The increase of evenness of distribution in the multi-bearing blade roots of steam turbines

Abstract

The operate reliability of multi-bearing blade roots of steam turbines largely depends on
uniformity of reactive forces distribution over bearing surfaces of teeth, since unavoidable
technological gaps within manufacture tolerances can lead to absence of contact on individual teeth
and overloading of structure elements.
Investigation of the stressed-deformed state of the three-bearing mushroom blade root,
which was carried out with help of a software package based on the finite element method, showed
the expediency of using improved geometry of the profile with special forms of bearing surfaces
that compensate technological gaps due to the crushing deformation and contact of teeth. This also
allows for a more even distribution of reactive forces over teeth and equalization of common and
local stresses.
The results of the work can be used in the power engineering industry, in the design and
operation of steam turbines.