Investigation of the conditions forming the operational characteristics of the friction wedge of the vibration damper

Abstract

The article explores the prospects of using new materials for the production of friction wedges in
vibration dampers for freight car bogies, taking into account the design requirements. Research has been
conducted on reducing harmful impurities in the composition of cast iron and improving its strength
characteristics. The article considers various options for the mass fraction of elements in the cast iron
composition, depending on the type of cast iron, and provides approximate data on hardness (HV) on the
walls of castings with different cross-sections. The reliability of the friction wedge vibration damper
(FWVD) has a significant impact on the service life of rolling stock, as the friction force created to
dampen vertical and horizontal oscillations of the wagon body decreases over time due to the wear of the
working surfaces of the friction wedge. The friction wedge is a rapidly wearing component: the average
mileage of grey cast iron friction wedges before replacement is about 100,000 kilometers. The annual
demand for FWVDs, solely for depot repairs, exceeds 100,000 units. During the wear process,
approximately 0.3 thousand tons of cast iron are irreversibly lost. Key research areas include optimizing
the chemical composition, enhancing the physicomechanical and tribological properties, as well as
mathematical modeling of FWVD performance under various operating conditions and predicting their
behavior in service.