Improvements in and relating to Electric Generators, Motors, and Transformers.
Year: 1893

page_text: Date of Application, 20th May, 1893
Complete Specification Left, 17th Feb., 1894-Accepted, 14th Apr. 1894
PROVISIONAL SPECIFICATION.
Improvements in and relating to Electric Generators, Motors, and
Transformers.
I, WALDEMAR FRITSCHE, of 4 Am Kupfergraben, Berlin, N., in the Empire.
of Germany, Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to an electric machine for continuous, alternating or
multiphase currents which acts as a generator, motor or transformer. The armature
of this improved machine is characterized by the fact that the armature core,
differing from the constructions heretofore employed, is divided perpendicularly to
the direction of motion so that strips are produced with intermediate spaces which
serve for the reception of the armnature winding. These strips may themselves be
employed as part of the armature winding and for deviating the currents. Accord-
ingly the magnetic field has to be so arranged that the whole passage of the lines of
force in the armature is also perpendicular to the direction of motion.
armature core must therefore be so placed between the north and south poles of the
magnets that the poles of the same name are always on one side, and are directly
opposite to those of different names. This arrangement permits of greatly
simplifying the construction of the armature and closing the magnetic circuit so
that the resistance of the air between the armature and magnets will be extremely
small.
The
In carrying my invention into practice I provide an armature which has the
form of a bell. The hollow cylindrical part of said armature which receives the
winding extends between the pole pieces of the electromagnets, the number of
which may for example be three. The armature is formed of iron strips having
intermediate spaces between them which serve for the reception of the wires
running parallel to the strips and to the armature shaft.
The strips are somewhat Z-shaped in form and one shank besides serving as an
armature core, may also be used as part of the winding, while the other shank
serves in that case to conduct away the current. The wires or conductors leave
the intermediate spaces between the strips at the two ends of the shanks and two
spaces at the two ends of the said shanks receive the connecting parts of the wires
or conductors either alone or together with the strips. The strips are then held by
a nave and a ring shrunk on.
In the case of a three-pole continuous current machine, poles of the same name,
for instance north poles are inside the armature and poles of the same name, namely
south poles which are in each case directly opposite to the north poles, are outside
the armature. The lines of force in the armature ring with all pass radially. The
brushes for collecting the current are arranged at suitable points. When the
strips are for instance designated by numerals 1 to 30, the current in one position
of the strips relatively to the magnetic fields will pass at the strips 1, 11 and 21
into the armature and leave at the strips 6, 16 and 26. The wires or conductors
themselves are connected with the strips in any suitable manner, and are insulated
from each other and from the strips.
In the case of a machine for alternating currents, only a portion of the strips is'
utilized for the winding.
It will be easy to produce windings for other numbers of poles and strips and for
multiphase currents.
The magnets appertaining to this armature are made of horse-shoe shape and.

page_text: may be suitably divided perpendicularly to the direction of motion, so that they
consist of single strips. A number of horse-shoe magnets may be excited by a
single common coil arranged in an annular box which carries the magnets.
If the magnet core is to be solid, four pairs of pole pieces which are parallel to
each other and constitute as it were two concentric bells may project from an
annular bridge piece the armature ring extending into the intermediate space
between the said bells.
According as the electro-magnets are stationary or rotary they are either firmly
connected with the frame, or fixed by a spider and a nave upon a shaft. The
armature and magnets may also be arranged double in which case the armature
strips are made of U-shaped form.
Dated this 20th day of May 1893.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in and relating to Electric Generators, Motors, and
Transformers.
I, WALDEMAR FRITSCHE, of 4 Am Kupfergraben, Berlin, N., in the Empire of
Germany, 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 :-
My invention relates to an electric machine for continuous, alternating or
multiphase currents which acts as a generator, motor or transformer.
The armature of this improved machine is characterized by the fact that. the
armature core, differing from the constructions heretofore employed, is divided
perpendicularly to the direction of motion so that strips are produced with inter-
mediate spaces which serve for the reception of the armature winding. These
strips may themselves be employed as part of the armature winding.
Accordingly the magnetic field has to be so arranged that the direction of the
lines of force in the armature is also perpendicular to the direction of motion.
The armature core must therefore be so placed between the north and south poles
of the magnets that the poles of the same name are always on one side, and are
directly opposite to those of different name. This arrangement permits of greatly
simplifying the construction of the armature and closing the magnetic circuit so
that the resistance of the air between the armature and magnets will be extremely
small.
In the accompanying drawing I have shown how my said invention can be
conveniently and advantageously carried into practice.
Figure 1 is a longitudinal section of a machine provided with my improved
armature.
Figure 2 is a cross section of the same taken on the line, x of Figure 1.
Figure 3 is a detail of one of the strips of which the armature is composed..
Figure 4 shows by way of example a diagrammatical view of the developed
periphery of the armature of a three pole continuous current machine.
Figure 5 is a diagrammatic view of an armature winding for alternating
currents.
Figure 6 is a longitudinal section of a magnet core constructed according to my
invention.
Figure 7 is a cross section of the same.
Figure 8 is a side elevation of the said core.
Figure 9 is an end view of the electro magnets and armature showing a modified
arrangement for carrying the same.
.::

