Abstract: A reciprocating shaft's sealing apparatus combined a ferrofluid seal with a C-slip-ring and a Yx-seal-ring, characterized in that the first O-ring (3), the first Yx-seal-ring (4) and the first C-slip-ring (5) are installed into the grooves of the first fixed base (2), respectively, the second O-ring (15), the second Yx-seal-ring (14) and the first C-slip-ring (13) are installed into the grooves of the second fixed base (16), respectively, the first fixed base, the first pole piece (7) installed with an O-ring, a magnet (10), the second pole piece (11) installed with an O-ring and the second fixed base are placed in series at the bottom of the charmer of the sealing base (1), the above parts are pressed tightly by the end cover by means of the bolts connected with the sealing base, and the ferrofluid is injected into the magnet before assembling. The apparatus solves the problem of leakage in the reciprocating type of compressors.

Abstract: A ferrofluid sealing apparatus with small diameter used in low temperature, in which the first bearing (6), the first magnetism isolating ring (9), the first pole piece (10) installed with the first O-ring (11), the magnet (13), the second pole piece (15) installed with the second O-ring (14), the second magnetism isolating ring (16) and the second bearing (17) are provided to abut against in series and are sandwiched between the two inner bosses of the outer casing (8). the large end cover (19) is installed on the outer casing (8) using screw 18 to press the second bearing (17), the ferrolluid (2) is injected into the inner torus of the magnet (13), the permeable casing (1) installed with the adjusting shim (20) is installed into the inner hole of the above assembled bearings and pole pieces, the permeable casing (1) is fixed with the small end cover (5) using screw (4), the parameters of the teeth on the outside of the permeable casing are selected in such a way that the width is 0.5 mm, the height is 2.

Abstract: A magnetic fluid sealing and packing ring sealing device for reciprocating shaft with the packing ring having three oblique mouths, characterized in that the first packing ring (2) with three oblique mouths, the first pole piece (3) with “O” rubber seal ring, the first permanent magnet (4), the second pole piece (5) with “O” rubber seal ring, the second packing ring (6) with three oblique mouths, the third pole piece (7) with “O” rubber seal ring, the second permanent magnet (8), the fourth pole piece (9) with “O” rubber seal ring, the third packing ring (10) with three oblique mouths, the fifth pole piece (11) with “O” rubber seal ring, the third permanent magnet (12), the sixth pole piece (13) with “O” rubber seal ring, the fourth packing ring (14) with three oblique mouths are placed at the end of sealed chamber (1) with “O” rubber seal ring in order, the sealed chamber (1) with “O” rubber seal ring is connected by the bolt (16) to press the above parts tightly.

Abstract: A magnet is embedded in an outer rotational shaft provided in a bearing hole of a case, and an outer magnetic circuit and an inner magnetic circuit are formed on the outer peripheral surface and inner peripheral surface of the outer rotational shaft, respectively. In a magnetic fluid seal device, magnetic fluid is filled in minute gaps coming in contact with the outer peripheral surface and inner peripheral surface of the outer rotational shaft, and the two rotational shafts can be strongly sealed by the magnetic circuits formed by a magnet. As a result, the rotational shafts can be rotated while supported in a non-contact style. In addition, the dimension can be reduced, and the number of parts can be reduced.

Abstract: Embodiments of the invention can provide systems, methods, and an apparatus for providing a magnetic seal. According to one embodiment, a system having a magnetic seal can be provided. The system can include a rotary machine having a first component and a second component. A magnetic seal can be mounted to the first component and positioned relative to the second component to provide a gap between the magnetic seal and the second component. The magnetic seal can include a first magnetic element and a compliant material adapted to adjust in response to a force exerted on the magnetic seal by a second magnetic element. The second magnetic element can be mounted to the second component so that the gap between the magnetic seal and the second component can be modified in response to the force exerted by second magnetic element on the magnetic seal.

Abstract: In a device or method for sealing a shaft against penetration of a two-component toner mixture comprising magnetic carrier particles and toner particles, an annular, stationary sealing device is arranged radially at a distance of an annular gap around the shaft. The annular gap is charged with a magnetic field. The annular gap is filled with a mixture of a semi-fluid, highly viscous barrier medium and magnetic carrier particles, and wherein the mixture in the annular gap contains 40 to 85 percent by weight or 15 to 60 percent by volume of the magnetic carrier particles.

Abstract: The technical field of the invention relates to magnetic sealing devices used for transfer of torque involving rotating parts. Industries that deal in chemicals and pharmaceutics have a requirement to mix materials such as gases and liquids. This is carried out by mixers and agitators and similar other equipment. All devices involve a shaft that comes out of the body of the equipment, that is to say it pierces the equipment. The location at which the shaft enters the equipment is a potential point of leakage. One of the technical problems that the present invention tackles is that of providing a secure sealing that will reduce leakage. The magnetic seal assembly disclosed in the present invention provides a magnetic sealing device that gives a safe, trouble-free, robust, and leak-proof contactless seal for agitator drives and similar equipment used for industrial scale applications.

Abstract: A magnetic fluid shaft-sealing device includes a seal cover (3) attached to a pump housing (1) in which a rotary shaft (2) is mounted. The seal cover (3) includes a shaft hole (33) extending from an inner end face (31) through an outer end face (32) along an axis. The seal cover (3) further includes an annular recess (36) formed in the outer end face (32) and around the shaft hole (33). An inner ring portion (363) is defined between the annular recess (36) and the shaft hole (33). A collar (4) is mounted around the rotary shaft (2) to rotate therewith and includes a first end (41) received in the annular recess (36) and around the inner ring portion (363) of the seal cover (3). A magnet (6) and two pole pieces (5) are mounted between an outer periphery (364) of the inner ring portion (363) of the seal cover (3) and the first end (41) of the collar (4).

Abstract: The present disclosure describes a magnetic fluid sealing device having a shaft centered with respect to a magnetic structure and rolling element bearing, as well as a method for centering the shaft in the device. A compressible ring located in a groove on the shaft is used to partially fill the gap between the shaft and the rolling element bearing and to make contact with the rolling element bearing. The compressible ring aligns and centers the shaft with the rolling element bearing. A liquid locking material is added to the gap and hardened to couple the shaft and compressible ring to the rolling element bearing. An alternative self-alignment mechanism is also disclosed.

Abstract: A magneto-fluidic seal includes a shaft, a pole piece, and a plurality of sealing fluid rings located between the shaft and the pole piece. The sealing fluid rings may be defined by the shaft and/or the pole piece and contain a ferromagnetic fluid. At least one channel having a bottom is defined by either the shaft or the pole piece. A shunt is located directly adjacent to the bottom of the channel. The thickness of the shunt is based on the energy differential in the plurality of sealing fluid rings as the fluid is displaced from one side of the sealing fluid rings to the other side of the sealing fluid rings.

Abstract: The present invention provides a magnetic fluid seal device which enables to avoid the increase of the torque due to the aggregation of the solute of the magnetic fluid or the condition in which it is unable to start. According to the magnetic fluid seal device of the present invention, the hearer 151 is buried in the area where the magnetic fluid seal portion 140 is position inside the shaft 110. The torque meter 171 detects the rotation torque and the starting torque of the shaft 110, and when it is larger than the standard value, the magnetic fluid seal portion 140 is heated via the heater 151 inside the shaft 110. Thereby, the temperature of the magnetic fluid 146 and 147 rises, the solute of the magnetic fluid 146 and 147 is dispersed which lowers the viscosity thereof, and the rotation torque and the starting torque of the shaft 110 is lowered.

Abstract: A magnetic fluid seal includes a pole ring having an inner diameter, a rotatable shaft having an outer diameter, the rotatable shaft configured to extend along the inner diameter of the pole ring between an atmosphere side and vacuum side, at least one magnet coupled to the pole ring, the at least one magnet configured to emit a magnetic field having a strength and a shape, and grooves formed on either the inner diameter of the pole ring or the outer diameter of the shaft, the grooves capable of containing ferromagnetic fluid. The ferromagnetic fluid contained the grooves varies so as to improve the performance of the magnetic fluid seal.

