Base unit and disk drive apparatus

1. A base unit for use in a disk drive apparatus in which a gas having a density lower than that of air is sealed in a housing space defined by a base member and a cover fixed to each other, the base unit comprising:

the base member, the base member being arranged to support a motor rotatable about a central axis extending in a vertical direction; and

a connector electrically connected to a wire arranged in the housing space; wherein

the base member includes:

a recessed portion arranged to extend in radial directions and recessed upward from a lower surface of the base member, the radial directions being directions perpendicular to the vertical direction or directions parallel to these directions; and

a hole portion arranged to pass through the recessed portion in the vertical direction;

the recessed portion includes a recessed portion loop-shaped surface being a loop-shaped surface perpendicular to the vertical direction;

the connector is arranged on a lower side of the recessed portion to cover the hole portion;

an adhesive is arranged between the connector and the recessed portion;

a minimum value of a gap distance between an outer end of the connector and an inner end of the recessed portion in a radial direction in which the outer end of the connector and the inner end of the recessed portion are opposed to each other with the adhesive therebetween is greater than a minimum value of a gap distance between an upper surface of the connector and the recessed portion loop-shaped surface in the vertical direction, in which the upper surface of the connector and the recessed portion loop-shaped surface are opposed to each other with the adhesive therebetween; and

the adhesive includes at least one of a class bead and a metal filler.

2. The base unit according to claim 1 , wherein a surface of the adhesive on a side closer to the hole portion is defined between the upper surface of the connector and the recessed portion loop-shaped surface.

3. The base unit according to claim 2 , wherein

the recessed portion loop-shaped surface includes a first recessed portion loop-shaped surface, and a second recessed portion loop-shaped surface arranged on a side of the first recessed portion loop-shaped surface closer to the hole portion; and

the surface of the adhesive is defined at the second recessed portion loop-shaped surface.

4. The base unit according to claim 1 , wherein at least a portion of a surface of the adhesive on a side opposite to a side closer to the hole portion is defined between the upper surface of the connector and the recessed portion loop-shaped surface.

5. The base unit according to claim 1 , wherein

the base member includes a collar portion recessed upward and arranged to project in a radial direction from an outer circumference of the recessed portion;

an extent to which the collar portion is recessed is smaller than an extent to which the recessed portion loop-shaped surface is recessed in the recessed portion; and

the connector includes a projecting portion arranged to project in the radial direction from an outer circumference thereof to be arranged in the collar portion.

6. The base unit according to claim 1 , wherein the recessed portion loop-shaped surface is arranged to have a degree of surface roughness greater than a degree of surface roughness of the upper surface of the connector.

7. The base unit according to claim 1 , wherein each of the outer end of the connector and the inner end of the recessed portion is arranged to have a degree of surface roughness greater than a degree of surface roughness of the upper surface of the connector.

8. A disk drive apparatus comprising:

the base unit of claim 1 ;

the cover;

the motor; and

an access portion arranged to perform at least one of reading and writing of information from or to a disk supported by the motor; wherein the motor and the access portion are accommodated in the housing space.