Screw Conveyor Wear Management on EPB TBMs: Shafts, Flights and Liner Planning

On an EPB TBM the screw conveyor is the machine's most punished assembly: it controls face pressure and muck discharge while handling saturated, often highly abrasive spoil. Wear concentrates on the screw shaft, the flight edges, the casing liners and the discharge door. In gravelly sands or crushed rock with high quartz content, flight thickness can drop quickly, and a worn flight no longer meters muck predictably, disturbing face pressure control before anything visibly fails.

The practical answer is measurement, not guesswork. Record liner and flight thickness at fixed intervals, tie the readings to geology and advance rate, and set replacement triggers well before the wear allowance is consumed. Carrying a spare screw shaft, a set of wear-resistant liners and discharge-door components turns a potential week-long emergency stop into a short planned intervention, especially on long tunnels where every shift already carries logistics risk.

That planning matters more in CIS markets, where hard-rock mountain drives and cold-climate winter logistics stretch resupply routes and can delay shipments at borders. OUSUN, based in the Deyang TBM industrial cluster in Sichuan, supplies screw conveyor shafts, flights, liners, seals and hydraulic/electrical spares factory-direct, with typical spares lead times of two to four weeks. Send drawings or part numbers to [email protected] to build a wear-parts kit before the drive starts.