Constituent parts of transmission systems

car transmission parts

Although the word transmission is used synecdocheally to refer to the gearboxactually it's all set of parts that transmits power from the engine to the wheels. That is, all the gears and mechanical organs that transmit movement so that the car can move.

Each of its constituent parts fulfills a specific task and in turn have to coordinate with the rest to work together. Hence it is a complex system in which when something fails, the fault can be transmitted to other components. For example, a damaged dual-mass flywheel can end up breaking the gearbox.

transmission of a car

Flywheel-clutch assembly

dual mass flywheel

Starting from the engine, the first element that we find is the dual mass flywheel. a piece that is attached to the crankshaft and therefore can be considered engine part instead of transmission. However, it is very relevant to the subject we are dealing with, since it has two very important functions so that the transmission does not receive too much mechanical stress.

Su first function is to exercise flywheel that allows a progressive change of revolutions. Without its weight, detonations inside the engine would cause the assembly to rotate too sharply. Which would cause breakage or premature wear of many parts, like the crankshaft to pistons.

Dual mass engine flywheel

Su second function Its the absorb engine vibrations. In reality the motor does not rotate with a constant speed in each revolution. Simplifying to a single cylinder, when a detonation occurs, the engine rotates at its maximum speed, but slows down as one revolution is completed. At the speeds it moves, that effect is perceived as a vibration, which would reach the rest of the pieces and possibly the interior of the passenger compartment.

This flywheel is called dual-mass because they are actually two flywheels connected by a system of springs. These absorb said vibration and allow a more homogeneous turn, to protect the different elements of the transmission and improve ride comfort.

Clutch

El clutch is that disc located between engine and gearbox, which we couple or uncouple from the dual-mass flywheel every time we step on the pedal. Its function is to allow us to disconnect the engine from the transmission for a moment, in order to change gear, and ensure a progressive union at start-up and at each change.

Clutch

The clutch exists in a car regardless of whether it is manual or automatic. Moreover, there are automatic changes that have two clutches like the DSG. Some clutchless models are the majority of 100% electric cars or those with a conventional combustion engine, but associated with an automatic transmission with a continuous variator.

Gearbox

The gearbox is located between clutch and drive shaft. It is in charge of changing the gears to modify the speed of rotation that is transmitted. Today, manual gearboxes have up to 7 gears and automatic gearboxes up to 10. The more gears you have, the more you can stagger the speeds that you can transmit to the drive shaft or the longer the gears can be to revolutionize the car less.

The gearbox is only part of the transmission.

The gearbox has to go in line with the engine. It will be useless to put a box with very long gears to a car with little engine torque. Simply because it will not be able to maintain speed or face the slightest slope with so few revolutions.

In contrast, an engine with a high power and torque will be wasted if it is not put in high gears. At least if you have efficiency as one of the objectives.

transmission shaft

The transmission shaft has the task of transmitting the movement that comes out of the gearbox to the drive shaft. However, it is only necessary in models with the motor placed on a different axis than the wheels it moves. For example, a BMW Serie 3 it has the engine in front, but it is rear wheel drive (propulsion). So you need a drive shaft that drives the rear wheels.

rear wheel drive The propeller shaft carries the power to the rear wheels.

You will also need this item all wheel drive cars. Even if they have one of the axles close to the engine, you still have to get some of the torque to the wheels farthest away. As the axles of a car have a certain movement allowed by the suspension, the transmission shaft has some cardans that give it mobility. For more details visit the article:

the transmission shaft
Related article:
The propeller shaft: what it is, how it works and what its parts are

Differential

The differential is in charge of two functions very important for a car to move. The primera of them is that of change the orientation of the rotary movement into one compatible with the axles of the wheels.

In other words, the transmission shaft rotates on a longitudinal axis with respect to the car, which cannot move the wheels. So the differential turns it into a turn on a transverse axis, which is compatible with its turn and therefore can move the car.

Differential of the transmission of a car

La second function is just as important, because with the previous one the vehicle could only move properly in a straight line. When a car goes around a curve, the inside wheel turns more slowly than the outside wheel. It is easy to see if we look at the fact that the outside wheel travels more distance than the inside one.

This does not cause any problem in an axle that does not receive the force of the motor, but things get complicated when the motor has to move the outer wheel more than the inner one. This is handled by differential. You can see it clearly in the following video:

bearings

The motion coming out of the differential is finally transmitted to the wheels thanks to the palieres. Which are nothing more than bars, which already rotate in the same orientation as the wheels. It is very important that they are in good condition as any deformation will cause annoying vibrations in the steering wheel and other components of the car.

CV joints

However, there is still one more element that deserves mention because of its importance: the CV joints. These pieces allow that the connection of the bearings with the wheels is not a simple axle welded to the hub. Since the wheel is always in motion, due to the steer axle truck and vertical or quasi-vertical movement of the suspension, the constant velocity joint is needed so that the rotation can continue to be transmitted even if the wheel axis is not perfectly aligned with the drive shafts.

These boards are covered by bellows, to keep the necessary lubricant inside. also misnamed log joints, name popularized by the comedy radio program Gomaespuma.

Images – Bill Abbott, twin-loc, h080, Dyl86


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      Adam said

    My car doesn't have a ballonette, how can I check it, it's a cutlas from 1999