Improvements in Rotary Phase Current Motors and Dynamos.
Year: 1891

page_text: Date of Application, 2nd Nov., 1891
Complete Specification Left, 6th July. 1892-Accepted, 6th Aug., 1892
PROVISIONAL SPECIFICATION.
[Communicated from abroad by Messrs. SIEMENS & HALSKE, of 94, Markgrafen-
strasse, Berlin, in the German Empire.]
Improvements in Rotary Phase Current Motors and Dynamos.
We, SIEMENS BROTHERS & Co. LIMITED of 12 Queen Anne's Gate,
Westminster in the County of Middlesex, Electrical Engineers, do hereby
declare the nature of this invention to be as follows:-
The production of rotary magnetic fields, the strength and angular velocity of
which remains constant during one revolution, is of importance in working rotary-
phase motors because every variation of the said two quantities produces detri-
mental heating in the armature of the motor. The constancy of the rotary
magnetic field is the more perfect, the greater is the number of the component
magnetic fields employed for producing the resulting rotary field. In the known
arrangements of rotary phase motors this fact is taken into consideration by
dividing each bobbin or coil carrying a single alternating current into two equal
coils which are situated diametrically opposite each other at the circumference of
the motor. In this way a four-bobbin motor could be produced with two
alternating currents whose phases are shifted relatively to each other; with three
such alternating currents, a motor with six spools, and consequently a doubling of
the component fields was obtained.
The present invention relates to an arrangement whereby a quadrupling of
the number of component fields is effected, instead of only a doubling.
This arrangement can be employed both in two-pole and in multiple-pole rotary
phase motors wherein any number of alternating currents can be used that are
shifted relatively to each other as regards their phases. In the following description
however, by way of example, only the simplest construction will be referred to in
which a motor having two poles is worked by means of three alternating currents
shifted relatively to each other as regards their phases; from this description, any
one conversant with the art will be readily able to apply the invention to motors
with more than two poles..
Figure 1 of the accompanying drawings shews diagrammatically the complete
arrangement for the transmission of power by rotary-phase currents.
The Thomson-Houston armature R is assumed to be rotating in a constant
magnetic field.
From the outer ends P1 P2 P3 of the three coils three alternating
currents Ja Jb Je are taken off which are led to the place of consumption
through the three conductors P₁ D₁, PÅ DÅ PÅ DÅ. These currents Ja Jb J c
will be designated in the following as the main currents. At the place of con-
sumption resistances or current-consuming apparatus of any known form may be
arranged either in the circuits P₁ D₁, &c., themselves or between these. The
currents which are generated in these resistances placed between the points D₁ &c.
will be termed branch currents. If in all three circuits, that is to say, between P₁
and D, &c. equal resistances are placed, and also three equal resistances between
the three circuits, namely between D₁, D₁, &c. there will be obtained in the three
circuits P, D, &c. three equal main currents J c. J b. J c. whose phases are shifted
relatively to each other to the extent of equal intervals of time, while in the three
intermediate conductors D, D,, D, D. D, D₁, three equal branch currents J₁ J, J,
will be obtained which are also shifted relatively to each other to the extent of
equal intervals of time. For this case the rule also applies that the strength of
the currents Ja Jb Jc are in the proportion of : 1 relatively to the strength
1
T T

page_text: If these six currents are represented as regards their phase and strength in a
polar diagram, this will appear as at Figure 2, in which the positive directions of
the currents are indicated by the full lines, and the negative directions by the
dotted lines, and where each current is shifted as regards its phase, relatively to
the two contiguous ones by the same amount namely in this case, by 30°.
According to the present invention, these currents are all caused to act in
combination for the production of a rotary field, and it will be seen at once that
by this means it will be possible to work a two-pole rotary phase motor having
twelve bobbins or coils by means of three conductors, if only care be taken
that the number of convolutions of those bobbins which carry the main
currents Ja±Jb± Jc are proportional to the number of convolutions of the
bobbins that carry the branch currents ±J, J, ± J, according to the ratio 1 : }
so that the number of ampere turns of all twelve bobbins shall be equal.
The practical carrying out of this invention is shewn by way of example by the
diagram Figure 3, which will be understood without further explanation.
The said invention is also applicable for the production of rotary phase currents,
as well as for working rotary phase motors as above described. Heretofore rotary
phase currents have been produced by the method indicated by Tesla, whereby
three or more equidistant plates on the commutator of an ordinary continuous
current armature are connected to collector rings fixed on the armature shaft from
which rings the desired rotary phase currents could be taken off so soon as the
machine was excited and set in motion.
According to the present invention this arrangement is altered in such manner
that, for example, the armature or ring of an ordinary continuous current machine,
is wound in the manner indicated diagrammatically at Figure 4 which corresponds
to the arrangement shewn at Figure 3. The ends P, P2 P3 of the windings are
led to the collector rings S, S, S,; if the field magnets be then excited and the
armature is rotated, rotary phase currents can be taken off from the collector
rings. This method of producing rotary phase currents differs essentially from
the above described existing method in that an essentially higher degree of
efficiency is obtained.
The described arrangement can not only be applied to continuous current
machines but also to alternate current machines which are suitably arranged
according to known methods for the production of rotary-phase currents.
The said arrangement can also be used for multipolar machines, as previously
described with reference to motors, or for the production of more than three
alternating currents, shifted relatively to each other as regards their phase.
It is also immaterial whether the armature coiled as described is rotated in a
stationary magnetic field, or remains stationary within a rotating magnetic field as
only the relative motion between the two has to be considered.
Dated the 21st day of October 1901
ABEL & IMRAY,
Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Rotary Phase Current Motors and Dynamos.
We, SIEMENS BROTHERS & Co. LIMITED, of 12 Queen Anne's Gate,
Westminster, in the County of Middlesex, Electrical Engineers, 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 :-
The production of rotary magnetic fields, the strength and angular velocity of
which remains constant during one revolution, is of importance in working rotary
phase motors, because every variation of the strength or velocity produces
detrimental heating in the armature of the motor. The constancy of the rotary

