• Title/Summary/Keyword: lock-up phenomenon

Search Result 12, Processing Time 0.015 seconds

A Ballooning Phenomenon of Torque Converter Torus Size for Automatic Transmissions (자동변속기용 토크컨버터 토러스 사이즈에 따른 팽창 현상)

  • Jang, Jaeduk;Lee, Woongcheol;Sung, Dukhwan
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.24 no.6
    • /
    • pp.702-708
    • /
    • 2016
  • The torque converter is deformed according to the rotating speed and control pressure when engine power is transferred to the transmission. This deformation, which is called ballooning phenomenon, occurs mainly at the outer side by the centrifugal force of the automatic transmission fluid (ATF) and the control pressure from the valve body. Although the torque converter is slightly deformed when rotating, the ballooning phenomenon affects fluid performance, efficiency and durability. Thus, expansion characteristics analysis is important in determining torus size, control pressure and structure. In this paper, an analysis equation and FEM model was developed to investigate the expansion characteristics. Using this model, structural analysis was performed to investigate the relationships between deformation and the torus diameter. The results were confirmed by comparing with the test results.

Critical and Flutter Speeds of Rotating Disks in Information Storage Devices (정보저장기기용 회전디스크의 임계속도 및 플러터 속도에 관한 연구)

  • 이승엽;윤동화
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2001.05a
    • /
    • pp.484-489
    • /
    • 2001
  • Recent trends in information storage devices disk are the transition from CD drives to high density DVD drives, the development of writable disk drives and the appearance of several high-density portable disk drives. In some flexible disk drives, self-excited disk vibrations become severe as rotation speed increases near or above critical speed. Critical speeds of CD/DVD, ASMO and floppy disks are experimentally measured and compared with analytical predictions. Flutter instability caused by aero-induced disk vibration at high speeds are experimentally observed. In ASMO, three nodal-diameter mode experiences its flutter at 8750 rpm with the frequency lock-on phenomenon. The CD/DVD disk does not have the aero-induce flutter up to 14,000 rpm.

  • PDF