Improvements in Dynamo Electric Machines,
Year: 1891

page_text: Date of Application, 13th Oct. 1891-Accepted, 28th Nov., 1891
COMPLETE SPECIFICATION.
Improvements in Dynamo Electric Machines,
I, EZRA TORRENCE GILLILAND, of 15 Dey Street, New York, United States
of America, Inventor, 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 consists in an improved frame of a dynamo electric machine and
in an improved provision for assembling the parts within the frame.
In constructing dynamos and motors great difficulty is encountered in centring
the journal bearings for the armature upon the axis of the polar cavity or
cylindrical space between the faces of the pole pieces within which the armature
is revolved. In machines in which the supports for the journal bearings are
mounted upon the base of the machine and fastened to it by bolts a slight
imperfection,e.g. in the bolt or its thread, will destroy the centring of the
journal bearing either by moving the support aside or by turning it upon its
base. To avoid this dowel pins are commonly inserted in the supports and
base. But however it may be accomplished it is always a difficult matter to
centre supports erected upon the base and they are liable to disarrangement.
And this is true of any support the centring of which depends upon the set of
a screw in its bed. It is the object of my invention to simplify and cheapen
the manufacture of dynamos and other machines of the same general class by
removing this difficulty and at the same time I secure other advantages herein-
after pointed out. I accomplish this by casting the field magnets and the
supporting arms for the journal bearings for the armature all in one piece of
iron and in such manner as to permit the boring necessary to finish the machine
ready for assembling to be done at one operation and also to provide for the
insertion of the armature and the coils of the field magnets into position in
the frame.
Having cast the field magnets and the supports for the journal bearings as a
single piece, or having cast the whole frame including these parts as a single
piece, I bore, at oue operation by well known methods, the supports and the
faces of the field magnets, upon a common center, by which is meant that the
centers of the orifices in the arms and of the curved faces of the field pieces
all lie along
a common axis, which is the axis of rotation of the armature, as
described below, reference being had to the accompanying drawings in which
Fig. 1, is a top view of the frame.
Fig. 2, is a view from the end through which the coils and armature are introduced
into position.
Fig. 3, is a longitudinal section on the line a-a of Figure 1.
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Fig. 4, is partly a longitudinal section and partly an elevation of the end shown
in Fig. 2.
Figs. 5 & 6, are details of the cylinder head.
Figs. 7, 8 & 9, the rocker arm which supports the commutator brushes.
Figs. 10 & 11, a modification.
Referring to Figures 1 to 9:
A is the frame of the instrument:
B is the arm or support for a journal bearing through which the field magnet
coils and the armature are introduced into position:
C is the arm or support for a journal bearing at the other end of the machine :
D is the pole & pole piece of one of the field magnets.
In constructing the machine the arm C is bored of proper size to receive a journal
bearing. The arm B is bored with an opening or orifice larger than the external

page_text: diameter of the armature or otherwise shaped to admit the armature into the polar
cavity. In practice the orifice is made circular and of equal diameter with the
polar cavity. To permit the introduction of the coils of the field magnets, which
are wound upon bobbins, a section of the rim about this orifice is cut away either
at the top or the bottom, or both (see Fig. 11) thus forming an opening through
the arm, and the base, or if desired the top, of the frame is cut away as shown
at F.
When the machine is to be assembled the coils of the field magnets are inserted
through the end B and slipped on to the cores. The armature is then inserted
through the circular orifice in B. One end of its axis is supported in the bearing
in the arm C. The other end is supported in the journal bearing in a plate or
other support which can be fitted into the orifice as the cylinder head G illustrated
in Figures 4, 5 & 6. Both the journal bearings of the armature axis are of
non-magnetic material.
On the cylinder head is cut a flange H which fits accurately within the orifice
in B. This cylinder head is bored turned off and faced at one operation and is
thereby accurately centred and aligned. The head is fastened to the arm by bolts
inserted through the holes J. As the rim of the cylinder head fits snugly against
the outer face of the arm B, no defect in the screws can effect more than a slight
rotation of the cylinder head; and since the journal bearing is at the centre of the
cylinder head, the centring or alignment is not destroyed thereby. Thus the
centring of the journal bearing is secured by the abutment of its support, namely,
the flanged cylinder head, against the inner walls and the outer face of the arm B.
Within the cylinder head is the oil well and feed K shown in Figures 5 & 6.
m
The rocker arm L of the commutator, illustrated in Figures 8 & 9, has a flange:
similar to H, and which is inserted into the same orifice, but from the rear of the
arm B. This rocker arm is cut away at O to slip over the axis of the armature.
In the flange m, is a notch or groove n extending around the whole or a part of
its circumference, in which plays a set screw P. This screw prevents lateral
movement of the rocker arm while it is being rotated, and locks the arm in any
desired position.
By extending the supports for the armature from the field magnet instead of
resting them upon the base it becomes possible to reduce the size of the base and
hence the weight of the frame and these supports help to hold the pole pieces of
the field magnets against the enormous attraction tending to draw them together.
Moreover since the supports connect the poles through the cores of the field magnets
they are in the magnetic circuit.
In the modification shown in Figs. 10 & 11, in which the arm B' is cut in two by
the openings E¹ E' in the rim it is necessary in order to secure the full advantage
of introducing the supports into the magnetic circuit to make the cylinder head of
magnetic material. The head used with either form is ordinarily made of cast
iron. The cut in the base of the frame shown at F is not necessary in this
modification.
It is obvious that each of the arms, B & C, may be bored with an orifice large
enough to admit the armature. Both journal bearings may in that case be
supported in cylinder heads. Where in the claims I specify that one arm is bored
to admit the armature I do not limit myself to so boring one of the arms only.
It is obvious that my invention is applicable to motors as well as dynamos and
the claims are intended to cover its application to the general class of dynamo
electric machinery.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is :-
I. In a dynamo the field magnets and support for the armature axis bored upon
a common centre the boring in one support being a circular opening to admit the

