Note: Descriptions are shown in the official language in which they were submitted.
~ 2201579
B~JS Dl~ A?~LE
Techrlical Field
~is invention relates to auto~notive vehicles and trive sy~ems therefor, especiall~
to a twin-drive arld a~le syste~ ~rhiGh is especially suitable for llse on buses.
13n~ tound,Art
Tw~-drive buses were in operation orl city streets ill the United States durihg the
early days of bus transport~tion and were ~escribed in patents iss1led d~ing that periot
The twin-dlive bus ~f~ered several advar~tages over th~ more widely ~sed single r~oto~
buses olCthat era For example, the passer~ger compartmel~t o~a t~in-~rive bus extended
the e~tire iength of the bus since t~ere was no hood, as was the case in single-motor buses
c~ the era. This affo~ded ~ l~rger pasSenger-carryillg capacity fo~ a given lerlgth of bus.
fi~ther advallta~e was that sm~ller ~otors could be used A still filrthe~ advantage was
tl~at no ~ el.Lial w~s required since ¢~ch motor drove th~ wheel (o~ w~cels) on o~ly o~e
side o~the bus, and the two ~otors and the respective d~Ive shaf'cs were cap~ble of
ope~ating at diffle~erlt sp¢eds.
Ea~lier twi~-motv~ buses had ce~tain disadvantages. ~mo~g these ~e~c the
fo~lovving: a "semi-floatin~" suspemsiorl ~hich plaGed weight load on rear a~le shafts and
drive train$, resulting in u~.cvell and rapid gear ~esr; a wor~ gea~ which is not
2 o satisf~Gtoly at ~ode~ate or Wgh vel~cle speeds, for t~n.C~ittin~ torque ~om a drive sha~
to a rear axle sha~t; and pollution ~hich wo~l~ be urlacceptable by today's standard~.
In spite o~t~e advantages, the twin-~otor bus fiell i~to di~use. F3uses ,ge1le~ally
have had a si~le eng~e loc~ted i~ the ~ear of the ~us, wllich drives the ~ear ~heels
through a conventional di~llti~l. P.~ne~ p~ovidi~g higher power coIltributcd to use of
2 5 a ~ gle en~ne, but such buses ~ave ~ad high floo~, even a*er the adv~nt o~the autor~atic
tr~n.qmi.i,qion T~is le~ds to passenger inconverl~ence and discomfort whe~ boarding and
leaving the bus, eVeh fior an average p~sengP,r having rlo physic~l impairments, and maJses
~xtre~e~ diffiGult the design arld implementation o~ a system fior ~oadirl~ and dischargi~g
P~ er~ having physical disabilities.
3 0 R~cently. there has be~n interest ill a low~floQr ~lect~ic h~brid ~E~V) bus having
good fil~l eGonoh~y and low pollu~ion, and generally ~aving the adva~tages o~earlier twin-
moto~ b~ses without the di~advantag~s.
22n 1 ~ 7 9
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S-lmm~rv of the In~ention
Based upo~ the ~oregoing, it is an object of the invention to his invention accordi~g
to pro~ride an automotive v~hicle ha~ing the ad vantages of the ~Win-rnotO~ d~ive
ar~ange~nent and overco~ing the deficiencies of the prior art. Tb.e inVehtion iS therefo~e
d~rected to a vehiGle compriSing first ~nd second motors disposed on opposite sides of a
longit~ dinal ce~ter line of the ~ehicle. The IllO~O~S illclude first arld second drive sha~s
ext~nfljn,~ longitu~ina.lly ~o~ and driv~n by said first and seGo~d motors respectively. The
vehicle fil~ther includes a fiull lloat~n~ drive axle assembly which comprises first aIId second
transve~sely spa~cd gear ~qemhljes, each Gomp~ising a gear ho-lsing having aII input gear
in driven relatiollship with one ofthe drive shaf'cs, and an output gear. Pirst and scco~d
a~ially alig;tled ~d transversely e7ftp-n~ljng a2~le shafts are dri~ gly connected ~o respective
output gears in tlle respeGtiYe fi~st a~d second gear housings. Al0~2g with thc drive sha~s,
first and seco~d Statiohary tubul~ axle housi~gs are joined to respective first and second
gear ~ousillgs and extend transversely outwardly thclt;rl~)nl. ~ stationary~horizontal
member is sec~red to the gear housings and e~tends ~nsversely firom the flrst gear
housing to the second gear housing ~t a lower elev~ion than the ~sear housin,~s Fi~st alld
secolld wheel ~ssernblies are rotatably mounted on the respective first a~d second tubular
axle l~ou~ings ~t d~hgly co~nected to respectiYe ~rst and second a~le sh~f'cs tocomplet~ the d~ve s~stem.
