Most engines for small vessels operating in coastal waters, such as fishing boats, are equipped with a reduction gear to reduce the engine's rotational speed. Small vessels are equipped with engines of fixed output and reduction gears of single reduction ratio only. This paper is a study on the development of a two-stage reducer capable of controlling the reduction ratio according to the light and full load conditions of a ship. Because the torque and rotational speed delivered to the propeller can be flexibly adjusted, the engine load can be maintained appropriately. In addition, because the engine room space is limited, the development of a two-stage reducer with an integrated power take off (PTO) was pursued to minimize the volume. Through this development, we were able to confirm a reduction in fuel consumption rate because we did not have to consume a lot of fuel to maintain maximum output. Reducing fuel consumption can result in reduced harmful exhaust emissions. Additionally, it can be expected that the frequency of failures that may occur due to overload can be reduced.

Abstract
1. 서 론
2. 실험장치 및 방법
    2.1 PTO 일체형 2단 감속기 설계
    2.2 동력발생장치 설계
3. 실험결과 및 고찰
    3.1 일체형 2단 감속기 성능 평가
    3.2 내진동 성능 평가
    3.3 내염 성능 평가
    3.4 감속기 회전 오차 평가
    3.5 감속기 전진 및 후진 시 유압 평가
    3.6 감속기 출력 응답 시간 평가
    3.7 실선 성능 평가
4. 결 론
References

• 이경환(Principal Researcher, Research Institute of Medium & Small Shipbuilding.) | Kyunghwan Lee
• 류영현(Professor, Division of Marine Mechatronics, Mokpo National Maritime University.) | Younghyun Ryu Corresponding author