| 摘要 |
PROBLEM TO BE SOLVED: To make a roller conveyable in a low noise by installing a lining layer by means of a high polymer viscoelastic material on the inner circumferential surface of a drum outer hull, further laminating it on the inner circumferential surface of this lining layer, and also installing an inner surface layer by means of a material being larger in acoustic impedance than the high polymer viscoelastic material. SOLUTION: A lining layer 2 by means of a high polymer viscoelastic material is installed on an inner circumferential surface of a metal drum outer hull 1, and further it is laminated on an inner circumferential surface of the lining layer 2 and an inner surface layer 3 by means of a material being large in acoustic impedance is installed. Here, a vibration produced by conveyance or the like of a hard member is propagated to the lining layer 2 consisting of the high polymer viscoelastic material as an elastic wave, and thereby in the layer, the vibration is absorbed into wane owing to viscoelasticity of the lining layer 2 as repeating the reflection in space between interfaces (a boundary surface 4 with the drum outer hull as well as a boundary surface 5 with the inner surface layer) at both sides consisting of coming into contact with a layer being larger in the acoustic impedance than the layer, and thus any possible noises is held down to lowness. In this connection, the lining layer is 3 to 15 N/cm<2> or so in compressive hardness, and thickness of the inner surface layer should be set to a range of 30 to 1000μm.
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