Abstract: A bicycle electric power generating device includes a shaft member, a rotation body coaxially rotatable relative to the shaft member, an armature provided on one of the shaft member and the rotation body and a magnet having circumferentially arranged poles provided on the other one to rotate relative to the armature. The armature includes a first yoke with at least one first yoke pieces, a second yoke with at least one second yoke pieces, and a coil. The first and second yoke pieces are arranged parallel to an axis of the shaft member so as not to overlap with each other in a circumferential direction of the shaft member. The magnet includes a first magnet facing the first yoke pieces in a radial direction of the shaft member and a second magnet facing the second yoke pieces in the radial direction.

Abstract: A single phase permanent magnet motor includes a stator and a rotor relative to the stator. The stator includes a stator core with a winding wound therearound. The stator core includes stacked first and second stator core laminations. The first stator core lamination includes a plurality of first pole shoes. The second stator core lamination includes a plurality of second pole shoes. The structures of the first pole shoes and the second pole shoes are different. The first pole shoes and the second pole shoes are stacked substantially along the axial direction of the motor. The present invention reduces vibration and noise caused by the use of a single type of core laminations in the prior art.

Abstract: An electrical rotary machine comprises a stator having a plurality of split cores arranged in an annular shape and a holding ring capable of retaining the plurality of split cores on an inner circumferential surface so that a surface pressure is applied to an outer circumferential surface of the split cores. The electrical rotary machine further comprises a rotor provided radially inside of the stator facing the split cores in a radial direction and rotatable relative to the stator. Each of the split cores includes a tooth portion extending in an radial direction and a back yoke portion extending in a circumferential direction. Each of the split cores further includes a slit penetrating an outer circumferential periphery of the back yoke portion except for either circumferential end of the back yoke portion.

Abstract: Permanent magnet synchronous machines (100) are described having good efficiency, as well as corresponding methods for making a stator (110) or stator teeth (114) for such machines. A method for fabricating a stator (110) for an axial flux permanent magnet synchronous machine is for example described comprising obtaining several sets of substantially identical laminates (302), and stacking the sets of substantially identical laminates (302) so that a subsequent laminate has a part overlapping (304) the previous laminate and a part not overlapping (306) the previous laminate. Alternatively, a method of manufacturing a stator (110) is described wherein the method comprises obtaining a set of laminates (302) connected to each other with a thin strip (402) of material and creating a stack by folding the laminates (302) along the thin strip (402) of material.

Abstract: A rotor includes a rotor core comprised of steel sheets that are laminated in the axial direction of the rotor core and a rotating component configured to rotate together with the rotor core. Each of the steel sheets has a positioning portion for circumferentially positioning the steel sheet with respect to the rotating component and is formed of a rolled steel material. For each of the steel sheets, the direction of rolling of the steel sheet is circumferentially offset from both imaginary lines X and Y by predetermined angles. Each of the steel sheets is shaped so that the circumferential position of the positioning portion thereof remains unchanged when the steel sheet is front-back inverted about the imaginary line X. When viewed along the axial direction, at least one of the steel sheets is front-back inverted with respect to and thus forms a mirror image of the other steel sheets.

Abstract: A disk drive device includes: a base member; a hub on which a recording disk is placed; a bearing unit arranged on the base member for rotatably supporting the hub; and a spindle drive unit for rotationally driving the hub, wherein the spindle drive unit includes a stator core having salient poles, a coil wound around each of the salient poles, and a magnet having a plurality of magnetic poles arranged in a circumferential direction opposed to the salient poles, the hub includes an outer cylindrical portion formed of a magnetic material and engaged with an inner periphery of the recording disk, and an inner cylindrical portion fixing an outer periphery of the magnet, the number of magnetic poles is an even number in a range of 10 to 16, and the number of salient poles is a multiple of 3 in a range of 12 to 24.

Abstract: A permanent magnetic rotor for an electric motor, preferably for an internal rotor motor, includes a laminated core consisting of several rotor sheets that are stacked in the axial direction. Permanent magnets are arranged in receiving pockets formed by recesses of the rotor sheets, the laminated core being composed of at least two differently shaped types of rotor sheets. Several rotor sheets of a first type of rotor sheet are provided as retaining sheets that respectively include a central yoke lamination section that is connected or can be connected to the rotor shaft and respectively one or more external pole shoe sections that are connected to the yoke lamination section by one or more connecting bars or bar sections, and several rotor sheets of a second type of rotor sheet are provided as intermediate sheets without connecting bars.

Abstract: A disk drive device includes: a base member; a hub on which a recording disk is placed; a bearing unit arranged on the base member for rotatably supporting the hub; and a spindle drive unit for rotationally driving the hub, wherein the spindle drive unit includes a stator core having salient poles, a coil wound around each of the salient poles, and a magnet having a plurality of magnetic poles arranged in a circumferential direction opposed to the salient poles, the hub includes an outer cylindrical portion formed of a magnetic material and engaged with an inner periphery of the recording disk, and an inner cylindrical portion fixing an outer periphery of the magnet, the number of magnetic poles is an even number in a range of 10 to 16, and the number of salient poles is a multiple of 3 in a range of 12 to 24.

Abstract: The present invention provides a rotating electrical machine including a rotor core that does not produce narrow areas in rotor slots even if circumferential ends of fan-shaped segment cores are displaced radially outwardly and circumferentially during operation. In the present invention, slots near circumferential ends of the fan-shaped segment cores are made larger than slots in circumferential intermediate portions of the segment cores. With such a configuration, even if the circumferential ends of the segment cores are displaced radially outwardly and circumferentially during operation, the circumferential ends of the segment cores forming the large slots do not protrude into the slots formed in the circumferential intermediate portions of axially adjacent segment cores, thereby preventing narrow areas from being produced in the rotor slots.

Abstract: A rotor includes: a rotor core fixedly attached to a rotational shaft and having a magnet-inserted hole portion; a magnet inserted into the magnet-inserted hole portion; and a resin portion injected into the magnet-inserted hole portion. The rotor core is constructed by axially stacking a plurality of electromagnetic steel sheets. The electromagnetic steel sheets include: an electromagnetic steel sheet having the magnet-inserted hole portion and a weight-reducing-purpose hole portion provided separately from the magnet-inserted hole portion; and an electromagnetic steel sheet located on at least one axial end of the rotor core and having a portion covering the hole portion formed in the electromagnetic steel sheet.

Abstract: A motor includes an output shaft rotatably provided, a rotor fixed to the output shaft and rotatable with the output shaft, a stator formed by a lamination of plurality of electrical steel sheets made by a magnetic material, the electrical steel sheets being punched by means of a press working, a coil wound at the stator, and a case accommodating the stator and the rotor and including a holder for holding the stator. The electrical steel sheets are arranged at one end of the stator in a lamination direction thereof and at the other end of the stator in the lamination direction thereof respectively. The electrical steel sheets include surfaces each at which a shear droop is formed. The surfaces of the electrical steel sheets face each other.