Abstract: A disc drive having a housing which encloses a clean room that is provided with a brushless DC drive motor having an external rotor and three pole shoes on a substantially ring-shaped stator for each two pole on the rotor. The stator winding is commutated by a three-phase commutation network in such a fashion that first, second and third networks in the stator winding are cyclically connected to an external DC source in accordance with rotor position. Each of the networks comprises at least one stator coil wrapped around a neck of a single corresponding one of the pole shoes.

Abstract: A brushless DC drive motor with an external rotor has three pole shoes on a substantially ring-shaped stator for each two poles on the rotor. The stator winding is commutated by a three-phase commutation network in such a fashion that first, second and third networks in the stator winding are cyclically connected to an external DC source in accordance with rotor position. Each of the networks comprises at least one stator coil wrapped around a neck of a single corresponding one of the pole shoes.

Abstract: A disk storage device having a clean chamber for a storage disk having a central opening is provided with a brushless drive motor. The drive motor includes a stator and a winding on the stator and further includes a shaft aligned with the rotation axis of said motor, and a magnetically conducting member supported for rotation about the rotation axis and having an inner wall coaxially surrounding the stator. A magnet fixed to the inner wall of the magnetically conducting member is radially spaced from the stator. The disk storage device further includes a hub positioned within the clean chamber and contiguous with the magnetically conducting member so that the hub and the magnetically conducting member together form an outer rotor of the drive motor. The outer rotor has a radially extending flange having a surface which supports said storage disk.

Abstract: A disk storage device having a clean chamber for a storage disk having a central opening is provided with a brushless drive motor. The drive motor includes a stator and a winding on the stator and further includes a shaft aligned with the rotation axis of said motor, and a magnetically conducting member supported for rotation about the rotation axis and having an inner wall coaxially surrounding the stator. A magnet fixed to the inner wall of the magnetically conducting member is radially spaced from the stator. The disk storage device further includes a hub positioned within the clean chamber and contiguous with the magnetically conducting member so that the hub and the magnetically conducting member together form an outer rotor of the drive motor. The outer rotor has a radially extending flange having a surface which supports said storage disk.

Abstract: A disk storage drive is provided with a brushless drive motor having a stator with a winding. An external rotor coaxially surrounds the stator and is spaced therefrom by a substantially cylindrical air gap. The rotor includes a permanent magnet and a soft magnetic yoke. A hub is provided that is concentric to the yoke and is connected to the rotor for rotation therewith. The hub has a disk mounting portion on its outer peripheral surface that can be passed through the central opening of a standardized storage disk for mounting the storage disks for rotation therewith. At least half of the axial longitudinal dimension of the stator winding and the rotor magnet interacting therewith is housed within the disk mounting portion of the hub. The hub is made from a non-ferromagnetic material that is suitable for storage drive clean chamber use after dimensional finishing of the hub.

Abstract: A brushless DC drive motor with an external rotor has three pole shoes on a substantially ring-shaped stator for each two poles on the rotor. The stator winding is commutated by a three-phase commutation network in such a fashion that first, second and third networks in the stator winding are cyclically connected to an external DC source in accordance with rotor position. Each of the networks comprises at least one stator coil wrapped around a neck of a single corresponding one of the pole shoes.

Abstract: A brushless direct current motor is energized by a power stage. Switches of the power stage are selectively switched by an electronic control device. In order to determine the correct commutation pattern, without using rotor position indicators such as Hall effect devices, the control device is arranged to sample the power fed to the motor. The samples, each responsive to a test signal or normal energization pulses received by the motor, in a ordered sequence define an analogue function whose parameters can be determined by mathematical analysis. The analysis applied to the samples derives the necessary commutation information and the energization signals in a rapid manner by employing a vector or complex number addition based on functions dependent on variable inductance in the operation of the motor.

