1. Due to there is no manufacture of differential shafts in the past few years, all of them relied on imports, and the price was expensive, which caused great economic pressure to the enterprises to be used and gave up using them.

2. Because the product grade of the enterprise is not high, the requirement for mechanical slitting is not high, the ordinary air expansion shaft and mechanical differential shaft can meet the basic use requirements, and the production scale of the enterprise is not large, the production pressure is not large, and there is no desire for urgent improvement, so they are not applied.

3. The propaganda of domestic manufacturers is not enough, and the supporting services are still insufficient.

4. Most manufacturers do not know enough about the functional differences between the air expansion differential shaft and the mechanical differential shaft and the ordinary air expansion shaft, especially do not have a clear understanding of the performance-price ratio of the air expansion differential shaft and other shafts, so they only think that the price of the air expansion differential shaft is higher, and there is no urgent requirement for enterprises to upgrade their products and maximize their benefits.

Knowledge of the air expansion shaft first need to rely on the slow accumulation of time in the process of operation, to understand the need for attention, when the operation of skilled time to understand its various problems, it is bound to be handy.