HYBRID SYSTEM

摘要

A hybrid system is provided with: an engine (10); a first and a second motor/generators (MG1, MG2); a first differential mechanism (20) that can mutually differentially rotate rotating elements to which an engine rotating shaft (11), an MG1 rotating shaft (62), an MG2 rotating shaft (63), and a drive wheel are individually connected; a second differential mechanism (30) with a plurality of mutually differentially rotatable rotating elements to one of which the MG1 rotating shaft (62) is connected; a first speed-change ratio fixing mechanism (40) that stops the operation of the first motor/generator (MG1) and that fixes a system speed-change ratio determined by the first and the second differential mechanisms (20, 30) to a constant speed-change ratio; and a second speed-change ratio fixing mechanism (50) that stops the rotation of the rotating elements of the second differential mechanism (30) other than the rotating element to which the MG1 rotating shaft (62) is connected, and that fixes the system speed-change ratio to an over-driving constant speed-change ratio.