公开(公告)号：JPH08240103A

公开(公告)日：1996-09-17

申请号：JP2666996

申请日：1996-02-14

Applicant: ABB RESEARCH LTD

Inventor： PEETAA ERUNSUTO ,  YAAKOPU RIYUNAA

IPC: F01D5/26 ,  F01D9/00

Abstract: PROBLEM TO BE SOLVED: To perform damping each blade vibration by attaching a ring having different poralizations and made of plural ring segments to a wall limiting flow of a turbine casing oppositely to a blade end in a radial direction, providing a each blade end with a cover plate made of electroconductive material. SOLUTION: A magnet ring 4 made of permanent magnetic material having magnetic polarizations 7a, 7b, 7c of S-N-S alternate and divided into three rings 6 are attached in a circumferential direction of a turbine casing 1, so as to surround a turbine impeller. A turbine blade 2 which is arranged oppositely to the magnet ring 4 in a radial direction has a cover plate 3 made of material of good electrical conductivity at its blade end 8. When the turbine blade 2 is vibrated, magnetic force line in the cover plate 3 of the blade is temporarily varied to induce eddy current in the cover plate 3 for generating Joule heat. Energy is thus diffused for damping the blade vibration.