Abstract: A magnet is embedded in an outer rotational shaft provided in a bearing hole of a case, and an outer magnetic circuit and an inner magnetic circuit are formed on the outer peripheral surface and inner peripheral surface of the outer rotational shaft, respectively. In a magnetic fluid seal device, magnetic fluid is filled in minute gaps coming in contact with the outer peripheral surface and inner peripheral surface of the outer rotational shaft, and the two rotational shafts can be strongly sealed by the magnetic circuits formed by a magnet. As a result, the rotational shafts can be rotated while supported in a non-contact style. In addition, the dimension can be reduced, and the number of parts can be reduced.

Abstract: A method of cooling a ferrofluid seal that includes moving air from an atmospheric side of the ferrofluid seal over one or more heat dissipating surfaces within the ferrofluid seal through an air path formed in the ferrofluid seal by incorporating one or more vent openings in a housing case and one or more fan blades on a surface selected from the group consisting of an outside surface of a shaft and an inside surface of the housing case where the space surrounding the shaft communicates with the one or more vent openings and where the moving air is caused by the rotation of the surface having the one or more fan blades.

Abstract: A magneto-fluidic seal includes a shaft; a sleeve surrounding the shaft; a housing made of soft magnetic material surrounding the sleeve; a magnet conducting a magnetic flux to the sleeve; and a magnetic fluid in a gap between the sleeve and the shaft, and/or in a gap between the sleeve and the housing. Optionally, the sleeve includes a channel on a longitudinal side, and wherein the magnet is positioned in the channel. The channel can be substantially circular or polyhedral. The magnet is preferably offset from a bottom of the channel, and oriented radially. Preferably, the magnet includes a plurality of segments, or flat plate-shaped magnets, arranged substantially evenly and circumferentially around the shaft.

Abstract: A system for mitigating a gas load imposed upon a high vacuum chamber, thereby reducing the overall pressure, includes a device mounted onto a rotating gantry. The device has a first chamber enclosing a high vacuum and a first region in which anode bearings are positioned. A rotatable shaft has a first portion extending into the first chamber and a second portion extending into the first region. A ferrofluid seal is positioned about the rotatable shaft and positioned between the first portion and the second portion, the ferrofluid seal fluidically separating the first chamber from the first region. At least one pressure-reducing unit is fluidically connected to the first chamber.

Abstract: A system for controlling a gas load imposed upon a high vacuum chamber includes a first chamber enclosing a high vacuum and positioned within an ambient environment, a second chamber enclosing a gas and positioned within the ambient environment adjacent to the first chamber, and a rotatable shaft having a first portion extending into the first chamber and a second portion extending into the second chamber. A ferrofluid seal is positioned about the rotatable shaft and positioned between the first portion and the second portion and the ferrofluid seal fluidically separates the first chamber from the second chamber. A control unit is attached to the second chamber and configured to control the gas enclosed in the second chamber such that a gas load in the first chamber is reduced.

Abstract: A self-cooling ferrofluid seal includes a housing having a housing case and an external pole piece integrally connected to the housing case where the housing case has a plurality of heat dissipating surfaces, a magnetic circuit within the housing formed in conjunction with the external pole piece, a rotatable shaft having one or more fan blades where the rotatable shaft is coaxially aligned within the housing, and a quantity of magnetic fluid between the rotatable shaft and the external pole piece forming a ferrofluid seal.

Abstract: A hermetic sealing system includes a chamber enclosing a high vacuum and positioned within an ambient environment and a rotatable shaft having a first portion extending into the chamber and a second portion extending out from the chamber. A ferrofluid seal is positioned about the rotatable shaft and positioned between the first portion and the second portion, the ferrofluid seal fluidically sealing the chamber. The ferrofluid seal assembly also includes a plurality of non-magnetic conductive elements configured to reduce an operating temperature in the ferrofluid seal assembly.

