Abstract: According to an embodiment, a bush includes a first member, a second member, and a third member. The first member is provided with a first hole having a first axis, and has a first outer surface having a second axis different from the first axis. The second member is provided with a second hole in which the first member is housed, and has a second inner surface that is in contact with the first outer surface and a second outer surface having a third axis different from the second axis. The third member is provided with a third hole in which the second member is housed and has a third inner surface that is in contact with the second outer surface.

Abstract: According to an embodiment, a high-rigidity plate includes: a first protrusion including a first top wall configured to support a vibration member and a first circumferential wall connected with an outer circumferential edge of the first top wall, the first protrusion being configured to protrude inside a housing or outside the housing; an intermediate part disposed at a position surrounding the first top wail when viewed along a first direction and connected with the first circumferential wall via a first bend; and an annular second protrusion including a second top wall disposed at a position surrounding the first top wall when viewed along the first direction and a second circumferential wall connected with the intermediate part via a second bend and connected with an inner circumferential edge of the second top wall, the second protrusion being configured to protrude inside the housing or outside the housing.

Abstract: According to an embodiment, a bush includes a first member, a second member, and a third member. The first member is provided with a first hole having a first axis, and has a first outer surface having a second axis different from the first axis. The second member is provided with a second hole in which the first member is housed, and has a second inner surface that is in contact with the first outer surface and a second outer surface having a third axis different from the second axis. The third member is provided with a third hole in which the second member is housed and has a third inner surface that is in contact with the second outer surface.

Abstract: According to an embodiment, a shower plate includes a first member and a second member. The first member includes a first wall provided with a plurality of first openings and internally including a room with which the first openings communicate. The second member includes a second wall provided with a second opening and arranged in the room. The second member is arranged at a position spaced apart from the first member, and allows one of the first openings facing the second opening to be replaced with another of the first openings by changing a position of the second member with respect to the first member.