Basic Theory on a Multi-Mode CVT

다중모드 무단 변속기의 구조이론에 관한 연구

  • Published : 2000.10.01


A planetary gear assembly is a key component to combine and/or split a power from the source. With a planetary gear assembly, a continuously variable unit extends its capacity by means of power bra nching mechanism. Power branching with one planetary gear assembly and one continuously variable unit is categorized into 12 basic types. Each type represents peculiar power transmitting characteristics. Additionally, a multi-mode (range) continuously variable transmission can be designed with accompanying clutches. A multi-mode continuously variable transmission changes the path through which the source power is transmitted. Each path has its own features, such as high efficiency. In this paper, some design principles are examined such as, criteria to guarantee the minimum power efficiency, and constraints to guarantee the smooth mode shift after discussing well-known features of multi-mode M mathematically.


Continuously Variable Transmission(CVT);Continuously Variable Unit(CVU);Infinitely Variable Transmission(IVT);Power Re-circulation/Split


  1. 송한림, 김정철, 김현수, '금속 벨트 CTV 차량의 동적응답특성과 변속비 제어 전자화,' 대한기계학회 논문집, 제 22 권, 제 5 호, pp. 738-747
  2. 장효환,전윤식, '자동변속기의 변속과동특성 해석,' 대한기계학회 논문집, 제 22 권, 제 3 호, pp. 654-662
  3. 이동준, '토크 컨버터와 유성기어계를 사용한 무단변속기의 해석에 관한 연구,' 1995년 서울대학교 석사학위 논문
  4. 정헌술, 이교일, '동적 구속조건을 적용한 자동변속장치의 효과적인 시뮬레이션 방법에 관한 연구,' 대한기계학회 논문집, 제 22 권, 제 3 호, pp. 504-518
  5. Per Mattsson, 'Continuously Variable Split-Power Transmissions - Conditions for a Mode shift,' SAE 933001
  6. Daniel J Dawe, Charles B. Lohr, 'A High Ratio Multi-Moded Vehicle Transmission Utilizing a Traction Toroidal Continuously Variable Drive and Traction Planetary,' SAE 932997