IMPROVEMENTS IN DYNAMO ELECTRIC MACHINES to be as follows:
Year: 1884

page_text: I WILLIAM MORRIS MORDEY of 144 Disraeli Road, Putney, in the County of
Surrey, Electrical Engineer, do hereby declare the nature of said invention for
"IMPROVEMENTS IN DYNAMO ELECTRIC MACHINES to be as follows:-
"
This invention has for its object the construction of an improved form of dynamo
electric machine (generator or motor) of the drum armature type, and has reference
to making the drum or cylinder of an undulated, corrugated, sinuous, or wavy form
externally; the undulations or alternate depressions and projections being in the
direction of its length. The poles or pole pieces of the field magnets are made
of a similar or corresponding undulatory or corrugated form, so that the polar
surfaces opposed to the armature are parallel to the surface of the latter. In drum
armatures as hitherto constructed the considerable proportion of the conductor
crossing the ends of the drum adds little or nothing to the useful effect, because it
does not pass through the magnetic field, or passes through it in such a manner
that little or no electrical energy is developed. These portions, introduce a useless
resistance and are therefore a cause of waste of energy. In machines constructed
according to my invention the proportion of the active conductor to that which is
idle and useless is much greater than in existing machines.
In building an armature according to this invention, one plan is to place on the
shaft or axle first a certain number of thin iron plates or washers, all of one
diameter, slightly separated from each other by strips of paper, or other insulating
material; and then in the same way a number of similar plates or washers
of larger diameter. These are followed by more washers of the smaller size,
and so on until the required length is obtained, when the plates are firmly clamped
by nuts and washers at the ends. Sometimes pegs of wood or other suitable
substance are used to give increased stability to the wider sets of plates. Air
passages for cooling purposes are formed by holes cut in the plates before they are
placed together as above described. Or the plates may be of gradually increasing,
and then gradually decreasing diameter, or several plates of one size may be
followed by a gradually increasing series, and then by more of equal, but
still larger size, and then by a decreasing series, and so on. It is evident that
many different ways of building armature cores according to my invention may be
employed, and that various contours or configurations of outline may be produced
according to circumstances.

page_text: The undulated or corrugated armature core so constructed is over-wound with
wire, strips, or bars of copper-preferably strips or bars, to serve as the conductor
in which the current is generated.
By the above described construction of armature and pole pieces a much greater
active magnetic surface is exposed than is possible with machines as hitherto made;
and, in consequence, a corresponding decrease is effected in the resistance of the
magnetic circuit, and an increase in the magnetic strength of the field.
This construction of armature and pole pieces is applicable with any even number
of poles.

page_text: I, WILLIAM MORRIS MORDEY, of 144 Disraeli Road, Putney, in the County of
Surrey, Electrical Engineer, do hereby declare the nature of my invention for
"IMPROVEMENTS IN DYNAMO-ELECTRIC MACHINES" 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 object the construction of an improved form of dynamo
electric machine (generator or motor) of the drum armature type, and has referenco
to making the drum or cylinder of an undulated, corrugated, sinuous, or wavy form
externally; the undulations or alternate depressions and projections being in tho
direction of its length. The poles or pole pieces of the field magnets are made of
a similar or corresponding undulatory or corrugated form. So that the polar
surfaces opposed to the armature are parallel to the surface of the latter. In drum
armatures as hitherto constructed the considerable proportion of the conductor
crossing the ends of the drum adds little or nothing to the useful effect, because it
does not pass through the magnetic field, or passes through it in such a manner,
that little or no electromotive force is developed. These portions introduce a
useless resistance and are therefore a cause of waste of energy. In machines
constructed according to my invention, the proportion of the active conductor to
that which is idle and useless is much greater than in existing machines.
Fig 1 is an end elevation of a machine constructed according to this invention.
Fig 2 is a longitudinal section through the armature and polepieces of the same;
and Fig 3 is a similar longitudinal section shewing a modified form of armature
and polepieces.
In building an armature according to this invention, one plan shewn in Fig 2 is
to place on the shaft or axle, first a certain number of thin iron plates or washers a
all of one diameter, slightly separated from each other by strips of paper, or other
insulating material; placed radially between the plates and then in the saine way
a number of similar plates or washers b of larger diameter. These are followed by
more washers of the smaller size a and so on until the required length is obtained,
when the plates are firmly clamped by nuts and washers at the ends. Sometimes
pegs of wood or other suitable substance are used, to give increased stability to the
wider sets of plates. Air passages c for cooling purposes are formed by holes cut
in the plates before they are placed together as above described. In placing the
conductor upon the armature I leave an opening from the external air to the ends
of the air-passages c.
The air which enters these passages passes radially between
the plates through the spaces between the strips of insulating material employed to
separate them, and out between the conducting strips or bars. Or the plates may
be of gradually increasing, and then gradually decreasing diameter. Or several
plates of one size may be followed by a gradually increasing series, and then by
more of equal but still larger size, and then by a decreasing series, and so on as
shewn in Fig 3. It is evident that many different ways of building armature
cores according to my invention may be employed, and that various contours
or configurations of outline may be produced according to circumstances; the pole
pieces P. P corresponding in form with the armature. The undulated or corrugated
armature core so constructed is overwound with wire, strips, or bars of copper-
preferably strips or bars, to serve as the conductor in which the current is generated,
and which are held in place by a binding wire in the usual manner. The conductors
and commutator are not shewn in the figures. I do not however limit myself to

page_text: the construction of the armature core in the above-described manner. It may be
constructed according to any of the modes suitable for drum armatures of the
ordinary form.
By the above described construction of armature and polepieces, a much greater
active magnetic surface, is exposed than is possible with machines as hitherto made;
and in consequence, a corresponding decrease is effected in the resistance of the
magnetic circuit, and an increase in the magnetic strength of the field.
This construction of armature and polepieces is applicable with any even
number of poles.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is -
.1 The construction of a dynamo electric generator or motor in the manner
described and shewn with reference to Figs 1, 2, & 3 of the drawings.
2. In an electric generator or motor of the drum type, the use of an armature of
an undulated, corrugated, sinuous, or wavy form externally; in conjunction with
poles or polepieces presenting to the said armature similar or corresponding
undulatory or corrugated faces, so that the polar surfaces are parallel or nearly
parallel to the surface of the armature, substantially as described.
Dated this 1st day of October 1884