Abstract: A magnetic fluid seal device, with two or more pole pieces disposed around a magnetic rotating element on both sides of a permanent magnet, each pole piece being formed by alternately joining and first and second magnetic disks differing in inside diameter is related. Tiny gaps are formed between the inner circumference of the magnetic disks having the smaller inside diameter in each pole piece and the outer circumference of the magnetic rotating element, and a magnetic fluid is magnetically captured in these tiny gaps. The magnetic flux density in these gaps is set larger than the saturated magnetization of the magnetic fluid captured in these gaps and the thickness of the first magnetic disks is set somewhare between 0.02 and 0.0 mm.

Abstract: A long life, very low friction pump for use in a heat pipe pump or the like s disclosed. A first pump uses magnetically confined ferrofluid rings are both sealer and lubricant for a sliding pump piston in a two sided piston pump that minimizes the seal pressures on both sides of the ferrofluid seals. A second pump uses a magnetically confined ferrofluid slug as a self-sealing and self-repairing pump piston.

Abstract: A bearing for a vacuum device having an annular permanent magnet disposed about a rotatable shaft which has one end exposed to low pressure and the other end exposed to atmospheric pressure in which the rotatable shaft has a spherical member formed on the high pressure end for mating with a concave bearing surface having a magnetic fluid interposed therebetween and the rotatable shaft has a plurality of grooves formed thereon for aligning with a plurality of rings formed on an annular pole piece in which a magnetic fluid is disposed between the rings and grooves, which can be formed on the shaft, for providing a high pressure seal.

Abstract: A bearing apparatus comprises a housing formed of a non-magnetizable material and having a bottom portion, a fluid lubricating type radial bearing device provided coaxial with the housing and having a magnetic fluid sealing section and a radial bearing section, a thrust bearing device provided at the bottom portion of the housing, and a rotating shaft of a permeable material rotatably supported by the radial bearing device and thr thrust bearing device to extend through the radial bearing device. The magnetic fluid sealing section is disposed on the opening side of the housing with a predetermined spacing away from the radial bearing section whereby a space is provided between the magnetic fluid sealing section and a liquid surface of fluid lubricant filled in the radial bearing section.

Abstract: Bearing assembly, in particular for an electric motor of a household appliance, which has a bearing sleeve of a synthetic material forming the running surface of the bearing, a shaft mounted in said sleeve, and a lubricant between the running surface of the sleeve and the shaft. The bearing sleeve consists of a synthetic material in which particles of a magnetic material are imbedded. The lubricant is a magnetic lubricant of which so small a quantity is present between the shaft and the running surface of the bearing sleeve that the lubricant forms an annular film of small axial breadth relative to the axial dimension of the sleeve.

Abstract: In a bearing unit using a hydrodynamic lubrication film (5 or 25) of a lubrication fluid, a shaft (2 or 22) comprises plural spiral grooves (6a, 6b or 26) thereon, at least one circumference groove (7a, 7b or 27) thereon and an inner passage ((8+9+10) or (29+30)), which leads the fluid pumped by the spiral grooves (6a, 6b or 26) to the circumferential groove (7a, 7b or 27), therein, thereby to produce both functions of a kinetic pressure bearing and a static pressure bearing.

Abstract: A bearing assembly comprised of a housing, a shaft extending through the housing, a bearing disposed between the housing and the shaft and a seal disposed among the housing, the shaft and the bearing. The seal comprises an annular magnet, a pole piece affixed to the annular magnet and a ferrofluid injected into a gap between the pole piece and the shaft. Thus, a magnetic circuit for retaining the ferrofluid is formed by the seal, the bearing and the pole piece.

Abstract: A bearing and magnetic fluid seal assembly includes a shaft mounted by axially spaced-apart bearings for rotation relative to a housing. A magnetic fluid seal includes an annular magnet axially positioned between the bearings in the space that is wasted and not utilized for any purpose, and a thin, disk-like annular polepiece positioned between one of the bearings and the environment to be protected by the seal. Magnetic flux from the magnet is conducted by a magnetically permeable housing or shaft to an annular gap between the outside diameter of the polepiece and the housing. A magnetic fluid is retained in the gap by the magnetic flux, thereby providing an exclusion seal. Embodiments utilizing radially and axially polarized magets are provided. A magnetic fluid seal can be provided at each end of the assembly. The bearings supporting the shaft can be magnetically permeable or nonmagnetic. The seal(s) can be electrically conducting or nonconducting depending upon the type of ferrofluid used.

Abstract: A ferrofluid seal apparatus and a method of assembling the seal apparatus, the seal apparatus comprising a housing, an annular permanent magnet and at least one annular pole-piece element, and a sealing ring to secure and seal the permanent magnet and the pole-piece element within the housing, the sealing ring having an inwardly extending shoulder at one radial end, to retain the permanent magnet and pole piece within the sealing ring. The sealing ring is composed of a deformable material and retains, by compressive force, the permanent magnet and pole piece, by press-fitting the sealing ring into the annular space between the outer surface of the permanent magnet and the annular pole piece and the inner surface of the housing, to secure the permanent magnet and pole piece within the housing.

