R220-9 Sun Gear Description
The YNF17470 sun gear (39Q6-42240) is a core transmission component used inside the Hyundai R220-9 travel final drive planetary gearbox. It plays a key role in converting hydraulic motor torque into controlled output power for machine movement.
Manufactured using high-strength alloy steel and processed under precision CNC machining standards, the gear ensures accurate tooth meshing with planetary gears and ring gear components. This reduces vibration, improves transmission efficiency, and enhances the overall stability of the travel system.
The heat treatment process increases surface hardness, allowing the gear to withstand continuous heavy-duty operation in harsh working environments such as mining, construction, and earthmoving applications. Strict dimensional control ensures consistent installation compatibility and stable gearbox performance.
Sun Gear 39Q6-42240 Technical Data Sheet
| Item |
Specification |
| Product Name |
Sun Gear / Gear Sun |
| YNF Number |
YNF17470 |
| OEM Part No |
39Q6-42240 |
| Teeth |
20T |
| Machine Model |
Hyundai R220-9 / R220LC-9 / R220-9VS |
| Application |
Travel Final Drive Gearbox |
| Material |
Forged Alloy Steel |
| Hardness |
HRC 45–55 |
| Processing |
CNC Precision Machining |
| Installation Position |
Planetary Gear System (Sun Gear) |
| Brand |
YNF |
| MOQ |
1 Piece |
| Origin |
China |
| Shipping Method |
Air / Sea / Express |
| Payment Terms |
T/T, Western Union, PayPal |
Sun Gear 39Q6-42240 Applications
| Industry |
Usage Scenario |
| Construction |
Excavator travel system repair |
| Mining |
Heavy-duty excavation operations |
| Quarry |
Continuous earthmoving work |
| Infrastructure |
Road and foundation projects |
| Repair Workshop |
Final drive gearbox rebuilding |
R220-9 Sun Gear Detail Display
The sun gear is a critical transmission component in a planetary gear system. In excavator travel gearboxes, it works together with planetary gears and ring gear assemblies to distribute torque efficiently.
Common failure causes include wear from insufficient lubrication, overload conditions, and improper gear meshing. Regular inspection and timely replacement are essential to maintain stable machine operation.
YNF Machinery also provides related R220-9 travel gearbox components, including:
- Planetary gear set
- Carrier assembly
- Ring gear
- Travel reducer housing
