BMC Training Presentation
BMC UNDERCARRIAGE SYSTEM
Component Assembly Assembly
Operation Principles
Bulldozer Assembly Power Take-off Torque Converte Converter r Universal Joint Transmission Transmission Unit Main Drive Steering Clutch Steering Brake Final Drive Track qui!ment Control S"stem #orking qui!ment Ca$in Floor % Fen&er Track Frame
BMC
Power Train
ngine Torque Torque Converte Conve rter r Universal Joint 'ear Bo( Main Drive Steering Clutch Final Drive Track S"stem
BMC
Power Tae-o!!
BMC Function: PT) !ower
Equipment: #ork s"stem !um! Transmission !um! Steering Pum!
Torque (on'erter Assembly * Type: "-element # sta$e # phase * Assembly: Pump% Turbine and &tator * There are many 'anes on these components !or usin$ oil to trans!er power
BMC
BMC * These " components combined with oil% $i'e us as smooth power transmission. * &a!ety 'al'e: !itted to oil input% ensures the input oil pressure is no more than ).*+MPa. * ,elie! al'e: !itted on oil output% ensures the oil pressure inside the torque con'erter is maintained below )./MPa.
BMC
Principles o! Torque (on'erter *
)il Flow+ Pum!, Tur$ine , Stator, !um! * There is mm clearance $etween !um! an& Tur$ine. an& transfers !ower $" )il/ There is no mechanical im!act. the" !rotect each other * 0ssist h"&raulic s"stem+ to resist loss of oil1 to maintain the normal oil tem!erature/
BMC
0peration o! Torque (on'erter * #hen the loa& increases. the &o2er groun& s!ee& is re&uce&. causing tur$ine s!ee& to slow &own/ But at this time the energ" from the !um! transfer to torque converter is not re&uce&/ This energ" is still transferring to the stator through the slowing tur$ine/ Then the energ" to stator from tur$ine. results in the tur$ine gaining torque. then the tur$ine out!ut torque is increasing/
BMC
Torque (on'erter 0peration #.(han$e torque automatically 1.Absorb 'ibration% prolon$ worin$ li!e ".2ood power transmission capability% dri'in$ at slow speed .&imple operation /. &tart smoothly% eliminates any shocs in power train 3.Easy maintenance
BMC
BMC
4i$h Torque (on'erter 0il Temperature
3ormall". SD Torque Converter Tem!erature of out!ut oil is 445-46 C/ For a short time. a higher tem!erature of 476-475 C is allowe&. $ut long term high tem!erature shows there is something wrong. for the following reasons+ #.&horta$e o! 0il Torque converter. transmission. main &rive. steering an& final &rive will take 768 of engine rate& !ower/ This !ower will transfer to heat energ". an& increase the oil tem!erature/ Therefore it requires enough oil to a$sor$ this heat/ o
o
9f the oil quantit" is not sufficient. the oil tem!erature will $e too high/
BMC 1.0il Pressure o! input and output output are incorrect 9f torque converter in!ut oil !ressure is not correct :Stan&ar&+ 6/;
5MPa= or the oil su!!l" is $locke&. return oil tem!erature will $e too high/ The flow of oil to oil cooler is re&uce&. an& the oil tem!erature too high
BMC ". 5ncorrect 0peration (cessive use of low engine s!ee& for e(ten&e& time. torque converter will work at low efficienc"/ Torque converter will lose !ower. an& transfer heat energ" lea&ing to high oil tem!erature/
Power Transmission (ase
BMC
* The t"!es of Transmission Case+ Base )!eration t"!e+ 4/Manual 'earshift ； /?"&raulic $ooster ； 7/Powershift Base Transmission t"!e+ 4/mechanical t"!e1 /Planetar" 'ear * Planetar" t"!e !owershift transmission case t"!e+ Planetar" 'ear. Multi-&isc clutch. ?"&raulic control. force& lu$rication/ * Function+ 4/na$le forwar& an& reverse /Select &ifferent gear ratio 7/Matche& with the torque converter. ena$les a wi&e range of !ower out!ut an& groun& s!ee&
Planetary 2ear &ystem
BMC C
The s"stem consists of+ 0+ Sun 'ear B+ Planetar" 'ears C+ @ing 'ear D+ Carrier The !lanetar" gears are installe& on the carrier $eing in constant mesh with the sun gear an& the ring gear