O In a seco~d aspect, the inverltio~ provides a drive ~heel and axle assembly which
comprises first and second transversely spaced gear assernblies. ~ach gea.r assembly
compnses a gcar housillg havi~g ah input gear adapted to be driven by an e~tern~l
lor~ihl~1~AIly exten~ing d~ive shaPt, and an output ge~r in ~eshing enga~emeht with th~
input gear and being adapt~d to dri~e an axle shaf'c. ~irst and seGond axial~y ali~3ned and
2 5 transversely ~xtellding axle shafts are d~ivingly corlnectç~i to respeGtive outl~ut gears, and
first ahd second stationary tubular axle llousings are joilled to respective fust a~d seco~d
gea~ housil~gs and extend transve~sely outwardly there~rom. A stationaly hori~:ontal
stiff~ing member is secured to the first and second ge~ housings ~nd e7~tends transve~sely
t~erebet~eell. The ~lirrr~ g m~mber is po~itioned at a lo~er el~vation than the gear
3 ~ housings. First ~nd se~ond whe~l assemblies are rotatably m~ ted orl respectiYe first and
seGond axle ho.usihgs ~nd drivingl~r connecte~ to ~espectiYe ffrst and second axle shafcs.
The l~r~fe~ d autonlotive ~ehicle is a passenger bu~. ~he present inventio
. ~ 2
2 2 0 ~ ~ 7 ~
provides several advantages over presently known passenger buses. First, a bus accor~
to the present invention can ~ave a lowe~ floo~ than a conve~tional bus. This ma~ces it
easier to loa.d a~d disGharge o~thopedically harldicapped p~ssengers, and also provides
greater co~nfiort to non-h~nt1ir.~rped passengers when boarding or leavin~ the bus.
Se~oIId, th¢ bus uses a fi~ll floati~g drive axle assembly in which all vehicle wei~t or load
is borne by stationaIy housing members~ so that the dri~re axles do not h~ve to bear vehicle
~iveight or load. Othe~ advahtages will appear ~om the ~raw~rlgs alld Sro~ the
specification wbich follovvs.
Bli~f Desc~iption of the D~a~in~s
Fig. 1 is a top view of a dnYe a7sle assenlbl~ a~d t~in drive trains theref~
according to a prefeïTed emloodirnellt of t~is in~re~tion
Fig. 2 is an e~d v~ew~ as seen ~om the ~ear of t~ vehicle, of the embodiment
sho~ in Fig. 1.
Fig. 3 is a~ enlarged s~ctional view o~a ~ rt;--~ial case housing a diIrel~l.Lial
r~e~h~n;~m which ~aybe used in a~ehicle ofthis invention.
Fig. 4 is an e~l~ged horizontal sectiona~ view, t~;en along line 4-4 of Fig. 2,
showing an alterna~ive ~ear housin~ d gea~s thereirl which may replace a conventiollal
dif~re~tial gear~ and an axle shaPc and housi~g therefore e~ ing tr~nsversely outwardly
2 0 fro~ the gear housing to one side of the vehicle.
;I)escr~ption of the Prefe~red ~mbodiments
T~is invention ~ill be dcscribed i~ detail lvith refe~ence to the },re~ d
embodiments thereof~ as illus~ated in the ~ccompa~ying drawi~s.
