Abstract
In order to get compatibility of speed up and safety for subway bogie truck, authors have developed new air suspension system such as differential pressure valve which is compensated proportional to air spring pressure, new air spring and new leveling valve. And the details of these equipments are introduced in "Development of Subway Bogie to Reduce Wheel Load Variation" of this paper fundamentally. In this paper, the practicability of these devices are evaluated in the field running test. Load deviation between empty car and fully loaded car would be a big issue for designing primary suspension of bogie to achieve the reduction of subway vehicle weight. Therefore, primary suspensions of bogiehould have both soft stiffness for empty condition and hard stiffness for loaded condition. In order to realize these characteristics of suspension stiffness, the newly designed coil spring with non-linear type has been developed for primary suspension. Comparing with conventional coil spring that has linear relationship of load against distortion of coil spring, the newly designed coil spring has the both characteristics of small gradient stiffness with light load and of large gradient stiffness with heavy load.
