Abstract: A fan includes a shaft, a first rolling bearing provided on one end side of the shaft in an axial direction of the shaft and having a first inner ring on an outer circumference side of the shaft and a first outer ring on an outer side in a radial direction of the first inner ring, a second rolling bearing provided on another end side of the shaft and having a second inner ring on the outer circumference side of the shaft and a second outer ring on the outer side in a radial direction of the second inner ring, a bearing housing accommodating the first and second rolling bearings, an elastic member between the first and second rolling bearings. At least one of the first and second rolling bearings is a loose-fit bearing. A resistance-applying part is interposed between the loose-fit bearing and the elastic member.

Abstract: A PM stepping motor includes: a stator assembly composed of two stator units which are axially coupled to each other with a molding resin material, and each of which includes: inner and outer yokes each having a plurality of pole teeth; a bobbin including inner and outer flanges; and a coil wound around the bobbin, thus providing two such inner yokes, outer yokes, bobbins and coils in total; a rotor assembly which includes a shaft and a magnet, and which is rotatably disposed in the hollow of the stator assembly; and two bearings to rotatably support the shaft of the rotor assembly, wherein the two bobbins are formed of the molding resin material to be consolidated with the two inner yokes, and wherein a plurality of protrusions are formed of the molding resin material to extend integrally from the outer flange of each of the two bobbins.

Abstract: In a small diameter stepping motor including two stator units each including a bobbin formed of an insulating material, each bobbin includes: a circular hollow cylinder portion having a winding; two flanges disposed respectively at the both ends of the cylinder portion; and a terminal structure disposed at one of the two flanges and including two terminal blocks and a pair of electrical contact members at which the lead-out lines of the winding are terminated, wherein the two terminal blocks are circumferentially shifted in position from each other with respect to the cylinder portion axis extend axially outwardly, and the terminal blocks of one bobbin intermesh with the terminal blocks of the other bobbin such that the terminal blocks of the one bobbin overhang a part of the winding wound on the other bobbin and vice versa when the two stator units are coupled to each other.

Abstract: A stator assembly is provided and includes a laminated core and a one-part insulator having cover walls for covering edges of the laminated core, wherein first projections and a second projection both having a height smaller than the difference between the height of the cover walls and the thickness of the laminated core are formed on one side surface of the insulator in such a manner as to make contact with a part of one axial end side surface of the laminated core, whereby a gap which corresponds to the projection distance of the first and second projections and which serves as a clearance space for chips scraped by the edges of the laminated core from the surfaces of the cover walls is provided between the insulator and the laminated core, resulting in ensuring that the insulator is snap-fitted on the laminated core in good shape.

Abstract: A stepping motor includes: a stator which includes a cup-like first (outer) yoke having a plurality of notches formed at its bottom plate, a second (inner) yoke, and a bobbin having a coil wound therearound and housed in the annular hollow space formed by the first and second yokes; and a pair of bearings each of which includes a hollow-cylindrical main body and a flange structure having a plurality of protrusions, and is attached to the stator such that the protrusions engage with the notches of the first yoke thereby preventing the bearing from rotating relative to the first yoke, and such that the protrusions make contact with a flange of the bobbin thereby precisely positioning the bearing relative to the first yoke with respect to the axial direction, which prohibits any portions of the bearing from protruding axially outwardly beyond the bottom plate of the first yoke.

Abstract: A rotor includes: a magnet having a circular cylinder shape and having a hole formed through its axial center, wherein the hole has in axial cross section a regular polygonal shape having flat portions and angle portions, and wherein a recess having a truncated cone shape is disposed at an axial end of the magnet such that the recess has its maximum diameter portion located at the axial end and has its minimum diameter portion communicating with the hole; and a shaft fitted in the hole of the magnet, wherein the outer circumference of the shaft makes contact with the flat portions of the hole of the magnet thereby forming a plurality of gaps between the outer circumference of the shaft and the angle portions of the hole of the magnet, and adhesive is filled in the gaps.

