Patent ID: 8460117
Filing Date: 2013-06-11
Classification: F16D,H05K

Abstract:
1. A power transmission device comprising: an electromagnetic wave-shielding wall partitioning a first space and a second space adjacent to said first space and blocking propagation of an electromagnetic wave between said first space and said second space; a rotating shaft rotatably provided and penetrating through said electromagnetic wave-shielding wall to transmit rotational drive force between said first space and said second space; and a bearing rotatably supporting said rotating shaft, said rotating shaft including a first shaft member supported by said bearing, a shaft joint part provided on an end of said first shaft member on said second space side, and a second shaft member provided to be rotatable together with said first shaft member with said shaft joint part interposed between said first and second shaft members, said first shaft member and said second shaft member being formed of a conductive material, said shaft joint part having an insulating part formed of an insulating material and blocking propagation of an electromagnetic wave between said first shaft member and said second shaft member, said bearing including an inner race component part and an outer race component part arranged opposite to each other, said inner race component part being formed to fit to said first shaft member and to be rotatable, said outer race component part being formed of a conductive material, being fixed to said electromagnetic wave-shielding wall, and having an annular close-contact surface in close contact with said electromagnetic wave-shielding wall, said rotating shaft further includes another shaft joint part provided on another end opposite to said end of said first shaft member and a third shaft member provided to be rotatable together with said first shaft member with said another shaft joint part interposed between said first and third shaft members, said third shaft member is formed of a conductive material, said another shaft joint part has another insulating part formed of an insulating material and blocking propagation of an electromagnetic wave between said first shaft member and said third shaft member, and said power transmission device further including comprising another bearing supporting said third shaft member, wherein said another bearing includes another inner race component part arranged opposite to said outer race component part and formed to fit to said third shaft member and to be rotatable, and said outer race component part is arranged to cover entire outer circumferential surface of said rotating shaft from said bearing to said another bearing.