The axlebox bearing for metro vehicles is a core safety component of the running gear, mounted in the bogie axle box to connect the wheelset and the frame and to carry radial loads and bidirectional axial forces between car body and wheelset. For the frequent start-stop operation, high-curvature track, short station spacing and heavy passenger loads of metro service, the bearing uses a double-row tapered roller design that is compact, high in load capacity and strong in impact resistance. Rings and rollers are made of carburising bearing steel, case-hardened and low-temperature tempered so that the surface is hard while the core stays tough, giving good resistance to fatigue spalling and shock. A self-sealing integral design with combined contact and labyrinth seals keeps out dust and water and retains the grease; the bearing is pre-greased with long-life railway grease at the factory, needs no topping up before fitting and offers long maintenance intervals. Built to P6 accuracy with clearance, vibration and sealing performance checked piece by piece, it fits the axle box interfaces of all domestic metro vehicle types and supports both new-build programmes and in-house reconditioning.
