Abstract: A wheel resonator, which is provided by integrating a first member having a first welding surface with a second member having a second welding surface and includes a volume chamber and a communicating tube. The volume chamber has a flat shape and is configured to extend along an outer surface of a vehicle wheel when the wheel resonator is attached to the vehicle wheel. The first welding surface and the second welding surface are welded to each other, and are provided on a single welding plane. The welding plane extends in a circumferential direction and a width direction of the vehicle wheel when the wheel resonator is attached to the vehicle wheel, is a plane on which the volume chamber is divided into two volume portions, and is a plane on which the communicating tube is divided into two communication portions. The communicating tube extends along the welding plane.

Abstract: A wheel resonator, which is provided by integrating a first member having a first welding surface with a second member having a second welding surface and includes a volume chamber and a communicating tube. The volume chamber has a flat shape and is configured to extend along an outer surface of a vehicle wheel when the wheel resonator is attached to the vehicle wheel. The first welding surface and the second welding surface are welded to each other, and are provided on a single welding plane. The welding plane extends in a circumferential direction and a width direction of the vehicle wheel when the wheel resonator is attached to the vehicle wheel, is a plane on which the volume chamber is divided into two volume portions, and is a plane on which the communicating tube is divided into two communication portions. The communicating tube extends along the welding plane.

Abstract: A filter element comprises an oil-impregnated filtering member, and a transmission preventing layer formed on a downstream side of the filtering member, for restricting transmission of at least the carbon dusts from the oil-impregnated filtering member. The filtering member may be formed like a ridge-like-folded structure. The transmission preventing layer may be formed of a coating layer having a resistance against a viscous oil that is impregnated in the filtering member. This coating layer may be formed uniformly as a whole or the thickness or the content of the coating layer may be increased partially. A ventilation shutting-off member (filling layer) may be formed as the transmission preventing layer in the root portion areas of the ridge portions. The transmission preventing layer may comprise a resistant component that is insoluble in the oil that is impregnated in the filtering member.

Abstract: A filter element comprises an oil-impregnated filtering member, and a transmission preventing layer formed on a downstream side of the filtering member, for restricting transmission of at least the carbon dusts from the oil-impregnated filtering member. The filtering member may be formed like a ridge-like-folded structure. The transmission preventing layer may be formed of a coating layer having a resistance against a viscous oil that is impregnated in the filtering member. This coating layer may be formed uniformly as a whole or the thickness or the content of the coating layer may be increased partially. A ventilation shutting-off member (filling layer) may be formed as the transmission preventing layer in the root portion areas of the ridge portions. The transmission preventing layer may comprise a resistant component that is insoluble in the oil that is impregnated in the filtering member.