DH420 Travel Reducer 401-00005A Excavator Final Drive For PC200 / PC220 Excavator

DH420 Travel Reduction Gearbox 401-00005A Final Drive for PC200/PC220 Excavator Excavator Machinery Parts

The travel reducer (popularly called travel gearbox) of an excavator is a core transmission element linking the hydraulic motor to the track drive wheel. It reduces rotation rate and boosts torque, generating low‑speed high‑torque driving force for tracks.Core Structure (Three‑Stage Planetary Gear Module)• Sun Gear: Linked to hydraulic motor input and serves as power source component.• Planet Gears: 3 to 4 gears orbiting the sun gear while spinning individually for power delivery.• Ring Gear (Internal Gear Ring): Fixed or floating design meshing with planet gears.• Planet Carrier: Outputs driving power to move reducer casing and track drive wheel.• Casing & Bearings: High‑rigidity casing offers dustproof and leakproof performance; heavy‑duty bearings support rotary operation.• Brake: Embedded multi‑disc parking brake, spring‑applied and hydraulically released, avoiding downhill rollaway.Working PrincipleHigh‑speed low‑torque power output from hydraulic motor enters travel reducer → three‑stage planetary gears perform progressive speed reduction → low‑speed high‑torque power is produced → drives tracks for movement.Typical Operational Faults and Causes
1. Irregular or amplified noise: Gear erosion, bearing damage, inadequate lubricant or degraded oil property.
2. Oil leakage trouble: Aging seal elements, casing cracks, overfilled oil level.
3. Poor traveling capacity / Track offset: Worn gears/bearings, unreleased brake, asymmetric performance of two‑side reducers.
4. Thermal overheating problem: Overload working, insufficient lubrication efficiency, weak heat emission, persistent brake drag.
5. Gear jumping or sticking issue: Broken gear teeth, damaged planet carrier, foreign substance invasion.

Company Profile