Minebea Company, Limited

Minebea Mitsumi Inc.

Minebera Co., Ltd.

Taketoshi Ohyashiki

Yuzuru Suzuki

Naoyuki Harada

Sakae Fujitani

Kunitake Matsushita

Hiroshi Sano

Makoto Kinoshita

Taichi Nishio

Hiroichi Shibata

Osamu Nakamura

Katsutoshi Suzuki

Kazuo Muramatsu

Kenichi Makino

Hideki Sakiyama

Hirohito Nakamata

A coil assembly in which a slack can be formed in a coil wire without increasing assembly cost, and a stepping motor using the same, are provided; the coil assembly includes a bobbinhaving flange portionsandat both ends thereof, multiple terminal pin embedding portionsarranged at one flange portion, a terminal pinembedded in the terminal pin embedding portion, and a coilof which an end portion of coil wireis entwined around the terminal pin, the coil wirewound around the bobbin, in which a concave portionwhich concaves to a radial direction of the bobbinand penetrates to an axial direction of the bobbinis formed between the terminal pin embedding portions, the coil wireexists from a base portion of the terminal pin, passes through the concave portion, started to be wound around the bobbin, and has a slack portionwhich exists in the concave portion

Coil assembly and stepping motor using same

A stepping motor uses a low-cost ferrite magnet instead of an expensive rare-earth magnet. The stepping motor has characteristics equivalent or superior to those of a conventional stepping motor. The stepping motor is provided with a rotor, a stator yoke, and bearingsandwhich rotatably hold the rotorwith respect to the stator yoke. The rotorhas a columnar shape and has plural magnetic poles arranged in the circumferential direction of the outer circumferential surface. The stator yokehas an outer cylindrical portion and an inner circumferential portion which surrounds the rotorand which has plural first pole teeth and plural second pole teeth. The outer diameter 'd' of the rotorand the outer diameter 'D' of the stator yokeare set so that the ratio of &#x201c;d/D&#x201d; is greater than 0.6.

Permanent-magnet stepping motor

Cutouts are formed in a front end plate disposed of a motor body. A thrust member, which has a hump segment to touch and press against a rear end surface of a rotary shaft frontward, is detachably attached to the motor body such that distal ends of arm segments of the thrust member are fitted into respective cutouts of the front end plate.

Thrust member attached to outer surface of motor body, and motor including same

In a motor portion of a linear actuator, a rear end cap and a front end protrusion, which are disposed respectively at the rear and front ends of a stator assembly, and which include rear and front bearings to rotatably support a rotor assembly, are formed by injection-molding simultaneously and integrally with a stator support member which fixedly supports constituent members of the stator assembly, whereby the stator assembly, the rear end cap, and the front end protrusion can be coaxially aligned to one another with a high degree of precision thus improving the assembling precision of the motor portion. Also, since the front bearing can be attached to the front end protrusion before an output shaft is attached, the rotation characteristic of the rotor assembly can be evaluated before the output shaft is attached.

Linear actuator, and production and inspection method thereof

A stator sub-assembly comprises: a coil bobbin which is composed of a cylinder having a winding of a magnet wire therearound, and a terminal block provided with terminal pins connected to lead wires of the winding and coupled stator yokes housing said coil bobbin therein and having a cutout for allowing the terminal block to protrude therethrough. The cutout has a width adapted to allow the terminal block to circumferentially shift rotationally about the center of an axial direction of the coil bobbin.

Stator sub-assembly, stator assembly, motor and manufacturing method of stator assembly

A bobbin comprises: a bobbin body consisting generally of a cylinder having a winding of a magnet wire therearound, and two flanges; and a bobbin cover formed generally into a cylindrical ring. The bobbin body includes a coil termination block protruding radially from an inner flange of the two and having terminal pins for external connection, and the bobbin cover includes a termination protector protruding radially from the bobbin cover and adapted to mate with the coil termination block when the bobbin cover is put over the bobbin body.

Bobbin provided with cover for protecting magnet wire

There is provided a stepping motor of low vibration realized by reducing cogging with a simple structure while maintaining the performances such as torque. A stepping motor of the invention is structured such that a stator unitis composed of a pair of stator sub-assembliesattached to each other in a back to back manner, each stator sub-assembly having a plurality of pole teethformed at its inner circumference and housing a coil inside thereof, a rotor unitis rotatably disposed with a small gap from the plurality of pole teethand having multiple magnetic poles formed on ah circumference thereof, the multiple magnetic poles of the rotor unitbeing formed by magnetizing the rotor unitalternately with an S pole and an N pole in a circumferential direction, and that while a magnetic pole width consisting of a width of the S pole and a width of the N pole in a pair is set to a predetermined constant value, the width of the S pole and the width of the N pole in each pair are set to be different from each other.

Stepping motor

The stator assembly of a PM stepping motor having a two-phase structure in which two stators arranged along the circumferential direction in such a manner that respective pole teeth are intermeshed together are combined back to back so as to phase-shift the respective pole teeth in the two stators at an electrical angle of 90&deg;. The field rotor magnet is so arranged as to face the respective pole teeth at a small distance, and is magnetized on its circumferential surface along the circumferential direction with a plurality of alternating N- and S-poles having a preset width not matching the pole tooth pitch of each stator.

