Design of a railway primary suspension utilising a resilient biasing device

Railway bogies are fundamental to vehicle stability, ride quality, and dynamic performance, with the primary suspension system playing a crucial role in isolating high-frequency vibrations and maintaining consistent wheel-rail contact and vehicle stability. This paper presents a novel resilient biasing device, protected under international patent WO/2025/027292, which integrates the functions of a spring and axlebox into a single component, thereby simplifying the architecture of the primary suspension system. The mechanical performance of this patented concept was assessed through finite element modelling, analytical methods and experimental validation to predict stiffness characteristics, induced stresses, and vibration transmissibility. Two design configurations, a single-loop and a multiple-loop configurations, were investigated for a reference vehicle comprising a 40-tonne carbody and a 5-tonne bogie against real-world load conditions. Both designs were found to deliver the required stiffness, maintain stress levels below the material yield limit, and provide effective vibration isolation. The single-loop design demonstrated advantages in terms of reduced mass, improved vibration isolation, and manufacturing cost-effectiveness. In contrast, the multiple-loop design offered lower stress levels, making it more suitable for applications involving higher payloads. The resilient biasing device can be geometrically and materially optimised to meet specific performance requirements, offering a versatile solution for primary suspension systems in rail vehicles. Moreover, the concept holds promise for broader application in the automotive and heavy vehicle sectors, as well as in other industries requiring integrated suspension and vibration isolation systems tailored to specific operational demands.