page_text: opening and having at its centre a bearing for the axis of the armature, substan-
tially as described.
II. In a dynamo the field magnets and supports for the armature axis made in
one piece and bored upon a common centre the boring in one support being a
circular opening to admit the armature into the polar cavity in combination with a
support fitting into the opening and having at its centre a bearing for the axis of
the armature, substantially as described.
III. In a dynamo the field magnets and supports for the armature axis which
connect the pole pieces magnetically through their cores all bored upon a common
centre the boring in one support being a circular opening to admit the armature
into the polar cavity in combination with a support fitting into the opening and
having at its centre a bearing for the axis of the armature, substantially as
described.
IV. In a dynamo the field magnets and supports for the armature axis which
connect the pole pieces magnetically through their cores made all in one piece and
bored upon a common centre the boring in one support being a circular opening to
admit the armature into the polar cavity in combination with a support fitting into
the opening and having at its centre a bearing for the axis of the armature, substan-
tially as described.
V. In a dynamo the field magnets and supports for the armature axis bored upon
a common centre the boring in one support being a circular opening to admit the
armature into the polar cavity in combination with a flanged cylinder head fitting
into the opening and against the face of the support and having at its centre a
bearing for the axis of the armature, substantially as described.
VI. In a dynamo the field magnets and supports for the armature axis made in
one piece and bored upon a common centre the boring in one support being a
circular opening to admit the armature into the polar cavity in combination with
a flanged cylinder head fitting into the opening and against the face of the support
and having at its centre a bearing for the axis of the armature, substantially as
described.
VII. In a dynamo the field magnets and supports for the armature axis which
connect the pole pieces magnetically through their cores all bored upon a common
centre the boring in one support being a circular opening to admit the armature
into the polar cavity in combination with a flanged cylinder head fitting into the
opening and against the face of the support and having at its centre a bearing for
the axis of the armature, substantially as described.
VIII. In a dynamo the field magnets and, supports for the armature axis which
connect the pole pieces magnetically through their cores made all in one piece and
bored upon a common centre the boring in one support being a circular opening to
admit the armature into the polar cavity in combination with a flanged cylinder
head fitting into the opening and against the face of the support and having at its
centre a bearing for the axis of the armature, substantially as described.
IX. In a dynamo the field magnets and supports for the armature bored upon
a common centre the boring in one support being a circnlar opening to admit the
armature into the polar cavity and having the rim cut away as shown at E. to
provide for assembling the parts of the machine in combination with a support
fitting into the opening and having at its centre a bearing for the axis of the
armature, substantially as described.
X. In a dynamo the field magnets and supports for the armature bored upon a
common centre one support being cut in two to provide for assembling the parts
of the machine and having faces that form arcs of a common circle in combination
with a support abutting against the faces and having at its middle point a bearing
for the axis of the armature sustained at the common centre by the abutment of the
support against the faces, substantially as described.
XI. In a dynamo the field magnets and supports for the armature which connect
the pole pieces magnetically through their cores all bored upon a common centre
one support being cut in two to provide for assembling the parts of the machine

page_text: and having faces that form the arcs of a common circle in combination with a
support of magnetic material abutting against the faces and having at its middle
point a bearing for the axis of the armature sustained at the common centre by
the abutment of the support against the faces substantially as described.
XII. In a dynamo the field magnets and supports for the armature one support
having an opening large enough to admit the armature into the polar cavity in
combination with a rocker arm carrying the commutator brushes sustained by said
support, and a support for a journal bearing fitting into said opening, substantially
as described.
XIII. In a dynamo the field magnets and supports for the armature one support
having an opening large enough to admit the armature into the polar cavity in
combination with a support for a journal bearing and a rocker arm carrying com-
mutator brushes, both fitting into said opening, substantially as described.
XIV. In a dynamo the field magnets and supports for the armature one support
having an opening large enough to admit the armature into the polar cavity, in
combination with a support for a journal bearing and a flanged rocker arm carrying
commutator brushes, both fitting into the opening, and a set screw to fasten the
rocker arm, substantially as described.
"
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XV. In a dynamo the field magnets and supports for the armature one support
having an opening large enough to admit the armature into the polar cavity in
combination with a support for a journal bearing and a flanged rocker arm carrying
commutator brushes, both fitting into the opening, the flange of the rocker arm
having a groove in which plays a set screw, substantially as described.
Dated this 12th day of October 1891.
H. D. FITZPATRICK,
70, Wellington Street, Glasgow, Agent.