Primary suspension for a railway truck, with a nonlinear characteristic spring and a swing arm.

摘要

A radius arm type truck capable of improving riding comfortableness in a fixed-number or less passenger state in a vehicle in which full passenger state is rare and substantially fixed-number passenger state is common, comprises a base frame (11), an axle box (13), a radius arm (12) rotatably supported by the base frame (11) at one end thereof and connected to the axle box (13) at an opposite end thereof, a lower spring seat (15) provided on the upper portion of the axle box (13), an upper spring seat (17) provided on the base frame (11), and a coil spring (1) mounted between the seat (17) and the seat (15), wherein the coil spring (1) is formed by a nonlinear characteristic spring having a tapered portion having a diameter that gradually decreases as it is closer to an end portion of a spring wire.