2 5 The prefe~red automotive vehi~le of this illVerltiOh iS a passenger bus, especially a
passen~er bus fio~ city transit use, ~aving motors located on opposite sides of a
lon~h-~lin~l center line o~the vehicle. The ~fe,~d motors are electnc motors, espeGially
alternating current (~C) electriG indllGtion motors. Thc bus may be an electriG hybrid (~
V) bus in vvhich thc motors are driven by generators which are powe~ed by one or mo~e
3 0 internal combustion eng~nes or tl ~bines. Alte~n~tiYely, the ~oto~s m~y be po~ve~ed by
electric storage batteries, ~hich can be ~echarged when the vehicle is not in senicc. A
vehicle r~ay ev~n be a t~aclcless t~olley i~ which t~e eleG~ic motors receive power directly
~ .. , ~ 3
~ ~201!57~
firor~ external overhead ~ires.
l~his description will be wit~ pal tiGular refe~ence to ~ vehicle having a single rear
axle and t~o wheel asse~blies, OnE at each side o~the ve~icle. Each wbeel assembly ~ll
typiGa~ly include two wheels7 an in~er wheel a~d a~ outer whe~l. ~ccording to a pre~e~red
e~bo-lim~llt the drive wheels are rcar wheels, and so that the dri~re a~le assembly herein is
a ~ear a7~1e assenlbly. Althou~ this disclosure is with referer~ce to a vehiGle h~ving a sing~¢
rea~ axle assembly, it w~ll be apparerlt that the invention can ~Iso be applled to ~ vehicle
hav~ng t~dem drive a~les (us~ally rear axles). In that case, it ~ay be advalltageous ~o
provide fou~ motors, so tllat each w~eel assembly has its ow~ motor and its ovvn drive
1 0 train.
Re~erring now to ~i~s 1 and 2~ an auto~otive vehicle drive system of the p~ese3lt
i~ve~tion has fi~t a~d second AC electric induction ~otors 10, which a~e equidistantiy
sitll~te~l on opposite sides (i.e., a lef'~ side ahd a rig~t side) of a longih7~in~11y extending
vehicle ce~er line A. These electriG motors may ~e powe~ed ~s described above.
Alternatively but ~ot preferably7 the electric motors 10 may be ~eplaced by inte~al
co~ ustion en~ines Ele~triG motors 10 are the drivi~g units of respective first and second
drive trains, w~ic~ are located on tlle le~SL side and the ri,~ht sioe, rcspecti~ely, of a ~notor
vehicle such as a ~us. The electric moto~s 10 have S~al~LS ~r~ich are coImeeted ~h~ough
universal joints or yokes 12 ~o ~eSpec~ive first and second drive sh~s 14. Dnve shafts 1
2 0 exterld horizontally, lon~tll~in~lly and I ~al wdldly ~om motors lO along a~es which are
parallel to the vehicle cer~er li~ A ~rlive~sal join~s or yokes 16 are pro~ded at the
re~ w~l~ cnds of shafts 1~ fo~ conne~tion to first a~d seGond i~put sbaflLs 18 of drive a~le
assembly 20. I)rive a~le asse~bly 20 is prefe~ably a rear axle assembly, since the vehi~le
d~i~Je wheels are prcferably located a~ ~he re~r of the vebide. I)rive axle assemSly 20
2s infhl~e~ first and second ge~r assemb~i~s 22 or 24, whiç~ are located eq~ ict~ntly on
opposi~e sides ofthe l~ n~tu~in~l center line ~ ofthe vchicle. T~e gear assen~bly 22 may
be a conventional di~c;~ ial 13ear ~ssembly 22, as sho~ in Figs 1 and 3, or may be a gear
~isç3nhly ~4, as sho~n in ~ig. 4~ co~t~inin~ only those ge~rs wbich ar~ required for
purposes o~this inve~tion.
3 0 Fig. 3 illllstrates in detail a gea~ assembly 22 ~bich houses converJ~iohal dif~erential
gears. ~s shown in Fig. 1, there are two su~h assembsies, one ~or e~ch ~rive ~rai~ Only
F: 1.. -- ~ . ' . S L~ 4
22 Q ~ 5 7 ~
one will be described in detaîl si~ce all parts in eac~ asse~bly are either ideIItical to or are
~irror images of the co~espo~ding part.s in the ot~r ~.~sernhly EaG~ gea~ asse~hbly 22
comp~ises a gea~ ~ousing 2~, which, in tu~, includes a statio~ary outer housing ~embe~
o~ difl~erential carrler 26 alld a statioha~y cove~ ~ which ~nay be affl~ed to th¢ carrier
s (e.g., by bolts not sho-vn). ~nput sha~ Ig is tot~tably journaled ih c8rrler 26 I?y means of
roller bearing asse~blie~ 30 Input sha~ 18 ter~inates at one ehd ~the end which is ~0mote
from drive shaflc 14) iIl a pihion gear 32. Ihput sha~ 18 thFoug~ pinio~ gear 32 d~ives a
rotatable ~i~elllial ~asing 34, whiGh ha~ a ~ing ge~r 36 bolted or otherwise ~l~edly
attached the~eto. Botb. pinion gear 3~ (a driving gear) and ring gear 36 (a d~iven gear) are
10 bevel gea~s. Casulg 34 is rotatably mountcd in car~ie~ 26 by means of ro~ler bea~ng
assernblies ~7.
A difI~ Li~l gear assembly as sho~ivrl in Fig 3 filrther i~cludes a mouIIting pin 38
w}lich extends across the diffe~ential casir~ 34, fou~ ~li¢~ Lial bevel E~ea~s 40, alld a p~i~
of side gears ~. One of tlle two side ~ea~s ~the gear to the right as seen irl Pig 3)
15 d~iv~ngly engages a rotatable olltput sha~ 50, which extends fronl the interior of gea~
housing 25 to a side of the vehicle. This may be accon~plished by collventio2lal means,
S-IGh as a splined Gonnection~ The ot~er side gear 4~ is not oper~tively connected to any
output ~ember.
It will be appa~ent that a co~ventional .li~ Llltial gear assembly is not re~uired fior
2 0 ~is invention, since th~re is onl~ one o~tput shaflc in ea.~h drive train. :Eior convenie~ce
(since di~e~e~tial gear assembl~es are usually readily available) a conventional di~ el.lial
gear assembly may be used. It may also be r~ ired to lock out the di~l~llLial gear, w~ich
may be accomplished by known ~neans.
~ second gear asse~bly 24, w~ich contams all of the gearin~ ~equired for ~he
2 5 purposes of this ihvention, iS showh in ~ig. 4. Ollly one gear assembly is ~ho~n since the
other (showll in Fig. 2) consists of parts which ~e eithe~ identical to or are mirro~ images
of co~espotldinE~ parts shown in ~g. 4. ;Referring now to Fig 4, gear asse~bly 24
includes a housing Gomp~sing ca~ier 26 and a cover ~8, which may be like t~e similarly
nu~bered parts shovvn in ~ig. 3 Input s~c 18 t~ough pinion gear 32 thereo~
3 0 inte~neshes with and drives ~ ring gear 3~, which may be bolted to a hollow casillg ~ so
that the ~o rotate together. ~ollow casing 48 is rotatably ~nolmted in the housi~ 4 by
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2~01579
~eans of roller beari~g asse~nblies 46 Casing 48 driYirlgly eT~ s output $ha~ 50. This
~nay be aGco~plished by conve~tional means, such a.s a splined connection.
It ~ill be ~ioted that the gear housi~g 25 contains only two gears7 i.e. a pinio~ ~ea~
3~ (a drivin~ E~e~) and a ring gea~ 36 ~a d~iv~n gea~), both ~f which may be hypoid g~ars~
5 wllich a~e strong a~d ~uiet in ope~ation. AIte~rlatively, gEars 3~ and 36 may be bevel gears
or the like.
