprehensive OEM Part Number Compatibility
This unit is a 100% direct "bolt-on" replacement for the following Komatsu factory part numbers and manufacturer codes:

Komatsu Part Numbers:

21W-60-41201 / 21W6041201

21W-60-41200 / 21W6041200

21W-60-41202 / 21W6041202

Manufacturer Codes (Teijin Seiki / Nabtesco):

TZ507D1000-02

TZ500D200000-K

GM09VN-A-32/53-2

Machine Fitment:

Komatsu PC78US-6

Komatsu PC78UU-6

Komatsu PC78MR-6

(Also compatible with select PC70-7 and PC75UU-3 models; please verify via serial number).

3. Technical Specifications & Performance
Motor Type: Variable displacement axial piston motor with integrated 2-speed (High/Low) travel function.

Gearbox Architecture: Multi-stage planetary reduction using induction-hardened alloy gears to withstand high shock loads.

Max Working Pressure: Rated for continuous operation up to 28.5 MPa (285 bar) to maintain original factory breakout and climbing forces.

Sealing: Heavy-duty "Mirror Seals" (Duo-Cone) designed to protect the gear system from mud, standing water, and abrasive soil.

Integrated Valve Block: Includes built-in relief and counterbalance valves to prevent over-speeding on slopes and ensure smooth braking.

4. Why Partner With a 13-Year Industry Expert?
Nabtesco/OEM Authenticity: We provide original-spec units that match the specific hydraulic curve of the Komatsu PC78. This ensures your machine tracks straight and responds accurately to joystick inputs.

Rigorous Bench Testing: Every unit undergoes a 100% performance test. We verify volumetric efficiency, brake holding torque, and smooth 2-speed shifting before shipment.

Factory-Direct Value: Access Original New units at competitive wholesale prices, providing a significant cost advantage over local dealership retail.

Global Rapid Logistics: Units are secured in reinforced, shock-proof export wooden crates. Delivery via DHL, FedEx, or UPS typically arrives in 3 to 7 business days.

5. Critical Installation & Maintenance Protocol
Gear Oil Commissioning: Final drives are shipped without gear oil. You must fill the planetary gearbox with SAE 80W-90 gear oil (approximately 1.5–2.0 liters) before operation.

Case Drain Connection: Ensure the case drain line is clear and connected to the correct port. Excessive backpressure in the motor case is the #1 cause of shaft seal failure.

System Flushing: If the previous motor failed due to internal mechanical breakage, the hydraulic tank and lines must be professionally flushed to remove metal debris.

Air Purging: After installation, lift the track and run the motor at low speed for several minutes to purge air from the hydraulic circuit before applying full load.

6. Ordering & Professional Support
Fitment Verification: To ensure 100% accuracy, please provide your Machine Serial Number and the number of sprocket mounting holes.

Instant Quote: Contact us today for up-to-date pricing, tiered quality options, and current stock availability.

Technical Guidance: Our expert team is available 24/7 to assist with installation procedures, hydraulic pressure settings, and troubleshooting.