The Automobiles with a combustion engine use a transmission for increasing drive force, reverse-move and maintaining non-load condition in general. In the Electric automobile system, output-axial can be operated just by controlling the motor manipulated with power. It also does not need reverse-gear by rotating the motor in the opposite direction. Designed to assemble two different types of planetary gear ratio and to be input torque of input-axial in sun gear and divide ring gear Ⅰ, Ⅱ and then after one of ring gear is fixed, in accordance with the planetary gear velocity ratio, the first gear has 0.136 decreased speed and second gear has 0.240 decreased speed, separately. While the planetary gear type transmission showed over the 92% of efficiency in the all of velocity range. The transmission proposed in this study can be expected to apply to the electric vehicle or others.

Abstract
 1. 서 론
 2. 변속기 설계 및 제작
  2.1 변속기 제작의 목적
  2.2. 유성기어 설계
  2.3 유성기어 모델링
  2.4 변속기 제작
  2.5 변속기 시험
 3. 실험 및 고찰
  3.1 회전수와 부하에 따른 출력효율 실험 결과
  3.2 회전수와 부하에 따른 온도변화 실험 결과
 4. 결 론
 참 고 문 헌

• 국창호(대림대학 자동차학과 겸임전임강사) | C. H. KOOK
• 김진태(대림대학 자동차학과 겸임전임강사) | J. T. KIM
• 오세훈(중앙대학교 기계공학부 교수) | S. H. OH