Richmond times-dispatch. [volume] (Richmond, Va.) 1914-current, 1921-03-06
.CUERRL|CH's LECTURE,
NO. TRANSMISSION
Auto Designer Must Decide What
Engine Is To DO in Pick
ing Size.
MUST OVER COME FRICTION
Motor of Large Turning Power Is
Necessary i'm Starting on Level.
Not Hard to Keep Automobile i'll
Motion.
LEt'rt ri: No. ri.
Shc Purpose and Principle m tho
ni.S

NaC ANA friuctpts 81 tn e
Transmission.
When the dcSi Gpor Of an aUtomC-
ol!c has 10 decide upon the size OF
ne engine. j" must consider wha;
look into this.
When the car is driven along a
level road tn" engine must over
c.omc the frirtion az the bearings in
Wind For this purpose an engine
of a certain bore and turning power
ana which VII give a certain mini
mum speed wifi suit.
When the Car, Is ascending hili
ne engine Will have TO overcome The
friction and wind resistance as be-
iipre, but. also, it Will hav. TO mt
INC gar from tho lower 80 tho higher
!rNet So IN engine OF mach larger
iuTnirg power. ana. therefore, horc.
VIII he necessary than for running
az the level,
Have you ever watched men push
,ns an auto. or wagon, about? II may
.sQnire the tul! strength of three.
men 20 start 1t moving but rs son,,
IS ~ - IN motion one man will lot
~. aha Whcn the car ha. some speed
.niIu VIII be able 10 keep the car i'm
rnoticn with comparatively little Of
Vii ihus. more powerful engine
car than for keeping /, going
So We nnd ;h,i q ,nurh
.arninS power is required from tli,.
'ShE'ne. whCn the car Is rIimi,,c
n n'd,, or when it is being started Int"
The car must be able 10 .sr.pd
49,. go STAR into motion. but eu
IN "l III Tine IL is travelling
un tnc level. This means thar IL fi,s
"hEinc ! built largo cnou.i, Ia rIi,,,t
,,l' mus for 40 per cont OF iii. -;r,n
IN IN mess ws,isht OF engine viii have
ti,,i - * Win the extra .nst of
go, ''c- Which would result there
.o; n s 10, d,sisner VII try to una
u,n" Wy 81 GSirg the smaller en-
hhi aiding some device which
"nahlc the engine 10 ais, t "'Lm
ynr, , me hin climbing ana siartin,
~, 1' '"f'' ttaciuS a set OF levers
Wis.," ine engine and the rear
WI accomplish this. As a
en- or tram oi gears. is -, svS,
80 ''Nt'S' III" problem ,lll h. Snlv.,i
y: i''"'lhs sets of gears between ,i,.
o,b, ne ana he rear wheels. or in
engine i r:',,E,, IH.ltc The power OF ,hc
~ them, Thus wc hnv. ~ WEES
mission '"r trans
Met us SEC how the gears ac, os
HAY" you ever watched safe ,,oy.r.
r,."Wh"r? What they do is shnw, ~
tlc Her. the point \ is In
ground II the distance Il is , ~
tines as great as the dis,nnr. ,
"H 'H.rtns pressure of i0n
MOUNTS al d. can exert "A pr.ssi,r. ~,
LOU pounCs at l.. va
Lei us now assume tina: - 40
v"H'er and +. the circurrfcrcnc, -,
,n" propeller shaft Of III. ni,tor,o
n.'' ana ina, ID is on the circuu
'''|h'r OF II gear II fastened tn this
haitr aS SHOWN In Fig II il ;,t,.s
pressure OF 900 pounds on the rir-
eh"ierenc" OF the shaft at r 10 drive
INC car up the stccpeSt grade then
~ hflNing the gear y. by the gear +
ma mating the engine OF sucn a
size. that II pressure of 100 pounds
cNrrtcd 10y the gear II on the gear
- The car Will be driven w this
Stccpest grade.
The room for the transmission of
~" automobile is necessarily limited
an! ii the single gear. ms shown,
W"r" used. IL would take MP NOR.
room than can he allowed for il. So
"" designer must look about for
some way OF using gears which will
lake NJ less room. and get give, IN.
required Leverage. Til. natural So
luton - 10 have sets Of gears. one
set, say. 10 give Il leverage OF 8. the
ether OF l-3. giving a total ley.rag.
OF Is times .. or 10
Let as, therefore. make the gear /?
smaller IN diameter. say, only ala
times ;hai Of tho shaft r. and then
lot US convert /. into a gear then let
us move the shaft, connected TO the
propeller smart TO IN. position shown
by ", Fig. 3. BY .ugw piaciug a gear.
j. having q diamH.cr ) times that OF
the shaft ii, and arriving this gear
by the gear l.. We wiz have TWO sets
OF SINAI. gears, ON" giving a lcvcra,sN
of Ia and the Other OF 5 - 10 |.
or 1t total .! 10.
Thus, Il Loco pounds Is required At
the circumference of II. only 3S3 -
pounds viii be required at +. the cir
OF the gear ], and as the
gear e u BIB the diameter of the
gear T., i VIII have n leverage OF
3 Ia 20 i. aud only 100 pounds viii
be required at the point -. which
is he pressure required from tn" en-
ginc as before.
Having the gcars placed as shown
means three shafts and three sets of
bearings for them. Ey placing the
gears II and l. on III" same center,
one sct or these bearings, and cousid-
cradle room can hc saved. In figure
{ | have shown Ni-w from the top
.! tho transmission as developed 80
Gar. with IN" gears J and j on the
same center.
As the gears l. ana |: are on the
speed. they are both fastened 10 the
same shaft j and =. However. re-
volvc ~ different speeds. and :" their
shaft must y" separate In order TO
save hearing bracket. however. tn"
rrar + is made hollow and is attach
ed 10 Il tube. OF sleeve. the end Of
ills shaft o. ] brinc inserted into II
"a that the bearing OF y also acts a.
.un. Of the bearings OF j This -
Nown by cutting away some OF tn"
gear J..