Spindle motor winding for miniature hard disk drive
View Patent ↗A spindle motor for implementation in a low profile hard disk drive is described; that spindle motor having a novel configuration for the torque generating portion. The spindle motor includes a hub coupled with a disk platter; that has a rotational axis about a suitable bearing system. A stator portion of material for conducting magnetic flux from the rotor poles, and having twelve stems and a plurality of windings, is configured to be disposed beneath the disk platter and coupled to the drive base. A rotor portion coupled with the hub having back iron ring with a permanent sixteen pole magnet radially polarized is closely radially disposed to the stator. The number of poles of the rotor portion has a defined proportion relative to the number of stems of the stator portion. The windings provide conductivity for creating an electromagnetic force applicable at the torque radius for rotation of the hub.
1. A spindle motor for implementation in a low profile hard disk drive, said spindle motor comprising:
a hub, having a rotational axis, to which a platter of said low profile hard disk drive is coupled, said hub coupled to a suitable bearing system;
a stator portion configured to be coupled to said low profile hard disk drive, said stator portion having twelve stems and a plurality of windings, said plurality of windings providing conductivity for creating an electromagnetic force;
a rotor portion coupled with said hub, said rotor portion having a permanent magnet radially polarized, said permanent magnet having sixteen poles, wherein the number of poles of said rotor portion has a defined proportion relative to the number of stems of said stator portion, said stator portion and said rotor portion are configured for disposition beneath said platter;
a torque radius interposed between said stator portion and said rotor portion; and
wherein a created electromagnetic force applied at said torque radius provides a torque to said rotor portion, said torque enabling rotation of said hub.
2. The spindle motor as recited in claim 1 wherein said stator portion is an outer stator and said rotor portion is an inner rotor.
3. The spindle motor as recited in claim 1 wherein said plurality of windings provide a three phase stator portion wherein each phase of said three phase stator portion is comprised of four stems, wherein each fourth stem of each said phase is oriented circumferentially opposite each second stem of each said phase and wherein each said second stem retains direct opposite radial symmetry relative to each said fourth stem of each said phase.
4. The spindle motor as recited in claim 1 further comprising:
a torque constant greater than a defined threshold and having a diametrical physical dimension less than a defined maximum.
5. The spindle motor as recited in claim 1 wherein said suitable bearing system is a bearing system selectable from the group of bearing systems essentially consisting of:
a rotating shaft fluid bearing system, a fixed shaft fluid bearing system, a rotating shaft ball bearing system, and a fixed shaft ball bearing system.
6. The spindle motor as recited in claim 1 further comprising
a disk clamping system, said disk clamping system providing constraints on an axial load upon said platter.
7. A low profile disk drive for data storage comprising:
a housing enclosing a clean chamber;
a data storage disk disposed within said housing;
a read/write head for each data storing surface of said data storage disk, said read/write head positionable within said clean chamber and for reading from and writing data to said data storage disk;
a spindle motor for rotating said data storage disk, said spindle motor comprising:
a hub, having a rotational axis, to which said data storage disk is coupled, said hub coupled to a suitable bearing system;
a stator portion configured to be coupled to said low profile disk drive, said stator portion having twelve stems and a plurality of windings, said plurality of windings providing conductivity for creating an electromagnetic force;
a rotor portion coupled with said hub, said rotor portion having a permanent magnet radially polarized, said permanent magnet having sixteen poles, wherein the number of poles of said rotor portion has a defined proportion relative to the number of stems of said stator portion, said stator portion and said rotor portion are configured for disposition beneath said data storage disk;
a torque radius interposed between said stator portion and said rotor portion; and
wherein a created electromagnetic force applied at said torque radius provides a torque to said rotor portion, said torque enabling rotation of said hub.
8. The low profile disk drive as recited in claim 7 wherein said stator portion is an outer stator and said rotor portion is an inner rotor.
9. The low profile disk drive as recited in claim 7 wherein said plurality of windings provide a three phase stator portion wherein each phase of said three phase stator portion is comprised of four stems, wherein each fourth stem of each said phase is oriented circumferentially opposite each second stem of each said phase and wherein each said second stem of each said phase retains direct opposite radial symmetry relative to each said fourth stem of each said phase.
10. The low profile disk drive as recited in claim 7 further comprising:
a torque constant greater than a defined threshold and having a diametrical physical dimension less than a defined maximum.
11. The low profile disk drive as recited in claim 7 wherein said suitable bearing system is a bearing system selectable from the group of bearing systems essentially consisting of:
a rotating shaft fluid bearing system, a fixed shaft fluid bearing system, a rotating shaft ball bearing system, and a fixed shaft ball bearing system.
12. The low profile disk drive as recited in claim 7 further comprising
a disk clamping system, said disk clamping system providing constraints on an axial load upon said platter.