| 摘要 |
PURPOSE:To prevent a rotor from vibration, by forming a relief passage partially guiding a steam flowed into a space between a labyrinth packing and a rotor to an understream, at the labyrinth packing positioned at an underside of inner peripheral surface of a nozzle diaphragm. CONSTITUTION:A packing holder 7a of a labyrinth packing 7 formed by dividing a circular ring 8 is inserted into and supported by a recessed part 5 defined on an inner peripheral surface of a nozzle diaphragm 3. Four labyrinth packings 7 positioned at an underside of a rotor 1 have a balance hole 10 bored therethrough, the balance hole 10 communicating an upstream side of inner peripheral surface 8 of the packing holder 7a with a downstream side 9 of the packing holder 7a for letting a part of steam of flow to a downstream side. This arrangement can prevent a rotor from vibration which can occur due to a pressure difference between upper and lower parts of the rotor. |
