Seagate Technology Incorporated

Societe Suisse Pour L'industrie Horlogere Management Services S.a.

Komp-act Sa

Seagate Technologies, Inc.

Marcel Jufer

Gunter Karl Heine

John C Dunfield

Kamran Oveyssi

Ross Fleming

Andre Pittet

Mai Tu Xuan

Mai T Xuan

Salvatore De Benedictis

A gripper mechanism includes a stator and a pair of mobile grippers moveably coupled to the stator via a linear bearing, the stator comprising a housing and a permanent magnet mounted within the housing, the mobile gripper comprising a support portion, a coil mounted on the support portion, and a gripper finger coupled to the support portion. The gripper mechanism further includes at least one magnetic locking mechanism comprising at least a first permanent magnet mounted on one of the stator and the mobile grippers, and a complementary soft magnetic material portion or magnet mounted on the other of the stator and the mobile grippers.

Electromagnetic gripper

Embodiments described include a electrical linear motor comprising a stator and an actuation shaft movable in a linear axial direction with respect to the stator. The stator comprising a casing, an electromagnet array mounted in the casing. The electromagnet array comprising a central orifice extending in the linear axial direction within which the actuation shaft extends. The actuation shaft comprising a permanent magnet arrangement comprising a plurality of magnetic pole segments. The electromagnetic array comprising a plurality of electromagnets to generate a magnetic field that in conjunction with the magnetic field of the permanent magnet arrangement generates an electromotive force between the stator and actuation shaft having a component in the axial direction to drive the actuation shaft relative to the stator.

Linear motor with stacked electromagnets

A brushless permanent-magnet direct current motor has a permanent magnet which is magnetized to create an offset angle between detent and mutual torques for providing sufficient starting torque for all relative orientations between the stator and the rotor of the motor. This is accomplished by providing a permanent magnet in which the global magnetization of the magnet has been disrupted by the application of a local magnetic field to a portion of the magnet, thereby to provide a magnetic anomaly in the global magnetization. Also, a method of magnetization of the magnet is described.

Method of magnetizing a ring-shaped magnet

A disc drive data storage system according to the present invention comprises a housing, a central axis, a stationary member which is fixed with respect to the housing and coaxial with the central axis, and a rotatable member which is rotatable about the central axis with respect to the stationary member. At least one data storage disc is attached to and is coaxial with the rotatable member. Upper and lower ball bearing assemblies interconnect the stationary member and the rotatable member. At least one rotor magnet is attached to the rotatable member. A back-iron is supported by the stationary member. A stator winding is attached to the back-iron and has a slotless structure. The rotor magnet, back-iron and stator winding have a common axial position along the central axis and the stator winding is magnetically coupled to the rotor magnet such that the stator winding and the rotor magnet cooperate to reduce excitation of pure tone vibrations in the disc drive data storage system and to reduce transfer of the vibrations to the housing through the ball bearing assemblies.

Slotless spindle motor for disc drive

Starting of single phase permanent magnet direct current motors in the desired direction of rotation is accomplished by providing a look up table stored in memory giving the correct sign or polarity of current for the angular position of the permanent magnet rotor of the motor. This stored look up table is developed by initially injecting current pulses of opposite polarity at different angular positions of the rotor, determining the difference between the rise times, and mapping the sign and the magnitude of the differences versus angular position. Thereafter, to start the motor in the correct direction, it is only necessary to inject current pulses of opposite polarity to know the angular position of the rotor and the polarity of the current required to start the motor in the correct direction. After the motor has been started, it is commutated by blanking the drive current at the zero crossings of the back emf. The current is turned off prior to a back emf crossing, and turned back on after the back emf crossing. The stored look up table tells how long to apply drive current before blanking because the table indicates how far away the zero crossing is, which is convened into the time remaining before blanking the drive current. Several embodiments of single phase motors are disclosed, as well as circuits useful for starting a motor and sensing back emf.

Method for starting and commutating a permanent-magnet direct current

An 'ironless' bearing spindle motor for rotating at least one disc about a central axis in a data storage device comprises a housing, a stationary member, a hub, and a stator. A rotor magnet is attached to the hub. A bearing interconnects the hub with the stationary member such that the hub and rotor magnet are rotatable about the central axis. The stator is coaxial with the hub and includes an ironless stator winding. The ironless stator winding minimizes low-harmonic acoustic vibration peaks in the spindle motor, resulting in a spindle motor having a very quiet operation.

Ironless spindle motor for disc drive

A feed arrangement enabling detection of the movement of a stepping motor d providing such motor with a series of long duration pulses in the event of failure to step responsive to a short duration pulse. The detector comprises means for sampling a first signal developed by the current in the motor winding and generating a second signal which is the integral of the first, in order to detect whether or not the motor has stepped. The invention is intended for use with micromotors as found in timepieces.

Movement detector for a stepping motor

The invention provides a feed arrangement for a stepping motor which enables step detection and responsive to failure to step applies a series of wide (long duration) pulses in place of the normal short duration pulses. The detector includes sampling means for a first signal developed by the voltage induced in the motor winding during a predetermined period and there are means to generate a second signal which is the integral of the first signal, the amplitude of the second signal indicating whether or not the motor has stepped. The invention may find use with a timepiece micromotor.

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Morges, Switzerland

Marcel Jufer