Abstract: A power transmission device includes an electromagnetic wave-shielding wall partitioning a first space and a second space adjacent to the first space and blocking propagation of an electromagnetic wave between the first space and the second space. The power transmission device also includes a first pulley arranged within the first space and a second pulley arranged within the second space. The power transmission device also includes a belt placed on the first pulley and the second pulley and extending through the electromagnetic wave-shielding wall to transmit rotational driving force between the first space and the second space. From the electromagnetic wave-shielding wall a hollow tubular member is protruded and allows the first space and the second space to communicate with each other. The belt extends through the inside of the tubular member.

Abstract: A power transmission device that includes an electromagnetic wave-shielding wall partitioning a space and a space, a rotating shaft penetrating through the electromagnetic wave-shielding wall to transmit rotating drive force, and a bearing supporting the rotating shaft. The rotating shaft includes a first shaft member supported by the bearing, a shaft joint part provided on an end of the first shaft member, and a second shaft member rotating together with the first shaft member. The first shaft member and the second shaft member are formed of a conductive material, and the shaft joint part has an insulating part formed of an insulating material. An outer race component part of the bearing has an annular close-contact surface formed of a conductive material.

Abstract: Provided is a power transmission device in which leakage of an electromagnetic wave between a space (1) and a space (2) can be suppressed. The power transmission device includes an electromagnetic wave-shielding wall (10) partitioning the space (1) and the space (2), a rotating shaft (20) penetrating through the electromagnetic wave-shielding wall (10) to transmit rotating drive force, and a bearing (80) supporting the rotating shaft (20). The rotating shaft (20) includes a first shaft member (30) pivotally supported by the bearing (80), a shaft joint part (50) provided on an end (31) of the first shaft member (30), and a second shaft member (40) rotating together with the first shaft member (30). The first shaft member (30) and the second shaft member (40) are formed of a conductive material, and the shaft joint part (50) has an insulating part (51) formed of an insulating material.

Abstract: A power transmission device includes an electromagnetic wave-shielding wall partitioning a first space and a second space adjacent to the first space and blocking propagation of an electromagnetic wave between the first space and the second space. The power transmission device also includes a first pulley arranged within the first space and a second pulley arranged within the second space. The power transmission device also includes a belt placed on the first pulley and the second pulley and extending through the electromagnetic wave-shielding wall to transmit rotational driving force between the first space and the second space. From the electromagnetic wave-shielding wall a hollow tubular member is protruded and allows the first space and the second space to communicate with each other. The belt extends through the inside of the tubular member.

Abstract: In a switchgear, by using a spring with a varying spring constant from closing to electrode opening as a loading spring, spring load in the opened electrode state is made smaller than a spring load in the closed electrode state to decrease the energy required from electrode closing up to electrode opening. Moreover, by using a spring in which a load in the opposite direction to a load in the closed electrode state works in the opened electrode state, the opened electrode state can be held securely.

Abstract: In a switchgear, by using a spring with a varying spring constant from closing to electrode opening as a loading spring, spring load in the opened electrode state is made smaller than a spring load in the closed electrode state to decrease the energy required from electrode closing up to electrode opening. Moreover, by using a spring in which a load in the opposite direction to a load in the closed electrode state works in the opened electrode state, the opened electrode state can be held securely.