page_text: Figure 10 shows a double arrangement of the armature and magnets, and
Figure 11 shows a modified form of armature strip.
In the machine shown in longitudinal and cross section in Figures 1 and 2, F
provide an armature A which when mounted has the form of a bell. The hollow
cylindrical part of the said armature which receives the winding extends between.
the pole pieces N S of the electro-magnets M, the number of which may for example.
be three. The direction of the lines of force is indicated by the dash lines in
Figure 4. The said armature A is formed of iron strips a having intermediate
spaces between them which serve for the reception of the wires i running parallel
to the strips and to the armature shaft.
The strips as shown in Figure 3 are somewhat Z-shaped in form, and one shank
thereof besides serving as an armature core, may also be used as part of the winding
while the other shank a² serves in that case to conduct away the current. The wires.
or conductors pass from the intermediate spaces between the strips and project
out at both ends of the said shanks a' and are connected here at c with the
wires of the adjacent spaces or with the strips a'. The strips are then held by a
nave o and a spring shrunk on.
In the diagram shown in Figure 4 the shanks a¹ of the strips are indicated by
thick dotted lines, the wires or conductors i and the connecting wires or conductors
arranged in the two spaces c by simple lines. The three magnetic fields are
indicated by section-lined rectangles. As all the poles on the inside of the
armature A, Figures 1 and 2 are of the same name, for instance N poles and all
the poles on the outside of the said armature are also of the same name, that is to
say, S poles, which are in each case directly opposite to the N poles. The lines of
force in the armature ring will all pass radially. The brushes for collecting the
current are arranged at the points I, I, I and II, II, 11" indicated by double.
arrows. Accordingly when the strips a are for instance designated by numerals 1
to 30, the current, in the position of the strips relatively to the magnetic fields as
shown in Figure 4 will pass at the strips 1, 11, and 21 into the armature and leave.
at the strips 6, 16 and 26. The passage of the current in the armature is thus.
shown directly, as indicated by the arrow heads on the lines representing the strips
and the wires. The wires or conductors themselves are connected with the strips in
any suitable manner, and are insulated from each other and from the strips.
Figure 5 shows the developed diagram of a winding for alternating currents..
In this case only a portion of the strips a' is utilized for the winding.
From these examples windings can be easily produced for other numbers of poles.
and strips and for multiphase currents.
The magnets appertaining to this armature are made of horse-shoe shape and may
be suitably divided perpendicularly to the direction of motion, so that, as shown in
Figures 1 and 2, they consists of single strips. The three horse-shoe magnets M
shown in these figures are excited by a single common coil S'arranged in an annular
box which carries the magnets.
If the magnet core is to be solid, the form shown in Figures 6, 7 and 8 may be
employed. In this case from the annular bridge or end piece m extend four pairs
of pole pieces N S which are parallel to each other and constitute as it were two.
concentric interrupted rings into the intermediate space between which extends the
armature ring.
According as the electro-magnets are stationary or rotary they are either firmly
connected with the frame, as shown in Figure 1, or fixed by a spider and a nave
upon a shaft as shown in Figure 9. The arinature and magnets may also be
arranged double, in the manner shown in Figure 10. In this case the armature
strips a are made of U-shaped form as shown in Figure 11.
I am aware that armatures divided perpendicularly to the direction of the motion
have been constructed heretofore; I am also aware that parts of the iron armature
have been used for conducting the electric current and I do not claim these:
arrangements broadly.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is -
First. An electric machine with a bell-shaped armature, the periphery of which
is divided perpendicularly to the direction of motion in such a manner that the free
shanks (a) of the several Z or U-shaped iron cores (a) are traversed by the lines
of force perpendicularly to the direction of motion, while the spaces between the
shanks receive the winding wires.
Second. An electric machine of the kind characterized in the first claim, in which
all or single shanks (a') of the iron core parts (a) are connected with the
winding (i) as conductors and are adapted to be utilized for conducting away
the current.
Third. An electric machine of the kind characterized in the first claim, the field
magnet of which consists of several horse-shoe magnets arranged about a common
annular bobbin.
1004
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.