Abstract: In a stepping motor including two stators and a rotor having two magnets, three dimensional relations, specifically a relation of Lm/Ls, another relation of d/2Lm, and still another relation d/D, are optimally determined while satisfying their respective ranges: 0.35?Lm/Ls?0.45; 0.77?d/2Lm?1.10; and d/D?0.45, where Lm is the axial dimension of the magnet, Ls is the axial dimension of the stator, d is the outer diameter of the magnet, and D is the outer diameter of the stator, whereby a space for accommodating a sufficient number of coil turns is secured maximally in the stator, and the inertia and the cogging torque of the rotor are reduced maximally, which leads to producing the highest possible torque at a high rotation speed range required.

Abstract: A stator assembly is provided and includes a laminated core and a one-part insulator having cover walls for covering edges of the laminated core, wherein first projections and a second projection both having a height smaller than the difference between the height of the cover walls and the thickness of the laminated core are formed on one side surface of the insulator in such a manner as to make contact with a part of one axial end side surface of the laminated core, whereby a gap which corresponds to the projection distance of the first and second projections and which serves as a clearance space for chips scraped by the edges of the laminated core from the surfaces of the cover walls is provided between the insulator and the laminated core, resulting in ensuring that the insulator is snap-fitted on the laminated core in good shape.

Abstract: A stepping motor has stators arranged at both end sides in the direction of a shaft of a rotor magnet, each of the stators includes inner and outer yokes having pole teeth opposed to the outer peripheral surface of the rotor magnet, at least the outer yoke among the inner and outer yokes has a tubular bending part, and the bending part is fixed to a cylindrical core made of a magnetic material.

Abstract: A stepping motor includes: a stator which includes a cup-like first (outer) yoke having a plurality of notches formed at its bottom plate, a second (inner) yoke, and a bobbin having a coil wound therearound and housed in the annular hollow space formed by the first and second yokes; and a pair of bearings each of which includes a hollow-cylindrical main body and a flange structure having a plurality of protrusions, and is attached to the stator such that the protrusions engage with the notches of the first yoke thereby preventing the bearing from rotating relative to the first yoke, and such that the protrusions make contact with a flange of the bobbin thereby precisely positioning the bearing relative to the first yoke with respect to the axial direction, which prohibits any portions of the bearing from protruding axially outwardly beyond the bottom plate of the first yoke.

Abstract: A rotor includes: a magnet having a circular cylinder shape and having a hole formed through its axial center, wherein the hole has in axial cross section a regular polygonal shape having flat portions and angle portions, and wherein a recess having a truncated cone shape is disposed at an axial end of the magnet such that the recess has its maximum diameter portion located at the axial end and has its minimum diameter portion communicating with the hole; and a shaft fitted in the hole of the magnet, wherein the outer circumference of the shaft makes contact with the flat portions of the hole of the magnet thereby forming a plurality of gaps between the outer circumference of the shaft and the angle portions of the hole of the magnet, and adhesive is filled in the gaps.

Abstract: A PM stepping motor includes: a stator assembly composed of two stator units which are axially coupled to each other with a molding resin material, and each of which includes: inner and outer yokes each having a plurality of pole teeth; a bobbin including inner and outer flanges; and a coil wound around the bobbin, thus providing two such inner yokes, outer yokes, bobbins and coils in total; a rotor assembly which includes a shaft and a magnet, and which is rotatably disposed in the hollow of the stator assembly; and two bearings to rotatably support the shaft of the rotor assembly, wherein the two bobbins are formed of the molding resin material to be consolidated with the two inner yokes, and wherein a plurality of protrusions are formed of the molding resin material to extend integrally from the outer flange of each of the two bobbins.

Abstract: In a small diameter stepping motor including two stator units each including a bobbin formed of an insulating material, each bobbin includes: a circular hollow cylinder portion having a winding; two flanges disposed respectively at the both ends of the cylinder portion; and a terminal structure disposed at one of the two flanges and including two terminal blocks and a pair of electrical contact members at which the lead-out lines of the winding are terminated, wherein the two terminal blocks are circumferentially shifted in position from each other with respect to the cylinder portion axis extend axially outwardly, and the terminal blocks of one bobbin intermesh with the terminal blocks of the other bobbin such that the terminal blocks of the one bobbin overhang a part of the winding wound on the other bobbin and vice versa when the two stator units are coupled to each other.

