Magnetic fluid hydrodynamic bearing

Claim 2

A bearing for a rotor comprising: a. permanent magnet means producing a magnetic field having north and south pole regions; b. magnetically-susceptible stationary bearing means in magnetic communication with the magnetic field at one of said north and south pole regions, said stationary bearing means having an annular cavity therein; c. a magnetically susceptible shaft having first and second portions for communicating with said magnetic field, said first portion rotatably disposed in said annular cavity and defining therebetween a constant gap length and a divergent pocket length contiguous with said constant gap length, said magnetic field being of substantially uniform density along said constant gap length and being of decreasing density along said divergent pocket length; d. magnetically susceptible field return means for communicating said magnetic field between said second shaft portion and said other of said north and south pole regions; and e. magnetically susceptible fluid means disposed in said gap and pocket lengths for rotatably supporting said first portion of said shaft, said fluid being retained in said pocket and gap lengths by said decreasing density of said magnetic field along said pocket length.

Claim 3

A hydrodynamic bearing comprising: a. permanent magnet means producing a magnetic field defining first and second pole regions; b. magnetically susceptible stationary bearing means in magnetic communication with one of said pole regions, said stationary bearing means having an annular cavity therein and an annular rim length contiguous with and terminating one end of said cavity; c. rotor means having a magnetically susceptible shaft, said shaft having first and second magnetic field communication portions, said first portion telescoped by said cavity and rim and spaced from said cavity by a uniform gap length and spaced from said rim by a divergent pocket length in communication with said gap length, said magnetic field being of substantially uniform density along said gap length and beiNg of decreasing density along said divergent pocket length; d. magnetically susceptible fluid means disposed in said gap length and divergent pocket length and retained in said gap and pocket length by said decreasing field density along said pocket length; e. magnetic field return means in magnetic communication with said second shaft portion and said other region of said permanent magnet means for communicating said magnetic field between said second shaft portion and said other pole region.

Claim 4

A hydrodynamic bearing comprising: a. permanent magnet means producing a magnetic field defining first and second pole regions; b. magnetically susceptible stationary bearing means in magnetic communication with one of said pole regions, said stationary bearing means having an annular cavity therein and an annular rim length contiguous with and terminating one end of said cavity; c. rotor means having a magnetically susceptible shaft, said shaft having first and second magnetic field communication portions, said first portion telescoped by said cavity and rim and spaced from said cavity by a uniform gap length and spaced from said rim by a divergent pocket length in communication with said gap length, said magnetic field being of substantially uniform density along said gap length and beiNg of decreasing density along said divergent pocket length; d. magnetically susceptible fluid means disposed in said gap length and divergent pocket length and retained in said gap and pocket length by said decreasing field density along said pocket length; e. magnetic field return means in magnetic communication with said second shaft portion and said other region of said permanent magnet means for communicating said magnetic field between said second shaft portion and said other pole region.

Claim 5

A gyroscope comprising: a. a housing having a cavity and an axis therethrough; b. a pair of magnetically susceptible bearing means supported by said housing along said axis, each said bearing means having an annular shaped opening communicating with said housing cavity; c. rotor means including a magnetically susceptible rotor shaft located along said axis in said housing and having ends telescoped by said openings in said stationary bearing means, said ends and said stationary bearing means defining therebetween a first length of substantially constant gap and a second length of divering gap, said diverging gap contiguous with said uniform gap and spaced intermediate said uniform gap and said cavity; d. magnetically susceptible, wettable, and nonconductive fluid means disposed in said uniform and divergent gaps for hydrodynamically supporting said shaft, said fluid completely filling said uniform gap and partially filling said diverging gap; e. permanent magnet means supported along said axis in contact with one of said stationary bearing means for producing a magnetic field of uniform density along said uniform gap length and of decreasing density along said divergent length, said field along said divergent gap length and said fluid therein cooperating to retain said fluid in said divergent gap length and also said uniform gap length; and f. magnetic field return means supported by said housing and communicating magnetically between said other pole region of said permanent magnet and said other stationary bearing means for providing a closed path for the magnetic field produced by said permanent magnet means from said first pole region of said permanent magnet means, through said first stationary bearing means, said shaft, said second stationary bearing means, and said field return means.

Claim 6

A gyroscope comprising: a. a housing having a cavity and an axis therethrough; b. a pair of magnetically susceptible bearing means supported by said housing along said axis, each said bearing means having an annular shaped opening communicating with said housing cavity; c. rotor means including a magnetically susceptible rotor shaft located along said axis in said housing and having ends telescoped by said openings in said stationary bearing means, said ends and said stationary bearing means defining therebetween a first length of substantially constant gap and a second length of divering gap, said diverging gap contiguous with said uniform gap and spaced intermediate said uniform gap and said cavity; d. magnetically susceptible, wettable, and nonconductive fluid means disposed in said uniform and divergent gaps for hydrodynamically supporting said shaft, said fluid completely filling said uniform gap and partially filling said diverging gap; e. permanent magnet means supported along said axis in contact with one of said stationary bearing means for producing a magnetic field of uniform density along said uniform gap length and of decreasing density along said divergent length, said field along said divergent gap length and said fluid therein cooperating to retain said fluid in said divergent gap length and also said uniform gap length; and f. magnetic field return means supported by said housing and communicating magnetically between said other pole region of said permanent magnet and said other stationary bearing means for providing a closed path for the magnetic field produced by said permanent magnet means from said first pole region of said permanent magnet means, through said first stationary bearing means, said shaft, said second stationary bearing means, and said field return means.

Claim 7

A bearing for a rotor comprising: a. permanent magnet means producing a magnetic field having north and south pole regions; b. magnetically-susceptible stationary bearing means in magnetic communication with the magnetic field at one of said north and south pole regions, said stationary bearing means having an annular cavity therein; c. a magnetically susceptible shaft having first and second portions for communicating with said magnetic field, said first portion rotatably disposed in said annular cavity and defining therebetween a gap length and a divergent pocket length contiguous with said gap length, said magnetic field being of decreasing density along said divergent pocket length; d. magnetically susceptible field return means for communicating said magnetic field between said second shaft portion and said other of said north and south pole regions; and e. magnetically susceptible fluid means disposed in said gap and pocket lengths for rotatably supporting said first portion of said shaft, said fluid being retained in said pocket and gap lengths by said decreasing density of said magnetic field along said pocket length.

Claim 8

A bearing for a rotor comprising: a. permanent magnet means producing a magnetic field having north and south pole regions; b. magnetically-susceptible stationary bearing means in magnetic communication with the magnetic field at one of said north and south pole regions, said stationary bearing means having an annular cavity therein; c. a magnetically susceptible shaft having first and second portions for communicating with said magnetic field, said first portion rotatably disposed in said annular cavity and defining therebetween a gap length and a divergent pocket length contiguous with said gap length, said magnetic field being of decreasing density along said divergent pocket length; d. magnetically susceptible field return means for communicating said magnetic field between said second shaft portion and said other of said north and south pole regions; and e. magnetically susceptible fluid means disposed in said gap and pocket lengths for rotatably supporting said first portion of said shaft, said fluid being retained in said pocket and gap lengths by said decreasing density of said magnetic field along said pocket length.