Kinematic synthesis of a novel type of the series of transmissions with independently controllable output speed

•Transmissions are of hybrid type with a control motor that controls the output speed.•Methodology to derive the transmissions is introduced.•Numerical example for an automotive transmission is carried out.•Transmission has superior efficiency and enables the optimization of prime mover speed.•Transmission is suitable for hybrid vehicles.

A power-split-type transmission with independently controllable output speed (ICTs) was recently proposed. It is capable of converting a variable or constant input shaft speed into a controllable output shaft speed independent of the input speed — without ordinary speed control system. However, this transmission has no practical significance, because of the huge control motor power and uncontrollable speed of one output shaft. The novel type of the hybrid ICT is proposed in this paper that consists of three differential gear trains and two ordinary gear drives, with input shaft of arbitrary speed and three more external shafts with mutually controllable speeds. The kinematic synthesis of the series of the proposed type of ICTs is carried out. The numerical example, assigned to a vehicle, is demonstrated where a continuous variation of required vehicle speeds at arbitrary riding conditions is achieved without using a speed control system. For the optimal speed of driving engine, i.e. for minimum fuel consumption at any vehicle speed, the engine speed control system is provided, with control motor that runs at speed forcing engine to run at optimal speed.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide