According to the air pressure form of the differential shaft , the differential shaft can be divided into a central air pressure differential shaft, a pneumatic side pressure differential shaft, a mechanical side pressure differential shaft and an air expansion shaft . The ball type differential shaft belongs to the central air pressure differential shaft. The central air pressure differential shaft is divided into the start locking central air differential shaft and the mechanical locking central air pressure differential shaft. The ball type differential shaft belongs to the pneumatic differential shaft of the mechanical locking center.

The shape of the ball-type differential shaft is characterized by the convex rolling beads on the slip ring, which is also named after it. Its structure is very similar to the key differential shaft, but it is somewhat different in function.