Abstract: A seal (40) provides sealing between two pressure zones (60, 62) and a rotating and non-rotating member (42, 52) by providing a first sealing member (46) between two seal lands (48, 50). A second seal (64) is mounted between the non-rotating member (52, 58) and one of the seal lands (50, 66) so as to control pressure around the seal lands (48, 50).

Abstract: A magnetic assembly for a multistage magnetic fluid rotary seal has a shaft, an annular permanent magnet, at least one pole piece and a radial gap formed between the shaft and the pole piece. The shaft and the pole piece have a plurality of trapezoidal-shaped ridges in opposing, non-contacting relationship forming the radial gap. The trapezoidal-shaped ridges have a flat top portion facing the radial gap and tapered sides that diverge away from the top portion.

Abstract: A magneto-fluidic seal includes a shaft; a sleeve surrounding the shaft; a housing made of soft magnetic material surrounding the sleeve; a magnet conducting a magnetic flux to the sleeve; and a magnetic fluid in a gap between the sleeve and the shaft, and/or in a gap between the sleeve and the housing. Optionally, the sleeve includes a channel on a longitudinal side, and wherein the magnet is positioned in the channel. The channel can be substantially circular or polyhedral. The magnet is preferably offset from a bottom of the channel, and oriented radially. Preferably, the magnet includes a plurality of segments, or flat plate-shaped magnets, arranged substantially evenly and circumferentially around the shaft.

Abstract: A magnetic fluid seal device that increases a permissible value of eccentricity for two members to improve sealability and decreases a variation of quality by injecting a magnetic fluid before assembling of parts, that saves structural members to achieve thinning, and that is easy to produce. An annular magnet 3 is buoyantly supported by the magnetic fluid 4 and 5 retained, and the space between a housing 1 and a shaft 2 is sealed by the annular magnet 3 and magnetic fluid 4 and 5.

Abstract: In an actuator, displacement resistance in axial movement of a slider is reduced to improve durability and enhance maintainability. At each side of the actuator, a slit is made between a top cover and a side cover. Magnetic bodies are provided on the surfaces of both side walls of the slit which face a fixing block of a slider and a magnetic fluid with a viscosity, surface tension, etc. is held between the magnetic bodies. At each side, the fixing block of the slider axially moves along the slit which is closed by the magnetic bodies.

Abstract: An apparatus and method are provided for sealing an outer surface 170 of a shaft 175 to an inner surface 165 of a hub 160. The seal includes a magnet 155, with top and bottom pole pieces 260, 265, and a ferrofluid 270 magnetically held in a gap 275 between the pole pieces 260, 265, and the hub 160 or the shaft 175. The top pole piece 260 has a cross-section that is L-shaped, with a horizontal portion 260a parallel to the magnet 155 and a shorter vertical portion 260b facing the shaft 175. In one version, the vertical portion 260b or the portion of the shaft 175 facing it is contoured to provide a flux gradient that axially concentrates the ferrofluid 270 in the gap 275. In another aspect, a catcher 335 is provided to reduce loss of ferrofluid 270 when the ferrofluidic seal 185 used to form an outside seal. In yet another aspect, a stationary ferrofluidic seal 345 is provided for sealing a stationary shaft 350 to a rotating hub 355.

Abstract: A seal apparatus provides the seal between inner and outer elements. The seal apparatus has a flexible sealing element for forming a seal with a first of the inner and outer elements. At least one support element is secured to the sealing element. The seal further includes means for magnetically interacting with the first element to bias the seal relative to the first element.

Abstract: A ferrofluid seal apparatus incorporating a multi-stage ferrofluid rotary seal adapted to provide a ferrofluid pressure-type seal about a shaft element extending between a first environment and a second environment, a first magnetic fluid disposed at one stage of the multi-stage rotary seal that faces the first environment, and a second magnetic fluid disposed at another stage of the multi-stage rotary seal that faces the second environment.

