Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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° in electrical angle or a full-pitch winding group which consists of windings wound at a pitch equal to 180° 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.

Abstract: An electric motor includes a rotor including magnetic poles whose number of pole pairs is P, P being a natural number, and a stator including windings. The stator includes (3/2)×P large teeth with a first pole pitch and (3/2)×P small teeth with a second pole pitch smaller than the first pole pitch. The large teeth and the small teeth are disposed so as to circumferentially alternate. The windings are wound concentratedly only on the large teeth. When the first pole pitch in electrical angle is X and the second pole pitch in electrical angle is Y, X is in a range from 144 to 180 degrees, and Y is equal to (240?X) degrees. The circumferentially adjacent windings are supplied with currents having a phase difference of 120 degrees in electrical angle therebetween, respectively.

Abstract: 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° in electrical angle or a full-pitch winding group which consists of windings wound at a pitch equal to 180° 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.

Abstract: 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 ?u, ?v and ?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.

Abstract: 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.

Abstract: 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 ?u, ?v and ?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.

Abstract: 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<(P/2)×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.

Abstract: An electric motor with reduced cogging torque and related method of determining a stator pole geometry are disclosed. The electric motor includes a rotor (80, 91, 96) and a stator (50A, 50B, 50C, 50D, 60A, 60B, 60C, 60D, 70A, 90B, 94B, 98) having a stator pole geometry incorporating non-magnetic body segments (110) and magnetic body segments (100) 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.

Abstract: 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.

Abstract: The motor includes a rotor including N-pole magnets and S-pole magnets located alternately along a circumferential direction of said AC motor, a stator core including a plurality of partial cores arranged coaxially along an axial direction of said AC motor each of said partial cores including a plurality of stator poles located along said circumferential direction so as to be on the same circumference, and a plurality of loop-like windings each of which extends in said circumferential direction while passing through, in said axial direction, interpole spaces between each two adjacent stator poles in said circumferential direction. The a phase angle difference between each adjacent two of said stator poles in said circumferential direction of the same one of said partial cores is set at a value smaller than 360 degrees for each of said partial cores.

Abstract: 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.

Abstract: 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<(P/2)×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.

Abstract: An electric motor with reduced cogging torque and related method of determining a stator pole geometry are disclosed. The electric motor includes a rotor (80, 91, 96) and a stator (50A, 50B, 50C, 50D, 60A, 60B, 60C, 60D, 70A, 90B, 94B, 98) having a stator pole geometry incorporating non-magnetic body segments (110) and magnetic body segments (100) 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.

Abstract: 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.

Abstract: A wound coil member alternately includes first ring layers and second ring layers in a row. The first ring layer is formed in a manner that a coil wire is concentrically and inwardly wound by the given number of turns. By contrast, the second ring layer is formed in a manner that the coil wire is concentrically and outwardly wound by the certain number of turns. Here, a portion of the coil wire that transfers between the first ring layers and second ring layers does not cross over, but only runs upon any adjacent portions of the coil wire. As a result, even after the wound coil member is compressed, the compressed coil member does not easily involve a local deformation. Breakage of the coil wire, reduction of the cross sectional area, or damage of the coating can be thereby restricted.

Abstract: 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.