According to the mid - length and long runners suffer frequently from the fatigue periostitis of tibia, It directly training the exercising and the progress of the result, I discuss the reason why it happens and state the effective methods to deal with it.

Against the problem that the bed of the four-row short cylinder rolling bearing inoverhang mill in high-speed wire plant cannot be automatically positioned, the wide barrel rolling bearingwas developed to substitute the original one to solve short working-life and rubber-buming of bearingunder abnormal uneven load.