Sumtiomo SH200 Swing Gearbox 1St Planetary Carrier Spider With Sun Gear Assy For Excavator parts

Sumitomo SH200 Swing Gearbox 1St Planetary Carrier Spider With Sun Gear Assy For Excavator parts

Product Overview

The first stage of the Sumitomo SH200 swing reducer works at the fastest end of the drive chain: it takes the high‑speed output straight from the swing motor and converts it into slower, stronger rotation for the second stage. That speed brings its own wear pattern — the sun gear spins faster than any other gear in the box, so spline fretting and tooth flank wear typically start here, quietly, long before the operator notices anything wrong. The carrier spider carries the planet set that makes this first reduction possible, and it does so under the constant reversals of digging cycles: swing forward, load, swing back, dump. In rental fleets and infrastructure work, where the SH200 runs long hours with frequent direction changes, the first‑stage assembly is usually the first part of the swing drive to require renewal. Typical warning signs are a high‑frequency whine at the start of each swing, a slight hesitation before rotation begins, and fine metallic powder in the drained gear oil. This aftermarket unit restores that first stage to original geometry — a straightforward replacement that heads off damage to the second stage and keeps the machine earning.

Technical Specification

Core Advantages

1. Spline and tooth durability matched to high‑speed input The sun gear at this stage rotates faster than any other gear in the reducer, so its spline and tooth flanks are case‑hardened to resist the fretting and wear that high‑speed contact produces. That is the difference between a first stage that lasts and one that sheds metal into the oil within a season.
2. Precise geometry that keeps the whine out of the cab A high‑pitched whine at swing start is almost always a first‑stage meshing problem. Ground profiles and controlled backlash keep the gear set rolling quietly, which also reduces the vibration that ages seals and bearings across the whole reducer.
3. A stable carrier that holds the planets true under reversal Frequent swing reversals put alternating stress on the carrier web. Forged construction plus stress relief keeps the spider dimensionally stable, so the planet bores stay round, the planets stay aligned, and the whole first stage keeps transmitting load evenly.
4. Verification that takes the risk out of the repair Before dispatch, key dimensions — spline fit, pin‑hole positions, tooth profile and hardness — are checked and recorded. The workshop can install directly against the original footprint, with no fitting work and no unexpected surprises mid‑job.
5. A repair path that suits owners, workshops and parts traders alike Renewing only the worn first stage protects the second stage and ring gear from progressive damage, and the cost stays a fraction of a full reducer exchange. Single samples, stock batches and scheduled supply are all straightforward to arrange.

Manufacturing & Quality Control

Every batch is traceable from incoming steel certification through forging, stress relief, machining, carburizing and finish grinding. Acceptance checks cover spline gauging, bore geometry, tooth profile, surface hardness and a rotation test on sampled units to confirm smooth running. Completed assemblies are rust‑treated, individually cushioned and packed in fumigated wooden cases for sea and overland freight. Sample orders and volume programmes are both welcome.

Frequently Asked Questions

• Q1: What specifically points to first‑stage wear on an SH200?

A: A high‑pitched whine at swing start, a momentary hesitation before the cab moves, and fine metallic powder in the swing oil. These usually appear before second‑stage symptoms and justify opening the reducer for inspection.

• Q2: Do I need to replace the sun gear if I buy the carrier spider?

A: Only if it shows pitting or spline wear. If the existing sun gear is sound, we can supply the carrier alone; otherwise the matched assembly guarantees fresh meshing surfaces.

• Q3: Can you confirm fitment for my machine before I order?

A: Yes — send the machine serial number and, if available, the part number on the old unit. We will verify the spline and dimensional configuration before dispatch.

• Q4: How do you protect the assembly during long storage?

A: Units are coated with preservation oil and kept in dry, sealed packing. For stock that sits for months, we recommend storing them indoors and re‑oiling the machined surfaces before installation.