Bearing unit for railway carriages

摘要

Emergence of fretting worn powder is to be suppressed, and intrusion of the worn powder that has emerged into an internal area of the bearing. A ring spacer (20) is interposed between an end face (M2) of an inner race (3) of the bearing (2) to be mounted on a wheel axle, and an end face (N2) of a rear cover (11) (ring member) to be mounted on the wheel axle (1) for axial positioning of the inner race (3) with respect to the wheel axle (1). An elastic seal ring (21) is integrally fixed to an outer periphery of the ring spacer (20). The elastic seal ring (21) is elastically fitted to an outer circumference of a recessed stepped portion (25) formed on the end face of the rear cover (11). The elastic seal ring (21) is thus pressed against the opposing end faces of the inner race (3) and the rear cover (11). Inside the elastic seal ring (21), a storage space for the worn powder is provided.