Abstract: A motor device configured to convey a fluid by driving a fan with a motor includes a position/speed acquirer configured to acquire a current rotation angle and a current rotation speed of the motor, a multiplier configured to calculate a flow-rate-constant target driving current by multiplying the rotation speed and a flow rate coefficient, and a current controller configured or programmed to control a motor driving current by setting, as a control target, the flow-rate-constant target driving current and to control a flow rate of the fluid to be maintained at a constant value which depends on the flow rate coefficient.

Abstract: An automatic icemaker includes a swing arm, an actuator swinging the swing arm, and a transmission section transmitting movement of the actuator to the swing arm. The transmission section includes a cam rotated by the actuator, a pivotally movable lever including an abutting portion abutting the cam and pivotally moved by the rotation of the cam, and a joint member to transmit the movement of the pivotally movable lever to the swing arm. As the swing arm, one of the first, second, and third swing arms is selected and provided. As the joint member, one of the first, second, and third joint members which corresponds to the selected one of the first, second, and third swing arms is selected and provided. At different positions on a board which extends in a vertical direction, the first, second, and third supporting portions support the first, second, and third joint members, respectively.

Abstract: A rotary electric machine includes a stator in which windings are arranged around a plurality of main poles of a stator core, and a hybrid type rotor arranged with an air gap between the stator and the rotor has a step angle for the rotor of about 4.09° and uses metal bearings for supporting a rotor shaft of the rotor. Setting of the step angle for the rotor to be about 4.09° can make a rotation angle of the rotor caused by excitation of the windings by an input pulse signal larger as compared with a typical motor having a step angle of about 1.8°. With this unique arrangement, the rotor can be rotated at higher speeds, increasing the motor efficiency. Therefore, the motor output at approximately the same level as that of a conventional motor can be obtained without keeping the air gap high precision. Due to this, even if inexpensive slide bearings, i.e.

Abstract: A stepping motor drive circuit includes a control-purpose controller including a control-purpose position detecting unit; a rotation command information inputting unit arranged to receive command information on the rotating position of the stepping motor; a control-purpose deviation calculating unit arranged to calculate a positional deviation between the rotating position of the stepping motor detected by the control-purpose position detecting unit and the rotating position included in the command information; and an amplitude value setting unit. The amplitude value setting unit switches operations of stator coils of the stepping motor pursuant to the command information, rotate the stepping motor to the rotating position included in the command information, and increase or decrease an amplitude value of a drive current fed to the stator coils during stoppage of the stepping motor depending on the positional deviation calculated by the control-purpose deviation calculating unit.

Abstract: An impeller includes a substantially cylindrical cup portion arranged to rotate about a center axis, a plurality of blades fixed to an outer circumferential surface of the cup portion for unitary rotation with the cup portion to draw air from one axial side and discharge the air to the other axial side, and an annular connector portion arranged to interconnect the blades. The connector portion has a substantially cylindrical shape in a position spaced apart about 70% to about 90% of the radial length of the blades from the base of each of the blades on the outer circumferential surface of the cup portion, and the ratio of a total axial height of the connector portion to a total radial gap between the outer circumferential surface of the cup portion and the inner circumferential surface of the connector portion is equal to or smaller than about 0.9.

Abstract: A drum rotating device enables a drum and a driving device mounted in the drum to be supported with a simple structure and which reduces the possibility that the driving shaft of the driving device may be offset with respect to the rotation axis of the drum. The drum rotation device includes the drum and the driving device arranged to drive and rotate the drum. The drum includes an outer cylinder, an inner cylinder arranged inside the outer cylinder coaxially therewith, and a support wall arranged to connect the outer and inner cylinders to each other at an approximately intermediate portion in the axial direction. The outer and inner cylinders are substantially cylindrical. The driving device is fixed to a frame at one axial end. The driving shaft of the driving device extends through the drum and is rotatably supported by the frame through a bearing at the other axial end.

Abstract: A rotary electric machine includes a stator in which windings are arranged around a plurality of main poles of a stator core, and a hybrid type rotor arranged with an air gap between the stator and the rotor has a step angle for the rotor of about 4.09° and uses metal bearings for supporting a rotor shaft of the rotor. Setting of the step angle for the rotor to be about 4.09° can make a rotation angle of the rotor caused by excitation of the windings by an input pulse signal larger as compared with a typical motor having a step angle of about 1.8°. With this unique arrangement, the rotor can be rotated at higher speeds, increasing the motor efficiency. Therefore, the motor output at approximately the same level as that of a conventional motor can be obtained without keeping the air gap high precision. Due to this, even if inexpensive slide bearings, i.e.

