The axlebox bearing for passenger cars is a key component of the car running gear. Compared with freight bearings, passenger bearings place greater emphasis on smooth running, low noise, high speed and ride comfort, which calls for tighter roundness and surface waviness of the raceways and closer roller sorting; the result is a low temperature rise, low vibration and low noise at speed. Passenger cars use an axle-box structure in which the bearing sits inside the housing, making routine inspection, maintenance and replacement easier; low-friction contact seals balance sealing reliability against running drag. Interface dimensions with the axle box, front cover and rear stop follow passenger bogie standards. Rings and rollers are again made of carburising bearing steel, heat-treated to an even hardness gradient and good dimensional stability, making the bearing suitable for the running gear of mainline passenger coach bogies, with grease grade and clearance group matched to the duty of the line.