Abstract: In a stepping motor including two stators and a rotor having two magnets, three dimensional relations, specifically a relation of Lm/Ls, another relation of d/2Lm, and still another relation d/D, are optimally determined while satisfying their respective ranges: 0.35?Lm/Ls?0.45; 0.77?d/2Lm?1.10; and d/D?0.45, where Lm is the axial dimension of the magnet, Ls is the axial dimension of the stator, d is the outer diameter of the magnet, and D is the outer diameter of the stator, whereby a space for accommodating a sufficient number of coil turns is secured maximally in the stator, and the inertia and the cogging torque of the rotor are reduced maximally, which leads to producing the highest possible torque at a high rotation speed range required.

Abstract: A stepping motor is provided and includes: a rotor; a stator comprising a stator yoke having pole teeth; and a molded case comprising a case body and a mounting flange. The case body is resin-molded such that outer faces of the pole teeth of the stator yoke are exposed, and the mounting flange is resin-molded integrally with the case body.

Abstract: There is provided a stepping motor including: a stator assembly; a rotary shaft which includes a lead screw portion and a plain portion with a rotor magnet disposed thereon, and which has both ends thereof rotatably supported by respective bearings; and a thrust mechanism which includes a resilient member provided in a recess formed at one end of the rotary shaft positioned toward the lead screw portion, and adapted to give an axial thrust force to the rotary shaft, and a point-contact member provided between the resilient member and one bearing of the respective bearings, the one bearing rotatably supporting the one end of the rotary shaft positioned toward the lead screw portion. Thus, the thrust mechanism is located out of and apart from the stator assembly which includes coils to radiate heat, and therefore is prevented from suffering influences from the heat radiated by the coils.

Abstract: A claw-pole type stepping motor comprises: a rotor assembly shaped substantially cylindrical, and having a center shaft; and a stator assembly composed of two cup-shaped stator units which are coupled to each other coaxially so as to axially sandwich the rotor assembly, and which each include a bobbin having a magnet wire wound therearound, and two pole tooth arrays magnetically connected to each other and shifted in phase from each other by an electrical angle of 180 degrees. In the motor, each stator unit further includes a cover ring which protects the magnet wire wound around the bobbin against resin injected when the stator unit is resin-molded for an integrated solid structure. The motor structured as described above can be successfully resin-molded so as to enable elimination of a motor case, thus achieving downsizing for the dimension of the eliminated motor case while maintaining a sufficient mechanical strength.

Abstract: A step portion (12) is formed on a table body (11) to be attached to a motor (20), and an ultraviolet curable adhesive as a resin (13) is applied to a mount-place forming position of the table body (11) including the step portion (12), and cured. The table body (11) is attached to the motor (20), and the surface of the resin (13) is cut while rotating a rotating shaft (21) of the motor (20). At this time, the step portion (12) prevents the peeling of the resin (13) against the force of moving the resin (13).

Abstract: A spindle motor, in which the number of parts is kept from increasing and the number of assembling processes is reduced, and which has mechanisms for self-balancing and centrally aligning a disk, comprises a motor assembly (31) for rotating a disk (30) as a recording medium, a turntable (12) for mounting the disk (30), and a holder plate (14) disposed under the turntable (12). The mechanism for self-balancing is structured such that a plurality of steel balls (16) are disposed within an annular space (22) defined by the turntable (12) and the holder plate (14), and the mechanism for centrally aligning the disk (30) is constituted by a plurality of claw-shaped aligning members (5) formed at the inner circumference of the holder plate (14).

Abstract: A claw-pole type stepping motor comprises: a rotor which is shaped substantially cylindrical, and which has a rotary shaft at its radial center; and two stators which are shaped like a cup, each have at least one magnetic coil, are coupled to each other so as to rotatably house the rotor with their magnetic coils located respectively toward both axial end faces of the rotor, and which each have two pole tooth arrays magnetically connected to each other such that magnetic phase difference therebetween at tips of respective pole teeth is 180 degrees in terms of electrical angle, and in the motor thus structure, three pipes of aluminum go axially through the two stators so as to hold together the two stators.