If you've ever driven a car with a broken rear shock absorber, you can experience the bounce that the shock absorber is designed to suppress as it bounces through every pothole, rippling in its wake. When the frame and the bridge do reciprocating relative movement and the piston in the shock absorber cylinder reciprocating movement, the oil in the shock absorber shell will repeatedly from the inner cavity through some narrow pores into another inner cavity. At this point, the friction between the liquid and the inner wall and the internal friction of the liquid molecules will form a damping force for vibration.