The paper describes developments in axles and transmissions for city bus and coach applications. For city buses, the trend towards low-floor designs will intensify. Drop-centre axles in combination with further improvements in conventional automatic transmissions will continue to offer considerable optimization potential as far as economic operation and comfort is concerned. Diesel-electric drives with wheel motors are discussed as a long-term possibility. For coaches, automated transmissions will become more common in addition to current manual transmissions. As far as both types of transmission are concerned, integrated hydrodynamic secondary retarders will be available and offer good economical and offer good economical performance with clear advantages regarding the installation space required. (A)
Abstract