Abstract: A brushless direct current motor is energized by a power stage. Switches of the power stage are selectively switched by an electronic control device. In order to determine the correct commutation pattern, without using rotor position indicators, the control device is arranged to tap the power fed to the motor. The samples received by the motor, in an ordered sequence, define an analogue function whose parameters can be determined by vector addition. The computations applied to the sample enable the necessary commutating information and signals to be generated in a particularly rapid manner.

Abstract: A disk storage drive is provided with a brushless drive motor having a stator with a winding. An external rotor coaxially surrounds the stator and is spaced therefrom by a substantially cylindrical air gap. The rotor includes a permanent magnet and a soft magnetic yoke. A hub is provided that is concentric to the yoke and is connected to the rotor for rotation therewith. The hub has a disk mounting portion on its outer peripheral surface that can be passed through the central opening of a standardized storage disk for mounting the storage disks for rotation therewith. At least half of the axial longitudinal dimension of the stator winding and the rotor magnet interacting therewith is housed within the disk mounting portion of the hub. The hub is made from a non-ferromagnetic material that is suitable for storage drive clean chamber use after dimensional finishing of the hub.

Abstract: A position sensor using a soft magnetic core and a permanent magnet for detecting linear or rotary movements of a part. In one embodiment, a differential transformer is provided with corresponding windings 3, 4 and 5, which are wound on a tubular carrier member 2. Provided inside the carrier member 2 are a saturatable core 6 with a V-shaped crosssection section and a control magnet 8 which slides on the inner surfaces. The core 6 is partially saturated on the contact surfaces, so that a virtual air gap is produced, so that the transformation ratio between the windings 3 and 4, 5 is controlled as a function of position. Other versions employ flat and/or meandering coil arrangements and, in two instances, rotational relative motion.

Abstract: A disk memory drive includes a brushless drive outer rotor motor having an internal space and a stator with windings. The outer rotor coaxially encircles the stator and a substantially cylindrical air gap is defined between the stator and the rotor. The rotor includes permanent magnets and a hub fixedly connected with the magnet. A disk mounting section is provided on the hub for accommodating at least one storage disk positioned in a clear space, the mounting section being adapted to extend through a central aperture of the storage disk. The windings and the magnets interacting with the windings are disposed for at least half of the axial longitudinal dimension thereof within a space surrounded by the disk mounting section of the hub. Bearings rotatably mount the rotor and the hub.

Abstract: A disk storage drive is provided with a brushless drive motor having a stator with a winding. An external rotor coaxially surrounds the stator and is spaced therefrom by a substantially cylindrical air gap. The rotor includes a permanent magnet and a soft magnetic yoke. A hub is provided that is concentric to the yoke and is connected to the rotor for rotation therewith. The hub has a disk mounting portion on its outer peripheral surface that can be passed through the central opening of a standardized storage disk for mounting the storage disks for rotation therewith. At least half of the axial longitudinal dimension of the stator winding and the rotor magnet interacting therewith is housed within the disk mounting portion of the hub. The hub is made from a non-ferromagnetic material that is suitable for storage drive clean chamber use after dimensional finishing of the hub.

Abstract: A step motor which, in addition to an exciter system for step-by-step movement, is provided with a further exciter system. As a result of the direct or indirect influence of the magnetic field generated by the secondary exciter system on the rotor which is supported so as to be able to move in an axial direction with respect to the stator, the rotor can be induced to move in a direction perpendicular to its step-by-step rotary motion, as well. Both exciter systems can be energized independently of one another, so that step-by-step rotary movement can be performed at any axial position of the rotor, and the rotor can be made to move in an axial direction during its rotary movement, as well as when it is at rest.

Abstract: A disk storage drive is provided with a brushless drive motor having a stator with a winding. An external rotor coaxially surrounds the stator and is spaced therefrom by a substantially cylindrical air gap. The rotor includes a permanent magnet and a soft magnetic yoke. A hub is provided that is concentric to the yoke and is connected to the rotor for rotation therewith. The hub has a disk mounting portion on its outer peripheral surface that can be passed through the central opening of a standardized storage disk for mounting the storage disks for rotation therewith. At least half of the axial longitudinal dimension of the stator winding and the rotor magnet interacting therewith is housed within the disk mounting portion of the hub. The hub is made from a non-ferromagnetic material that is suitable for storage drive clean chamber use after dimensional finishing of the hub.

