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7 LABORATORY WORK № 4
GEAR BOX

7.1 The purpose of the work. Study of the structure of the
gearbox of the car.
7.2 Knowledge and skills. As a result of laboratory work
the student must know:
- typical location of transmission elements;
- structure of elements of transmissions of different types;
- Acquisition of disassembly and assembling of gearboxes.

7.3 General Terms and Conditions. The gearbox is
designed to change in a wide range of torque transmitted from
the engine to the driving wheels of the vehicle when moving
from position and overclocking. In addition, the gearbox
provides reverse gear and allows for long periods of time to
disconnect the engine and drive wheels required when the
engine is idling while driving or in the parking lot.
On modern domestic cars predominantly mechanical step
gears with toothed gears are used. The number of forward gears
is usually equal to four or five (excluding back gear).
Transmissions are switched by moving gears that
alternately engage with other gears, or locking the gears on the
shaft using synchronizers. The synchronizers align the
rotational speed of the gears that are activated, and block one of
them with the driven shaft. The gears or synchronizers are
driven by the driver when the coupling is off.
Depending on the number of gears in the forward gear of
the gearbox, there are three-stage, four-step, etc. The main
details of the three-speed gearbox (Figure 7.1): drive shaft 1,
driven shaft 5, intermediate shaft 6, mounted in the box case.

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