Development of Creep Decreased Axlebox Suspension of Cone-Shaped Multi-Layer Rubberspring

An axle-box suspension spring manufactured with a steel and rubber multilayered structure was developed to minimize the maintenance workload and to reduce the weight of a bolsterless bogie designed nearly twenty years ago. However, the rubber material deteriorates due to aging, especially creep phenomena that cause a loss in spring height, and eventually requires axle-box height adjustment. Optimizing the mix proportions of the rubber compound elements such as a carbon black, an anti-oxidation stabilizer, enables a stable axle-box height to be maintained and could decrease creep phenomena by 40%. We have also verified that the developed rubber spring ensures vehicle dynamic properties equivalent to the current rubber material.