Abstract: A disk storage drive is provided with a brushless drive motor having a stator with a winding. An external rotor coaxially surrounds the stator and is spaced therefrom by a substantially cylindrical air gap. The rotor includes a permanent magnet and a soft magnetic yoke. A hub is provided that is concentric to the yoke and is connected to the rotor for rotation therewith. The hub has a disk mounting portion on its outer peripheral surface that can be passed through the central opening of a standardized storage disk for mounting the storage disks for rotation therewith. At least half of the axial longitudinal dimension of the stator winding and the rotor magnet interacting therewith is housed within the disk mounting portion of the hub. The hub is made from a non-ferromagnetic material that is suitable for storage drive clean chamber use after dimensional finishing of the hub.

Abstract: A disk memory drive includes a brushless drive outer rotor motor having an internal space and a stator with windings. The outer rotor coaxially encircles the stator and a substantially cylindrical air gap is defined between the stator and the rotor. The rotor includes permanent magnets and a hub fixedly connected with the magnet. A disk mounting section is provided on the hub for accommodating at least one storage disk positioned in a clear space, the mounting section being adapted to extend through a central aperture of the storage disk. The windings and the magnets interacting with the windings are disposed for at least half of the axial longitudinal dimension thereof within a space surrounded by the disk mounting section of the hub. Bearings rotatably mount the rotor and the hub.

Abstract: A step motor which, in addition to an exciter system for step-by-step movement, is provided with an axial exciter system. As a result of the direct or indirect influence of the magnetic field generated by the secondary exciter system on the rotor which is supported, so as to be able to move in an axial direction with respect to the stator, the rotor can be induced to move in a direction perpendicular to its step-by-step rotary motion, as well. Both exciter systems can be energized independently of one another, so that step-by-step rotary movement can be performed at any axial position of the rotor and the rotor can be made to move in an axial direction during its rotary movement as well as when it is at rest.

Abstract: A disk memory drive includes a brushless drive outer rotor motor having an internal space and a stator with windings. The outer rotor coaxially encircles the stator and a substantially cylindrical air gap is defined between the stator and the rotor. The rotor includes permanent magnets and a hub fixedly connected with the magnet. A disk mounting section is provided on the hub for accommodating at least one storage disk positioned in a clear space, the mounting section being adapted to extend through a central aperture of the storage disk. The windings and the magnets interacting with the windings are disposed for at least half of the axial longitudinal dimension thereof within a space surrounded by the disk mounting section of the hub. Bearings rotatably mount the rotor and the hub.

Abstract: Electric motor with a substantially cylindrical air gap between the stator and the rotor, the stator being fitted to a bearing support for the rotor shaft bearing. In order to reduce noise emissions, the stator is connected to the bearing support by means of an elastic damper and the stator and bearing support are separated from one another by an air gap adjacent at least part of their facing faces.

Abstract: A disk storage drive is provided with a brushless drive motor having a stator with a winding. An external rotor coaxially surrounds the stator and is spaced therefrom by a substantially cylindrical air gap. The rotor includes a permanent magnet and a soft magnetic yoke. A hub is provided that is concentric to the yoke and is connected to the rotor for rotation therewith. The hub has a disk mounting portion on its outer peripheral surface that can be passed through the central opening of a standardized storage disk for mounting the storage disks for rotation therewith. At least half of the axial longitudinal dimension of the stator winding and the rotor magnet interacting therewith is housed within the disk mounting portion of the hub. The hub is made from a non-ferromagnetic material that is suitable for storage drive clean chamber use after dimensional finishing of the hub.