D
0 B
Planetary 2ear system
BMC
Principle o! Planetary 2ear system 9f the carrier is fi(e&. the torque is transmitte& from sun gear to !lanetar" gear. an& is transmitte& from !lanetar" gear to ring gear to make the ring gear rotate/ @otation &irection of ring gear is o!!osite from sun gear/ A: &un 2ear B: Planetary 2ear (: ,in$ 2ear 6: (arrier
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Principle o! Planetary 2ear system
BMC
9f the ring gear is fi(e&. the torque is transmitte& from sun gear to !lanetar" gear/ The !lanetar" gear rotates $" itself. at the same time rotates aroun& sun gear/ @otation &irection of the !lanetar" gear shaft is o!!osite from sun gear/ 9t is a slow&own outfit that !ower in!ut from sun gear. out!ut from carrier
A: &un 2ear B: Planetary 2ear (: ,in$ 2ear 6: (arrier
BMC
The a$ove !rinci!les are structure !rinci!le of 3o/4.7.> !lanetar" gear s"stem/ The sun gear is active in 3o/4 Planetar" 'ear s"stem The carrier is active in 3o/7 % > Planetar" 'ear s"stem
BMC This is structure an& !rinci!le of 3o/ !lanetar" gear s"stem/ The rotate &irection is contrar" with 3o/4 !lanetar" gear s"stem/
BMC
&611 powershi!t transmission system
Consists of > !lanetar" gear s"stems with > clutches. an& 4 locking clutch :no !lanetar" gear s"stem= an& housing. in!ut shaft. en& gear an& out!ut $evel gear/ 3o/4 clutch is for Forwar& 'ear 3o/ clutch is for @everse 'ear 3o/7 clutch is for 7r& 'ear Shift 3o/> clutch is for n& 'ear Shift 3o/5 lock clutch is for 4st 'ear Shift
BMC
BMC
&611 powershi!t transmission system
The > !lanetar" gear s"stem clutchAs washers an& &isc are the same. $ut the &isc quantit" is &ifferent/ 9ts &esign is $ase& on transmission torque/
The 7o. o! (lutch
7o.# 7o.1 7o." 7o. 7o./
8asher 9ty
" 1 # # 1
6isc 9ty
" 1 1 "
BMC 3o/4- > !lanetar" gear s"stemsA structure are same. clutchesA washer an& &isc are same. $ut the &isc quantit" an& !iston is &ifferent/
BMC Metho& of fi(ing of each !lanetar" gear is as this figure. it is actuate& $" the clutch/ En$a$ement of En$a$ement clutch is actuate& $" oil !ressure from control valve !ushing !iston 7/
BMC 6isen$a$ement of 6isen$a$ement clutch is actuate& $" return s!ring 77 which !ushes !iston 7 to original !osition after oil !ressure is cut off/ The function of &isc s!ring > is to im!rove o!erating s!ee& of !iston 7 an& im!rove release the &iscs/
BMC This figure is a &rawing of 3o/5 locking clutch/ #hen the clutch &isengages. oil in the c"lin&er $o&" 4 $" the action of centrifugal force/ Disks canAt &isengage quickl". onl" $" &isk s!ring / This can make the clutch half &isengage/ This will cause &ifficult" for ne(t gearshift/ 9n or&er to eliminate this !ro$lem. the $all check valve 4< is incor!orate& in the !iston after the rotar" clutch/
BMC 7o./ (lutch is a loc clutch. #hen this clutch engages. !ressure oil from controlling valve enters into oil cavit" an& !ushes !iston . at the same time. the oil !ushes check valve $all 4< to !lug the hole of valve/ The clutch is engage& quickl"/
BMC 7o./ (lutch is a loc clutch. #hen the !ressure oil from controlling valve is cut off. $" the action of centrifugal force. $all 4< can move to the &irection of arrow in this figure/ 0t this time. the hole of valve cage is o!ene& an& the oil is &raine& off/
Forward #st &peed &peed
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Forward 1nd &peed
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Forward "rd &peed
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Transmission ;ubrication and (oolin$:
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5ts a !orced lubrication system% !rom abo'e and below% two ways di'ided throu$h a 'al'e. Transmission (ase lubrication pressure is ).#1Mpa.