Permanent magnet stepping motor having pole teeth misaligned by an electrical angle

There is provided a stepping motor of low vibration realized by reducing cogging with a simple structure while maintaining the performances such as torque. A stepping motor of the invention is structured such that a stator unit is composed of a pair of stator sub-assemblies attached to each other in a back to back manner, each stator sub-assembly having a plurality of pole teeth formed at its inner circumference and housing a coil inside thereof, a rotor unit is rotatably disposed with a small gap from the plurality of pole teeth and having multiple magnetic poles formed on an circumference thereof, the multiple magnetic poles of the rotor unit being formed by magnetizing the rotor unit alternately with an S pole and an N pole in a circumferential direction, and that while a magnetic pole width consisting of a width of the S pole and a width of the N pole in a pair is set to a predetermined constant value, the width of the S pole and the width of the N pole in each pair are set to be different from each other.

An inner rotor type motor has a plurality of stator magnetic poles projecting inwardly from a stator yoke surrounding the outer periphery of a shaft, of which a plurality of stator magnetic poles, some, at least the same number as the number of the phases of the driving voltage, are each provided with a driving coil and a decelerating coil wound around the same and form long stator magnetic poles ( ), while the remaining stator magnetic poles are each made shorter than the long stator magnetic poles, not provided with a winding, and form short stator magnetic poles. Further, the motor has a rotor rotating centering around the shaft and having rotor magnets made up of permanent magnets disposed in a confronting relationship with salient poles of the stator magnetic poles.

Motor structure for use with optical disks

In a rotor structure of a spindle motor, an underside of a turntable and a top surface of a rotary yoke are integrated with each other by insert molding to eliminate an air gap therebetween in prior arts to thereby allow a stator assembly within the rotary yoke to increase its thickness and also enhance the rigidity of the integrated components while dimensions of the motor remaining unchanged, moreover, simultaneous integration with any components of a rotary shaft, a chucking magnet and a rotary magnet being advantageous in reduction of the assembling steps.

Rotor structure of spindle motor

A high-quality bearing with improved controllability which is capable of performing a smooth movement with low vibration, low noise, and high rotation accuracy is provided stably in a short time and at low cost. Grooves of a desired configuration are provided in the outer circumferential surface of a mandrel having an outer diameter slightly smaller than the inner diameter of the metal bearing . The mandrel is inserted into the inner circumferential surface of the metal bearing . The metal bearing is inserted into a reducing jig or housing having an inner diameter slightly smaller than the outer diameter of the metal bearing , thereby causing plastic deformation of metal and forming desired ridges on the inner circumferential surface of the metal bearing . When the bearing has an outer diameter D and an inner diameter d, the reducing jig or housing has an inner diameter A, and the mandrel to be inserted into the inner circumferential surface of the bearing has a diameter B, the dimensional relationship between the individual components is established such that an interference ratio (D&minus;A)/D is in the range of 0.005 to 0.035 and (d&minus;B)/d is equal to or smaller than 0.005 provided that D>A and d>B are satisfied.

Metal bearing and method of manufacturing the same

A terminal of a motor is provided, in which a connection between a coil and an external circuit can be carried out securely and with a good workability, while saving material resources and enhancing safety relating to environmental pollution. A terminal ( ) consists integrally of a magnet wire binding section ( ) to connect to a magnet wire ( ) of a coil ( ), an external connection section ( ) to connect to an external circuit and a support base section ( ) to press-fit into a terminal block ( ) of a bobbin ( ) and hold the terminal ( ), and the magnet wire ( ) is plasma welded for connection through to the external connection section ( ) (terminal ). The connection of the terminal is carried out by welding (plasma welding), thus the end of the magnet wire of a motor ( ) is connected without using solder containing lead. As a result, since lead is not used, material resources can be saved and safety relating to the environmental pollution can be enhanced. Since the support base section ( ) press-fits into a hole of the terminal block ( ) of the bobbin ( ), a direction and position of the terminal ( ) are settled to thereby increase the stability.

Terminal structure of a motor

Electromagnetic conversion efficiency of an electric rotary machine is enhanced and reduction of leakage flux due to magnetic discontinuity can be realized without providing holes for positioning and fixing salient poles in a stator ring. Outer appearance and decency of the electric rotary machine as a product are also improved by not allowing lower ends of salient poles of an armature assembly to be exposed on an outer surface of the electric rotary machine. For this purpose a radial gap type electric rotary machine comprises a field magnetic pole consisting of a permanent magnet which is supported rotatably and an armature assembly consisting of a plurality of divided salient poles which oppose the field magnetic pole with a small air gap therebetween and are radially arranged with respect to a rotation axis. The armature assembly includes a first ring made of a soft magnetic member for receiving the plurality of salient poles and a second ring made of a soft magnet member for receiving the first ring.

Electric rotary machine

The present invention provides, at low cost, a stator structure of a high-performance motor, which gives off lower temperature rise, strives for a more highly efficient magnetic circuit, and achieves lower power consumption at highspeed rotation, while at the same time striving to achieve a stable rotor position by preventing rotor float at highspeed rotation. In a highspeed motor comprising a stator including a stator yoke made of a soft magnetic material and coils composed of magnet wires wound on salient poles of the stator yoke; A rotor including a field magnet includes a permanent magnet so as to face the salient poles of the stator by way of an air gap and a shaft as the center of rotation in the center thereof; and a base plate having a housing which has two bearings for rotatably holding the rotor in the center of the stator, improvement being that the stator yoke is constituted by winding a soft magnetic steel sheet.

Growing community of inventors

Shizuoka-ken, Japan

Taketoshi Ohyashiki