Breakdown of the gearbox.
We call gradual gearboxes, which have a specific and limited number of different gear ratios (degrees) between the engine crankshaft and the car propeller shaft. This gradualness is achieved by means of a number of gears, which, depending on the driving resistance, can be activated while the vehicle is moving. Therefore, with the same torque on the engine crankshaft can be obtained, depending on the ratio of the gears engaged, different values ​​of the torque on the driving wheels of the car changing in proportion to the ratios.
Continuously variable gearboxes are called gearboxes, by means of which an infinitely large number of gear ratios between the engine crankshaft and the driving wheels of the car are achieved, the gear shifting takes place continuously. Finding the ratio appropriate for given motion conditions between the torque on the engine crankshaft and the torque on the driving wheels of the car takes place automatically in most cases. This is due either to the design of the gearbox itself, or by using special auxiliary devices. The continuously variable transmissions may be mechanical, electric or hydraulic.