Main 6ri'e >&611? * Assembly: Bevel gears ?ori2ontal Shaft Bearings S!rocket ?u$ * Functions: Power train gear re&uction to increase the final &rive torque
BMC
&teerin$ (lutch * Function: To &isengage the shaft &rive an& control steering * Type: #et. multi-&isc. s!ring loa&e&. h"&raulic se!arate&. normall" engage&/ * &prin$ !orce F7/ tons
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&teerin$ (lutch 0peration
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&teerin$ Brae * Function: The $rake on the outsi&e of steering clutchAs outsi&e &rum. re&uce& the r!m of the final &rive on that si&e/ * Type: #et $an&. h"&raulic $ooste& control
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&teerin$ Brae 0peration
or!ar"
Re#erse
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&teerin$ Brae (ontrol ;ina$e throu$h 'al'es
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&teerin$ (ase ;ubrication and Breather
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* There are 7 associate& com!onents. Main &rive. Steering Clutch an& Steering Brake/ The" are lu$ricate& an& coole& $" the oil in steering case/ The oil level can $e checke& with oil &i!stick * Steering case has a $reather to $alance insi&e an& outsi&e !ressures/
Final 6ri'e * Final Drive+ )ne Set Final Drive on each si&e/ * stage s!ur gears re&uction/ Floating Seal an& )-ring to contain oil. then connecte& outsi&e with $reather/ * 0ssem$ling S!rocket hu$ an& gear requires 6 tons force with s!ecial tools/
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Trac &ystem --- 8alin$ 2ear * Assembly: Track Frames Track @ollers Carrier @ollers @ecoil s"stem Track Shoes quali2er
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,ecoil system !or Trac * Function: 4/ Maintain track tension a$sor$ the vi$ration of i&ler * 7ote: the fi(e& !ressure is 6/7; tons. it requires s!ecial fitting tools
BMC
Measurement o! Trac Tension
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use a ruler !lace& on the track grousers $etween carrier roller an& i&ler. the measure &istance is C ， C676mm SD7 track has more wi&e. the &istance is $igger $etween carrier roller an& i&ler. the measure& &istance is C76->6mm
Idler
Carrier roller
5dler * Function: 'ives gui&ance for track chain an& maintains track tension * ;ubrication There are lu$ oil in the cage that is seale& $" floating seal. $etween i&ler an& su!!ort housing/ The oil ca!acit" is <68/
BMC
To Ad@ust 5dler (learance *
9f the clearance is over limit . the i&ler will swing. an& track links off centre an& will wear the s!rocket/ * 9f Clearance in one si&e 0 ＞ >mm. it must $e a&Euste& into 06/5-4mm * 9f Clearance of u! an& &own :BC=G5mm it must $e a&Euste& into :BC=mm 。
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Trac ,oller * First it carries &o2er weight. secon&l" it !revent track chain moving off centre of track frame * Bushing an& float seal is similar to i&ler
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Trac &hoe Assembly * Su!!orts all of the &o2er weight. an& &etermines the groun& !ressure * Four high strength $olts fi( track shoe onto track link. $olt torque+ SD4+<6kg/m SD+<kg/m SD7+466kg/m
BMC
BMC
Trac supports ") tons bulldozer wei$ht% and i! the worin$ conditions are bad% it will wear more quicly% so use and maintain it correctly. 4/
)ften check the tension of track shoe/ use a ruler !ut the track grousers $etween carrier roller an& i&ler. the measure is C C6-76mm1 SD7 track is more weight. the &istance is more large $etween carrier roller an& i&ler. the measure is C76->6mm ，
#hen the work is har&. the track shoe assA" will nee& to $e a&Eust tighter1 if the work is mo&erate . the track shoe assA" tension can $e a&Euste& $ack/
BMC
/ The s!rocket segments nee& $e re!lace& when the s!rocket segments wear un&er the limit/ 7/ DonAt &rive &o2er har& an& avoi& track &amage an& e(cessive wear/ >/ 9f there is e(cessive track !la" an& noise. "ou must sto! an& check tracks an& machine/ 5/ #hen the &o2er across the railwa" line. "ou must &rive it across the railwa" at right angle. an& &onAt change s!ee&. &onAt sto! an& reverse. avoi& track shoes locking in railwa" line/
