Improvements in and relating to Electric Motors and Dynamo Electric Machines.
Year: 1892

page_text: Date of Application, 17th May, 1892-Accepted, 9th July, 1892
COMPLETE SPECIFICATION.
Improvements in and relating to Electric Motors and Dynamo
Electric Machines.
We, ROBERT LUNDELL and EDWARD HIBBERD JOHNSON, both of 44 Broad
Street, New York, United States of America, Electricians, 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 for its objects, First, the construction of an electric motor
in such manner as to conceal all the operative parts thereof, Second, the arrange-
ment of all of the parts thereof in the most compact and symmetrical manner and
Third, to afford a simple, cheap and efficient manner of accurately centering the
armature between the field poles and in its journal bearings.
These several objects are accomplished by the practice of the methods and the
use of the apparatus hereinafter described.
In the accompanying drawings,
Figure 1 represents a longitudinal section through the body of this improved
electric motor taken on line 11, Figure 3, looking in the direction of the arrows.
the armature and its axle being shown in clevational view.
Figure 2 is a view showing the interior of one of the field magnet cores looking
in the direction of the arrows at right angles to the line 2-2 in Figure 1, the
other field core having been detached and the field magnet coil and armature
removed so as to illustrate the interior contour of the field magnet core.
Figure 3 is a longitudinal sectional view taken through Figure 1, looking in
the direction of the arrows, the armature and field magnet coil having been
removed; the commutator brushes appearing one in elevation and the other in
section with their free ends resting upon the commutator illustrated in broken line.
Figure 4 is a side elevational view of one of these improved motors supported
by a standard and base, and provided with a well known form of rotary fan.
Referring now to the drawings in detail, B B' represent the field magnet cores
which are so constructed that they constitute at one and the same time the pole
pieces P P and a spherical two-part enclosing shell held together by bolts or
screws 6 extending through ears E three or more in number. These two semi-
spherical pole pieces are so cast, or otherwise constructed, that their inner ends
resting over the opposite ends of the armature A, and near the centre of the field
magnet coil M, embrace a minimum amount of magnetic metal and that a cross
section through either one of said poles P P at any point between the end of the
field coil and its centre shall equal in area the like-cross section through.the exterior
shell made by the same plane. It will be observed that the axis of the field maguet
coil wound upon the spool S lies when in position on an angle with the axis C of
the armature A, and that by such an arrangement one is enabled to give to the
opposite poles P P¹ magnetism of opposite polarity and further that by virtue of
this arrangement all of the magnetic lines of force are concentrated at points
directly opposite the poles of the armature as it rotates and all of these lines are
utilized in a most effectual manner.
The armature A is of any preferred construction and is provided with the usual
commutator L against which rest the ends of two commutator brushes c preferably
of carbon held in position by metallic sleeves which in turn are secured by
bayonet joint connections, as shown with rubber or vegetable fibre tubes s firmly
ccured in openings drilled through the magnetic shell B, as clearly illustrated in
Figure 3. $ are spiral springs within the sleeves s¹ for giving to the commutator
D077