Output sha;Pcs 50 of the two gear asserIIblies 22 or 24 ~e axially aligned axle sha~s
which extend outwardly alorlg a com~on transve~se axis B ~o~ the respecti~e gearhousings 25 to respeGtive sides of tlle vehicle. l~ach output shaPL 50 rnay terminate at its
10 outer end i~ a cirGular dis~-like end oap 51 l~ach of the output shaP~s or axle sha~ts 44
r~ay be replaced by 8. pair of coaxial shafts ~rhich drivi~gly erlgage each othe~ so tha~ they
rotate t~gether~ but ordinarily a single s}~a~t is used.
Surroundin~ eaGh re~ axle sha~ 50 is a stationa~y tubul~r axle hou~ing 52, shownbe~e as beLng fo~ed by two cotlcentr~c tubes 5~ and 56 such that the ~nside diameter of
l S the first t~be 5~ is the sa~e as or slightly less than the outside diameter of the spi~dle or
second tube Sfi. Botll tubes are concentfic with t~e axle s~aft SQ ~Ithou~sh shown as
separate components, the tubes 54 ~nd ~6 may be made as one integral compone~t if
~esired. ~ach axle shafl: 50 and each tubular ho~sir~g 52 exterlds from a gear housing ~5 to
a side of thc bus, and tenDinates at an oute~ end urhicl~ is in proximity with a wheel
2 0 asse~bly. The ou~er end of each a7~1e housing ~ is sli~htly inboard of the outer en~ o~the
co~res~orlding a7~1e; shaft 50 (to pe~it end cap 51 to e~tend radially outwardly form the
axle shaflL SO), However, each axle housin.~ 5~ (and, specificaIly, spindle S6 thereof)
e~ends transversely out~oa~d of a major po~tion of a wheel assembly (to be described in
~cta~l subse~uently~ mounted the~eon, Tubular housirlg 52 is secured, for e~ar~ple by
25 bolts (not shown), welding or other suitable SeGU~ing ~netllod~ to th,c gea~ housing 22 o~
~4.
~ tendulg fro~n one gear housirlg 25 to the other is a transverse horizontal
:,LiD~e.~ g mem~e~ 60 This stif~elling member liO unitizes the rear axle assembly ~0 and
the two dnve t~ains therein irlto a unita~y str,ucture. ~t also m~int~in.q the two d.rive 3xle
3 0 shaf'cs 50 irl axial ali~nmerlt ~nd in substantially ~orizonta~ position (~nless the vehicle
wei~ht load ori one side of the center li~e i~ appreciably gre~ter tha~ on the other). This
2 2 û ~ 5 7 ~
~ember must be strollg, si~ce it is subjecte~ to cornpressive skesses by vellicle weight or
load thereon. Stif~ening rnember 60 ma.~ be either a solid bar or a hollo~ tube, bu~ t}le
~atter is ~1 ~re~l~d because the gre~ter st~ength-to-weight ratio.
Stiff~nin3~ me~ber 60 is placed at an elevation lowe~ tha~ that of the gear housings
5 2S and the rear axle sha~cs ~iO. A pair of vertical and do~vnwa~dly exte~ding housin~3
co~nectillg members 62, whiGh may be hollow~ connect the sti~enirll3 me~ber ~ivith gear
housihgs 25. ~or ease of repair, the sti~ening membe~ 60 rrlay be remo~ably af~ed to the
~ear housings 60. 'rhis may be ac~om~lished either by forxr~ing the deperlding ~ousing
member 62 integral ~ith ~espective gear hou~ings 25 and joining the sti~ening rlleml~er 60
10 to the depe~ding ho~sing ~¢mber 62 by bolts, or by fo~ing the ~LiLr~ g membe~ 60 a~d
the two housing me~bers 62 as a unit, a.nd aff~Lxi~g the two ~ousiIIg me~bers 62 by bolts
to ~espective geQr ~ous~s 2~. Sti~fening ~em~er 60 is placed at a lower elevation than
that of the gea~ housings ~2 or 24 so t~at the ~llS can have a low floor F ~sho~ in a
broken line in Fig. 2), lower tha~ the top level of the gea~ housirl~s 2~ a;nd eve~ lower than
15 the d~ive ~le s~aPcs 5~. Floor level F Frlay ~e the floor level th~ougllout t~e entj~e b~s,
e~n-lir~ the length of the bus and the erltire width of the ~ous ex¢ept at the fi ont w~eel
assemblies (not shown) and t~.e rear wheel Assenlblies ~shown in Figs 1 ~d 2) and the gea~
hollsings 25. Even i~ the v~cimty of the gea~ housirl~s 25, the low ~oo~ ~ is wide enough
to provide a center aisle T~e low floor ~ac~litates loadiIlg of both orthopedic~lly
2 o haIIdicapped passellgers (inf ~ in~ t~ose who use ~;vheelc}lai~s) and passenge~s having no
orthopedic impai~ent.
