Abstract: A seal arrangement for sealing a gap between two housing parts, the gap being situated between opposite end faces of the housing parts. In the first housing part, there is a first receiving groove on the first end face, in which first receiving groove a sealing strip is arranged which protrudes out of the receiving groove and lies against a first outer flank. The sealing strip engages in an opposite second receiving groove of the second housing part and lies against a second outer flank. For position securing purposes and to achieve a sealing effect, even if there is no differential pressure, a spiral strip is provided, which spiral strip is situated in the first receiving groove and exerts an elastic force on the sealing strip.

Abstract: A bearing seal includes a seal case, a sleeve, and a thrust bumper disposed between the seal case and the sleeve to define spacing between the seal case and the sleeve during assembly of a wheel end implementing the bearing seal. The thrust bumper includes polytetrafluoroethylene.

Abstract: A secondary flow suppression structure includes: a turbine rotor blade including an outer shroud; a turbine stator vane located rearward of the turbine rotor blade and including an outer band; a seal surface facing the outer shroud at a radial outside of the outer shroud; a fin projecting from the outer shroud toward the seal surface; and a cavity formed between the seal surface and the turbine stator vane, formed in an annular shape extending in a circumferential direction, and provided with an opening portion opening radially inward on a virtual surface of the seal surface extending rearward. A front end of the outer band is positioned at the same height as the virtual surface in a radial direction, or positioned radially inward of the virtual surface.

Abstract: A sealing system which is designed to leverage the centrifugal acceleration of solids and liquids due to the natural rotation of the roller, expelling them outside, preventing most of the contamination from trying to penetrate the roller seals. Excess of contaminants that is not centrifugally expelled is blocked by the following internal sealing system.

Abstract: A transmission includes a first housing part, a second housing part connected to the first housing part, and bearings accommodated in the first housing part and supporting an input shaft in a rotatable manner. The input shaft projects through a recess that extends through the second housing part, and a cover part is connected to the first housing part. The cover part or a flange part inserted into the cover part accommodates a sealing system, which provides sealing with respect to the input shaft. The second housing part has an inlet for lubricating oil, which terminates in an axial bore being open with respect to the side of the first housing part facing the cover part, and in a second annular space. The opening of the axial bore facing the cover part is covered and/or sealed by the cover part, and rolling elements of two bearings at least also restricting and/or surrounding the second annular space together with the first housing part.

Abstract: A labyrinth seal includes a seal case with an inner-diameter leg encircling a rotation axis, and an insert fixed in the seal case and encircling the rotation axis. The labyrinth seal also includes a slinger encircling the rotation axis and wrapping around the inner-diameter leg to cooperate with the seal case to form a first part of a labyrinth path. The slinger rotates relative to the seal case. The labyrinth seal also includes a rotor that encircles the rotation axis, cooperates with the insert to form a second part of the labyrinth path, and interlocks with the insert to limit axial movement of the rotor when the rotor rotates relative to the insert. The labyrinth seal may be combined with a bearing cone, a bearing cup, and a plurality of rollers to form a roller bearing assembly.

Abstract: A hydrostatic seal configured to be disposed between relatively rotatable components. The hydrostatic seal includes a seal carrier. The hydrostatic seal also includes a beam extending axially from a forward end to an aft end, the beam cantilevered to the seal carrier at one of the forward end and the aft end, the beam free at the other end. The hydrostatic seal further includes a bellows seal operatively coupled to the seal carrier and in contact with the beam.

Abstract: A bearing system that accepts a journal of a roll includes a housing defining a cavity and having a forward wall that defines an opening into the cavity, the opening configured to accept the journal through the opening and into the cavity. A sleeve is positioned within the cavity of the housing, the sleeve configured to surround the end of the journal. A first seal is positioned within the cavity of the housing adjacent to the forward wall of the housing, the first seal having an engagement surface. A second seal is positioned within the cavity of the housing and operably connected to the sleeve, the second seal having an engagement surface in contact with the engagement surface of the first seal.