Abstract: A hydrostatic bearing system utilizing ferromagnetic fluid exclusively as working fluid including that used for sealing for preventing the ferromagnetic fluid itself from escaping outside the bearing. In order to accomplish the objects and function, the hydrostatic bearing system proposed here comprises, in addition to ordinary parts or components used in the conventional type, a fluid chamber for containing the ferromagnetic fluid as a working fluid, a circulating passage, at least a recovery groove for collecting the fluid squeezed out of the fluid chamber, a magnetic seal to prevent the fluid from escaping and at least an impelling device to forcibly deliver the ferromagnetic fluid at a predetermined pressure and flow rate. The impelling device can be constructed utilizing a shifting magnetic field, or multilayered rings fabricated of piezo-electric components, or of impelling cylinders having axially lengthenee or reduced in length.

Abstract: A bearing and magnetic fluid seal assembly includes a shaft mounted by axially spaced-apart bearings for rotation relative to a housing. A magnetic fluid seal includes an annular magnet axially positioned between the bearings in the space that is wasted and not utilized for any purpose, and a thin, disk-like annular polepiece positioned between one of the bearings and the environment to be protected by the seal. Magnetic flux from the magnet is conducted by a magnetically permeable housing or shaft to an annular gap between the inside diameter of the polepiece and the shaft. A magnetic fluid is retained in the gap by the magnetic flux, thereby providing an exclusion seal. Embodiments utilizing radially and axially polarized magnets are provided. A magnetic fluid seal can be provided at each end of the assembly. The bearings supporting the shaft can be magnetically permeable or nonmagnetic. The seal(s) can be electrically conducting or nonconducting depending upon the type of ferrofluid used.

Abstract: A rolling bearing comprising an outer race and an inner race situated coaxially therein both races defining an annular space therebetween and a row of rolling members in the annular space between the races, and generally annular ring seals, having inwardly directed sides and inner and outer peripheral areas, for sealing off from the surroundings, on either side of the rolling members, the annular space between the races wherein a lubricant is present, wherein the inwardly directed sides of the sealing rings is formed with at least one cavity containing a fluid magnetic lubricant, and a magnetic forming magnetic fields, the poles of which fields are located on either side of the cavity, near the races.

Abstract: A rolling bearing comprising at least one outer and one inner race situated coaxially therein and a row of rolling members situated in a space between these races and first and second seals for sealing the space between the races off from the outside surroundings on either side of the rolling members, to prevent a lubricant present from escaping to the outside and to prevent foreign matter from penetrating into the space from outside, the first seal being generally annular and the second seal comprises a sealing lip that is in communication with one of the races and having an inwardly directed side which rests springily against the other race, the first annular seal having an end portion that lies behind the inwardly directed side of the sealing lip, at a short distance from the other race thereby defining first, open, slot-shaped annular space between the seals and the said inner race and which space contains a quantity of magnetic fluid, and a magnet forming a magnetic field whereby such fluid is held withi

Abstract: An electric motor including an integral ferrofluid bearing provides significant reduction in non-repeatable runout, stray flux, and audible noise over conventional motors using ball bearings. The motor includes a hub and a base, with the base attached to a tapered magnetically permeable shaft which defines an inner bearing race, and the hub attached to an internally tapered, magnetically permeable sleeve which defines an outer bearing race. Permanent magnets surround and are rotatable with the sleeve to provide mangetic fields which interact with the stator winding to cause rotation of the hub and sleeve. In addition, the permanent magnets form magnetic flux paths with the shaft and the sleeve to maintain ferrofluid lubricant between the inner and outer bearing races.

Abstract: A low friction bearing arrangement includes first and second poles of magnetically permeable material which define first and second pole surfaces which are spaced apart. The first and second poles also define first and second side surfaces, respectively, which are aligned. A quantity of ferrofluid, positioned intermediate the first and second pole surfaces and adjacent the first and second side surfaces, is held by means of a fringing magnetic flux between the first and second side surfaces at a level which extends beyond the side surfaces. A rotatable shaft of nonmagnetic material is supported on the quantity of ferrofluid and is held out of contact with the side surfaces thereby, such that the shaft may be freely rotated.

Abstract: A ferrofluid seal for a bearing application with a stationary shaft about which a hub rotates. The seal consists of a permanent magnet and one or more annular pole pieces which form a magnetic circuit with the bearing shaft. The magnetic circuit includes an annular gap between the shaft and the pole pieces in which the magnetic flux traps a magnetic fluid which bridges the gap to form a seal. The shaft is tapered in the gap area to form a wedge-shaped gap which accommodates changes in the magnetic fluid volume due to temperature variations while holding the fluid within the magnetic field to maintain the seal. The pole piece which forms the gap has a straight annular face located at a constant radial distance from the shaft axis. At high operating temperatures expansion of the magnetic fluid causes the fluid to fill the taper of the shaft, but, since the shaft is stationary, fluid spash is eliminated. The straight surface of the pole piece controls fluid splash caused by centrifugal force.

