Denso Corporation

Asmo Co., Ltd.

Other

Shizuoka University

So-ken Corporation

Shinji Makita

Masayuki Nashiki

Hideji Yoshida

Yoshiyuki Takabe

Naohisa Mimura

Tomohiro Saitou

Yoshinobu Kamada

Koji Ito

Akira Kato

Eisuke Takahashi

Masanori Yasuda

Yasuhide Ito

Jun Yamaoka

Tomohiro Saito

Yasuaki Aoki

Masami Fujitsuna

Masao Tokunaga

Tomohiro Aoyama

Kazuhiro Hayashi

Etsuro Yoshino

Junichi Asama

In an electric motor, a magnetic bearing generates an electromagnetic force between multiple permanent magnets and a coil and rotatably supports an other side of a rotation shaft in an axis line direction. The rotation shaft is configured to be capable of being inclined with a rotation center line using a bearing side of the rotation shaft as a fulcrum. An electronic control device controls a current that flows to the coil such that an axis line of the rotation shaft approaches the rotation center line due to a supporting force which is the electromagnetic force between the multiple permanent magnets and the coil. Accordingly, the rotation shaft is rotatably supported to be freely rotatable by a magnetic bearing and the bearing.

Electric motor, control device, and motor control system

A control apparatus for is a rotating electric machine applied to a control system including a power conversion circuit, a rotating electric machine, and a capacitor. The control apparatus selects two types of active voltage vectors that sandwich a command voltage vector that is applied to a rotating electric machine from a power conversion circuit and have a phase difference of 60 degrees therebetween. The control apparatus selects, of two types of active voltage vectors that sandwich the command voltage vector and have a phase difference of 120 degrees therebetween, one of two types of active voltage vectors that differs from the two types of active voltage vectors selected earlier, based on a driving state of the rotating electric machine. The control apparatus controls the power conversion apparatus to perform switching operations to control the rotating electric machine, based on the selected three types of active voltage vectors.

Control apparatus for rotating electric machine

A stator for a rotating electric machine includes an annular stator core and a plurality of winding groups mounted on teeth of the stator core. Each of the winding groups is either a short-pitch winding group which consists of windings wound at a pitch shorter than 180&#xb0; in electrical angle or a full-pitch winding group which consists of windings wound at a pitch equal to 180&#xb0; in electrical angle. The winding groups include at least one short-pitch winding group pair which consists of two short-pitch winding groups that respectively belong to two different phases and are circumferentially adjacent to each other. The two short-pitch winding groups are arranged so as not to overlap each other in a radial direction of the stator core. There are no other winding groups interposed between the two short-pitch winding groups in the circumferential direction of the stator core.

Stator for rotating electric machine

An AC motor having loop windings is provided, which is able to reduce unbalance of three-phase impedance to enhance the motor efficiency. Three loop windings of the three phases are interlinked with magnetic fluxes &#x3a6;u, &#x3a6;v and &#x3a6;w of the respective phases to provide magnetic paths of the three phases. The magnetic paths of the three phases are connected to the respective stator poles of the three phases to configure the motor. The magnetic path of each of the three phases is formed by processing an electromagnetic steel plate using bending to provide a motor configuration having multiple stator poles. Magnetic fluxes of two or more stator poles of the same phase are collected to a single magnetic path to form a three-dimensional three-phase magnetic path without allowing close contact with a magnetic path of a different phase.

AC motor with loop windings and improved magnetic flux paths

A brushless motor and a related control device are disclosed in a structure wherein a stator has U-phase, V-phase and W-phase stator poles, with two of the U-phase V-phase and W-phase stator poles carry thereon respective phase windings, in the absence of a selected phase winding related to a remaining one of the U-phase V-phase and W-phase stator poles. The respective phase windings have end portions connected together at a junction point. A three-phase alternating voltage is applied to the respective phase windings and the junction point to allow the stator to have an electromagnetic action thereby drivably rotating a rotor. The stator poles may be formed in trapezoid shapes to minimize interference between associated component parts for easy assembly in high productivity and efficiency with a reduction in torque ripple.

Motor with simplified structure and related control device

An ac motor is provided which includes a plurality of looped windings each of which extends in a circumferential direction of a stator. The stator is equipped with N stator pole groups made up of magnetic poles arranged along a circumference thereof. The looped windings are disposed adjacent each other in an axial direction of the stator. The number P of the rotor magnetic poles and the number M of the magnetic poles of the stator are selected to meet a relation of M&#x3c;(P/2)&#xd7;N. This structure permits the number of the magnetic poles of the stator to be decreased, which ensures desired air gaps between the magnetic poles of the stator, thus minimizing a leakage of magnetic flux between the magnetic poles of the stator to increase torque to be outputted by the motor.

