Abstract: A bearing structure includes a housing having a bore that penetrates the housing, a rotation shaft inserted into the bore, an annular first metal bearing and an annular second metal bearing, which are provided apart from each other in an axial direction in the bore and rotatably support the rotation shaft, and a ventilation passage provided in the housing. The ventilation passage is formed on the housing-side contact surfaces which are formed on an inner surface of the housing, and bypasses at least one of the first metal bearing and the second metal bearing. Through ventilation passage, a closed area sandwiched between the both first metal bearing and second metal bearing inside the bore communicates with an outside area.

Abstract: A motor-operated fan apparatus is made up of a brushless motor and a centrifugal fan. The brushless motor has: a rotary shaft vertically disposed on a substrate in a rotatable manner; a stator disposed coaxially with the rotary shaft; and a rotor integrally disposed on the rotary shaft. The centrifugal fan has: a disk part which covers the brushless motor and is fixed to the rotary shaft; and a multiplicity of vane parts which are disposed so as to be elongated from an outer edge of the disk part. A ventilation control member is provided in a space between the rotor and the disk part to block the air flowing from the substrate side to the space between the rotor and the disk part.

Abstract: An electric motor comprises a yoke in which permanent magnets are held, the yoke including a cylindrical yoke body having a bottom and an auxiliary yoke in which the yoke body is fitted, at least one engaging opening provided in one of said yoke body and auxiliary yoke and a deformable band provided in the other of said yoke body and auxiliary yoke. The deformable band is fitted in the engaging opening in a state that the yoke body and auxiliary yoke are fitted.

Abstract: An electric motor comprises a yoke in which permanent magnets are held, the yoke including a cylindrical yoke body having a bottom and an auxiliary yoke in which the yoke body is fitted, at least one engaging opening provided in one of said yoke body and auxiliary yoke and a deformable band provided in the other of said yoke body and auxiliary yoke. The deformable band is fitted in the engaging opening in a state that the yoke body and auxiliary yoke are fitted.

Abstract: A brushless motor for a blower fan unit has a circuit structure constituted by a drive control circuit and a fuse member. The drive control circuit supplying drive current comprises a first circuit section for eliminating surges of electric power and a second circuit section for controlling magnetic field generated by the stator. The first and second circuit sections are three-dimensionally arranged with a predetermined space therebetween. The fuse member electrically connects the first and second circuit sections. An end portion of the fuse member is welded with the first circuit section, and the other end portion of the fuse member is soldered with the second circuit section. The fuse member cuts an electrical connection between the first and second circuit sections when a temperature of solder becomes higher than a predetermined temperature.

Abstract: A brushless motor for a blower fan unit is comprised of a heat sink which has a heat radiating portion and a pair of supporting legs extending from both opposite sides of the heat radiating portion. A free end portion of each supporting leg is in contact with an electric circuit board. A pressing member has a pressing portion, a pair of positioning portions perpendicularly extending from opposite end portions of the pressing portion, and a pair of connecting portions projecting from the pair of positioning portions respectively. The connecting portions are engaged with supporting legs of the heat sink respectively. The pressing portion presses switching devices to the heat sink. The positioning portions are inserted into the through-holes of the electric circuit board respectively.

Abstract: A brushless motor for a blower fan unit has a circuit structure constituted by a drive control circuit and a fuse member. The drive control circuit supplying drive current comprises a first circuit section for eliminating surges of electric power and a second circuit section for controlling magnetic field generated by the stator. The first and second circuit sections are three-dimensionally arranged with a predetermined space therebetween. The fuse member electrically connects the first and second circuit sections. An end portion of the fuse member is welded with the first circuit section, and the other end portion of the fuse member is soldered with the second circuit section. The fuse member cuts an electrical connection between the first and second circuit sections when a temperature of solder becomes higher than a predetermined temperature.

Abstract: A brushless motor for a blower fan unit is comprised of a heat sink which has a heat radiating portion and a pair of supporting legs extending from both opposite sides of the heat radiating portion. A free end portion of each supporting leg is in contact with an electric circuit board. A pressing member has a pressing portion, a pair of positioning portions perpendicularly extending from opposite end portions of the pressing portion, and a pair of connecting portions projecting from the pair of positioning portions respectively. The connecting portions are engaged with supporting legs of the heat sink respectively. The pressing portion presses switching devices to the heat sink. The positioning portions are inserted into the through-holes of the electric circuit board respectively.

Abstract: A power element mounting structure for use in a brushless motor comprises a circuit board; a spring plate of metal, the spring plate being resiliently mounted, through a first mounting structure, on the circuit board keeping a given space therebetween; a plurality of power elements disposed on the spring plate to form a semi-assembled unit; a heat dissipation member of metal having a plurality of heat dissipation fins on an outer surface thereof, the heat dissipation member being mounted, through a second mounting structure, on the semi-assembled unit in such a manner that an inner surface thereof faces toward the power elements; and a plurality of spring pieces defined by the spring plate, the spring pieces being arranged to press the power elements against the inner surface of the heat dissipation member.

Abstract: A power element mounting structure for use in a brushless motor comprises a circuit board; a spring plate of metal, the spring plate being resiliently mounted, through a first mounting structure, on the circuit board keeping a given space therebetween; a plurality of power elements disposed on the spring plate to form a semi-assembled unit; a heat dissipation member of metal having a plurality of heat dissipation fins on an outer surface thereof, the heat dissipation member being mounted, through a second mounting structure, on the semi-assembled unit in such a manner that an inner surface thereof faces toward the power elements; and a plurality of spring pieces defined by the spring plate, the spring pieces being arranged to press the power elements against the inner surface of the heat dissipation member.