Vibrations are caused by the sequence of impulses. In case of the vibrations connected with the speed of the movement, these impulses are generated by an imbalance of any element rotating together with a wheel which is transferred to the corresponding suspension bracket of wheels. Frequency of these impulses changes with a speed of the movement. Usually they are extinguished thanks to special the picked-up design of elements and support of a suspension bracket, except vibrations of strictly certain frequency of "own fluctuations of a suspension bracket" which depend on its longitudinal rigidity. The moments of emergence of own fluctuations of forward and back suspension brackets usually strongly differ and they can be expressed through the speed of the movement as "the swing radius" of wheels does not change.

The number of impulses for one turn of a wheel is the relation between the moment of emergence of own fluctuations of the corresponding suspension bracket expressed through the speed of the movement and the speed of the movement at the time of emergence of vibrations (see the table of emergence of own fluctuations of forward and back suspension brackets of cars which the real Technical note concerns).

There are two types of an imbalance.

– Unbalance: an imbalance of masses = one impulse on a wheel turn.

– Radial beating: geometrical deformation = one or several impulses on a wheel turn.

Vibrations arise on the following knots and details:

– the rotating elements (tires, disks of wheels, decorative caps of wheels, brake mechanisms, shaft of the drive of wheels, a hollow semi-axial gear wheel of differential of the MKP open type);

– the damping elements (shock-absorbers, fastenings and/or the damping elements of a suspension bracket, a stretcher, the rack steering mechanism, a steering column, seats, etc.).