Daily tobacco leaf-chronicle. (Clarksville, Tenn.) 1890-1895, 1890-03-26
ISOLATED MACHINES.
PROVIDING INDEPENDENT POWER
FOR DRIVING THEM.


vide each machine with an individual or in
dependent power for driving Naturally
these methods divide themselves, considered
from the motive end, into three parts
steam, air and electricity. The advantages
TO be derived from such subdivision of power
are apparent. When a power is used solely
for the propulsion of one machine it is under
the sole control of the operator using that
machine. No matter what system is used,
this method does away entirely with all ex-
pense, both constructive and operative, con
nected with the use of shafting and reduces
most materially the expense of wear and
tear. As an additional advantage, when the
machine is used only when needed, all ex-
pense ceases when the operator has no further
use for that particular machine. The disad-
vantages are the first cost, wear and tear and
the expense of maintenance. In this, of
course, it is apparent that whether a steam
engine, air motor or an electric motor be
useG the first cost is greater as compared with
the cost of extending "A shafting and driving
the machine through the usual belts and pull
leys. This, as is evident, initiates against
the use of an individual driving power for
each machine
Considering the three motors which are
possible as individual powers for the driving
of isolated machines steam is out Of the
question for several evident reasons Com
pressed air has been used with more or less
success in Paris, as was recently noted in The
Iron Age, and yet the advantages to be de-
rived from its use are not equal to the ex-
IRENE disadvantages arising from the neces-
sary piping peculiar to the machine itself
and the deficiency in the power obtained.
Doing away, therefore, with the two medi-
ums which are very similar in their operation
steam and compressed air-we find ourselves
confined to the electrical motor As self
regulating machine this is beyond all doubt
the superior of any machine now in the mar
ket for the generation of power, for the sim
pie reason that of the power brought to it
it will transmit, in the best forms, 90 or %
per cent as effective work Again, it re-
quires no attendance whatever, except occa-
sional oiing. In wear and tear it is reduced
to mere journal wearing, which may be over
come by proper fabrication and construction
of parts, and in attention it requires practi-
cally nothing. Further than this, it requires
no piping whatever to carry away hateful
gases, for the simple reason that it generates
nothing.
In point of regulation it is as effective as
the best steam engine governor, because the
motor as now built is guaranteed to run with
in 2 per cent of the speed regulation provided
by the contract. This regulation is ndepend-
emit of any outside influence, as the motor is
so constructed that an excess of current will
act to decrease the speed, while at the same
time an excess of load will act to increase the
current, so that the two are counterbalanced
within the 2 per cent. mentioned.
4 I,J 10, l,o 8
the electric motor is that it is essentially a
rotary engine The power is applied to the
development of rotary motion in contradic-
ton to that applied in the ordinary steam
engine as Il reciprocating motion, and in
consequence there is no lost motion in the
engine. The power being applied continually
and at all times to the periphery of the wheel
obvates those difficulties which have origi-
mated in the ordinary steam engine in chang
ing the reciprocatng to the rotating motion.
Concerning the efficiency of the electric
motor as now constructed, VIC fnd that thr ee
essential questions affect the result: First, it
is necessary to change the power as mani
Tested in steam under pressure to electricity.
Then this electricity must be conveyed along
a suitable conductor to the motor. Finally,
the power so conducted must be reconverted
Taking the power of the steam engine as TO-
we can convert 30 per cent. into the dynamo
as electricity. The latter we can convey for
short or long distances, as may be necessary,
and will lose according to the resistance of
the wire a smaller or greater percentage OF
the initial current generated by the dynamo
Assuming this average loss due to resistance
of the conducting wire as 10 per cent, we
hox dol n motor
per cent. of the effective power of the engine
The best electric motors rs now constructed
will deliver in effective work from 80 to 90
per cent. of the electrical power supplied to
them through the conductors. We therefore
have in work actually performed by the cleo
trio motor from 10 TO Is per cent of the
actual work performed by the steam engine
which may be near or far away, and the dis
tance of which governs as will be understood
from the above, the effective work performed
by the motor
! 1t is very evident from this, which is every
day practice, that the electric motor pos
sesses, in n certain sense, decided advantages,
when considered in connection with dyna-
mo and transmitting wire, over any other
method of transmitting power from known
source TO the point of destination; but it is to
be remembered that while the electric motor
possesses these advantages in regard to econ
omy, self regulation and economy of main
tenancc, it is also evident that it labors under
most decided disadvantages. Considered from
this aspect the first and most evident feature
is the high speed. An electric motor of three
or five horse power, placed in an isolated po-
sition to run large lathe or planer requir-
ing this amount of power, must have its in
itial speed of 800 or 1000 revolutions of its
armature per minute reduced down to the 100
or 125 required 10y the driving shaft operat-
ing the machine 10y the introduction of a re-
Iducing mechanism The latter must neces
sarily be either of the worm or gear pattern.
| This introduction of quick revolving parts
and of the several parts needed TO reduce the
motion from the high speed 10 that of the
low speed needed to drive the machine, leads
to wear of the parts not only in the motor
itself, but in the intermedium through which
its power is transmitted.
! The good points of the electric motor are
not appreciated rs they should be- The cleo
trio motor would be more extensively used il
its driving shaft, or, in other words, its arma-
ture shaft, were reduced in speed. The ordi-
nary mechanic, knowing that he wants only
a speed of fifty revolutions a minute to drive
his machine, will look with suspicion upon
any power which travels at a speed Of 1,500
revolutions a minute
/ Another feature which acts against the
introduction of the electric motor in cases
where it should apparently be used is the
first cost. Considering the horse power de
rived from il and the cost q construction,
this is unnecessarily high. The influence thus
exerted against the adoption of the motor by
the manufacturers has done much TO retard
its introduction. We see no reason to prevent