MECHANISM FOR DRIVING DYNAMO ELECTRIC MACHINES
Year: 1884

page_text: I WILLIAM PHILLIPS THOMPSON Fel. Inst. P.A. of the Liverpool and London
Agency for Foreign Patent Solicitors 6 Lord Street Liverpool in the County of
Lancaster, Civil Engineer do hereby declare the nature of the said Invention for
MECHANISM FOR DRIVING 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 :—
Fig. 1 is a plan view with the friction-pulley in section. Fig. 2 is a front
elevation with part of the friction-pulley broken away, the bearings of the
counter-shaft in section, and the pulley on the counter-shaft omitted, Fig. 3 is a
plan view with the friction-pulleys in section, showing a modification of the
Invention for use when it is desired to run several countershafts or dynamos from
one driving-shaft. Fig. 4 is a side elevation of this Invention as applied directly
to the armature-shaft of a dynamo.
In driving dynamo-electric machines by a reciprocating engine having a
fly-wheel on the crank-shaft, the speed of the shaft varies, decreasing as the shaft
approaches the dead-centers, and this causes fluctuations in the speed of the
armature of the dynamo and variations in the electric current.
This Invention aims to equalize the speed of the armature; and it consists in
attaching to the crank-shaft a friction-pulley, which engages with a friction-pinion
placed on the armature-shaft, or on a counter-shaft provided with a heavy belt-
pulley, when more speed is required than can be obtained by direct connection
with the armature-shaft.
A represents the crank-shaft of a reciprocating steam-engine, A¹ being the crank,
and A³ a wrist-pin thereon.
B represents a friction-pulley, fastened on shaft A.
D represents a shaft journaled in bearings H, H', which may be a counter-shaft,
Figs. 1, 2, 3, or the arinature-shaft of a dynamo, Fig. 4, on which is fastened a
friction-pinion, C, engaging with friction-pulley B. When shaft D is used as a
counter-shaft to obtain speed, there is secured on it a belt-pulley, E, from which a
belt runs to a smaller pulley on the armature-shaft, and usually a fly-wheel, F,

page_text: though this may be dispensed with by making the rim of pulley E heavy enough
to act as a fly-wheel. When shaft D is the armature-shaft, the armature is
generally heavy enough to act as a fly-wheel. Bearings H, H¹, are set by a
dove-tail joint, M, M³, in a suitable frame, G, and lugs on the lower surface
thereof engage with the threaded ends of rods I, 1', set rotatably in frame G, and
provided with hand-wheels K, K', by which said rods can be rotated, and the
position of bearings H, H', changed to regulate the pressure between pulley B and
pinion C.
In Fig. 3 is shown an arrangement by which the Invention can be arranged to
drive four dynamos from a single shaft. The various parts are mere reduplications
of the similarly lettered parts in Figs. 1 and 2, and the operation is too obvious to
need description.
By transmitting the power through friction mechanism from the engine to the
dynamo, either directly or through the medium of a counter-shaft, and weighting a
wheel or pulley on the driven shaft to act as a fly-wheel, there is prevented, in a
large measure, any variation in speed of the armature, and thus produce a steady
current.
Having now particularly described and ascertained the nature of the said
Invention, and in what manner the same is to be performed, I declare that
what I claim is:-The combination, with the crank-shaft of a reciprocating steam
engine, of a counter-shaft driven from the crank-shaft by friction mechanism and
having thereon a fly-wheel, substantially as and for the purposes set forth
Total : 10th
ML 1001