The agitator with a reducer are usually using on the process of a water treatment. However, working the reducer at the field, a lubricant oil can leak out. It causes an environment pollution and a water service/sewerage pollution problem. In this study, the reducer with a drywell structure is developed in order to prevent the oil leakage. The drywell structure is that the reducer bottom housing and the support column of an output shaft are united, and taper roller bearings are in the bottom housing. During the development of the reducer, a mockup and a prototype are made by using CAD and a high speed CNC machine. Then, to prove the performance of the prototype, the performance tests, unload working test and the mechanical torque efficiency test, are conducted by the torque meter device. Also a motor velocity(rpm) control system is developed by a PID control according to the working loads(MLSS data). The results of the test are shown that the maximum torque efficiency is 88.45%, the oil leakage and the abnormal noise do not occur during the work. Therefore the reducer with the drywell structure and the motor rpm PID control system is successfully developed.

Abstract
 1. 서론
 2. 교반기의 개요
  2.1 교반기의 특성
  2.2 감속기의 특성
 3. 누유방지(Drywell) 구조 감속기 설계
  3.1 감속기 설계 요구 조건
 4. 설계도 및 시제품 제작
  4.1 2D-CAD 설계
  4.2 3D-CAD 설계
  4.3 실물 크기 모형 제작
  4.4 시제품 제작
 5. 감속기 모터 rpm 제어시스템 개발
  5.1 PID 제어시스템
  5.2 모터 rpm 제어시스템
 6. 시제품의 성능평가
  6.1 성능평가 시험 장치
  6.2 무부하 작동 시험
  6.3 토크 전달 효율 시험
 7. 결론
 참고문헌

• 오상엽(상주대학교 자동차공학과) | S. Y. OH