| 摘要 |
PURPOSE:To prevent damage of associated members by forming a packing fin, which forms a narrow and a wide passage in a leakage line for the working fluid of turbine, from a bimetal and thereby preventing narrowing of the leakage line during low temp. operation by means of bending of the packing fin. CONSTITUTION:A turbine rotor 1 is provided at its surface with two or more axially stretching circumferential groove 2 coaxially with the axis of rotor's 1 rotation. A circular arc formed packing ring 4 is fixed to the casing 3 by an expansive member 5 such as spring. The packing ring 3 is provided, at its surface facing the turbine rotor 1, with two or more packing fins 6 in the axial direction of the turbine rotor 1. Here each packing fin 6 consists of a bimetal made by jointing two plates 7, 8 with different thermal expansion coefficients. Accordingly if the turbine rotor 1 and casing 3 are thermal contracted with drop of the temp. to cause narrower gap between them, the packing fins 6 are bent to attain the intended purpose. |
