Show Construction and Operation of Differential Gears dears of The Automobile E Explained for Benefit of Motorists I Forms Form Part rt of f Description i 1 Oil OU Company's Series on Lubrication tion Illustrated tr td description on of oftie f Tb The mn tie the differential gears bears concerning con ron c which the a average C motor motorist t ha ba has a hazy buy has bas been Oil on Company as U Vacuum prepared d b by the fc 1 part of its ith series on the n of ot ott t Hi if c carThe car car car- r- r The Rear gear compartment i is C generally located lo 10 lo- lo tid nt at or about the centre of th the rear axle when shaft drive Is employed The purpose e c of the differential h is II to permit hermit the outer wheel hecl of a motor driven vehicle hido to describe a n greater creator arc than thanHie the Hie Inner wheel in or in rounding travelling at a s speed d a It corner corner- each wheel of rotation proportional to the distance It H covers corers I. I e. e the differential permits fife rear wheels to at different rate rates cl of f sp speed J 4 cI The explanation of or th the action of nf the a can n be best e illustrated by hy the thc s several parts partial construction con con- bem being illustrated in the 0 figures j 1 1 2 and 3 Con Construction Fi Figure re 1 illustrates in to principle th the I driving parts of or the differentiate differential consist consist- In of the propeller shaft A upon the thed tad nd d of or which it firmly fixed the driving pinion gear cear car fB n B shown in mesh with the driving bevel r C Upon the face of rear gear C is bolted the differential housing E which acts as s a bracket or frame hoMing holding one or more studs fF F upon Pitch each ich of which is mounted d a t differential pinion g gear r G which is Ls free tree to rotate Only ono one shown hown The driving herd bevel pear gear C O and md differential dif dif- l housing E F arc are free to rotate te as tc Int ast independent unit about the common common com com- mon ails Y X of the rear axle atle shafts ts and wh wheels not shown In Ci figure 2 we e have hare Te introduced the rear reap wheel 1 I L one of the axles K H and anda a differential axle scar hear car IT H m. m the latter tatter being in in mesh with the differential pinion gear cear r G Figure 3 illustrates the same ame view as figure 2 with the addition of or the other wh wheel 1 III a axle lc shaft Kl KI and differential differential axle scar hear HI Hl All AU the elements clemente necessary necessary nrc- nrc essary ry for or a d description of the differential the driving shaft and the parts operating through h the medium of the differential sere ire re here shown The rear wb wheels Js are driven n b by in in- pendent axle shafts which are similar hat bit of slightly different lengths The wh wheels are mounted at the oU outer r ends The inner end of each axle shaft Is or ot to receive I A r p r 4 I I 1 f. o. o r I I ct V f. f I. I 1 I. I hl JI I A A o I y r. r iz 0 v 0 n n 1 4 Ii ft 1 r i F 19 t I A B t F E t ty f y G r X Kt rt I It L 1 t I f I FIg Fg 3 I I tho the differential axle gears ars by m means of which the axle shafts ts and wheels are art turned For analysis of or the p principle of operation operation opera opera- tion of these g gears rs we ha have hae e illustrated the differential pinion gear G as being in size sizo the same as the differential axle rear car CH H In ID reality the d di differential fenD 1 pin pin- ion gear is generally one half the size If f the differential axle gear bear O Operation First condition conditio figure jare 3 In making clear dear the function of tt tl-ti I differential it is a assumed that the rear reul end of the automobile is ir P I I allowing in the thc scar rear r wb wheels to toroth rotate rot freely the car r remaining station ary dry With the cn engine inc in motion tion the clutch rn 3 P d the he transmission gears Cl'S in me mesh h turning ruing the in driving shaft A in the direction di- di r tion indicated by hy the arow ow the resultant resultant re r- re- re sult nt action of the differential and the moin moving cl elements ment i is as ag Allows Driving pinion gear B ll fixed to th the Tear ear end of the driving shaft A rotates As e gear lear C in the direction di indicated by hy byI hythe ry rythe I I the arrow t Tb The differential 31 cJ casing in E B bolted to driving bevel bent gear nr C CD C also turns in the same Fame direction As the rear rEu wheels vh ls M r and Ml n axle aole shafts l K and Kl ICI and the differential axle gears II n nand and III Ill are free Cree to move mon they rot rotate te in inthe inthe the till same direction ct the two differential differential dif dif- if- if axle gears eArs If U and Ill III are locked by hy the tb differential pinion gear G Wheels fL TJ T and LI axle shafts K H and Kl ICI differential 1 axle gears ca n II and HI differential in cl casing CE E and nd driving bevel beel gear ear C C all an rot rotate tc a ai as a n unit about the axis axis ui X T in the direction indicated by bythe bythe bythe the arrow Both rear wheels therefore turn at atthe atthe atthe the same rate of s speed cd and md in road service service ser ser- v vice c under this condition the automobile will mo move forward COrnard in a 1 straight path Second condition fi figure re 3 I With the rear end of or the still tm rI raised ed assume wheel I L to be held stationary t With engine power applied in tho the same manner as indicated under UDder the first condition the action of th the differential differential dif dif- and the moving cl elements is as ns follows follows- Driving herd bevel tear sear r 0 and the differential differential differ differ- casing nJ E EL bolted to it it are re rotated in the direction as indicated by the arrow Th The differential axle gear nar II n the ri right ht hand one ono Is stationary ry As the differt differ- differ Uial t l pin mini r C I 1 on its stud F is revolved a about ut the axis X X-V it is forced to rotate on its it i stud F in rolling around roand on the Differential axle gear II n in revolution revolution ThIlI u making makin one complete tion bont r-bont the axis X X-T the differential pinion gear G makes one complete rota- rota ti tio on tin Its Itc stud F P by 11 rolling on the stationary stationary sta sta- axle gear H B Since gear G is in mesh with gear r Ill III this rolling of or gear tear G forces gear c r rIll III Ill to rotate nt at an additional speed td which will compensate for the enemy which has been lost by the stoppage o of gear ear II The differential axle gear ear HI m th the left hand one oDe is therefore subjected tn to two mo motions one motions one ons-one one revolution due doe tl to Its being brIng in mesh with the differential pinion gear ear r 0 G which has been bodily revolved about the axis Y X and the other duo duoto to tho the forward turning mon movement of the differential f fr r pinion gear I G Ci Cin in n rolling r n I u once around the stationary differential axle gear 13 Il H The rear wheel LI Il has made two forward revolutions due to the two motions motions mo mo- Just described while white the driving b bevel nl gear fru C and nil differential casing I C E have made one forward revolution Summary In a similar manner it may be shown that any difference in rotation of or the rear ren wheels is com compensated for by br th the rotation of r f the differential pinion gear cr 11 0 on its ifs it stud F while hile revolving bodily about the axis asks Y X Any rotation of or the differ pinIon hear gear car G means mes that it rolls rolla on one of the differential axle gears ca and the amount of motion in ic rolling on the on one gear ear is transmitted to the other other- as an additional additional ad ad- ad turning and driving effort Any retarded motion of one wheel rev results re r snits in accelerated motion of the oth other r. r The power of the engine is thus transmitted trans tran n to the rear wheels in proportion to I the distance each rh rl wheel 1 travels |