(1) the cross-section shrinkage of the elliptic curve barrel is lower than that of the arc-shaped deep drawing barrel, that is to say, the product of the elliptic sections changes slowly, thus reducing the extrusion pressure of the barrel wall materials in the process of excavation.Good for discharging material in hopper.In the change of elliptic curvature, only in arc A n, the curvature of the curve at the barrel end is greater than that of the arc curve, and the projection of the curve on the X-axis only accounts for about one fourth (L) of the length of the barrel, and the remaining three quarters are more stable than the change of the arc.It can meet the requirement of fast and clean discharge of bucket.