Gearboxes are used to transfer energy from one machine to another. This is a mechanical process where torque is increased or decreased to control the speed of a moving vehicle or machine.
While this article talks about vehicles and gears, it should be mentioned that gears are used in almost all devices that require a change of motion. Check this website for more.
Now back to cars. In cars, the power transmitted from the crankshaft (rotating axle that drives power from the engine) to the driving shaft (found under the car which is responsible for powering the wheels) is done with the help of gears.
Every time a gear in an automobile is changed, one of two things happen.
- The speed of the vehicle may increase or decrease.
- The direction may change (at a right angle).
There are various kinds of gearboxes, each with a specific power. The gear ratio in a gearbox determines the level of force required.
In automobiles, transmissions can be controlled with the help of a gearbox. There are three kinds of transmission that can be used in cars. Let’s have a look at each in detail now:
In this type of transmission, speed is controlled by changing the gears manually. Moreover, manual transmission can be of two types These are:
- Sliding mesh
- Constant mesh.
In case of sliding mesh, straight cut spur gears are used where the gears rotate freely and it depends upon the driver to control the transmission manually from one speed to another as per the road requirement.
The driver needs to time the gear correctly to avoid the clashing of gears that produces a loud grinding noise because the gear teeth collide.
In constant mesh, there’s a pair of helical gears or diagonally cut helical gears that are permanently meshed together, unlike in sliding mesh. Therefore, in this type of manual transmission, the speed changes very smoothly with no grinding noise when gears are changed because there are synchronized rings embedded on gears.
This type of manual transmission is mostly used in racing cars and equipment used in agriculture.
- Automatic Transmission
This type of transmission reduces human effort and interaction and changes the gear automatically.
In case of automatic transmission, there are no clutch pedals besides the acceleration pedal because there’s no need to change the gears manually, as when the car accelerates or decelerates, the gears are altered automatically.
- Continuous Variable Transmission
CVT is also quite similar to automatic transmission but with a few modifications and upgrades. It is gradually replacing the automatic transmission and can already be found in cars like Nissan Rogue and Honda Civic.
In automatic transmission, the gear ratio is limited to gear 4/5 or 6 but in CVT( continuously variable transmission), the gear ratios are unlimited with minimum and maximum speed values.
Thus, the velocity of the input shaft is maintained at a constant speed, giving a more smooth experience while the gears are changed. Most importantly, CVT transmission is more efficient than the automatic transmission in cars.
Comparing all three types of transmissions, it can be concluded that manual transmission gets better fuel economy than the other two, however, automatic and CVT eliminate the hassle to manually operate the car speed.