~ o~ olltal spring pads 64 a~e ~orlned on top of the respecti~e gear ~ous~n,gs 25,
for ~eceiving springs 66 ~rhich fiorm part of a vehicle suspe~sio~ system. Springs 66 are
sho~ diagr~1n~A~ir. llly in chain lines as air spri~gs, wllich a~e the ~r~led fo~m of
2 5 sp~ings. ~ part of the vehicle ~eig~t, that is, that po~tion which i8 bor~e by thç ~ear
wheels aTld ti~es, is borne by ~he air springs 66 and the sprin~ pads 6~.
pair of wl~eel assemblies 70 are rotatably mounted on outer port.ions o~
~espective spindles S~ at l~s~;Live sides (the le~ side a~d t~e right side) of the vehicle.
E:ach wheel assembl~ 70 comprises a hub 72 which is rotatably ~ounted on an oute~
3 0 portio~ of a~le hnu~in~ 52 (and specifically spindle S6) by mea~s o~ a plurality o~ roller
bearing asse~lies 73. ~Iub 7~ is attaGhed by bolts 74 to tb~e end cap 51 o~ axle shaft 50.
.. ~ r 7
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1 5 7
, ~1
The hub 7~ is also secured ~o spindle 56 by nuts 81 or other suitable ~echanism. ~
plu~ality of mou~ti~g studs 76 secure wheel rims (not shown) and a ~rake d~m 78 to hub
72. Normally, the vehicle wiU have double wheels (an inside w~eel ~2ld an o~ltside ~heel)
o~ ~he a}~le, and S07 p~efierably, two wheeI rims are secured to the ~ub 72. (If the ~us has
5 tarldem rear axles, eaGb. rear ~le ~ill no~mally have double wheels on each side of t}~e
bus.~ A ~eel a~sembly filrther includes a bra~e s~oe 80. The br~lce StrllGture is not
shown i~ detail ~,ince it may be conve~tional a~d ~orms no part of the in~e~tion.
Modular de~ign and const~uction ~e used i}l the practice of this ~ventioll.
Compo~e~ts ca~ be ~e~ovably sec~red to~ether, for e~ample, by bolt~g, as p~eviously
10 e~crl~in~rl. Thus, SL~ rnember 60 can ~e removab~y secured p~eviously by bolts, to
both gear housings ~ Each a~le ~ousing 52 can be secured, e.g., by bolts, to an adJac~nt
gear housi~.g 25, The invention ~ay utili~e a convelltional spindle a~rangenlent, whi~ in
tu~n mal~es it possible to use standard or existi~g prod~ction hubs, brakes, brake drums,
a~de hollsings, a~le shafl:s~ and gear assernhli~ This also ~nakes it possible to ~epair or
1~ replace one compollent witho~t disturbing other con~ponents. Fo~ ç2~ample, ~ gear
assembly 22 or 24 ~an be removed ~OIIl the vehicle w~thout havin~ to remove the wheels
a~d other comporlents, such aS the a~le housinE~s 52. This also mak~,:s ~t possible to ~eplace
compOIlents ~ith larger or s~all0r co~ponents havin~ the same fimctiotl. ~or e~mple, if
o~e desires a b~s ~aving a wider o~ narrower ~'track" (which is the di~ta.nce between
2 0 whcels on the two opposite sides o~a bus) one replaces the origin~l axle ~afts 50 aIld axle
~ousings 52 with longer or s~Oner axle shafcs alld axle ho~sings as desired. Alterna.tively,
tlle length of t~be 60 could be ch~nged to accomptish a sim~Iar purpose Simil~ly, one can
replaGe the ge~r assemblies 22 or 24 wi~ gear assemblie~ ~ho~e ~ousings are of larger or
smaller gear ratios, ~vhere applupliate, and can replace co~ventional lli~er~l,tial assemblies
2 5 22 (with tlle .li~e~ c~ locked out) with speciall~ des;gn~d gear assemblies ~4 hav~ng onl~
the necessaIy gears, or ~ice wrsa.
