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  lOMoAR cPSD| 59595715 I N T R O D U C T I O N T O  AUTOMOTIVE ENGINEERING 
Assoc. Prof. Dr. Duong Ngoc Khanh 
Dept. of Transportation Engineering 
School of Mechanical Engineering  khanh.duongngoc@hust.edu.vn  1          lOMoAR cPSD| 59595715   1     
 . C o n c e p t a n d C l a s s i f i c a t i o n  Sedan  Convertible 
Uses center body pillars, or “B” pillars, 
between the front and rear doors. A 
hardtop does not use “B” pillars. 
Uses a vinyl or cloth top that  can be raised and lowered  Hatchback  Station Wagon 
The large rear door allows easy 
Provides a large rear interior compartment  access when hauling items  4        lOMoAR cPSD| 59595715         lOMoAR cPSD| 59595715   2   
 . D r i v e t r a i n s y s t e m  Functions: 
To couple the engine to the driving wheels; 
To increase torque from the engine to the active wheels ; 
To change the traction and speed at the wheels to suit the motion  conditions; 
To uncouple power transmission when needed ; 
To reverse movement (reverse gear) .  Components:  Clutch;  Transmission/Transaxle;  Propel er shaft;  Front/Rear axle.  8        lOMoAR cPSD| 59595715   2   . 1 . C l u t c h  Functions: 
❑ Used to connect and disconnect the engine and manual  transmission or transaxle; 
❑ Allows the driver to control power flow between the engine and  transmission or transaxle; 
❑ To serves as a safety device of the drivetrain system.  Classify: 
❑ Clutch (Manual transmission); 
❑ Torque converter (Automatic transmission);  ❑ Others.  10        lOMoAR cPSD| 59595715   2      
 . 1 . C l u t c h ( B a s i c P a r t s )  Components:  • pilot bearing  • flywheel  • clutch disc  • pressure plate  • release bearing 
• clutch housing (bell housing)  • clutch fork  • clutch release mechanisms  • clutch start switch  12        lOMoAR cPSD| 59595715   2   
 . 1 . C l u t c h ( A c t i o n )  Engaged 
• When the driver releases the clutch pedal, the spring pressure 
inside the pressure plate pushes forward on the clutch disc 
• This locks the flywheel, disc, pressure plate, and transmission input  together 
• The engine rotates the transmission input  14        lOMoAR cPSD| 59595715   2         
 . 1 . C l u t c h ( H y d r a u l i c R e l e a s e M e c h a n i s m )  ❑ Uses a simple  hydraulic circuit to  transfer clutch  pedal action to the  clutch fork.  ❑ Components:  • clutch pedal  • clutch cylinder  • hydraulic line  • slave cylinder  • release fork/level  16        lOMoAR cPSD| 59595715   2 
 . 2 . T r a n s m i s s i o n  Functions: 
❑ Uses various gear combinations (ratios), to multiply engine speed 
and torque to accommodate driving conditions; 
❑ To uncouple power transmission when needed; 
❑ To provide a reverse gear.  Classify:  ❑ Manual Transmission (MT) 
❑ Automotive Transmission (AT)  18        lOMoAR cPSD| 59595715   2      
 . 2 . T r a n s m i s s i o n ( A u t o m a t i c T r a n s m i s s i o n ) 
❑ Does not have to be shifted by the driver; 
❑ Uses an internal hydraulic system and, in most cases, electronic  controls to shift gears; 
❑ Internal clutches or bands control gearsets to provide various gear  ratios; 
❑ Input shaft is connected to the engine crankshaft through a torque  converter.  20        lOMoAR cPSD| 59595715   2      
 . 2 . T r a n s m i s s i o n ( G e a r R a t i o ) 
• The number of revolutions a drive gear must turn before the driven  gear completes one revolution 
• Calculated by dividing the number of teeth on the driven gear by the 
number of teeth on the drive gear  Gear Ratio =  # of driven g ear teeth  # of drive gear teeth 
Example: If the drive gear has 12 teeth and the driven gear has 24 
teeth, the gear ratio is two-to-one   Gear Ratio =  24 = 2, written  2:1  12  22        lOMoAR cPSD| 59595715   2      
 . 2 . T r a n s m i s s i o n ( T r a n s m i s s i o n G e a r s ) 
The input shaft gear turns the countershaft gears, which then turn  the output shaft gears  24        lOMoAR cPSD| 59595715   2      
 . 2 . T r a n s m i s s i o n ( S e c o n d G e a r ) 
• The first gear synchronizer is slid away from the first gear 
• The second-third synchronizer is then engaged 
• Power flow is through the second gear on the output shaft 
• The gear ratio is about 2:1  26        lOMoAR cPSD| 59595715   2      
 . 2 . T r a n s m i s s i o n ( R e v e r s e G e a r ) 
• The synchronizer is moved into the reverse gear on the output shaft, 
locking the gear to the output shaft 
• Power flows through the countershaft, reverse idler gear, reverse  gear, and to the output shaft  28        lOMoAR cPSD| 59595715   2   . 2 . T r a n s a x l e 
Short drive axle assemblies connect the 
transaxle output to the hubs and wheels  30        lOMoAR cPSD| 59595715   2      
 . 2 . T r a n s a x l e ( M a n u a l T r a n s a x l e )  32        lOMoAR cPSD| 59595715   2      
 . 2 . T r a n s a x l e ( S e c o n d G e a r )  34        lOMoAR cPSD| 59595715   2      
 . 2 . T r a n s a x l e ( F o u r t h G e a r )  36        lOMoAR cPSD| 59595715   2   
 . 2 . T r a n s a x l e ( N e u t r a l )  38        lOMoAR cPSD| 59595715   2       
 . 2 . A ut o m a t i c T r a n s m i s s i o n ( T o r q u e C o n v e r t e r )  ❑ Impeller  • Driven by the engine 
• Integral part of the housing 
• Produces oil movement within the converter  ❑ Turbine  • Driven by the impeller 
• Splined to the transmission input shaft 
• Fits in the front of the housing 
• Oil is the only connection between the impeller and the  turbine  ❑ Stator  • Improves oil circulation 
• Increases efficiency and torque by directing the oil flow  toward the turbine 
• Helps make use of nearly all the force produced by the  moving oil 
• Located between the impeller and the turbine, mounted on  a one-way clutch  40