Hybrid transmissions are a component being researched and developed by major automakers to reduce fuel consumption and emissions. Power-split hybrid transmissions utilize two or more motors to enable continuously variable gear shifting and control the operating points of the engine and motor, thereby reducing engine fuel consumption and emissions. This study proposes a systematic design method for a two-mode hybrid system that minimizes power circulation. To achieve this, we design a two-mode hybrid system that combines three-axis and four-axis systems using two planetary gears and two clutches. We also propose a structure that operates only in modes where power circulation does not occur, thereby improving transmission efficiency.

Abstract
1. 서 론
2. 동력전달 구조
    2.1 동력전달 구조 분류
    2.2 3축 시스템 구조
    2.3 복합 분기 시스템 구조
3. 동력특성 분석
    2.1 3축 시스템 동력 전달특성
    2.2 4축 시스템 동력 전달특성
4. 2-모드 구조 설계
5. 결 론
References

• 성덕환(Professor, Dept. of Automotive, Suwon Science College) | Sung Dukhwan Corresponding author
• 송한림(Dept. of Smart Mechanical Engineering, Shin Ansan University) | Song Hanlim