Overview and classification of advanced schemes of multithreaded combined energy transmissions based on their kinematic analysis

Abstract

The article deals with the existing and promising modern automotive multithreaded combined energy transmissions, based on the principle of separation of power for the electrical and mechanical streams. These combined energy transmissions due to the presence in their design of continuously variable electric transmission allow obtaining an arbitrary gear ratio from the engine to the wheels, while maintaining high efficiency inherent to manual transmission. It allows to assume that multithreaded combined energy transmissions are promising for use in hybrid vehicles as evidenced by the successful operation of Toyota Prius automobile. The article describes 16 different schemes of electromechanical transmissions. Some of them are actually applied in practice, while others exist only as prototypes or theoretical projects. On the basis of the kinematic analysis, including determination of number of operating modes and degrees of freedom as well as the construction of kinematic plans for different of operating modes the classification of multithreaded combined energy transmissions by type of differential mechanism (mechanical part of transmission) was proposed. There were allocated single-mode and multi-mode multithreaded combined energy transmissions. The last ones were divided into three classes, depending on the method of obtaining different modes: stepped, variable and combined. Moreover, within each class transmissions with differential at input, differential at output with complex power division were identified. This review allows to get acquainted with possibilities of application of multithreaded combined energy transmissions in road transport, to understand its strengths and weaknesses, identify promising areas of application of multithreaded electromechanical transmissions of various types.