Aero-engine inner casing, inter-stage casing and aero-engine

The utility model relates to an aero-engine inner casing, an interstage casing and an aero-engine, the aero-engine inner casing comprises a first part (10) and a second part (20) which are split, the first part (10) and the second part (20) are fixedly connected, and a formed integral structure is provided with an inner ring (11), an outer ring (12), a first end wall (13) and a second end wall (14), the first end wall (13) is connected with the first ends, in the axial direction of the inner casing (1), of the inner ring (11) and the outer ring (12), the second end wall (14) is connected with the second ends, in the axial direction of the inner ring (11) and the outer ring (12), of the inner ring (11) and the outer ring (12), and a cavity (Q) is defined by the inner ring (11), the outer ring (12), the first end wall (13) and the second end wall (14). 本公开涉及一种航空发动机内机匣、级间机匣及航空发动机，其中，航空发动机内机匣包括：分体的第一部分(10)和第二部分(20)，第一部分(10)和第二部分(20)固定连接，且形成的整体结构具有内环(11)、外环(12)、第一端壁(13)和第二端壁(14)，第一端壁(13)连接在内环(11)与外环(12)沿内机匣(1)轴向的第