Armature for Alternating Current Motors.
Year: 1899

page_text: COMPLETE SPECIFICATION.
Armature for Alternating Current Motors.
I, JAMES BURKE, of Oudenarderstrasse 23/30, Berlin, in the Empire of Germany,
Electrician, 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 object of the present invention is the construction of armatures for alterna-
ting current motors, in such a manner that all the parts constituting the arma-
ture can be made by machinery thus facilitating and cheapening their manufacture.
The armature core is made up in the usual way of laminae of iron or steel,
provided with notches intended to receive the winding of the armature.
The winding consists of conducting elements made preferably of copper, each
element forming a closed circuit in itself.
If these closed circuit elements are placed into the slots of the armature core,
so that each will embrace two or more armature teeth and the armature is placed
in a rotating magnetic field, currents will circulate in each individual conducting
element, thus creating a turning moment between the armature and the rotating
magnetic field.
Figs. 1, 2 and 3 shew different forms of such conducting or closed circuit
elements.
Fig. 4 is a side view of part of an armature core, with closed circuit elements R R
embracing the armature teeth Z within the armature notches.
Fig. 5 represents a view of part of an armature shewing the arrangement of the
closed circuit elements in the armature notches.
These closed circuit elements form definite paths of circulation for the currents
arising therein, predetermined by the dimensions and form of the elements.
The closed circuit elements may be insulated from each other by placing thin
layers of mica or other suitable insulating material between them, but their inner
resistance is 'so exceedingly low, that there is no perceptible leakage across
surface contacts existing between the single elements, if no insulating material
is placed between them, and each individual closed circuit element will form an
individual circuit for itself.
It is for this reason that this method of making armatures for induction motors,
must not be confounded with the well known short circuit armature on which
wires or rods of copper are drawn through or placed on an iron core, all these
being connected with each other at each end of the core, thus forming one general
short circuit throughout the armature, individual circuits not being possible with
that method of construction.
Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed, I declare that what I
claim is:-
1. An armature for induction motors which consists of an iron core with notches
and closed circuit conducting elements placed in these notches, these conducting
elements being such that when the armature is placed in
rotating macuatio

page_text: field, currents circulate in each individual conducting element thus producing a
turning moment between the armature and the rotating magnetic fields.
2. A conducting element for the armatures of induction motors such, that when
a number of them are assembled on an armature in such a manner that each
embraces two or more teeth, and the armature is placed in a rotating magnetic
field, currents circulate through the definite path of each conducting element, and
the currents in each conductor are independent of each other, these independent
currents causing a turning moment between the rotating field and the armature.
Dated this 27th day of November 1899.
ABEL & IMRAY,
Agents for the Applicant.