Doosan DH225-7 Swing Gearbox 1St Planetary Carrier Spider With Sun Gear Assy For Excavator parts

Doosan DH225‑7 Swing Gearbox 1St Planetary Carrier Spider With Sun Gear Assy For Excavator parts

Product Overview

This complete first‑stage planetary carrier spider and sun gear assembly serves as the primary reduction core component fitted inside the swing reducer of Doosan DH225‑7 mid‑size crawler excavator. It directly receives torque input delivered by swing motor output shaft, performs initial speed reduction and torque amplification, then transmits driving power to the secondary planetary set to realize upper‑house slewing movement. This machine is widely engaged in general earth‑moving, quarry material handling, road foundation construction, site leveling and medium‑load demolition tasks. Under frequent forward‑reverse slewing cyclic impact loads, ageing sealing components and degraded gear lubricant allow metallic wear debris and construction dust to invade gearbox inner cavity, triggering spline galling, gear tooth pitting, carrier spider deformation and pin‑hole ovalization. Typical failure symptoms include harsh metallic grinding noise inside swing gearbox, jerky and discontinuous cab rotation, insufficient initial swing torque, abnormal high temperature on reducer housing, and metallic sediment found during swing gear oil change. Manufactured strictly following original forging drawings and gear engagement parameters, this aftermarket assembly supports direct drop‑in replacement and effectively prevents cascading damage to other costly internal gearbox components.

Technical Specification

Core Advantages

1. Forged alloy construction adapted for mid‑size excavator frequent swing impact load Carrier spider and matching sun gear are forged from premium alloy steel blanks. After carburizing quenching heat treatment, gear tooth surfaces and internal splines obtain high surface hardness while retaining reliable core toughness. This component can withstand frequent instant impact torque produced during swing start‑stop and compound digging‑slew actions, lowering risks of tooth chipping, spline abrasion and carrier spider distortion under complicated dusty site working conditions.
2. Pre‑inspected gear meshing tolerance delivers smooth primary slewing performance Every finished assembly passes tooth profile inspection and backlash measurement before shipment. Tightly controlled meshing clearance minimizes transmission vibration and frictional grinding noise. When the excavator executes coordinated boom‑arm‑bucket plus swing compound operations, it maintains stable primary power transfer and avoids cabin stutter or jerky rotation caused by insufficient gear fitting accuracy.
3. Original replicated mounting structure cuts overhaul downtime for mid‑size machines Critical dimensions including carrier outer contour, sun‑gear spline specification, pin‑shaft hole layout and depth fully match OEM specifications. Field maintenance technicians can complete component swap directly without modifying gearbox housing or adjusting internal fitting gaps. For equipment rental fleets and local repair workshops, it shortens machine stand‑still hours and reduces economic loss caused by project suspension from swing system breakdown.
4. Stress‑relief annealing eliminates forging residual stress Stress‑relief annealing removes internal residual stress generated during hot forging, improving long‑term structural stability under cyclic shock loads. Combined with high‑precision machining for pin shaft holes and bearing seats, it slows premature wear of mating planetary gears and bearings, extending the overall service life of the complete swing reduction unit.
5. Budget‑friendly partial overhaul alternative for mid‑size excavator fleets Instead of purchasing a full‑set expensive swing reducer unit, individually replacing the worn first‑stage planetary carrier and sun‑gear assembly helps customers control overhaul expenditure. It is highly suitable for machinery repair shops, construction equipment operators and global Doosan mid‑excavator spare‑parts wholesalers.

Manufacturing & Quality Control

Our production workshop specializes in planetary transmission spare parts for Doosan mid‑tonnage excavator swing gearboxes. Full‑process quality supervision covers raw‑material composition verification, forging appearance inspection, heat‑treatment hardness testing, gear‑tooth precision detection, spline dimension validation and sample no‑load running‑in test. Only fully inspected‑qualified products move to packaging workflow. Finished assemblies are coated with anti‑rust preservation oil, wrapped with shock‑absorbing cushion materials and packed in export‑compliant fumigated wooden cases to prevent collision deformation and rust corrosion in long‑distance sea‑land logistics. We support bulk wholesale, stable batch supply, small trial orders are acceptable for worldwide purchasers.

Frequently Asked Questions

Q1: What abnormal phenomena indicate inspection or replacement of 1st planetary carrier and sun‑gear assembly? A: If your Doosan DH225‑7 excavator produces loud grinding noise inside swing gearbox, cabin rotates jerkily and intermittently, initial swing power drops obviously, reducer housing overheats, or metal particles are found in swing gear oil during oil‑drain maintenance, you should disassemble swing reducer for internal inspection promptly.

Q2: Will this assembly fit other excavator models? A: This component is engineered for Doosan DH225‑7 swing gearbox. Though some other models look similar in external appearance, internal gearbox configurations may differ. Please double‑verify relevant OEM part numbers before placing order to avoid installation mismatch.

Q3: What essential installation notes during gearbox overhaul? A: Completely clear all metal debris and old gear‑oil residue inside swing gearbox housing prior to installation. Meanwhile inspect wear condition of planetary gears, bearings and oil seals. After assembly completion, refill qualified swing gear oil, execute low‑speed no‑load swing running‑in test before putting machine into formal construction work.

Q4: Warranty scope explanation A: Our warranty covers defects caused by raw‑material and manufacturing flaws. Damage resulting from foreign‑object intrusion, insufficient gear‑oil lubrication, severe overload impact and improper disassembly‑installation will not be included under warranty coverage. Please strictly comply with Doosan official service manual for swing gearbox overhaul procedures.