Abstract: A ferrofluid seal incorporates a metal seal comprised of two knife-edges and a flat metal washer is formed between a pole piece and the housing at the axial interface between the parts. One knife edge is machined into the inner face of the housing flange and the other knife edge is machined into the opposing pole piece face. This metal seal effectively seals the pole piece to the housing with a seal suitable for ultra high vacuum applications.

Abstract: A magnetic fluid seal device that increases a permissible value of eccentricity for two members to improve sealability and decreases a variation of quality by injecting a magnetic fluid before assembling of parts, that saves structural members to achieve thinning, and that is easy to produce. An annular magnet 3 is buoyantly supported by the magnetic fluid 4 and 5 retained, and the space between a housing 1 and a shaft 2 is sealed by the annular magnet 3 and magnetic fluid 4 and 5.

Abstract: A high-performance magnetic fluid sealer which maintains light-shielding property even when an interval change of a gap is large and a method for easily mounting a magnetic fluid sealer. A pair of annular magnets are supported by levitation from a lens barrel by magnetic levitation force which a magnetic fluid imparts in a fitting groove in the inner peripheral face of a lens barrel. Therefore, even when the lens barrel is greatly eccentric to the lens barrel, the pair of annular magnets move radially so as to keep a constant gap from the lens barrel with the magnetic fluid.

Abstract: A magnetic bearing isolator assembly. The assembly comprises first and second body parts, a ferromagnetic ring and a plurality of magnets received in spaced apart pockets. The first body part has a circumferential groove for receiving a ring of a ferromagnetic material. A radially outer groove in the first body part accommodates the second body part which has an outer, frusto-conical surface which is very slightly larger than the diameter of the smaller axial surface on the first part. The first and second parts are made from a composite fluorocarbon-carbon-graphite material with substantial glass filling therein.

Abstract: In order to make labyrinth seal lips on the periphery of a metal moving part of a turbomachine, a thick layer of refractory material that adheres to the metal is made prior to assembling the moving part, the refractory material advantageously comprising at least one metal selected for example from Fe, Co, and Ni, together with at least one ceramic selected for example from borides, nitrides, carbides, and refractory oxides. The labyrinth seal lips that are to be made are machined to their final dimensions in the deposited thick layer.

Abstract: The present invention relates to a spindle motor with a magnetic seal. A method and an apparatus are described for sealing spindle motors, preferably those used for disk storage units.

Abstract: In a housed state, a magnetic fluid 4 is positioned in a groove 11 and spaced from the outer circumference of a lens barrel 10, so that a fluorochemical surface modification film of the outer circumference of the lens barrel 10 can be prevented from deteriorating at a position to confront the magnetic fluid 4 in the housed state. Therefore, the deterioration of the fluorochemical surface modification film of the outer circumference of the lens barrel 10 does not proceed earlier at a local region, so that the premature wetting of the outer circumference of the lens barrel 10 with the magnetic fluid 4 can be prevented to elongate the lifetime of a light shielding device 1.

Abstract: A seal assembly (10) includes a first seal element (12) defining a fist sealing surface (14); displacement means including at least one electromagnet (20) operatively coupled with the first seal element (12), the displacement means being operable to displace the first seal element (12) via the, or each, electromagnet (20); and a second seal element defining a second sealing surface (28) associated with the first sealing surface (14), the first and second seal elements providing a seal. The invention extends to a combination comprising a gas turbine and a seal assembly. The invention further extends to a method of controlling a spacial relationship between respective sealing surfaces of two seal elements.

Abstract: In a ferrofluid seal that supports a pressure differential between a low pressure side and a high pressure side, a reservoir is created between a first seal stage at the low pressure side and its adjacent seal stage. The volume of the reservoir is relatively large compared to the volumes of the interstage areas between the other seal stages. In addition, a controlled leakage path bypasses the first stage from the reservoir to the low-pressure area. The leakage rate through the bypass path is controlled so that gas in the reservoir leaks to the low-pressure area relatively slowly, for example, the bypass path might equalize the pressure across the first stage over a five-minute interval. This arrangement prevents a seal stage burst from disgorging a large gas volume into the low-pressure side.

