Automatic versus semi-automatic transmission. We check the similarities and diffrences

Most drivers probably associate that there are three types of gearboxes. Here is a brief description of each.

• Manual transmission (a.k.a. manual) is characterized by the fact that the driver selects the right gear for himself. He does this by setting the gears in the appropriate position,
• Semi-automatic transmission is subject to the driver’s control (just like a manual transmission), but at the same time it should be added that the gear change is carried out by a controller mounted in the car,
• Automatic transmission works without human involvement. The computer, which intelligently manages the system, independently “decides” the current gear setting.

We want to focus on the last two systems.

Semi-automatic transmissions. In automotive for almost 100 years

People began dealing with the first semi-automatic transmissions in 1917. It was then that they debuted in the American design of the now defunct Premier brand.

A nod to this solution was made a dozen years later, in 1936, by Wilhelm Maybach. His famous Zeppelin car model included a 6-speed preselection gearbox. It worked as follows: moving the paddle at the steering wheel between positions N-1-2-3-4-5-6 involved selecting a gear. This one was engaged when the driver added gas. The backpressure of air created in the engine intake duct was transferred to the actuator, which activated the gear.

How the semi-automatic transmissions work?

Automatic transmissions. From a luxury novelty, to widespread use

Automatic transmissions trace their pedigree to premium cars. Until a dozen years ago, they were installed only in expensive cars and were a kind of marker of prestige. Today they are far from luxury, because they are installed in an increasing number of cars, especially in the US, where virtually every car is an “automatic.” It is, by the way, widely believed that automatic transmissions are synonymous with driving comfort.

The creator of the first automatic transmissions is considered to be Alfred Horner Munro, who developed a prototype of the solution in the days before World War II. However, already after the global conflict, in 1948, the first two-speed automatic transmission was officially developed at Buick. It was soon to be sold throughout Europe.

Characteristics of automatic transmissions

The job of the automatic transmission is to match the gear ratio to the engine’s operation and the car’s current speed without driver input. Everything is done in an automated way, thanks to the software installed in the vehicle.

WHAT COMPONENTS DOES AN AUTOMATIC TRANSMISSION CONSIST OF?
An automatic transmission consists of three main parts or systems, responsible for its smooth operation. These include:

• Gear set. That is, a set of gears that perform the operation of the gear ratio. However, a well-chosen gear oil, such as FUCHS, is necessary for their proper operation,
• Gear control unit. Its main task is to control gear ratios and control such variables as oil temperature, speed or rpm. Such information then goes to the computer, which changes gears hydraulically,
• Clutch to the engine. In this role are kinetic gears, which rely on the kinetic energy of water or oil. The task of this component is to transfer torque from the drive shaft to the driven shaft.

Automatic or semi-automatic? Which will perform better?

Both solutions have their supporters and opponents. Below we discuss the reasons for such extreme opinions.

ADVANTAGES AND DISADVANTAGES OF SEMI-AUTOMATIC TRANSMISSION

Semi-automatic transmission is the ideal option for those drivers who enjoy dynamic driving, want to have a sense of control over their car, but also gain convenience. This is because the human role is limited to modifying the position of the transmission. At the same time, you can decide for yourself what moment to change gear.

Unfortunately, freedom and convenience come at a price. You get inferior performance, i.e. lower acceleration and lower top speed of the engine. In addition, the semi-automatic works slowly.

On the other hand, there is no such thing as a bad thing. Because it gives the drive unit a longer service life.

ADVANTAGES AND DISADVANTAGES OF AUTOMATIC TRANSMISSION

Automatic transmissions are appreciated by people who, above all, value driving comfort and not having to change gears themselves. This works especially well in city driving, when practically non-stop you have to throw in “one” and “two”, brake, reduce, etc.

The great advantage of automatic transmission is that it is possible to achieve a very smooth ride and reduce the load on the engine. And as a result, its service life is increased.

This does not mean that there are no disadvantages in case of automatic transmissions. For although by opting for such a transmission, you gain a longer lifespan for the drive unit itself, in the event of a breakdown, it can be expensive to repair. This is the result of a complex design, much more elaborate than, for example, in manual transmissions.