| 摘要 |
PROBLEM TO BE SOLVED: To prevernt rotation of a drum from being stopped by contact with a casing by fixing a cushioning member having a rising wall part with a thickness almost equal to a space between a drum end face and a casing face, rigidly to the casing face. SOLUTION: At the time of installing a casing 1, a cushioning member 20 formed of wear resistant resin with a thickness almost equal to a space L to one end face 2b of a perforated drum 2 charged with a mixture is formed in ring shape with almost the same diameter as the end face 2b so as to cover the whole end face 2b excluding an opening part 2c. The inner peripheral edge part of the cushioning member 20 is formed to protrude into the perforated drum 2 so as to provide a rising wall part 24 brought close to a peripheral edge part 2f of the opening part 2c. The space L between the perforated drum 2 and the casing 1 can therefore be always filled up with the cushioning member 20, and even in case the space dimensions change, the generation of a clearance between the end face 2b and the cushioning member 20 can be prevented by the rising wall part 24. |