[object Object]

An electric motor with reduced cogging torque and related method of determining a stator pole geometry are disclosed. The electric motor includes a rotor () and a stator (A,B,C,D,A,B,C,D,A,B,B,) having a stator pole geometry incorporating non-magnetic body segments () and magnetic body segments () as magnetic reluctance equalizing elements to provide an equalized magnetic body distribution along a circumferential periphery of the stator. The method comprises defining a first group of stator poles skewed at an electric angle of 360/(2S), defining a second group of stator poles deviated from the first group of stator poles by an electric angle of 180 degrees, and synthesizing the first and second groups of stator poles pieces to provide a stator including a plurality of stator poles defined in the stator pole geometry to have an equalized magnetic flux distribution pattern along a circumferential periphery of the stator.

Electric motor with minimized cogging and related method of determining stator pole geometry

A brushless AC motor has a rotor, N stator pole group, and plural loop-configuration stator windings. The rotor has magnetic poles with alternating N poles and S poles circumferentially disposed at equal interval. The stator has plural stator poles divided to N stator pole groups. Each group is formed circumferentially on the stator with each of adjacent pairs of the groups mutually differing in circumferential position by a desired amount. The stator windings are formed circumferentially on the stator, with each winding disposed immediately adjacent to a corresponding one of the stator pole groups, with respect to a rotor axis direction. As an example, the stator pole has an approximate parallelogram shape in which a top side and a base side of the stator pole in axis direction of the stator has an approximately same width in rotational direction, and the positions of the top side and the base side is shifted in rotational direction to each other.

AC motor

A reluctance-type motor include a stator having a plurality of salient stator-poles, a rotor having a plurality of salient rotor-poles, a multi-phase coils mounted in the stator, and a driver circuit for driving said multi-phase coil. The driver circuit starts to supply drive current to the multi-phase coils when the salient rotor-poles and the salient stator-poles come across each other. In other words, the drive current is supplied to the multi-phase coils when the inductance thereof is zero.

Reluctance-type electric motor

A reluctance-type motor comprises, for each of its rotor and stator, a core that has a cylindrical ring and a plurality of salient poles protruding from the ring in a radial direction of the ring. Each pole has a bottom width and a top width in a circumferential direction of the core at its bottom and at its top, respectively. The bottom width is sized to be larger than the top width, and the ring has a width sized to be larger than a half of the top width of the pole. The pole may be shaped to have a round corner at the bottom or in a trapezoid in which the bottom width is larger than the top width. The core may have a plurality of thin magnetic plates stacked in an axial direction of the core, each plate has a plurality slits in each protrusion which forms the pole, and each plate has a thickness which is less than 5 times of a maximum width of each slit.

Reluctance-type motor having widened bottom

In a q phase-reluctance type motor including a rotor having 2n rotor protrusions with an arc angle X&deg;, a stator having 2m stator protrusions with an arc angle Y&deg; and m pairs of exciting coils, each of the pairs of exciting coils is disposed around one of the stator protrusions spaced apart at 180&deg; in mechanical angle, and the following conditions are met: q&gE;5, X&deg;, Y&deg;>360&deg;/(n&times;q), X&deg;&plus;Y&deg;&equals;180&deg;/n&minus;&agr;&deg;, where &agr;&deg; is a counter torque marginal angle which is larger than 0&deg;.

Reluctance type motor

A reluctance type motor apparatus comprises switching devices for energizing phase coils of a motor, diodes for circulating discharge currents of the phase coils, a current sensor for detecting a sum of currents flowing in the phase coils, and a control circuit for controlling energization of the phase coils so that the detected sum of the currents equal a predetermined reference current. The current sensor is positioned between the phase coils and junctions between the phase coils and the diodes. Phase currents supplied to energize the phase coils are varied in dependence on the rotational position of the rotor so that the output torque of the motor does not include ripple.

Reluctance type motor apparatus and driving method capable of reducing ripples in motor output torque

A wiper device is composed of a wiper blade and a wiper arm connected to the wiper blade, a first drive link having a stationary joint rotatably secured to a portion of a vehicle, a second drive link having a first movable joint and a second movable joint connected to the wiper arm. The second drive link and the wiper arm are arranged so that the first movable joint can move along a track crossing a straight line connecting the stationary joint and the second movable joint. The first and second drive links are folded when the wiper arm is going to turn and reverse its course.

Growing community of inventors

Kakamigahara, Japan

Shinji Makita