Abstract: A slip ring device includes a hollow pipe-shaped shaft rotatably supported inside a tubular body of a main case through a bearing and an electricity-collecting body integrally and concentrically provided in the shaft. The electricity-collecting body preferably includes a plurality of electricity-collecting rings and a plurality of insulating rings alternately layered with one another. The slip ring device further includes a plurality of brushes held by the main case and tip end portions making sliding contact with outer circumferential surfaces of the electricity-collecting rings and a plurality of lead lines introduced into the shaft. The lead lines include tip end portions electrically connected to the respective electricity-collecting rings. Two or more of the lead lines include shielded lines.

Abstract: An impeller, a fan apparatus, and a method of manufacturing the impeller are provided. The impeller includes a support portion, a plurality of rotor blades, and a joining member. The joining member is a substantially annular member provided to strengthen the rotor blades against influence of a centrifugal force, and extends in a circumferential direction along a circle centered on a central axis so as to join the rotor blades to one another. In each of the rotor blades, a point of intersection of a leading edge of the rotor blade with a radially outer end of the rotor blade is positioned forward, with respect to a rotation direction, relative to a point of intersection of the leading edge with an outside surface of the support portion. The joining member is positioned radially inwards of the radially outer end of each of the rotor blades.

Abstract: A permanent-magnet rotary electric machine preferably includes a stator and a rotor opposed thereto via an air gap. The stator includes a stator core having 4m (m is an integer equal to or larger than 2) main poles each having inductor teeth at a tip thereof. The rotor includes two rotor units adjacent to each other in the axial direction. Each rotor unit includes a pair of rotor magnetic poles and a permanent magnet arranged therebetween. The permanent magnets in the rotor are axially magnetized in opposite directions to each other. Each rotor magnetic pole has magnetic teeth on its outer periphery at a regular pitch. The rotor magnetic poles in each rotor unit are arranged such that the magnetic teeth of one rotor magnetic plate are offset by half a pitch from those of the other rotor magnetic pole, and the magnetic teeth of adjacent rotor magnetic poles are aligned with each other in the axial direction.

Abstract: A motor driving circuit for full-wave single-phase driving a motor includes a position detection unit, a turn-on signal generation unit, and switching devices that define an H-bridge circuit. The turn-on signal generation unit includes a differential amplifier arranged to produce a trapezoid wave signal, and a square wave generation circuit arranged to produce a square wave signal, wherein the trapezoid and the square wave signals are respectively supplied to control terminals of lower switching devices in the H-bridge circuit. Further, one of the lower switching devices is turned on and off according to a voltage level of the square wave signal, and the remaining lower switching device is turned on and off when a voltage of the trapezoid wave signal becomes higher than an operation voltage of the remaining lower switching device, wherein a non-conducting interval is provided for the motor coil according to the operation voltage.

Abstract: A serial axial fan unit includes a first axial fan arranged to rotate about a central axis, a flow control device connected to the first axial fan along the central axis, and a second axial fan connected to the flow control device along the central axis. The flow control device preferably includes a wind tunnel portion, a base portion, and a plurality of flow control vanes. A flow of air caused by rotation of first blades has a whirl velocity component in substantially the same direction as the rotation direction thereof. This whirl velocity component is converted to a velocity component in a direction parallel or substantially parallel to the central axis by interference of first stationary vanes. The above arrangement provides an improvement in air volume characteristics of a serial axial fan unit including two axial fans arranged in series.

Abstract: A hybrid type stepper motor preferably includes a two-phase eight-main-pole stator and a rotor defined by two rotor units each having a pair of rotor magnetic poles with a permanent magnet interposed therebetween. Each rotor magnetic pole has fine teeth at a regular pitch. The permanent magnets are magnetized in opposite directions to each other. The adjacent rotor magnetic poles of the rotor units are arranged with their fine teeth aligned with each other in the axial direction. Each main pole has six inductor teeth including: a pair of innermost inductor teeth arranged at the first pitch in the central portion of the main pole; a pair of intermediate teeth on the outside of the innermost inductor teeth at the second pitch therefrom; and a pair of outermost inductor teeth on the outside of the intermediate inductor teeth at the third pitch therefrom. The first, second, and third pitches are all different from the pitch of the fine teeth of the rotor magnetic pole.

Abstract: A first part formed of a first material is positioned to a second part formed of a second material, which is different from the first material in degree of modification due to environmental variation, by contacting surfaces of the first and second parts. At least three projections are formed on the contact surface of the first part along a circle whose center is coincident with a reference point. Grooves are formed on the contact surface of the second part so that the respective projections are fitted therein and that have wall surfaces to which the projections can contact at the inner and outer sides of the projections. The width of the grooves is determined so that the projections contact the inner or outer wall surface of the grooves even when the first and second parts deform in different degrees due to environmental variation.