Air-bearing motor assembly for magnetic recording systems
First Claim
Patent Images
1. A motor assembly for use in a magnetic disk drive system comprising:
- a cylindrical shaft;
a stator secured to said shaft, said stator having an electromagnetic coil disposed upon the longitudinal axis of said shaft;
a rotatable hub housing said shaft and said stator;
a magnetic means attached to said hub disposed radially about said stator for interfacing electromagnetically with said coil to rotate said hub relative to said shaft;
first and second cylindrical sleeve members affixed to said hub and disposed about respective first and second ends of said shaft, with said stator being disposed between said first and second cylindrical sleeve members;
said sleeve members each having an inner air-bearing surface with a radial dimension which is slightly larger than the radial dimension of said shaft such that a gap exists between said shaft and each of said sleeve members,wherein the rotational movement of said hub relative to said shaft causes a pressurized air film to develop within said gaps.
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Accused Products
Abstract
An electric motor for a magnetic disk memory device includes a conical hub and a conical plane or grooved base and an integral air-bearing which significantly reduces non-repeatable runout, audible noise, and vibration. The base is rigidly attached to the shaft while the hub, which carries all of the load, rotates on the air cushion created by a pressurized air film. An upper sleeve controls the pressure fluctuation in the air film in a dynamic condition. In a static condition, the hub rests on a dry lubricated surface. The force developed due to the pressurized air film balances the rotating member in any condition.
33 Citations
25 Claims
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1. A motor assembly for use in a magnetic disk drive system comprising:
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a cylindrical shaft; a stator secured to said shaft, said stator having an electromagnetic coil disposed upon the longitudinal axis of said shaft; a rotatable hub housing said shaft and said stator; a magnetic means attached to said hub disposed radially about said stator for interfacing electromagnetically with said coil to rotate said hub relative to said shaft; first and second cylindrical sleeve members affixed to said hub and disposed about respective first and second ends of said shaft, with said stator being disposed between said first and second cylindrical sleeve members; said sleeve members each having an inner air-bearing surface with a radial dimension which is slightly larger than the radial dimension of said shaft such that a gap exists between said shaft and each of said sleeve members, wherein the rotational movement of said hub relative to said shaft causes a pressurized air film to develop within said gaps. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A motor assembly for use in a magnetic disk drive recording system comprising:
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a stationary motor shaft having a cylindrical outer surface and first and second ends; a first stationary base having a first cylindrical opening provided therein and a laterally extending first axial surface, said first end of said shaft being disposed within said first cylindrical opening; a second stationary base having a second cylindrical opening provided therein and a laterally extending second axial surface, said first end of said shaft being disposed within said second cylindrical opening, said first and second axial surfaces facing one another; a stator secured to said shaft, said stator having an electromagnetic coil disposed about the longitudinal axis of said shaft; a rotatable hub housing said shaft and said stator; a magnetic means attached to said hub disposed radially about said stator for interfacing electromagnetically with said coil to rotate said hub relative to said shaft; a first cylindrical sleeve member affixed to said hub and disposed about said second end of said shaft, said first sleeve member having an inner air-bearing surface of a first predetermined radial dimension which is slightly larger than the radial dimension of said shaft at said second end such that a first gap exists between said shaft and said first sleeve member; said stator disposed between said first stationary base and said first cylindrical sleeve; a second cylindrical sleeve member affixed to said hub and disposed about said first end of said shaft, and second sleeve member having an inner air-bearing surface of a second predetermined radial dimension which is slightly larger than the radial dimension of said shaft at said first end such that a second gap exists between said shaft and said second sleeve member, said second sleeve member also having two sleeve aligning surfaces which are substantially coextensive with said first and said second axial surfaces of said first and second bases, said sleeve aligning surfaces and said axial surfaces disposed at an angle with respect to the longitudinal axis of said shaft such that said sleeve aligning surfaces and said axial surfaces resist radial and axial movement of said hub relative to said shaft; wherein the rotational movement of said hub relative to said shaft causes a pressurized air film to develop within said first and second gaps, and also between said sleeve aligning and said axial surfaces. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. An air-bearing motor assembly for a disk drive recording system comprising:
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a stationary motor shaft having a cylindrical outer surface and first and second ends; a first stationary base having a first cylindrical opening provided therein and a laterally extending first axial surface, said second end of said shaft being disposed within said first cylindrical opening; a second stationary base having a second cylindrical opening provided therein and a laterally extending second axial surface, said second end of said shaft being disposed within said second cylindrical opening, said first and second axial surfaces facing one another; a stator secured to said shaft, said stator having an electromagnetic coil disposed about the longitudinal axis of said shaft; a rotatable hub housing said shaft and said stator, said hub including an upper plate having a laterally extending axial surface; a magnetic means attached to said hub disposed radially about said stator for interfacing electromagnetically with said coil to rotate said hub relative to said shaft; a first cylindrical sleeve affixed to said hub and disposed about said first end of said shaft, said first sleeve member having an inner air-bearing surface of a first radial dimension which is slightly larger than the radial dimension of said shaft at said first end such that a first gap is created between said shaft and said sleeve member, said first sleeve member also having an additional bearing surface which is substantially coextensive with said axial surface of said upper plate; said stator disposed between said first stationary base and said first cylindrical sleeve; a second cylindrical sleeve member affixed to said hub disposed about said second end of said shaft, said second sleeve member having an inner bearing surface of a second radial dimension which is slightly larger than the radial dimension of said shaft at said second end such that a second gap is created between said shaft and said second sleeve member, said second sleeve member also having two additional bearing surfaces which are substantially coextensive with said first and second axial surfaces of said first and second bases, said axial surfaces and said additional bearing surfaces of said second sleeve member form an angle with the longitudinal axis of said shaft such that said axial surfaces and said additional bearing surfaces of said second sleeve member resist radial and axial movement of said hub relative to said shaft; wherein the rotational movement of said hub relative to said shaft causes a pressurized air film to develop within said first and second gaps and between said additional bearing surfaces. - View Dependent Claims (20, 21, 22, 23, 24, 25)
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Specification