To prevent a sealing plate from falling down, the sealing plate serving to seal peripherally a gap formed between an outside element and an inside element.

There are disposed peripherally a plurality of base plates 38 each having a predetermined thickness, in which there is fixed a sealing plate 30 extending vertically and comprising thin plates extending vertically in a gap formed between an outside element and an inside element 28, and to an outer peripheral surface side stator 28a of the inside element 28 upper and lower portions of both width direction end surfaces of the base plate 38 are directly welded and fixed.