TRANSMISSION SYSTEM

TRANSMISSION SYSTEM

(Differential, Driveshaft, Propeller shaft, Universal Joint)


It transmits the power from the engine to the rear wheels of a vehicle. (for rear-wheel driven vehicles or to the front wheel for front-wheel driven vehicles)

The rotational motion is transmitted to the differential by the propeller shafts.
Depending upon the vehicle number of shafts varies.

1.When the engine starts the piston reciprocates, due to which the crankshaft rotates.

2. The crankshaft is connected to the flywheel.

3. A clutch plate is in contact with the flywheel.

4. The pressure plate of the clutch transmits the rotating motion to the gearbox which consists of the driving shaft.

5. The driving shaft is connected to a flange, which connects to the propeller shaft. For this type of joint a universal joint is used.

6. If the length vehicle is more, then two to three propeller shafts are connected in series.

7. There is another flange at the end of the propeller shaft which is connected to the pinion....(to the differential).

8. From the differential rotating motion is transmitted to the wheel drum.




Propeller shaft:




Flange (circular disklike thing)
and hanger bearing

Hanger Bearing (support bearing): 

  • It is used to hold (support) the propeller shaft to the chassis.
  • They have bearings(rolling material to reduce friction and wear and tear during the rotation of the shaft. 
  • Bronze hanger bearings are used as they are often oil-impregnated for self-lubrication.


Ball Bearings

Horizontal gaps are called as Splice 

Splice: 

  • Made at the collar (end) of the propeller shaft where a connection is to be made by the universal joint.
  • It is a type of joint.


Universal joint fork



Rear-axle:

Wheel Drum(R), Rear axle, Differential, Rear axle, Wheel Drum(L)

Rear Axle Shaft
top of the rod there is a pinion which rotates
 with the sun gears of the differential one 

Differential:


Differential assembly
on the crown gears, there is a spider which holds 4 the planet gears in place
and two sun gears (on each side i.e. represented horizontally in the picture)
Spider 
It provides 90⁰transmission of rotational motion. 
i.e. From flywheel to the axle shaft of rear wheels.
It is a mechanism which is helpful during turning of a vehicle.
When a vehicle is taking a turn, the inner wheel (in the direction of turns )rotates at a slower rate than the rotation of the outer wheel.
if they rotate with the same rate then slip may occur and cause wearing of tyres)











  1. PINION (Bevel Pinion): Propeller shaft end is a pinion which has Hypoid/ Spiral teeth, used to rotate the crown wheel.                                           
  2. CROWN WHEEL: The direction in which the crown wheel rotates is at 90 to the rotation of the pinion(or the propeller shaft).                               
  3. BEVEL GEARS (Sun Gears): They are used to rotate the two half shafts (due to which the wheel rotates).                                                                 
  4. PLANET GEARS (spider gears): They are fixed( coupled to the crown wheel. so when the crown wheel spins planet gears also rotate along with the crown wheel. these gears also can spin around their axis. Generally, 2-4 spider gears are used for effective load sharing)                                           
  5. SPIDER: It is used to keep the planet or spider gear in position (i.e. coupled to the rotational motion of the crown wheel ). the spider gears can also spin around its axis (the cylindrical portion of the spider) 


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