page_text: brushes end movement as they wear away on the commutator L. tt are binding
screws to which are secured the conductors running to the source of electrical
supply not shown. It is obvious therefore, that the commutator brushes are
entirely concealed and may be quickly and readily removed for repairs, F and
F are caps which act as oil chambers and are secured to the parts B, B', by
screw threads, as shown.
a is an air vent in the cap F and a similar vent may be provided in the cap F.
n and m are grooves or channels adapted to admit air to the interior of the machine
and to carry the drip oil from the inner portions of the axis back to the oil-chambers M'.
RR are flat oil-conveying rings or washers of well known form extending into
the oil chambers M' and carried by the axle C.
D D represent Babbitt metal bearings cast in position around the axle C in
accordance with the novel method of centering an armature which will now be
described. A "dummy" armature is used having the substantial length of the
armature A and a diameter a trifle greater; said armature having first been carefully
centred upon an axis C. One end of the axis is inserted into one portion of
the field magnet core, say B, and then the other portion of the field magnet
core B is placed in position and the parts clamped firmly together by the
bolts passing through the lugs or ears E.
It will be understood, of course,
that under this condition of affairs the dummy armature is held in this clamped
position by the clamping action of the poles P P₁ and that the ends of the
armature shaft are in proper alignment in the journal-boxes made by the hollow
enlarged portions N N of the parts B B¹ the opposite ends of the dummy armature
resting against the internal portions of the journal-boxes N N. The molten
Babbitt metal D is now poured into the outer end of the journal-box N and allowed
to cool or set about the free end of the axis C. The positions of the entire
apparatus are now reversed and molten Babbitt metal D' poured about the other
end of the shaft C, and allowed to cool as before. The bolts may now be removed
and the two parts B B drawn apart leaving the Babbitt metal journal-bearings in
correct alignment for the actual armature. A which is a duplicate in form of the
dummy armature except that it is of slightly smaller diameter to admit of the
necessary air space between it and the field poles P P. The two halves B and B!
are then taken by a machinist and the air vents m, m, grooves n n and the space
which admits the right hand oil ring R, are all drilled and cut as will be fully
understood on inspection of Figures 1 and 3.
Instead of using a dummy armature of slightly greater diameter than the actual
armature the latter may be used in connection with the aligned shaft and the
method of casting the journal-bearings D D' already described. In this event one
would surround the armature with a coating of paper, wire or other material,
before securing it in position between the poles B B in the manner already
described, the coating thereon being of such thickness that when removed after
the parts have been separated the necessary air space will result for the free rotation
of the armature.
Many of the features of this invention are as applicable to dynamo electric
machines as to electric motors, as will be fully understood by those skilled in
the art.
Although the improved motor as illustrated, is especially adapted to the driving
of a fan and sustained on a base K and standard G by screws entering the
screw-holes ff, it may be utilized for all purposes where motors of this type are
needed.
It is old in the art to conceal all the parts of an electric motor within a spherical
shell made of two parts, and no claim is hereinafter made broad enough to include
such a structure. It is not believed, however, that any one has heretofore
constructed an electric motor in which the field magnet poles were integral with
two hemispheres, nor is it believed that any one has utilized a single field magnet
coil in a motor of this type.

page_text: It is believed also to be broadly new to centre an armature in its journal-bearings
between the field poles in the manner described and to enclose a rotary armature
and its effective field poles wholly within the influence of a single surrounding field
magnet coil, and the claims, in this particular, are also designed to be of the most
generic scope.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. An electric motor having a rotary armature and two field magnet poles all
surrounded by a single field magnet coil, substantially as described.
2. An electric motor having its armature entirely surrounded by a single field
magnet coil which surrounds also the effective field magnet poles, substantially as
described.
3. An electric motor having the axes of its field magnet and armature coils
inclined at an angle to each other with field magnet poles included in the angular
space between said coils, substantially as described.
4. Two semi-spherical field magnet cores having internal pole pieces and a single
field magnet coil substantially as described.
5. Two semi-spherical field magnet cores having internal pole pieces integral
therewith substantially as described.
6. A semi-spherical field magnet core having an internal pole piece integral
therewith, a rotary armature and a single field magnet coil, substantially as
described.
7. A pair of semi-spherical field magnet cores enclosing a single field magnet
coil and a rotary armature substantially as described.
8. Two hemispheres made of magnetic material having internal pole pieces cast
integral therewith and a single field magnet coil which surrounds the pole pieces
and a rotary armature, substantially as described.
9. Two hemispheres of magnetic material having internal pole pieces integral
therewith and means for holding the said hemispheres together, substantially as
described.
10. Two hemispheres of magnetic material having each an internal semi-
cylindrical pole piece integral therewith and each overlapping the other, substantially
as described.
11. Two hollow hemispheres of magnetic material having each a semi-cylindrical
pole piece integral with its inner face a rotary arinature journalled in the opposite
hemispheres and lying between the pole pieces, in combination with a single field
magnet coil, substantially as described.
12. An electric motor having all of its parts enclosed in a two part magnetic
shell which sustains the journal bearings of the armature shaft and the commutator
brushes, the latter being adjustably secured in insulating sleeves, substantially as
described.
13. An iron clad electric motor consisting of two hemispheres of magnetic
material having the journal bearings of the armature shaft in the opposite hemi-
spheres, and cominutator brushes secured in one of said parts in insulating sleeves,
substantially as described.
14. The described method of centering an armature of an electric motor or dynamo
electric machine consisting in clamping it between the field magnet poles and then
casting the journal bearings about the shaft and in journal boxes integrally attached
to the field magnet cores.
15. The described method of centering an armature of an electric motor or
dynamo electric machine, consisting in securing a dummy armature between the
poles of the machine and then casting the journal bearings in place about the ends
of the armature shaft, and finally removing said dummy armature.
16. The described method of centering an armature of an electric motor

page_text: · consisting in clamping the field poles of the machine about the body of the
armature and then casting the journal bearings around the journals of the
armature shaft.
Dated this 24th day of May 1892.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants.