IMPROVEMENTS IN DYNAMO-ELECTRIC MACHINES
Year: 1882

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for an Invention
of "IMPROVEMENTS IN DYNAMO-ELECTRIC MACHINES." A communication
from abroad by Bernard Lande, of the City and State of New York, United
States of America.
COMPLETE SPECIFICATION filed by the said William Robert Lake at the
Office of the Commissioners of Patents on the 21st February 1882.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent
Agents, Southampton Buildings, London. "IMPROVEMENTS IN DYNAMO-ELECTRIC
MACHINES." A communication from abroad by Bernard Lande, of the City and
State of New York, United States of America.
This Invention relates to that class of machines for generating electric currents
having a paramagnetic ring armature, around which an electric conductor is
wound, and which is caused to revolve in magnetic fields, and comprises certain
improvements in the paramagnetic ring, whereby it and the electric conductor
wound thereon are kept at a moderate and safe temperature, and certain improve-
ments in the construction of the frame and inducing electro-magnets and their
poles, whereby the machine is rendered very compact and efficient, and simple and
economical in construction.
Dr. Antonio Pacinotti in the year 1860 invented a machine having a para-
magnetic ring-armature, provided with pole-pieces, between which an electric
conductor was wound forming one continuous circuit, and joined at intervals to
commutator-plates in such a manner as to produce a current of electricity constant
in direction and intensity, when the armature was caused to rotate before the poles
of the feed magnets of the machine.
A modification of the "Pacinotti" machine in which the pole pieces of the ring-
armature were omitted, and the whole of the ring surrounded by the electric
conductor in one continuous circuit was patented by Messrs. Gramme and
D'Ivernois in the year 1870

page_text: Now the armature forming part of my present improvements in dynamo-electric
machines is the same as the "Pacinotti " armature in its principle of operation, and
in the method of winding the conductor thereon, and also in the construction of
the paramagnetic ring as regards the projecting pole pieces, but with this essential
difference, namely, that the "Pacinotti" ring and projecting pole-pieces were solid,
whereas the pole-pieces of my improved armature, as well as the parts of the ring
surrounded by the conductor, are provided with air passages so arranged as to cause
constant currents of air to pass through the interior of the ring as it rotates for the
purpose above stated.
The other improvements, as well as the particular construction of the armature,
will be fully understood by the following description, and by reference to the
accompanying Drawing, in which
Figure 1 is a longitudinal section of a dynamo electric machine embodying my
improvements, and
Figure 2 is a transverse section of the same on the line x, x, Figure 1.
Figure 3 is a plan showing the frame in central horizontal section.
Figure 4 shows, partly in transverse section, and partly in side elevation, two
arrangements of the air passages for the circulation of air through the armature,
the dividing line being that indicated at y, y.
Figure 5 is a longitudinal section of the armature, partly on the line y¹, y², &
Figure 4.
Figure 6 is a transverse section of the armature showing another arrangement
of the air passages, and
Figure 7 is a transverse section of the same on the line z, z, Figure 6.
The armature consists of the flat ring a, and the pole pieces b, b, projecting an 2
equal distance on the inside and outside of the same, and also on its onds, thus
leaving recesses in which is wound the insulated electric conductor c, the outside
layer of which is flush with the peripheral and end surfaces of the said pole
pieces b, b.
The armature when so wound with the insulated conductor c is secured at the 3
central part of the inside periphery of the polar extensions b, b, to the ring & of a
diamagnetic wheel, of which e, e, are the spokes, and f the hub.
The ring a, and polar projections b, b, are cast in one piece, and preferably of
malleable iron, which is cored out so as to provide air passages through the said
ring and polar projections, the same continuing to the exterior periphery only, or 3
through both the exterior and interior peripheries of the pole pieces b, b.
At the right hand side of the line y, y, Figure 4, the air passages g, g, are shewn
as passing through the centre of the parts of the ring a, on which the wire c is
wound, and out at the sides as shown in section in Figure 1, thereby allowing the
air flowing through the passages g, g, to come in contact with the wire c, and also 4
to flow between the various turns of such wire. Further contact of the air with
the wire may be effected by perforating both parts of the ring a, as shown at g¹,g¹.
The air passages g, g, extend out through the external periphery of the polar
extensions b, b, by the openings h, h.
At the left hand side of Figure 4 the air passages g, g, are shown as having 4
exits h, h, at the external periphery of the polar projections b, b, as well as
openings i, i, at their internal periphery; the said openings i, i, being at the side
of the rim d of the diamagnetic wheel, as shown in Figure 7. These two sets of
openings h, h, and i, i, provide for a better circulation of air through the
passages g, g, as the armature revolves.
The air passages g, g, as shown in the two arrangements of the same in Figure 4,
may also in each case be considered as one continuous air passage through the
armature, having deflectors formed by the connecting pieces j, j, in the body of
the polar extensions b, b, to give the right direction to the air through the
opening h, h, or the openings h, h, and i, i.
In Figures 6 and 7 the air passages g, g, are shown as commencing at on tho
exterior periphery of each of the polar projections b, b, passing through the-parts”
5
5

page_text: of the ring a, as before described, and ending at i on the interior periphery of each
succeeding polar extension.
:
It is obvious that a constant circulation of air takes place through the air
passage as the armature rotates, and so keeps both the iron rings and the
surrounding insulating wire comparatively cool, thus adding to the effectiveness of
the machine by preventing any great increase of resistance on account of the
increase of temperature in the wire, and preventing damage to the same by
excessive heating.
The improvements in the frame of the machine consist in forming the base
plate k, and side pieces 1, 2, of one piece of metal, and connecting the said side
pieces at their upper ends by the top plate m.
The side pieces Z, Z, are provided at their centres with bearings 1, 12, in which the
shaft n rotates, and on them above and below these bearings are wound the field
magnet coils o, 0.
The connecting pieces c¹, c¹, of the conductor c, pass out to the commutator q,
through the guard collar p, and through grooves formed in the contact surfaces of
the shaft n, and the sleeve n', which forms one of the journals of the shaft n, the
said journal n being larger in diameter than the journal at the other end of the
shaft. The latter is provided with a key n², which fits into a keyway cut in the
hub f, which with the guard collar p, just fills the space between the bearings 1, 2,
so that there is no end play to the armature. On the shaft n, just outside the
bearing, is secured the driving pulley r.
To facilitate the placing of the armature in the frame, the bearing & may be
separable from its side piece of the said frame, so that the ends of the connecting
pieces c¹, c', of the conductor c, may be readily passed through the grooves under
the sleeve n', when the shaft is being passed through the hub f. The bearing l¹ is
then slipped over the sleeve n', and secured to its side piece L, as shown in
Figure 3.
The magnetic field poles consist of the grooved curved castings 8, 8', so con-
structed as to allow the armature ring to rotate freely therein, the surfaces t, t¹, of
the grooves facing the outside periphery and the surfaces of the sido flanges u, u¹,
the ends of the armature ring. These grooved curved poles & and s¹ are rigidly
secured to the top plate m, and base plate k of the frame.
To further surround the conductor on the armature by the poles 8, 8¹, to more
fully utilize the induction in the conductor c from the poles of the field magnets,
I in some cases bolt the curved plates v, v³, to the inside edges of the flanges u, u',
as shown in Figures 1 and 2.
There is no novelty in my present improvements in dynamo-electric machines as
regards the method of connecting the conductor c with the commutator q, nor in
the method of winding and connecting the coils o, o, of the field magnets, and
therefore it is unnecessary to further describe the same. The methods embodied
in the "Pacinotti," "Gramme," and "D'Ivernois," or other machines embracing the
same principles, may if desired be used in my improved machine.
Having thus fully described the said Invention as communicated to me by my
foreign correspondent and the manner of performing the same I wish it understood
that I claim,-
First. A ring armature, on the "Pacinotti" principle, composed of one piece of
metal, and having air passages extending through the parts on which the induced
conductor is wound, and out at the external periphery of the polar projections,
substantially as and for the purpose specified.
Second. A ring armature, on the "Pacinotti" principle, composed of one piece of
metal, and having air passages extending through the parts on which the induced
conductor is wound, and out at the external and internal peripheries of the polar
projections, substantially as and for the purpose specified.
Third. A ring armature core composed of the parts a, a, and the polar exten-
sions b, having air passages 9, g, and openings h, h, in combination with the
conductor c, wound on the said parts a, a, substantially as above şet forth.

page_text: Fourth. In a ring armature core, the combination of the polar projections b, b,
the depressions a, a, for the reception of the conductor c, the air passage g, g, the
openings h, h, in the outside periphery, and the openings i, i, in the inside
periphery of the said polar projections, substantially as above set forth.
Fifth. The armature composed of a paramagnetic ring with polar projections b, b,
and having air passages as described, and an insulated electric conductor wound
thereon between the polar projections in combination with the diamagnetic
wheel d, e, f, substantially as above set forth.
n,
Sixth. A frame for dynamo-electric machines composed of a base plate k, and
side pieces 1, 2, having bearings 1, 2, in their centre for the armature shaft and
forming cores, for the coils of the field magnets o, o, substantially as above
described.
Seventh. The combination with the frame k, l, l, m, of the grooved curved
poles 8, 8, substantially as above set forth.
Eighth. The combination of the frame k, l, l, m, the poles 8, 8', having the side
flanges u, u², and the curved plates v, v¹, substantially as above described.
Ninth. In a dynamo-electric machine, the ring armature a, b, c, the diamagnetic
wheel d, e, f, the poles 8, 8', the frame k, l, l, m, the field armature coils o, o, on the
side pieces 1, 1, and the bearings for the armature-shaft in the centre thereof,
substantially as above set forth.
Tenth. A ring-armature core composed of the parts a, a, and polar extensions b,
having air passages g, g, and openings h, h, in combination with the deflectors j, j,
substantially as above set forth.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Twenty first day of February, in the year of our Lord
One thousand eight hundred and eighty two.