DESIGN AND ANALYSIS OF T-SHAPE DOVETAIL FOR IMPROVEMENT IN PERIPHERAL VELOCITIES

ASP GOUTHAM1*, Y.DHANASEKHAR2
Page No. 81-90

From the olden days in synchronous machines for attaching mechanically pole windings to the
shaft dovetails are used. In general T-shape or Hammered head section is used as type of dovetail.
Hammered head dovetail is a modification of T-section. Now a day there is a lot of demand for the
Steam turbo generators. These synchronous generators require high runaway speed. High speeds
can be achieved by using the forged shafts or by using high strength material for the punched
spiders. Forged shafts are economically not preferable due to reason of more lead times and costly
machining processes etc. Laminated spider type shafts are used in some cases. It is limited by the
strength of the material, i.e. limitation in getting high strength material economically is difficult. To
overcome above constraints Modification of dovetail section could be the one of possible solution to
overcome above constraints for a high peripheral velocity. This is explained step by step in this
report, from developing base line for the T-section dovetail model to possible modifications into
new geometric models. Percent of improvement in peripheral velocities are calculated with respect
to base model.
Keywords: Dovetail, Peripheral velocity, Shaft, T-Section.