The sequential gearbox is an attempt by designers to combine the advantages of an automatic and a manual gearbox in one product. The experiment can be considered successful, but the new unit has its own design and operation features.
In translation, sequensum means "sequence". A sequential gearbox can be considered a mechanical unit in which a separate device controls the clutch. That is, in a car equipped with the described gearbox, there will also be 2 pedals, as in a car with an “automatic”, but the gears must be switched manually (in some cases, automatic switching is also possible).
Principle of operation
When you turn on the gear yourself and press the gas pedal, special sensors inform the electronic unit, which transmits a signal to the box. It also has sensors that transmit their signal about the speed of the car to the progressive block. The latter, in turn, makes adjustments to the speed limit, coordinating the work of the gearbox mechanisms. This takes into account the number of revolutions of the engine, the operation of the air conditioner and the readings on the instrument panel.
Gear shifting is carried out by means of servo drives (actuators), which are hydraulic on the sequential box. If the servos are electric, then such a gearbox is called robotic (in practice, the gearbox with both hydraulics and electric actuators is called robotic). The command to change gear is given by the driver in manual mode or using the on-board computer.
Features of sequential gearbox operation
The principles of operation resemble an automatic transmission, however, the sequential unit is characterized by the efficiency and reliability inherent in a manual transmission. Moreover, the "robot" is much cheaper than the "machine". The main feature of the sequential box is the ability to switch from low gear to high without losing speed, which invariably drops when using a mechanical unit. On a number of modern cars, the sequential gearbox is controlled by buttons located on the steering wheel, which allows you to switch without taking your hands off the steering wheel.
Another plus for cars equipped with a "robot" is lower fuel consumption when compared with an automatic transmission. The lack of a third pedal helps beginners get up to speed quickly, while experienced drivers can choose between manual and automatic gearshifts.
The disadvantage of robotic boxes is low wear resistance, which is especially pronounced under heavy loads or an aggressive driving method. Therefore, when operating this type of gearbox in manual mode, it is important to switch from one speed to another in time (you need to feel the moment). Otherwise, breakdowns are inevitable, and the repair of the "robot" is quite expensive.
