Abstract: A housing lining for a piston engine, drive motor, or machine composed of a sound-absorbent layer of fibers. The fibers are compressed and glued to form an essentially pore-free supporting frame at least in the vicinity of the edge of the layer.

Abstract: A housing lining for a piston engine, drive motor, or machine composed of a sound-absorbent layer of fibers. The fibers are compressed and glued to form an essentially pore-free supporting frame at least in the vicinity of the edge of the layer.

Abstract: A noise damper comprising a molded part of polymer material having at least two chambers which are designed as resonators with resonant frequencies that differ from one another. The molded part consists of a closed-cell material. The resonators are formed of essentially cup-shaped protrusions that open toward the sound source, the molded part on the side facing the sound source being covered by an orifice plate comprising at least two openings leading into each chamber. The molded part and the orifice plate are detachably joined together.

Abstract: A panel element for insulating acoustically undesirable vibrations is disclosed. The panel element comprises a closed-cell foam element for closing off a hollow body provided with an opening on at least one side. The foam element possesses a mounting structure by which it can be fastened to the hollow body. The foam element is configured to the shape of the opening, and has on its perimeter a mounting structure. The mounting structure consists of a self-contained peripheral groove open in the direction of the boundary. The groove and the boundary can be brought into engagement with one another in a sealing and positive manner.

Abstract: A wheel lining with a structure made of a polymer, mounted at a distance from wheel, self-supporting, and impermeable to air. The lining is double-walled and incorporates at least two chambers. The walls of the chambers the facing the wheel are provided with at least one opening each to form Helmholtz resonators.

Abstract: A housing lining is disclosed with a self-supporting and airborne sound-absorbing layer of fibers. The fibers are compressed and glued together at least in the region of the edge surrounding the layer on the outside, to form an essentially pore-free supporting frame. The supporting frame may be provided with a cup-shaped bulge which comprises sound absorption surfaces which have a sound impedance of 20 to 200 Rayl.

Abstract: A bellows that is affixable by way of a connecting sleeve to a machine part, and is made of polymer material and has folds formed, at least in one partial area, in the shape of a screw thread. The connecting sleeve is provided with at least two retaining elements that are distributed in the circumferential direction and project inwardly and/or outwardly from the top surface of the connecting sleeve, the retaining elements being able to be forced into engagement with snap-in locking elements of the machine part, which exhibit a groove following the direction of the folds.