It is shown in fig. 5 that the maximum stress is 57.52MPa, which occurs at the contact position between shear cylinder and wing boards. In addition, bottom of the region where the wing boards being welded with the front plate is a relatively larger stress area.As it shown in fig. 6 that the maximum displacement is 0.377mm, which occurs at the lower end of the intermediate position of the front plate. The upper end of the intermediate position and the two ribs are also the bigger displacement area.