page_text: magnetic field is the more perfect the greater the number of the component
magnetic fields employed for producing the rotary field. In the known arrange-
ments of rotary phase motors this condition is provided for, to a certain extent, by
dividing each bobbin or coil intended for carrying a single alternating current into
two equal coils placed diametrically opposite to one another at the circumference
of the motor. In this way a four-bobbin motor could be produced with two
alternating currents whose phases are shifted relatively to each other; with three
such alternating currents, a motor with six bobbins, and thus the number of the
component fields could be doubled.
The present invention relates to an arrangement whereby the number of
component fields is quadrupled, instead of being only doubled.
This arrangement can be employed both in two-pole and in multiple-pole rotary
phase motors wherein any number of alternating currents can be used that are
shifted relatively to each other as regards their phases.
In the following description, however, by way of example, only the simplest
construction will be referred to, in which a motor having two poles is worked by
means of three alternating currents shifted relatively to each other as regards their
phases.
From this description, persons conversant with the art can readily apply the
invention to motors with more than two poles.
Fig. 1 of the drawings accompanying the Provisional Specification shews
diagrammatically the complete arrangement for the transmission of power by
rotary phase currents.
The Thomson-Houston armature R is assumed to be rotating in a constant.
magnetic field.
From the outer ends P1 P2 P3 of the three coils, three alternating
currents Ja Jb Je are taken off which are led to the place of consumption
through the three conductors P₁ D, P₂ D₂, P, Ds. These currents Ja Jb Jc in
what follows will be designated as the main currents. At the place of consumption
resistances or current-consuming apparatus of any known form may be arranged
either in the circuits P, D, &c. themselves or between these.
The currents which are generated in these resistances placed between the
points D¹ &c. will be termed branch currents. If in all three circuits, that is to
say between P and D₁ &c. equal resistances are placed, and also three equal
resistances between the three circuits, namely between D, D, &c. there will be
obtained in the three circuits P, D, &c. three equal main currents Ja Jb Je whose
phases are shifted relatively to each other to the extent of equal intervals of time,
while in the three intermediate conductors D₁ D2, D, D3, D, D₁, three equal
branch currents J, J, J, will be obtained which are also shifted relatively to each
other to the extent of equal intervals of time. For this case the rule also
applies that the strength of the currents Ja Jb Jc is to the strength of the
currents J₁ J, J, in the proportion of 2 to 3.
If these six currents are represented as regards their phase and strength in a
polar diagram, this will appear as as Fig. 2 in which the positive directions of the
currents are indicated by the full lines, and the negative directions by the dotted
lines, and where each current is shifted as regards its phase relatively to the two
contiguous ones by the same amount, namely in this case, by 30°.
According to the present invention, these currents are all caused to act in
combination for the production of a rotary field, and it will be seen at once that by
this means it will be possible to work a two pole rotary phase motor having
twelve bobbins or coils by means of three conductors, if only care be taken
that the number of convolutions of those bobbins which carry the main
currents JaJb± Je are proportional to the number of convolutions of the
bobbins that carry the branch currents + J₁ ± J₂ ± J₂ according to the
ratio 3 to 2, so that the number of ampère turns of all twelve bobbins shall be
equal.

page_text: "
The practical carrying out of this invention is shewn by way of example by the
diagram Fig. 3, which will be understood without further explanation.
The said invention is also applicable for the production of rotary phase currents,
as well as for working rotary phase motors as above described.
Heretofore rotary phase currents have been produced by the method indicated
by Tesla, whereby three or more equidistant plates on the commutator of an
ordinary continuous current armature are connected to collector rings fixed on the
armature shaft from which rings the desired rotary phase currents can be taken off
so soon as the machine is excited and set in motion.
•
2
According to the present invention this arrangement is altered in such manner
that for example, the armature or ring of an ordinary continuous current machine,
is wound in the manner indicated diagrammatically at Fig. 4, which corresponds
to the arrangement shewn at Fig. 3. The ends P₁ P, P3 of the windings are led
to the collector rings S, S, S₁; if the field magnets be then excited and the
armature rotated, rotary phase currents can be taken off from the collector rings.
This method of producing rotary phase currents differs from the existing method
above referred to in that a higher degree of efficiency is obtained.
The described arrangement can not only be applied to continuous current
machines but also to alternate current machines which are suitably arranged
according to known methods for the production of rotary phase currents.
The said arrangement can also be used for multipolar machines, as previously
described with reference to motors, or for the production of more than three
alternating currents, shifted relatively to each other as regards their phase.
It is also immaterial whether the armature coiled as described is rotated in a
stationary magnetic field, or remains stationary within a rotating magnetic field, as
only the relative motion between the two has to be considered.
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
In rotary phase motors or dynamos the arrangement in combination with three
or more conductors of quadruple the number of bobbins with suitably proportioned
resistances or their equivalents, substantially as described.
Dated this 6th day of July 1009
ABEL & IMRAY,
Agents for the Applicants.