A base member includes a recessed portion extending in radial directions and recessed upward from a lower surface of the base member, and a hole extending through the recessed portion in the vertical direction. The recessed portion includes a recessed portion loop-shaped surface defining a loop-shaped surface in the radial direction. A connector is located on a lower side of the recessed portion to cover the hole portion. An adhesive is located between the connector and the recessed portion. A minimum value of a gap distance in the radial direction between an outer end of the connector and an inner end of the recessed portion 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 in the vertical direction distance between an upper surface of the connector and the recessed portion loop-shaped surface, in which the upper surface of the connector and the recessed portion loop-shaped surface are opposed to each other with the adhesive therebetween. The adhesive includes a filler.