LeTourneau Tech's NOW, Volume 5, Number 11, June 1, 1951 Page: 2
This periodical is part of the collection entitled: LeTourneau University Archives and was provided to The Portal to Texas History by the LeTourneau University Margaret Estes Library.
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The Torque Converter In The
Construction Equipment IndustryGeography
I DIDN'T learn much geography in
school, but I picked up just a little
in traveling hither and yon around
this globe. For instance, the Panama
Canal is east of Miami and the Pacific
entrance is east of the Atlantic en-
trance. I would have thought that the
Tennessee R i ve r flowing s out h
through the state of Tennessee would
naturally empty into the Mississippi
River, but it doesn't. It empties into
the Ohio River. It has been proposed
to put locks in the Tombigbee River
coming down through Alabama and
a short canal from its upper end to
the Tennessee would enable ships to
get all the way from the Mobile Bay
on the Gulf of Mexico to the Ohio
River without bucking any current
as in going up the Mississippi. Would-
n't that be something, steam up
through some quiet waters and locks
letting nature's water lift your boat
then float down stream on the Ten-
nessee all the way to the Ohio. Well,
I'm for it. Of course I would be, as a
manufacturer of construction ma-
chinery, and brother, I'm coming out
with a new machine some of these
days that will dig a canal so cheap it
will make your head swim. The other
day I saw a picture of an enormous
machine that would move 1,000 tons
an hour. The one I'm talking about
will move 6,000 tons an hour with
only one man needed to operate it.
But I'm for this canal because it would
make cheap transportation. Cheap
transportation means cheaper raw
materials at the place of usage.
Cheaper raw materials means cheaper
machinery, autos, trucks and tractors.
Cheaper machinery means cheaper
food, cheaper housing. It takes in the
necessities and the luxuries.
I heard about a girl the other day
sent over here from a foreign country
to go to school and get an education.
She wanted to take a job and work
and earn part of her education money
but she couldn't because her visa only
allowed her in this country for an
education, and they were afraid she
would put someone else out of a job.
I say there is plenty of work to be
done, and there is no limit to how
much we can do profitably to raise
Continued on Address PageTORQUE CONVERTER-In the
past few years, that name has begun
to play an increasingly important role
in the industrial and consumer mar-
kets. Torque converters are being
used in automobiles, trucks, busses,
motor drives, engine drives, tractors
-and now in the high speed con-
struction equipment field. What is a
TORQUE CONVERTER? How does
it work? What are its advantages-
its disadvantages? How does it fit in
the construction industry? Can it
make money for the contractors? Why
is it being adopted by LeTourneau?
FLUID COUPLING-B e fore an-
swering these questions, let us talk
for a moment about a device called
a "fluid coupling." A fluid coupling
is nothing more or less than a clutch
that transmits power by means of a
liquid in motion, rather than by fric-
tion between two. clutch surfaces.
You have all seen the principle of
a fluid coupling in action-when you
stir a glass of tea! As your spoon goes
around and around at the top of the
glass, the sugar at the bottom begins
to move, and soon it is moving at the
same speed as the liquid. Replace the
spoon and sugar with paddles, connect
the lower one (the sugar) to a power
take off shaft, and you have, in the
roughest sense, a fluid coupling.
A fluid coupling, like a friction
clutch, cannot increase engine torque
-it can merely take the torque, or
turning force, produced by the engine,
and transmit it to the drive train.
FLUID COUPLING ADVAN-
TAGES-What, then, are the advan-
tages of a fluid coupling over a friction
clutch?
I. The power is transmitted through
oil, and therefore is completely cush-
ioned-no shock or vibration can be
transmitted from the engine to the
power train or vice versa.
2. Power is applied smoothly and
continuously u n d e r all operating
conditions.
3. Breakage, wear and maintenance
in the power train is reduced dras-
tically.
4. At engine cranking speeds, there
is little or no drag in the fluid coupling,
and the engine can therefore be started
easily without disengaging a clutch.
These advantages of a fluid coupling
over'a friction clutch drive would in
themselves be more than enough to
justify the use of the fluid coupling inhigh speed, heavy duty, construction
machinery. But let us go on to the
torque converter, and then see where
we stand.
TORQUE CONVERTER PRINCI-
PLES-Strange as it may seem, every
one of us has used and operated a
torque converter-the conventional
gear shift type transmission in an
automobile. When you put a car in
first or second gear to climb up a
steep grade or to accelerate, you are
merely gaining more torque, or pulling
effort, on your drive wheels at the
expense of speed. The horsepower of
the engine (torque times speed) stays
the same, but you can increase the
pulling effort and reduce the car
speed by shifting gears. The car trans-
mission, therefore, is a torque conver-
ter that multiplies the engine torque
through gears at predetermined and
fixed ratios.
HIGH LOw
The hydraulic torque converter
does exactly the same job-but it
does it through oil instead of gears;
it does it automatically; and it does it
with an infiniate number of ratios. It's
just as though your car transmission
had 1,000 or more gear selections in-
stead of just three, and the correct
one to most efficiently meet the accel-
ration, grade and ground conditions
was selected for you automatically.
HOW DOES A TORQUE CONVER-
TER MULTIPLY TORQUE? As-
sume we have a revolving door
through which are marching a line of
troops at a uniform rate. Each man
gives the door a. push as he goes
through, which is just enough to keep
the door revolving steadily. Now put
a load or a drag on the door so that
it slows down-the men will begin to
pile up until, when the door is going
half speed, two men will be pushing
at the same time, and the push (or
torque) on the door will be doubled.
As the door slows down still more
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LeTourneau Technical Institute. LeTourneau Tech's NOW, Volume 5, Number 11, June 1, 1951, periodical, June 1, 1951; Longview, Texas. (https://texashistory.unt.edu/ark:/67531/metapth1526658/m1/2/?q=%22~1~1%22~1: accessed July 16, 2024), University of North Texas Libraries, The Portal to Texas History, https://texashistory.unt.edu.; crediting LeTourneau University Margaret Estes Library.