Abstract: Compensation for shaft excursion in a seal housing is achieved with a fluid film bearing in which bearing fluid is supplied to the bearing region at a pressure and flow rate which depend upon shaft rotational speed. In a disclosed embodiment, the bearing fluid is provided from a centrifugal fluid seal which delivers part of its fluid to the bearing region as a function of centrifugal pressure. A magnetic fluid seal is employed for zero and low speed operation. The shaft includes an annular collar which rotates in an annular cavity formed in a seal cartridge which is rotationally stationary but capable of small axial displacements to compensate for axial shaft displacement. A spring biases the cartridge in opposition to the axial forces of the magnetic fluid seal so as to axially balance the system at zero and low shaft speed operation.

Abstract: Provides new magnetic fluid bearings and magnetic fluid seals incorporating a pressure responsive system for automatically controlling the supply of magnetic fluid to the magnetic fluid feed area of such bearing or seal. The system for controlling the supply of magnetic fluid includes a reservoir of magnetic fluid and a conduit leading from the reservoir to the magnetic fluid feed area of the magnetic fluid bearing or magnetic fluid seal. A portion of the conduit is subjected to a magnetic field which establishes a pressure responsive magnetic fluid plug in that portion of the conduit to automatically control the flow of magnetic fluid to and from the reservoir as a function of the difference in pressure between the magnetic fluid feed area of the bearing or seal and the reservoir.

Abstract: A composite ferrofluid bearing and seal apparatus which comprises a ferrofluid seal apparatus which contains disposed therein a bearing element, to form a ferrofluid-film bearing with the surface of a shaft, the ferrofluid seal apparatus retaining the bearing ferrofluid film within the bearing cavity, by forming a ferrofluid O-ring seal, held by magnetic flux, at each end of the bearing element, the composite ferrofluid bearing and seal apparatus acting to contain the bearing ferrofluid film within the fluid-film bearing cavity and to exclude gases from being entrained in the ferrofluid.

Abstract: Sealing and bearing means by use of ferrofluid, in which a magnet is utilized effectively in cooperation with grooves engraved on one surface thereof, the grooves having the function for generating the dynamic pressure of the ferrofluid. The ferrofluid is retained in a gap between a rotary shaft and a magnet of cylindrical or disc type enclosing the rotary shaft concentrically. The magnet performs excellent two functions of bearing and sealing respectively.

Abstract: The compact ferrofluid seal and radial bearing assembly, particularly useful for the support and sealing of a shaft, such as a computer disk drive shaft, where space is at a premium, which assembly comprises a magnetically-permeable radial bearing apparatus having inner and outer race elements, moveable elements, and a cage element to retain the moveable elements, and a ferrofluid single-stage seal apparatus comprising a radially-polarized permanent magnet to retain a sealing amount of ferrofluid in a radial gap between the inner and outer race elements.

Abstract: A ferrofluid thrust and radial bearing assembly for a rotatable shaft element, which assembly comprises: a housing characterized by a shaft-receiving space, to define a radial bearing inner surface and a thrust bearing surface at the one end of the shaft-receiving space; a shaft element within the shaft-receiving space, one end of the shaft element disposed to rotate on the thrust bearing surface, and the other end of the shaft extending from the other end of the housing; a ferrolubricant in the shaft-receiving space, to form a lubricant for the thrust bearing and the radial bearing assembly; and a ferrofluid exclusion seal at the other end of the housing and about the other end of the shaft-receiving space, the exclusion seal comprising an annular permanent magnet and at least one annular pole piece, one end of which extends into a close, noncontacting relationship with the exterior surface of the shaft, to form a radial gap, and the ferrofluid within the shaft-receiving space defining a ferrofluid seal at t

Abstract: This specification discloses a carriage apparatus including a carriage movable relative to a fixed base bed and driven by a feed screw or the like. Means for well guiding the movement of the carriage is provided between the base bed and the carriage. A ball nut threadably fitted on the feed screw for driving the carriage is coupled to the carriage through a housing, and means for absorbing displacement of the ball nut is provided between the two. Further, to prevent chiefly the rotation of the ball nut, a bellows having high rigidity for torsion and low rigidity for the other forces is provided between the ball nut and the carriage.

Abstract: Generator rotor, including an inner and an outer concentric rotor part having a non-drive side and enclosing a high vacuum space, a first and a second bearing disposed on the non-drive side, a hollow shaft end of the outer rotor part being supported in the first bearing, a journal of the inner rotor part being extended through the hollow shaft end and separately supported in the second bearing, a high-vacuum contactless liquid seal disposed between the hollow shaft end and the journal and having a sealing gap formed therebetween, a co-rotating sealing-liquid reservoir connected to the liquid seal, and magnetic field means for holding magnetic sealing liquid in the sealing gap.