Tlle presellt in~entil~n also protects the drive axles 50 from defl¢ction caused by
vellicle load or weight. In other ~ho~ds, the present inverltion provides a fi~lly floati~g
drive ~xle assembl~ for a twin motor (or more b~oadly, a plural Inotor) ve~icle That
30 portion o~ehicle weight ~vhich is borne by the ~ear axle ~ssembIy 20 is tr~n~rnitted
through air springs 66 to spring pads 64, ~hich are forIIled on the ~ear housings 2~. ~rom
F~ ' l'L 8
~ 2 ~ 9
t~e~e such stress is ~r~n,cmitted transversel~r out~a~dly throug~ the cpindles 52 to t~e whe0l
assemblies 7~, which are ~otatably ~ounted on t~e spindles S~. Vehicle load or w0ight is
the~ tr~ncmitt~d ~om the ~heel assemblies to ground~ gin.1~ tires (not s~own).
Loolcing at weight load t~n.~mi.qsion f~o~ another vit wpOill~ (SincE unde~ ~ewton7s laws,
5 for every action there is a~ equal an opposite reaction~ eight lo~d bome by the ground-
erlg;~ wheels is a~ .,illed through ~heel ~ssemblies 70 to spin~les 56, a~le tubes 5~,
alld ho~sing ~emberc ?5, thence to sprin~ pads 6Lt and vehiGle springs ~i6 By mourlti~g
t~e wheel assemblies on stationary a~i;le housings 52 and not on t}le axle shafts SO
themselves, the a~e sh~fts SO are out o~ the pat~ of weight load t~ncm~ on a~d ~o are
10 not sllbject to stress~causin~g deflection. Ir~ short, t~e axle sh~fts 50 are noln-load bearin,g.
This greatly inGreases axle sha.ft life and minill1i7~s premature axle sha~ failure. This also
m~es it possible to optinaize parts, s~ch ~s axle shafts SO, to perfo~ a single fiulGtion.
Thus, the design ofthe a7sle sha.f~s 50 can be ~,~LiL~ ed for deli~ering tor~ue f~or~ the g~ar
assem~lies 22 or 24 to the wheel assemblies 70. Fsilure o~axle sha*s from ove~ torquing
15 is very unlil~ely to occw. ~n contrastr arl axle assembly design in w~ich axle sh~fts Garly
torque to t~e wheel$ a~d support t~e weight of the ~e~iGle~ there is a danger ofoverloadillg the a~le shafts with co~pound loadi~g, whiGh typically will c~use exGessive
~tigue and ~ay even cause a wheel to fall off.
~ filrther advantage of t~e present inventioll is that i~ utilizes hypoid or bevel gears~
2 0 rather thall worm gears (as shown ill published information concerning an olde~ bus mode])
where tr~.qmi~.~ioIl of tor~ue fro~ a drive shaflc to all a~le shaft.
~ Vbile this inverltion has beell desc~ibed with ~eference to the best mode and
~r.3rell ~d embo~ t it vvill ~e understood tha.t this description i~q by wa~ of illust~ation
and not by ~ay of li~tation. Va~ious modif;c l~ions can be made w~t~out departin~ ~o~
2 5 the scope a~d sp~rit of tl~is inventioll.
r \ '!'~'~ ........... ~.UY
