Improvements in Armatures for Dynamo Electric Machines.
Year: 1891

page_text: Date of Application, 14th Dec., 1891
Complete Specification Left, 13th Sept., 1892-Accepted, 15th Oct., 1992
PROVISIONAL SPECIFICATION.
Improvements in Armatures for Dynamo Electric Machines.
We, BUCHANAN STEWART PATERSON, of Victoria Works, Gateshead-on-
Tyne, in the County of Durham, Electrical Engineer, and JOHN BROKENSHIRE
FURNEAUX of Victoria Works, Gateshead-on-Tyne, aforesaid, Mechanical
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention has reference to armatures of the drum type.
In order to permit efficient ventilation without a hollow shaft the sheet metal
discs of which the armature is composed are punched each with a polygonal hole
in the centre, and from each side of the polygon a semi-circular or other piece is
punched out or removed. The shaft is of a corresponding polygonal cross
sectional form, but has longitudinal grooves in each side of the polygon. The
arrangement is such that when the discs are placed on the shaft the recesses
in the sides of the polygonal holes coincide with the grooves in the shaft which
are made to extend beyond the retaining flanges of the armature thus air passages
are formed through the core.
Each disc is made with a radial slit starting from one of the sides of the central
hole.
In building up the armature core there are placed on the shaft a number of
such discs with all their radial slits coinciding sufficient to form a radial channel
of suitable width communicating with one of the grooves of the shaft,-
-a second
set are arranged so that their radial slits communicate with the next groove on
the shaft and so on with respect to other sets, so that when all the discs are
in place they form with their slits a series of radial channels arranged spirally
round the core, thus providing for efficient ventilation throughout.
For carrying the windings slots are cut in the discs parallel to the axis of
the shaft each slot extending through a number of discs whose aggregate
thickness is equal to the length of a driving lug.
In building the armature these slots are disposed according to the number of
driving lugs desired along the core so as to form when the armature is complete
a series of short slots into which the driving lugs of wood or other insulating
material are driven, and in which they are firmly held by the burred edges of the
discs.
At each end of the armature is provided an annular insulator of hard wood
having its inner part approximately of dovetail or wedge form and it is held in
place by a disc of suitable metal such as brass having its outer part approximately
formed to engage with the inner part of the annular insulator.
Dated this 14th day of December 1891.
W. LLOYD WISE,
Per F. J. Brougham,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Armatures for Dynamo Electric Machines.
We, BUCHANAN STEWART PATERSON, of Victoria Works, Gateshead-on-
Tyne, in the County of Durham, Electrical Engineer, and JOHN BROKENSHIRE
FURNEAUX of Victoria Works, Gateshead-on-Tyne, aforesaid, Mechanical
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 :-
This invention has reference to armatures of the drum type.

page_text: In order to permit efficient ventilation withont a hollow shaft the sheet metal
discs of which the armature is composed are made each with a polygonal hole in
the centre, and from each side of the polygon a semi-circular or other piece is
punched out or removed. The shaft is of a corresponding polygonal cress sectional
form, but has a longitudinal groove in each side of the polygon. The arrangement
is such that when the discs are placed on the shaft the recesses in the sides of the
polygonal holes coincide with the grooves in the shaft which are made to extend
beyond the retaining rings or flanges of the armature thus air passages are formed
through the core.
:
Each disc is made with a radial slit starting from one of the sides of the central
hole.
In building up the armature core there are placed on the shaft a number of
such discs with all their radial slits coinciding sufficient to forin a radial chanuel
of suitable width communicating with one of the grooves of the shaft, a second
set is arranged so that their radial slits communicate with the next groove on the
shaft and so on with respect to other sets, so that when all the discs are in place
they form with their slits a series of radial channels arranged spirally round the
core, thus providing for efficient ventilation throughout.
For carrying the windings slots are cut in the discs parallel to the axis of the
shaft each slot extending through a number of discs whose aggregate thickness is
equal to the length of a driving lug.
In building the armature these slots are disposed according to the number of.
driving lugs desired along the core so as to form when the armature is complete
a series of short slots into which the driving lugs of wood or other insulating
material are driven, and in which they are firmly held by the burred edges of the
discs.
At each end of the armature is provided an annular insulator of hard wood
having its inner part approximately of dovetail or wedge form and it is held in
place by a disc of suitable metal such as brass having its outer part approxi-
mately formed to engage with the inner part of the annular insulator.
In the accompanying drawings,
Fig. 1 is a side elevation, partly in section, of an armature constructed according
to this invention, the winding being removed.
Fig. 2 is a cross section on the line a Fig. 1; and
Fig. 3 is a side view, to a large scale, of one of the slotted sheet metal discs.
3 3 are
1. 1 are sheet metal discs each formed with a central polygonal hole 2 and a
radial slot 3, the sides of the hole being each formed with a semi-circular recess 4.
5 is the armature shaft of corresponding polygonal form in cross section, and
66 are longitudinal grooves formed in the sides thereof, these grooves being also of
semi-circular form in cross section and forming with the recess 4 a number of
longitudinal air passages, of which there are eight in the example shown.
the radial air passages formed by arranging the discs in sets so that the radial
slots 3 of the discs forming each set correspond. Each radial air passage communi-
cates at its inner end with one of the longitudinal air passages, the several channels
being arranged spirally around the armature core as shown in Fig. 1.
driving lugs of suitable insulating material such as pear wood or elm, arranged in
annular series around the armature core and between which the armature winding
is placed, each of these lugs being firmly held within a slot or recess 8. The
discs 1 are placed between retaining rings or discs 9 of suitable metal such as
brass. 10 is a nut screwed upon the armature shaft and by tightening which the
armature core will be forced against a collar 5 on the shaft 5 and the several discs
firmly clamped between the two rings or discs 9.
7. 7. are
As will be seen the grooves 6 extend through the ring or disc 9, and the nut 10
is formed with holes 10" that communicate with the air passages, so that when the
armature is rotated air can circulate freely through the air passages and channels
and thereby keep the armature cool. It will also be seen from Fig. 1, that the air
channels 3 are arranged in rows that correspond with some of the longitudinally
་

page_text: arranged driving lugs 7, so that when the winding is in place it will not materially
obstruct the flow of air through such channels.
11, 11 are annular insulators of material such as hard wood, over which the
armature winding is led. Each of the insulators has its inner part 11* of approxi-
mately dovetail or wedge form in cross section and is clamped in place between the
correspondingly formed outer part of the adjacent ring or disc 9 and the end
disc 1.
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. An armature for a dynamo electric machine wherein the sheet metal discs
of which it is partly composed are each slotted radially and formed with a
central polygonal hole and with recesses at the sides of the hole, and are
mounted upon a shaft of corresponding polygonal cross sectional shape formed
with longitudinal grooves, the arrangement being such that when the discs are
in place on the shaft, the recesses in the discs and the grooves in the shaft
form longitudinal air passages that communicate with the radial air passages
formed by the radial slots in the discs, so that air can circulate through such
passages and channels when the armature is rotated, substantially as herein
described.
2. The improved armature constructed substantially as described and shown..
September 1992.
W. LLOYD WISE,
Per F. J. Brougham,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicants.