Improvements in and relating to Dynamo Electric Machines..
Year: 1887

page_text: COMPLETE SPECIFICATION.
Improvements in and relating to Dynamo Electric Machines..
We, ROBERT DICK, Manufacturer, and RANKIN KENNEDY, Electrical Engineer, both
of the Electric Lamp Works, 115 Woodside Road, Glasgow, Lanarkshire, do hereby
declare the nature of our Invention and in what manner the same is to be performed
to be particularly described and ascertained in and by the following statement in
writing, reference being had to the accompanying sheet of Drawings, and to the
letters and figures marked thereon, that is to say:-
This Invention comprises a new or improved construction of dynamo electric
machine, for generating electric currents of alternating polarity, of either high or low
tension or electro-motive force; whilst producing an increased generation of electric
energy, as compared with such machines heretofore constructed.
And in order that our said invention and the manner of performing or carrying the
same into effect or practice may be properly understood, we have hereunto appended
an explanatory Sheet of Drawings, in which the same reference letters are used to
indicate corresponding parts in all the Figures where shown.
Figures 1 and 2 are end and side elevations respectively, while Figures 3 and 4
are corresponding sectional elevations, all illustrating one modification of our new or
improved construction of dynamo electric generator with a disc form of armature, as
applicable for producing alternating currents of high or low tension or electro-motive
force. While Figures 5 and 6 represent end and side sectional elevations respectively,

page_text: broken away, illustrating another modification of our new or improved construction of
alternating current generator with a cylindrical form of armature.
Referring to the modification shown in Figures 1 to 4 of these Drawings, this
construction of electric generator illustrating our improvements consists of two side
vertical cheek plates A A', each preférably formed in two sections secured together
by snugs and bolts at A" the lower sections being cast with suitable horizontal sole or
basement plates and secured together at bottom and top by snugs and bolts at A2 and
by intermediate transverse stay bolts at A³. On the inside surface of each of the
cheek plates A A', lateral projecting radial poles a are cast at suitable intervals apart,
the whole making up a vertical circle on each side of the disc armature B. These
projecting pole pieces a face one another on each of the cheek plates A A¹, and are
each separately wound in the vertical direction with coils of insulated copper wire a,
and forin the fixed field magnets of the generator. A vertical disc armature B is
mounted between the projecting pole pieces a¹ a¹ of the cheek plates A A¹, and
carried on a horizontal shaft C, supported in a long bush bearing C₁, in a projecting
or overhung bracket C² cast on one of the cheek plates A¹, and in a similar outer
bearing in a vertical pedestal C³, erected near the machine. The armature B, consists
of an internal ring wheel B' with arms and boss secured to the shaft C, and with
laminated soft iron hoops or plates B wound on to the ring B, and having coils or
bobbins of insulated copper wire b wound transversely or radially round the laminated
plates and the inner side of rim, at suitable distances apart, and these are connected
together in series. The fixed field magnets a a¹, are excited by a current from a
separate continuous current dynamo electric machine, or other source of electric
energy. While the armature B b, is rotated between the poles a', a¹ of the field
magnets a a¹ by an endless band passed over a pulley D on its shaft C, from the
flyweel of an engine, or any adjacent suitable prime moving shaft. Collectors or
commutators c, c, c, are mounted on and insulated from the overhung end of the
armature shaft C, and receive through connecting wires, the currents generated by
the successive approach and recession of the coils b on the rotating armature B 6 to
and from the fixed field magnet poles at, a¹. Collecting brushes c¹, c¹, c², are mounted
on an overhung bracket E, at the side of the machine, and supply the collected
currents of alternating polarity to the terminal wires at e, e, e, leading to the
consumption circuit.
In our new construction of alternating current generator, the successive poles a¹, a¹,
round the circumferential rings of each of the plates A and A¹, are alternately of
North and South polarity, so that the lines of force here attract each other in the
circumferential direction. That is a North and a South pole are formed alternately
round the ring of poles on each of the plates A and A', so that two north and two
south fixed poles respectively face each other on opposite sides of the armature B b,
and thus the lines of force between them repel one another. By this improved
arrangement the lines of magnetic force are made to pass from the fixed magnet
poles a¹, a', by induction to the coils 6 on the rotating armature B, in the same
direction as the armature rotates, instead of transversely as in alternating current
generators heretofore constructed, and thus an increased generation of electric energy
is thereby obtained.
Referring to the modification of our improvements shown in Figures 5 and 6, in
this arrangement the armature is constructed in the form of a cylinder B with
projecting teeth 61 on its outer surface. Coils of insulated copper wire b are wound
longitudinally round each of these teeth 61, in the hollow spaces between the teeth,
and the whole of the coils bare connected together in series, as in the arrangement
shown in Figures 1 to 4. In this construction the fixed pole pieces a¹ facing each
other are made longer beyond their coils a to approach or coincide with each other
across outside the cylindrical armature, and the armature b, 62, B2 is made to rotate
on the in or underside of them, instead of between them, as in the arrangement shown
in Figures 1 to 4, and in this case the shaft C might have a bush bearing Cin
the cheek A. The wires a of the fixed field magnets are preferably connected in
parallel arc.

page_text: Having now particularly described and ascertained the nature of our said invention
and in what manner the same is to be performed we declare that what we claim is,
First. The construction, or arrangement and combination of the parts of a dynamo
electric generator for producing currents of alternating polarity of either high or low
tension or electro-motive force, all substantially as herein described, in reference to
and shown in the accompanying Drawings.
Second. In alternating current dynamo electric machines, the forming of fixed
radial field magnets a, a', having poles a¹ a¹ of opposite polarity facing each other,
that is two north and two south poles facing each other alternately round the traverse
of the armature, all substantially as, and for the advantages herein described in
reference to and shown in the accompanying Drawings.