Electric Motors.
Year: 1894

page_text: Date of Application, 7th Nov., 1894-Accepted, 8th Dec., 1894
COMPLETE SPECIFICATION.
Electric Motors.
I, CHARLES RIORDON, of Corner King and Bay Streets in the City of Toronto,..
in the County of York, in the Province of Ontario, Canada, Esquire 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:-
My invention relates to improvements in electric motors and the object of the
invention is-first-to design a motor in which the eddy currents will be reduced to
a minimum and the hysteresis completely done away with and secondly-
-to provide
a compact means for winding the armature in which there will be the least possible
danger of short circuits and it consists essentially-first-of constructing the core
of the armature in cylindrical form with longitudinal recesses of substantially the
width between the cores of the field magnets, the core of the armature being loose
on the shaft and maintained from revolving by the lines of force passing through
the field magnets and core and the armature being constructed in cylindrical form
around but free from the core and supported on suitable discs and-secondly--of
winding the armature with a series of wire loops with the sides substantially arc-
shaped hevel to fit the discs and the ends arranged to over top each other and
substantially rectangular in form, the sides of the loop passing across underneath
the field being arranged to come underneath the opposite side of a corresponding
loop, all the loops being arranged around the discs as hereinafter more particularly
explained.
Fig. 1, is a longitudinal section through my motor.
Fig. 2, is a cross section through the line -y Fig. 1.
Fig. 3, is a detail of the manner of winding the armature.
In the drawings like letters of reference indicate corresponding parts in each
figure.
A, is the main shaft of the motor, which is journalled in suitable bearings and,
B, B, is the core of the armature, which is made in two parts. C, are the end discs
of the armature and, C', the central disc and, D, is the wire of the armature. The
two parts of the core, B, are separated by the central disc, C, and are separated
from the shaft, A, by a sleeve, B', of a non-magnetic metal such as brass. The
core, B, B, has arc-shaped recesses, b, the edges of which coincide in position with
the edges of the cores, e, of the field magnets, E, which are suitably bolted to the
frame, F, thus forming an air gap in the core between the cores of the field
magnets.
The end discs, C, C, and central disc, C¹, are rigidly secured to the shaft by
screws, c, c, and, c'. The wire D, of the armature forms a complete circle around
the core, B, and is comprised of a series of substantially rectangular loops arranged
around the periphery of the discs in the manner shown in Fig. 3, in which it will
be noticed that the sides of the section of four loops are formed on an arc-shaped
bevel to fit the discs perfectly. The sides, d, of each loop fit over the opposite
side, d', of a corresponding loop and this is the arrangement around the complete
periphery of the discs with the exception that the ends, d², of the loops over top or
are piled on each other as indicated in Fig. 2. The two ends, d³, and d', of each
coil lead to corresponding sections, e, in the commutator, E, which is suitably formed
and insulated from the shaft.
It will be seen from the construction of motor above described that the lines of
force passing from the field magnets to each other through the armature and core
will necessarily take an inward course on account of the recesses, b, and consequently

page_text: there will be no fluctuation of the field at that portion of the armature between the
field magnets that is the point opposite the recesses, b, where the polarity is changed.
The core on account of the peculiar construction of the recesses,, will be prevented
from revolving although the shaft will revolve within it thereby minimizing the
eddy currents and absolutely dispensing with any hysteresis, which would result if
the core of the armature revolved.
It will also be seen that sparking is absolutely prevented by having the
recesses, b, as a weak field is thereby maintained at the point of change of polarity.
The construction of my armature it will be noticed from what has been before
described minimizes the danger to short circuits and is most compact.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, 1 declare that what I
claim is :-
1. In an electric motor the combination with the exterior field magnets, of a
hollow cylindrical armature comprised of wire loops suitably supported and secured
to the main shaft of the motor and a solid core located within the armature
magnetically insulated from and loose on the shaft and provided with recesses in its
periphery between the ends of the cores of the field magnets whereby the lines of
force maintain such core from rotating on the shaft as and for the purpose specified.
2. The combination with the exterior field magnets of a hollow cylindrical
armature supported on discs and comprised of a series of loops substantially
rectangular arranged in sets abutting each other the sides of the loops of each set
being arc-shaped and each side being arranged to fit beneath the side of the
adjacent loop of the set, so as to form a complete cylinder of double layer arc-shaped
wire sides, the ends of the wire of each loop being connected to corresponding
sections in the commutator and a solid core loose on the shaft and magnetically
insulated from it by a suitable sleeve and provided with recesses located between
the cores of the field magnets as and for the purpose specified.
3. In a motor of the class described a hollow cylindrical armature comprised of a
series of substantially rectangular wire loops arranged in sets, the side of each loop
of each set fitting under the corresponding side of the next adjacent loop of the set,
so as to form a complete cylinder of double layer arc-shaped sides, the ends of the
loops being arranged to over top each other and the ends of the wires of each loop
being connected to a corresponding section of the commutator as and for the purpose
specified.
Dated the 7th day of November 1804
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.