Automobile Ball Joint
The Ball Joints are spherical bearings that connect control arms to steering knuckles. They are used in all Vehicles and work similarly to the ball-and-socket design of the human hip joint. The Ball Joint has a round, ball-like head that swivels inside a cup-like socket.
The Ball Joint allows free movement in two planes at the same time, including rotation in those planes. Combining two such joints with control arms enables motion in all three planes, allowing the front end of an automobile to be steered along with a spring and shock suspension to enhance the ride quality and make it comfortable.
The Ball Joint are the pivot points for the front wheels in nearly all modern vehicles. While using its predecessor Kingpin Style Suspension, the freedom in Suspension design using it was very limited, but by using ball joints on top and bottom allows for 3-axis motion and so removes all the constraints on the control arm axes being exactly parallel, so caster can be freely adjusted, typically by asymmetric adjustment of the position of the control arm inner pivots, while camber can be adjusted by the symmetric adjustment of these same pivots.
This ability to comfortable fine-tune Ball-Jointed suspension allows manufacturers to make the automobile stable, quieter, and easier to steer, compared to the older kingpin style suspension. The smoother ride also increases tire tread life, since the ball-joint suspension allows better control of suspension geometry and provides better tire to road contact.