Integral turning gear for turbine rotors

Abstract

An integral turning gear is machined onto one-half of a turbine rotor shaft coupling or on a pedestal of a rotor shaft for engagement with a motorized pinion for rotating the shaft of the turbine, for example during shutdown. The gear teeth are integrally formed on the coupling or shaft and do not require additional length of axial rotor span or introduce significant stresses. The motorized pinion may engage the integral turning gear teeth to rotate the rotor, for example, during turbine shutdown to prevent the rotor from sagging while cooling from elevated temperatures.

1 . A coupling for a turbine rotor comprising: 
 turbine rotor shaft sections axially aligned with one another and having registering end portions, each shaft section including an integral radial flange having a bolt circle including bolt openings about the registering end portions;    bolts through said registering bolt opening of the rotor shaft sections to secure the shaft sections to one another; and    gear teeth integral with one of said flanges; for engagement by meshing engagement of a pinion enabling the rotor for rotation upon connecting the pinion and the gear teeth.    
   
   
       2 . A rotor according to  claim 1  wherein said end portions include end faces of said shaft sections in abutting relation with one another.  
   
   
       3 . A steam turbine comprising: 
 a turbine rotor shaft forming part of a low pressure section of the steam turbine;    said rotor shaft including turbine rotor shaft sections axially aligned with one another and having registering end portions;    each shaft section including an integral radial flange having a bolt circle with bolt openings about the registering end portions;    bolts through registering bolt openings of the rotor shaft sections to secure the shaft sections to one another;    gear teeth integral with and about one of said flanges; and    a pinion gear in engagement with the gear teeth on the one flange for turning the rotor.    
   
   
       4 . A turbine according to  claim 3  wherein said end portions include end faces of said shaft sections in axial abutting relation to one another.  
   
   
       5 . A steam turbine comprising: 
 a turbine rotor shaft forming part of a steam turbine;    said rotor shaft having a radially outwardly projecting flange formed integrally with the shaft;    gear teeth integral with and about an outer diameter of said radially outwardly projecting flange; and    a motorized pinion gear in engagement with said gear teeth on said flange for turning the rotor.