CPC F04D 29/054 (2013.01) [F04D 19/002 (2013.01)] | 6 Claims |
1. A fan, comprising:
a shaft comprising an outer peripheral surface that comprises:
a first circular-arc portion; and
a first flat portion; and
a boss portion comprising a fitting hole with an inner peripheral surface that comprises:
a second circular-arc portion; and
a second flat portion, wherein
the second circular-arc portion corresponds to the first circular-arc portion,
the second flat portion corresponds to the first flat portion,
the second flat portion comprises a notch in an end portion in a width direction of the second flat portion,
the notch of the second flat portion comprises a notch surface that forms a pressure receiving surface where the notch of the second flat portion is in surface contact with the first flat portion when the shaft rotates, and
when viewed in an axial direction of the shaft, a length of a portion where the notch of the second flat portion and the first flat portion contact each other during rotation of the shaft is longer than a distance between the first flat portion and the second flat portion when the shaft stops.
|