A Review of Hydrokinetic Fluid Drives and Their Possibilities for the British Motor Industry

Abstract

The history of the development of hydrokinetic fluid transmissions is traced from its origin by Föttinger to the present time, and the important early developments and types of device are recorded. Consideration is given to special design features and current practice for the use of these devices in transmissions for motor vehicles, and the theoretical basis of design is reviewed briefly. Four important aspects of a specification for an automatic transmission for motor vehicles are enumerated, and the hydrokinetic fluid drive is shown to have characteristics specially suited to the fulfilment of this specification. The trend of development after the 1939–45 war of these drives in the United States of America is discussed, and appears to be reaching finality. The application of this American experience to European conditions is considered; some versions of the automatic fluid transmission show possibilities for achieving an acceptable operating performance for lower power/weight ratio applications. The wider range of torque conversion necessary for the more popular cars results in a more complicated and costly transmission, so that it does not yet appear likely that this form of automatic transmission will become universal in the British industry.