Improvements in the Armatures of Multipolar Dynamo Electric Machines.
Year: 1898

page_text: Date of Application, 17th Oct., 1898-Accepted, 17th Dec.; 1898
COMPLETE SPECIFICATION.
Improvements in the Armatures of Multipolar Dynamo
Electric Machines.
}
We, SIEMENS BROTHERS & Co., LIMITED, of 12, Queen Anne's Gate, Westmin-
ster, S.W., Electrical Engineers, ROBERT DUMAS, of 71, Elliscombe Road, Old
Charlton, Kent, Mechanical Engineer, and GEORGE SYLVESTER GRIMSTON, of
Glenluce Road, Blackheath, S.E., Electrical Engineer, do hereby declare the
nature of this invention and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement:
1
This invention relates to the construction of the armature and means of fixing
the core plates of a dynamo electric machine in such a manner that the plates
are held firmly in opposition to the centrifugal force to which they are subjected
when the armature revolves at high speed.
Fig. 1 of the accompanying drawings is an elevation partly in section of part
of an armature having its core plates fixed according to this invention.
Fig. 2 is an elevation of one of the plates, and Fig. 3 is an elevation of one
of the outer plates of each of the groups which are separated to give ventilating
spaces between them.
Fig. 4 shews the fixing of the plates of an armature made with spokes without
a rim, and Fig. 5 shews a modification according to which the core plates arę
made with projecting dovetails.
Referring first to Fig. 1, each of the arms A projecting from the rim of the
armature has a division D along its middle, and terminates in outwardly pro-
jecting dovetails B between which is a seating for a pair of wedge keys E E.
The core plates Care punched to the form shewn in Fig. 2, and those of them,
shewn in Fig. 3, which are the outer plates of each of the groups, that are
separated to give ventilating spaces between them, have the sides of their dovetail
notches strengthened by strips F rivetted on their margins.
The plates being all strung on the arms A their notches fitting somewhat
loosely on the dovetails B the wedge keys E are driven so as to spread out the
two sides of each arm A thus causing the dovetails B to take firm hold of the
core plates which are afterwards clamped together by bolts G.
As shewn in Fig. 4 each of the spokes A¹ is divided for some distance from
its end and is made with dovetails which are made to take firm hold in the dove-
tail notches of the core plates C by driving the wedge keys E.
As shewn in Fig. 5 the dovetail tongues 131 may project from the core plates C
into dovetail spaces between the armis A¹ being secured by driving wedge keys E
so as to widen out the divided ends of the spokes A¹.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what
we claim is:-
1. Fixing the core plates of a multipolar dynamo electric machine to the arms
or spokes of the armature by making the arms or spokes with laterally projecting
dovetails radially dividing the arms or spokes, engaging on them dovetail notches

page_text: of the core plates, and widening out the divided arms or spokes by driving wedge
keys between the divided parts, substantially as described with reference to
Figs. 1 and 4..
2. The modified fixing of the core plates by making them with dovetail pro-
jections engaging them in dovetail spaces between the radially divided spokes,
and widening out the spokes by means of wedge keys, substantially as described
with reference to Fig. 5.
Doted th
131 1