Abstract: An axial flow fan includes: an impeller, a hub of which is attached to a rotation shaft of a rotation driving device; and a venturi casing that surrounds an outer circumference in a radial direction of the impeller and includes a suction port and a discharge port facing each other in an axial direction of the rotation shaft. A positive pressure surface of a plurality of blades integrally attached to the hub includes a plurality of step portions that is curved so as to comply with a curved shape of a front edge portion in a rotation direction of the blades.

Abstract: To provide a motor control device which can apply an electric brake to a motor when power supply is stopped, and achieve a miniaturization and a cost reduction. A first switch 11 through a sixth switch 16 connects respective coils L1, L2 and L3 included in a motor to an electric power source 20. The capacitor C accumulates the power supplied from the electric power source 20. A seventh switch 17 connects the capacitor C to a fourth switch 14 through the sixth switch 16, when the power supply from the electric power source 20 is stopped. The operation of the seventh switch 17 causes the fourth switch 14 through the sixth switch 16 to operate by the power accumulated in the capacitor C, and respective coils L1 to L3 are short-circuited to apply the brake to the motor.

Abstract: There is provided a stator that suppresses degradation in insulating performance and pressure-resisting performance without an additional insulating member, that can shorten a work time, and improve winding efficiency of a wound wire and heat radiation performance. The stator 1 includes a yoke part 10 of an annular shape, tooth winding portions 21 that protrude inward from the yoke part 10 and around which an electric wire 30 is wound, and a tooth end portion 22 formed on an inward side of the tooth winding portion. The stator 1 is formed by stacking steel plates in a direction corresponding to a rotational axis of a motor.

Abstract: There is provided a stator that can suppress degradation in insulating performance and electrical strength performance, shorten a work time, and improve winding efficiency and heat radiation. The stator 1 includes a yoke part 20 formed to be annular, a plurality of tooth parts 30 protruding from the yoke part 20 in an inward direction perpendicular to an axial direction O of a rotor when the rotor is arranged in the yoke part 20, and protecting members 40 each of which is attached to both end surfaces of the tooth part 30 in the axial direction O to protect a corner of the tooth part 30. The protecting members 40 have a length in a slot 38 between the tooth parts 30 shorter than a half of an entire length of the tooth part 30 in the axial direction.

Abstract: An axial-flow fan includes an impeller mounted on a rotating shaft of a rotary drive device and a venturi casing surrounding an outer periphery of the impeller in a radial direction and including a suction port and a discharge port facing each other in an axial direction of the rotating shaft . An inner surface of the venturi casing includes a suction-side slant part 31 expanding the suction port outward in the radial direction of the impeller, a linear part continuing from the suction-side slant part and forming an axial flow of a fluid with the impeller, a discharge-side slant part 34 expanding the discharge port outward in the radial direction of the impeller, and a curved part connecting the linear part and the discharge-side slant part.

Abstract: A low-cost magnetic encoder that facilitates generating sinusoidal magnetic flux is provided. First and second permanent magnet arrays each include a plurality of permanent magnets arranged such that magnetic poles having the same polarity face each other, and magnetic yokes disposed on side surfaces of the plurality of permanent magnets. The permanent magnets and the magnetic yokes are arranged side by side at a predetermined pitch in the moving direction of a magnetic piece array. First and second magnetic detectors corresponding to the first and second permanent magnet arrays are disposed in a positional relationship allowing detection of leakage magnetic flux generated when the permanent magnet arrays and the magnetic piece array are displaced with respect to each other.

Abstract: An electric machine includes a magnetic pole piece array including a plurality of magnetic pole pieces spaced along a permanent magnet array. The permanent magnet array is in immovable relation with winding portions. The pitch of a plurality of permanent magnets and the pitch of a plurality of magnetic pole pieces are determined such that magnetic flux flows through two of the permanent magnets magnetized in the same direction and located in the permanent magnet array with one permanent magnet interposed between the two permanent magnets, and also flows through one or two of the magnetic pole pieces facing the one permanent magnet interposed between the two permanent magnets and magnetized in a direction of magnetization different from the direction of magnetization of the two permanent magnets.

Abstract: At least a rotor fixing portion and a bearing fitting portion are combined to form a hollow rotary shaft. The rotor of a rotary motor portion is fixed on the rotor fixing portion. A thrust radial bearing is fitted on the outer periphery of the bearing fitting portion and a screw nut is fitted to the bearing fitting portion. The rotor fixing portion and the bearing fitting portion are coupled with screw member(s) which are inserted into the hollow rotary shaft from one axial end of the hollow rotary shaft and axially extend inside the bearing fitting portion and the rotor fixing portion. A flange portion of the screw nut is fixed on an abutment portion of the bearing fitting portion in abutment with an end surface of an inner race of the thrust radial bearing that is located on the one axial end side.