Abstract: A centrifugal fan that is light in weight and has a structure that restrains vibration are provided. The centrifugal fan includes a resin upper casing, a resin lower casing, an impeller, a motor, and a circuit board. The impeller, the motor and the circuit board are housed between the resin upper casing and the resin lower casing. Radial ribs and a concentric ribs for reinforcing are formed at a bottom surface of a concave part of the lower casing. Resin pins are provided in a standing manner at these rib parts, and the circuit board is fixed to the lower casing by the resin pins.

Abstract: A motor device includes a motor having coils of three phases and a single-phase coil. The motor device includes a drive circuit of a first system capable of supplying a drive current to the coils of the three phases and a drive circuit of a second system capable of supplying a drive current to the single-phase coil. The drive circuit of the second system is different from the drive circuit of the first system. The drive circuit of the first system includes a three-phase inverter circuit connected to one end of each of the coils of the three phases, and the drive circuit of the second system includes a single-phase inverter circuit connected to both ends of the single-phase coil.

Abstract: A motor drive controller includes a control unit configured to control a motor drive unit, wherein the motor drive unit includes switching circuits for the three-phase windings, respectively, each of the switching circuits including two switching elements, wherein the control unit is configured to place a first switching element among the two switching elements in an “on” state for an energization period while placing a second switching element among the two switching elements in an “off” state, to place the second switching element alternately in the “on” and “off” states for the energization period while placing the first switching element in the “off” state, and to control the second switching element in an overlapping period during which two adjacent windings among the three-phase windings are placed in a same energization state, such that a magnitude of energization of the two adjacent windings changes gradually in a linear or nonlinear fashion.

Abstract: A motor device includes a motor having coils of three phases and a single-phase coil. The motor device includes a drive circuit of a first system capable of supplying a drive current to the coils of the three phases and a drive circuit of a second system capable of supplying a drive current to the single-phase coil. The drive circuit of the second system is different from the drive circuit of the first system. The drive circuit of the first system includes a three-phase inverter circuit connected to one end of each of the coils of the three phases, and the drive circuit of the second system includes a single-phase inverter circuit connected to both ends of the single-phase coil.

Abstract: A valve device for a cooling water system of a motor vehicle, with a housing including a first connection and a second connection for a first liquid circuit, and a third connection and a fourth connection for a second liquid circuit, wherein the first connection is permanently fluidically connected to the second connection, and with a valve unit including a movably mounted valve element with which a thermally activatable spring element is associated, and which opens a connection between the third connection and the fourth connection in a first end position and cuts off the connection in a second end position. The thermally activatable spring element is arranged in a chamber located between the first connection and the second connection, which is permanently cut off from the third and the fourth connection and which preloads the valve element in the direction of the second end position.

Abstract: A motor drive controller includes a control unit configured to control a motor drive unit, wherein the motor drive unit includes switching circuits for the three-phase windings, respectively, each of the switching circuits including two switching elements, wherein the control unit is configured to place a first switching element among the two switching elements in an “on” state for an energization period while placing a second switching element among the two switching elements in an “off” state, to place the second switching element alternately in the “on” and “off” states for the energization period while placing the first switching element in the “off” state, and to control the second switching element in an overlapping period during which two adjacent windings among the three-phase windings are placed in a same energization state, such that a magnitude of energization of the two adjacent windings changes gradually in a linear or nonlinear fashion.

Abstract: A rotating device includes a retained assembly including a spherical retained member with a spherical encircled face, and an encircling member that includes an annular end face which encircles the spherical retained member and which extends outwardly in a radial direction, a retainer assembly including a retainer member which includes an encircling face encircling the encircled face and which retains thereinside a part of the spherical retained member, and a facing member that faces the encircling member in an axial direction, the retainer assembly supporting the retained assembly in a freely and relatively rotatable manner, and forming a fluid dynamic bearing mechanism, and a thrust dynamic pressure generating groove formed in at least either one of a surface of the encircling member and a surface of the facing member, which surfaces face with each other in the axial direction.

Abstract: A rotating device includes a retained assembly including a spherical retained member with a spherical encircled face, and an encircling member that includes an annular end face which encircles the spherical retained member and which extends outwardly in a radial direction, a retainer assembly including a retainer member which includes an encircling face encircling the encircled face and which retains thereinside a part of the spherical retained member, and a facing member that faces the encircling member in an axial direction, the retainer assembly supporting the retained assembly in a freely and relatively rotatable manner, and forming a fluid dynamic bearing mechanism, and a thrust dynamic pressure generating groove formed in at least either one of a surface of the encircling member and a surface of the facing member, which surfaces face with each other in the axial direction.

Abstract: A fan motor includes: a rotor configured to be rotated so as to generate air movement; a stator configured to rotatably support the rotor via a fluid dynamic pressure bearing; and a driving mechanism configured to rotationally drive the rotor with respect to the stator. The rotor comprises a hub fixed to an impeller. The stator includes a bottom housing which supports a sleeve. The fan motor is configured to have a thickness of 3.2 mm or less along the rotational axis R of the rotor.