Abstract: A blower fan unit includes a housing, an impeller, an outlet, and a positioning mechanism. The impeller is mounted in the housing. The impeller rotates around a rotation center axis and generates an air current in a centrifugal direction from the rotation center axis. An outlet is formed in the housing and located in a centrifugal direction from the rotation center axis. A positioning mechanism is connected to the housing and makes the position of the housing change along the rotation center axis at each angular position around the rotation center axis.

Abstract: A blower fan unit includes a housing, an impeller, an outlet, and a positioning mechanism. The impeller is mounted in the housing. The impeller rotates around a rotation center axis and generates an air current in a centrifugal direction from the rotation center axis. An outlet is formed in the housing and located in a centrifugal direction from the rotation center axis. A positioning mechanism is connected to the housing and makes the position of the housing change along the rotation center axis at each angular position around the rotation center axis.

Abstract: A conductive roller is arranged so as to project from an opening of an upper surface of a circuit board unit removably accommodated in a rack. An opening of the rack is covered by a conductive thin plate. When the circuit board unit is accommodated in the rack, the roller fits in the opening of the rack and pushes the conductive thin plate. Thus, the circuit board unit and the rack are brought into electrical contact to perform electromagnetic shielding.

Abstract: A conductive roller is arranged so as to project from an opening of an upper surface of a circuit board unit removably accommodated in a rack. An opening of the rack is covered by a conductive thin plate. When the circuit board unit is accommodated in the rack, the roller fits in the opening of the rack and pushes the conductive thin plate. Thus, the circuit board unit and the rack are brought into electrical contact to perform electromagnetic shielding.

Abstract: A reservoir tank of the present invention employed in a liquid cooling system is provided with a plurality of outlets for feeding out the coolant and a plurality of inlets to which the coolant returns after cooling electronics devices. These outlets are provided at the center of bottom of the tank and these inlets are provided at the external circumference of the outlets. Incident angle of the inlets to the tank is inclined from the vertical line of tank so that the coolant generates a whirlpool around the vertical axis of tank. A cylindrical partition may be provided between the center of the bottom having the inlets and the circumferential part having the outlets, so as to prevent a short path of the coolant flowing from inlets to the outlets. In this case, holes may be provided at the partition so that the coolant stirred at the outside of partition flows to the outlets therethrough.

Abstract: A cooling system for an electronic apparatus which cools the electronic apparatus using a plurality of cooling fans and controls the rotational speed of the cooling fans in accordance with the temperature of apparatus to be cooled or the temperature of the inlet air or the air to be exhausted. Operation of the electronic apparatus may be continued with high reliability even when one or more fans fail by using simplified circuitry which causes other normal cooling fans to operate at full speed.