Abstract: A cylindrical case main body, and a connecting ring body fitted and fixed to a first end of the case main body and having an annular groove open in the centrifugal direction, are provided. The connecting ring body has a notch open to a side opposite to a second end of the case main body. Into the notch of the connecting ring body, a reinforcement body is fitted, and the reinforcement body has an arc-shaped groove continuing to the annular groove of the connecting ring body in a state where the reinforcement body is fitted into the notch of the connecting ring body. In addition to attaining high rigidity, reduction in weight and reduction in manufacturing cost can also be achieved.

Abstract: A cylindrical case body made of a composite material; a linking ring made of Al, which is fitted and fixed to a rear end portion of the case body and has an annular groove which receives a reverse thrust load from a reverse thrust transmission body; and ring constituent bodies made of Ti alloy, each of which is placed in the rear end portion of the case body and has an arcuate groove which undertakes a reverse thrust load larger than that received by the linking ring, are included. The ring constituent bodies are fitted in notches of the linking ring and are brought into contact with, and are fixed to, outward receiving walls of the linking ring, whereby the ring constituent bodies are positioned relative to the case body in the axis direction and in the radial direction respectively, and the annular groove and the arcuate grooves are allowed to continue to each other. The ring constituent bodies made of Ti alloy, which receive a large reverse thrust load, can be placed with high positioning accuracy.