manual transmission 965


The manual transmission is one complex machinery. it contains so many meshed gears and is also known as the gearbox. well is there a way to learn it all in a simple way? I’ll elaborate :-

 

Above we see a simple diagram of an engine coupled to a gearbox via a clutch system which comprises of a clutch pedal, master cylinder slave cylinder, clutch plate & pressure plate, release bearing onto the fly wheel. well cover all this part by part in this article :-

In neutral all the synchronizers or dog clutches are at the center hence motion is carried from the crankshaft via gears to the lay shaft but it does not enter via any gear hence the main shaft is not rotated.

in 1st gear the synchronizer is pushed to the left by the stick shift as the clutch pedal is pressed and rotational motion moves from the crankshaft in the engine to the fly wheel via gears to the lay shaft via gears to the main shaft that goes all the way back to the differential or front axle in gear reduction. as explained in my wheel drive systems article.

in 2nd gear the synchronizer or dog clutch is pushed to the right by the stick shift as the clutch pedal is pressed and motion moves from the engine to the flywheel to the lay shaft via gears to the main shaft via gears all the way to the wheels via differential or front axle.

in 3rd  gear the second dog clutch or synchronizer is pushed to the left by the stick shift and engages the third gear as the clutch pedal is pressed. motion is then transferred from the engine to the flywheel and via gears to the lay shaft and on to the main shift via gears to the differential or front axle. please note that the speed increases as the gears are increasing.

in 4th gear the the second dog clutch or synchronizer is pushed to the right by the stick shift and engages the fourth gear as the clutch pedal is pressed. motion is then transferred from the engine to the flywheel and via gears to the lay shaft and on to the main shift via gears to the differential or front axle i.e in the same gear ratio i.e direct drive.

in 5th gear the third dog clutch or synchronizer is pushed to the left by the stick shift and engages the fifth gear as the clutch pedal is pressed. motion is then transferred from the engine to the flywheel and via gears to the lay shaft and on to the main shift via gears to the differential or front axle in a higher gear ratio i.e overdrive.

In this reverse gear the third dog clutch or synchronizer is pushed to the right by the stick shift and engages the fifth gear as the clutch pedal is pressed. motion is then transferred from the engine to the flywheel and via gears to the lay shaft and on to the main shift via gears to the differential or front axle. The idler gear reverses the rotation of the lay shft from the main shaft.

The necessity of the transmission arises because an engine only supplies a limited amount of torque therefore the purpose of the transmission is to multiply power of the engine while keeping it in the correct r.p.m range. the gears must be shifted as speed increases to avoid the transmission red line.

 

when you step on the clutch you disengage the engine from the transmission whereas when you step off the clutch you engage the engine with the transmission. it should be noted that the engine is always rotating it is the clutch mechanism that separates the two i.e the engine from the transmission with the help of the pressure plate, clutch disc, release bearing and fly wheel. the springs in the clutch disc help smoothen engine pulsation.

when the clutch is disengaged the pressure plate is forced away from the flywheel by release bearing therefore releasing the clutch disc. when the clutch is engaged the pressure plate is forced back to the fly wheel sandwiching the clutch disc. A cable is then used from the release bearing to the clutch pedal.

There are three types of gears used in transmissions :-

  1. Spur gears – used in reverse gears because they are noisy.
  2. Spur bevel gears – used in differential
  3. Helical gears – used in manual transmission. 

 


Leave a comment

Your email address will not be published. Required fields are marked *

965 thoughts on “manual transmission