Design Study and Validation of a Two-Stage Spur Gear Transmission for a Passenger Vehicle

Abstract

This paper presents the design and validation of a two-stage spur gear transmission for a passenger vehicle. The gearbox must enable a laden mass of 1100 kg to achieve both a maximum speed of 100 km/h and a gradability of 30◦ , within a compact packaging envelope. This study integrates vehicle resistance analysis, tractive effort calculations, gear ratio determination, and stress verification according to ISO 6336 and Shigley’s design methodology. Engine data and vehicle resistances are used to compute tractive effort curves, confirming that the design achieves the required performance while maintaining adequate safety margins. The final results demonstrate that the proposed gearbox provides reliable performance under duty cycle conditions, following the transmission design framework described by Naunheimer et al.