Abstract: A rotary cylinder apparatus which prevents a fluid from leaking from a contact portion of a piston and a cylinder member and consequently enables efficient rotation. The rotary cylinder apparatus comprises: a rotary cylinder member 2 which has cylinder chambers 22 and 23 formed thereto so as to pass through a rotary shaft center O and rotates around the rotary shaft center O; pistons 3 and 4 demonstrating reciprocating linear motion in the cylinder chambers 22 and 23; a piston holding member 5 which holds the pistons 3 and 4 and rotates around a rotation center X eccentric from the rotary shaft center O of the rotary cylinder member 2; and a casing 6 which rotatably supports the rotary cylinder member 2 and has at least one inlet 61 and at least one outlet 62, wherein the pistons 3 and 4 are rotatably supported at a position away from the rotation center X of the piston holding member 5 by a fixed distance and with that position at the center thereof.

Abstract: In a housed state, a magnetic fluid 4 is positioned in a groove 11 and spaced from the outer circumference of a lens barrel 10, so that a fluorochemical surface modification film of the outer circumference of the lens barrel 10 can be prevented from deteriorating at a position to confront the magnetic fluid 4 in the housed state. Therefore, the deterioration of the fluorochemical surface modification film of the outer circumference of the lens barrel 10 does not proceed earlier at a local region, so that the premature wetting of the outer circumference of the lens barrel 10 with the magnetic fluid 4 can be prevented to elongate the lifetime of a light shielding device 1.

Abstract: A motor or bearing which incorporates the use of a capillary seal adjacent a bearing race between the shaft and surrounding hub or housing. The seal may take a plurality of forms, including a straight capillary seal; a seal formed between the housing and a seal ball having different radius of curvatures (preferably with the housing internal surface having a larger radius); or a centrifugal capillary seal comprising a male cone supported on a fixed or rotating shaft, and a female cone supported on a housing. The use of a capillary seal rather than ferrofluid seal should also provide a reduction in resistance across the seal gap compared to a ferrofluid seal.

Abstract: A magnetic fluid seal with an excellent quality for reduction of leak of magnetic fluid. Among the projections of the pole pieces, the projections, that are nearest to the permanent magnet, are placed at positions intruding into the permanent magnet sides to hold the magnetic fluid in a space between the projections and the surface of the shaft.

Abstract: Disclosed is a high-performance magnetic fluid sealer which maintains light-shielding property even when an interval change of a gap is large and a method for easily mounting a magnetic fluid sealer. A pair of annular magnets (2, 3) are supported by levitation from a lens barrel (6) by magnetic levitation force which a magnetic fluid (4) imparts in a fitting groove in the inner peripheral face of a lens barrel (5). Therefore, even when the lens barrel (6) is greatly eccentric to the lens barrel (5), the pair of annular magnets (2, 3) move radially so as to keep a constant gap from the lens barrel (6) with the magnetic fluid (4).

Abstract: An exhaust apparatus for a differential exhaust mechanism having a labyrinth seal and a plurality of vacuum pockets includes a differential exhaust system for evacuating the vacuum pockets and an exhaust system for evacuating a chamber of exhaust gas. The differential exhaust system and the exhaust system are connected by control valves that can be opened and closed, enabling communication between the vacuum pockets and the interior of the chamber to be opened and closed (or connected and disconnected) as well. The valves are opened when a vacuum is being formed inside the chamber or when a malfunction occurs in the exhaust system, thus connecting the vacuum pockets and the chamber and preventing excessive pressure from building up on the hydrostatic bearing.

Abstract: A seal assembly for co-operation with a shaft comprising a seal member which, in use, in a first position, forms a seal against the shaft, a seal housing for retaining the seal member, means for applying a radially inward force to the seal member and means for applying a radially outward force to the seal member so that, when the means for applying a radially outwards force is operated, the seal member is dilated to a second position thereby enabling the seal assembly and the shaft to be fitted and disassembled in conventional manner, when the means for applying a radially outward force is removed the means for applying a radially inward force to the seal member returns the seal member to the first position.

