The OEM discontinued this excavator’s bearing. We measured it in 2 hours — it’s been running 3 years.

A 15-year-old imported excavator, its slewing bearing discontinued by the OEM, drawings lost long ago. In the old days, that machine was looking at a three-month wait for an original part — or retirement.

We handled exactly this last month for a mining project in South America. We’re a core slewing bearing supplier to XCMG, and we’ve been doing this kind of work for 20 years.

Our engineers don’t switch on the instruments first. They talk to the operator first. Any noise lately? Binding? Grease leaks? The machine talks before the gauges do — and those symptoms tell us where to measure.

The original markings were long gone, the tooth faces heavily worn; ordinary tools had nothing to grab onto. We swept the raceway curvature with a coordinate measuring machine, re-checked bore and OD with digital micrometers, and ran a tooth runout gauge across the full gear. Bore, OD, bolt-hole pattern, tooth module, pressure angle — all captured, dimensional error within 0.01 mm. The pressure angle gets special attention: the replacement has to mesh with the excavator’s original pinion. Get the module or pressure angle wrong, and it either won’t engage properly or it runs noisy and wears out fast.

We recorded the operating conditions too: maximum load, rotation speed, ambient temperature. Those three decide which way the optimization goes.

Total measurement time: two hours.

But measuring only tells you what the old part looked like. What makes a replacement outlast the original is what happens next.

This excavator runs in high-impact mining conditions, so we deepened the raceway hardening layer from 3 mm to 5 mm. For coastal wind sites with salt spray, we add zinc passivation. For designs that leak grease, we upgrade to a double-lip seal. Every change is confirmed with the customer first — mounting dimensions never move, so nothing has to be modified on the machine to fit it.

Drawings follow GB/T 2300-2018 and are issued within two working days: material grade, heat treatment process, and inspection requirements all specified on the sheet. Customers can take the drawings, or have us build the part — we cover non-standard slewing bearings up to 6 meters in diameter across seven structure types, with 24-hour after-sales response and full warranty.

The replacement installed with zero binding and has now run three years without a failure.

People often ask how we can measure accurately, draw fast, and deliver reliably. There’s no secret: we’ve done this more than a thousand times, and our database holds 1,000+ models. After a thousand repetitions, you know where each step goes wrong before it does.