You're talking about that little thing on the casing of the fan motor. Press it to swing the head of the motor and change the wind direction. Lift the motor, stop shaking your head and reach a fixed wind direction?

The swing function of ordinary electric fans is realized by the swing mechanism. The swinging mechanism is mainly composed of a reduction box, a swinging connecting rod and a control mechanism. The gearbox reduces the high speed of the motor to 5-6 rpm. The swinging linkage mechanism is composed of a connecting rod and a swinging rod, and is connected by a crankshaft to drive swinging positioning, so that the fan head moves along an arc trajectory. That little thing on the motor housing is the controller used to control the separation and meshing of gears, just like the clutch of a car. Press the gear to bite, the motor swings its head and the wind direction changes. The motor stops swinging when the landing gear is lifted.