IMPROVEMENTS IN DYNAMO-ELECTRIC AND ELECTRO-DYNAMIC MACHINES
Year: 1884

page_text: I, LEVI JOHN GROVES, of 131 Hope Street, Glasgow, in the County of Lanark,
North Britain, Engineer, do hereby declare the nature of my said invention for
IMPROVEMENTS IN DYNAMO-ELECTRIC AND ELECTRO-DYNAMIC MACHINES" to be as
follows that is to say:-
16
My said Invention has principally for its object to improve the construction,
and mode of mounting and ventilating of the rotating armatures of dynamo-
electric machines for producing electric currents, and is also applicable to electro-
dynamic machines or motors for converting electric currents into mechanical
power.
In carrying out my Invention I secure upon the main shaft or spindle of the
machine two end cheeks or disks of gunmetal, bronze, or other suitable non-
magnetic metal such disks being formed with holes or slots to receive the ends
of bars of bronze or other suitable non-magnetic metal for supporting the armature
core, the said bars being parallel to the shaft.
14
The armature core is composed of a number of flat rings formed of thin sheets
of soft iron, preferably having between them plies of paper or other thin insulating
material. The iron rings may be made with or without external projections or
pole pieces" and with or without notches or indentations on their inner edges.
There may be any convenient number of the bronze bars but it is not desirable
to have more than what are required for strength. The bars pass through the
iron rings and fit in the notches when there are any on the inner edges of the
rings. Each bar has projections formed or adjustably fixed on it near its ends in
positions to confine or bind together the iron rings, the extreme ends of the bars
passing through the slots in the bronze end disks and having nuts screwed on
their outer ends if thought desirable. The bronze bars are of tapered section so n.s
to be thinner at their inner edges to give more room for the passage of the coils
of insulated conducting wire which are wound in the usual way round and through
the armature consisting of the combination of iron rings. The component parts
of the armature are held together by the bronze bars before being placed on the

page_text: shaft or attached to the end disks, so that the armature can have the coils of
insulated conducting wire wound on and through it without difficulty.
When the iron rings of the armature are made without iuner notches to engage
on the bronze bars, rods may be passed longitudinally through holes in them to
insure their all rotating together.
When the armature has been wound it is in the form of a hollow cylinder, and
when mounted on the end disks the interior is entirely unoccupied excepting by
the shaft, and currents of air can be easily driven through it in any convenient way
to ventilate and cool it.
The field magnets may be electro or permanent magnets of any suitable
known kind,
Dated this first day of October 1884

page_text: CORTMEIE DE ECIFICATION.
I, LEVI JOHN GROVES, formerly of 131 Hope Street, now of 45 Bothwell
Street, Glasgow, in the County of Lanark, North Britain, Engineer, do hereby
declare the nature of my said invention for "IMPROVEMENTS IN DYNAMO-ELECTRIC
AND ELECTRO-DYNAMIC MACHINES and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement that is to say:-
19
My said Invention has principally for its object to improve the construction
and node of mounting and ventilating, of the rotating armatures of dynamo-
electric machines for producing electric currents and is also applicable to electro-
dynamic machines or motors for converting electric currents into mechanical
power.
A rotating armature as made according to my Invention is shown upon an
accompanying sheet of explanatory drawings, figure, 1, of these drawings being
a longitudinal section. Figure, 2, is an inside face view of one of a pair of end
disks by means of which the armature is secured upon the shaft. Figure, 3, is a
side elevation of one of a number of longitudinal bars which being held by the
end disks support the armaturo core, an end elevation and a cross section of the
bar being shown at opposite ends of the figure. Figure, 4, is a transverse section
of the complete armature. In these drawings the same reference numerals are
used to mark the same or like parts wherever they are repeated.
In carrying out my Invention I secure upon the main shaft or spindle, 5, of the
machine two end cheeks or disks, 6, of gun-metal, bronze, or other suitable non-
magnetic metal, such disks being formed with slots, 7, (or it might be holes) to
receive the ends of bars, 8, of bronze or other suitable non-magnetic metal,
for supporting the armature core, 9, the said bars, 8, being parallel to the
shaft, 5.
The armature core, 9, is composed of a number of flat rings formed of thin
sheets of soft iron, preferably having between them plies of paper or other thin
insulating material; or the rings themselves may be coated with some non-
conducting substance. The iron armature rings, 9, may be plain on their outside
edges, as shown in the drawings, or they may be made with projecting parts to
form"
'pole pieces." The rings, 9, may also be plain inside, or they may have
notches or indentations as shown so that they may be more securely carried by
the longitudinal bars, 8. There may be any convenient number of the bronze
bars, 8; but it is not desirable to have more than what are required for strength.
These bars, 8, pass through the armature rings, 9, and fit in the notches when the
rings are formed therewith. Each longitudinal bar, 8, is by preference formed with
projections, 10, or these may be adjustably fixed on it near its ends in positions
to confine or bind together the iron armature rings, 9, the extreme ends of the
bars passing through the slots, 7, in the end disks, 6. These bar ends and the
slots or holes for them in the end disks, 6, may be made round or of any con-
venient shape; and if thought desirable may be made to project beyond the outer

page_text: faces of the disks and may have nuts screwed on them. The longitudinal bars, 8,
are by preference made of tapered section so as to be thinner at their inner edges
to give more room for the passage of the coils, 11, of insulated conductor, which
coils, 11, are wound in the usual way round and through the armature core con-
sisting of the combination of iron rings, 9.
The component parts of the armature are held together by the bronze bars, 8,
before being placed on the shaft, 5, or attached to the end disks, 6, so that the
armature can have the coils, 11, of insulated conductor wound on and through it
without difficulty.
When the iron armature rings, 9, are made without innor notches to engage on
the bronze bars, 8, rods may be passed longitudinally through holes in them to
insure their all rotating together.
When the armature has been wound it is in the form of a hollow cylinder, and
when mounted on the end disks, 6, the interior is entirely unoccupied excepting
by the shaft, and currents of air can be easily driven through it in any convenient
way to ventilate and cool it. Thus a helical fan or propeller may be fixed on the
shaft to cause the air to move through in one direction. The ventilation may be
further promoted by arranging the iron armature rings, 9, with spaces between
some of them, the coils, 11, being also wound so as to leave spaces, so that air may
pass from the hollow interior outwards through the spaces in the core, and dissipate
any heat produced by the working of the machine.
The field magnets used with my improved armature may be electro or permanent
magnets of any suitable known kind.
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
The constructing and combining together of the parts by which the rotating
armature of a dynamo-electric or electro-dynamic machine is carried and attached
to its shaft in the improved manner, substantially as herein before described.
Dated this twenty-fifth day of June 1885