Abstract: A stationary ferrofluidic seal for sealing a stationary shaft to a rotating hub. A formed magnetic is attached to the rotating hub, bounded by upper and lower members to form a shaped cavity. A stationary ring is attached to the shaft and extends into the cavity, which is filled with a conductive ferrofluid. The cavity has a uniform, concave cross section over at least part of its surface. The end of the stationary ring distal from the shaft is shaped so that in the region containing the fluid, the ring and cavity surface are equidistant from a set of points defining the seals “characteristic contour”.

Abstract: A bearing guided ferrofluid seal and seal carrier system that may be used with a bearing assembly with an outer annular ring surface. A seal carrier of the present invention has a carrier ferrofluid seal surface and a carrier bearing surface that includes a first carrier bearing surface and a second carrier bearing surface. A ferrofluid seal may be attached to the carrier ferrofluid seal surface and fixtured to the second carrier bearing surface. The second carrier bearing surface may be attached to the outer annular ring surface. In one preferred embodiment the first carrier bearing surface may be attached to the upper annular ring surface. In a separate preferred embodiment the ferrofluid seal may be attached to the carrier ferrofluid seal surface so that the seal inner diameter of the ferrofluid seal is fixtured to the second carrier bearing surface in order to minimize runout.

Abstract: A spindle-drive motor for hard drives having a baseplate, a shaft and one or more bearings for rotational mounting of a rotationally driven rotor, with at least one magnetic fluid seal arranged between the stationary part and the rotating part of the spindle-drive motor. The seal is formed of an upper and a lower yoke lamination and a magnet disk arranged between the yoke laminations, where a concentric chamber is formed so that it is open toward the inside on one side to hold a magnetically conducting fluid. A flux concentrating lamination extends into this chamber. In one embodiment of this invention, the flux concentrating lamination is in direct or indirect contact with one end face of the inner bearing ring of the bearing, while the outer part of the magnetic fluid seal is in direct or indirect contact with the end face of the outer bearing ring of the bearing.

Abstract: Magnetic fluid seals containing housings, magnets, pole pieces, gaps, magnetic fluids, shafts and bearings of standard type are modified to permit operation at two levels of magnetic intensity in the gaps. During exposure to the operating pressure difference that a seal is designed to withhold, the magnetic field intensity in the gaps is maintained at a relatively low intensity. Subsequently, the magnetic field intensity in the gaps is increased to yield burst-free operation. Various embodiments for adjusting the magnetic field intensity are disclosed. These include: magnetic fluid seal with a variable magnet to pole-block spacing; seal with hollow-shaft flux intensifier; seal with surrounding flux diverter; and seal with an internal magnetic coil that furnishes opposing magnetomotive force.

Abstract: A stationary ferrofluidic seal for sealing a stationary shaft to a rotating hub. A formed magnetic is attached to the rotating hub, bounded by upper and lower members to form a shaped cavity. A stationary ring is attached to the shaft and extends into the cavity, which is filled with a conductive ferrofluid. The cavity has a uniform, concave cross section over at least part of its surface. The end of the stationary ring distal from the shaft is shaped so that in the region containing the fluid, the ring and cavity surface are equidistant from a set of points defining the seals “characteristic contour”.

Abstract: A flexible magnetic brush seal is employed as a low flow fluid film seal and/or a diffusion and mass transfer prevention seal in a hydrogen generator to seal between a hydrogen atmosphere and a fluid on an opposite side of the seal. The brush seal is formed of a magnetic rubber flexible material, enabling the seal to be flexed and altered in dimension to fit a number of different sealing environments of different dimensions. The magnetic properties of the brush seal enable temporary securement of the brush seal to a brush seal holder prior to final securement.

Abstract: The present invention relates to a spindle motor with a magnetic seal. A method and an apparatus are described for sealing spindle motors, preferably those used for disk storage units.