Disk device with constrained layer configurations between inner and outer covers

1 . A disk device comprising:

a magnetic disk;

a housing that includes a base, a first cover, and a second cover, the base being provided with a housing space in which the magnetic disk is disposed, the first cover being mounted on the base to cover the housing space, the second cover being mounted on the base to cover the first cover;

a constrained layer that includes a first face and a second face, the first face facing the first cover, the second face being located opposite to the first face, facing the second cover, and being inclined to the first face; and

a first adhesive material that is interposed between the first face and the first cover, wherein

the magnetic disk is configured to rotate around a first rotation axis,

the constrained layer extends around the first rotation axis, and

an outer diameter of the constrained layer is smaller than an outer diameter of the magnetic disk.

2 . The disk device according to claim 1 , further comprising

a sealing material, wherein

the first cover is provided with a first vent hole that connects a clearance between the first cover and the second cover to the housing space,

the second cover is provided with a second vent hole that connects the clearance to an outside, and is sealed by the sealing material,

the constrained layer and the first adhesive material are disposed in the clearance, and

the housing space and the clearance are filled with gas that is different from air.

3 . The disk device according to claim 1 , wherein

the second cover is welded to the base.

4 . The disk device according to claim 1 , wherein

the second face is inclined to the first face in such a way that a distance between the first face and the second face decreases outward in a radial direction that is orthogonal to the first rotation axis.

5 . The disk device according to claim 1 , further comprising

a second adhesive material that bonds the second cover to the second face.

6 . The disk device according to claim 1 , further comprising:

a head stack assembly that includes a magnetic head and a carriage, the magnetic head being configured to read and write information from or to the magnetic disk, the carriage being configured to move the magnetic head around a second rotation axis;

a voice coil motor that rotates the carriage around the second rotation axis; and

a second constrained layer overlapping the voice coil motor in a direction along the second rotation axis.

7 . The disk device according to claim 1 , wherein

the base includes a bottom face and a side wall, the bottom face facing the magnetic disk, the side wall protruding from the bottom face, and surrounding the magnetic disk, and

the second face is inclined to the first face in such a way that a distance between the first face and the second face decreases toward the side wall.

8 . The disk device according to claim 1 , wherein

the constrained layer includes an end face that is provided at an end of the constrained layer in a direction along the first face, and

the second face is inclined to the first face in such a way that a distance between the first face and the second face decreases toward the end face, and is connected to the end face.

9 . The disk device according to claim 1 , wherein

the first cover is provided with a recess, and

at least a portion of the constrained layer and the first adhesive material are housed in the recess.