Abstract: Bearing and bearing protector with improved performance characteristics, reduced material use, lower cost of manufacturing and maintenance. Bearing protector includes air permeable element (e.g., wool, felt) that is configured to allow passage of air while preventing dust and other particulars from entering the bearing thereby improving bearing operation and longevity. Felt may be impregnated with a lubrication fluid to provide additional lubrication and protection. A self-lubricating bearing (SLB) is manufactured from an engineering plastic and is fitted with integrated bearing protector. The self-lubricating bearing includes one or more linear groves. When fitted onto an axle, the groves may receive excess plastic material that may occur during thermal expansion of the bearing during operation due to friction and heating. Plastic material may include an antifiction agent and the groves may be packed with consistent lubricant in order to reduce friction and improve performance.

Abstract: Conveyer pulley with improved performance characteristics reduced metal use, lower labor use manufacture, assembly and maintenance. The pulley includes a tubular housing, an axle pre-fitted with disks supports, two plastic endcaps press-fitted into the housing. Two self-lubricating plastic bearings with integrated bearing protectors are fitted onto the axle and into the end caps and are being kept in place by two retaining rings. Protector element of the bearing is fabricated from felt that is impregnated with a lubrication fluid. Inner grooves of the bearings may be packed with consistent lubricant.

Abstract: Disclosed herein may be a sealing structure for turbines, and a turbine and a gas turbine having the sealing structure. The sealing structure is mounted on a sealing housing of a vane sealing assembly of the turbine to prevent combustion gas passing through a blade of the turbine from being drawn into an internal space between a disk of the turbine and the sealing housing. The sealing structure may include a mounting plate mounted to the sealing housing, and baffles which are provided on the mounting plate at positions spaced apart from each other and protrude toward the disk. Therefore, thanks to the sealing structure, turbulent currents are generated in the flow of combustion gas that passes through the turbine blade. The generated turbulent currents block space between the sealing structure and the turbine disk, thus preventing the combustion gas from flowing into the internal space.

Abstract: A seal member (80) for a rotary regenerative scrubber (10) includes a hub (30), a rim (48) circumferentially surrounding the hub, and a plurality of spokes (86) extending from the hub to the rim. The hub, rim, and spokes define an axially facing seal face (88) configured to form a sealing engagement with an opposed seal surface of a rotary regenerative scrubber, and a mounting face (90) axially opposed to the seal face configured for mounting to a rotor assembly (20) of a rotary regenerative scrubber. The seal face includes a labyrinth seal (92) defined therein.

Abstract: A labyrinth seal including a stator and a non-contacting rotor, and annular elastomeric seals. The confronting surfaces of the stator and rotor define at least one interface passage, including a radially-outermost annular interface passage between an annular, outermost, radially-extending projection of the stator and an annular rearwardly-extending distal projection of the rotor that overlaps the radially-extending projection of the stator, the radially-outermost annular interface passage tapering outwardly and rearwardly at an acute angle relative to an axial reference line. The annular elastomeric seals are stationary with the stator during dynamic operation of the rotor, and are not contacted by a surface of the rotor during dynamic operation. The interface can also have two radially-disposed exclusion chambers, the outer exclusion chamber being defined in part by a radially-inboard projection of the rotor.

Abstract: There are provided a step seal, a seal structure, a turbo machine, and a method for manufacturing a step seal. The step seal suppresses leak of a fluid from a gap between a first structure and a second structure and is formed on the first structure so as to have a clearance between the step seal and a seal fin formed on the second structure. The first structure and the second structure face each other in a radius direction with the gap inbetween and rotate around an axis line relative to each other. The step seal includes: a step seal body having a step face facing an upstream side of a flow direction of the fluid and an opposed face facing the second structure; and a protrusion formed between the step face and the opposed face.

Abstract: In accordance with one aspect of the present disclosure, a roller bearing seal assembly is provided that includes a seal case and a rotor having a unitary, one-piece construction. The rotor is connected to the seal case and is rotatable relative to the seal case about an axis. The seal case and rotor include interfering portions that limit axial separation of the rotor and the seal case. In one embodiment, the rotor and seal case include at least one snap-fit connection that permits the rotor and seal case to be readily assembled. The at least one snap-fit connection includes the interfering portions which inhibit axial separation of the rotor and seal case after the rotor and seal case have been assembled.

Abstract: An apparatus relating to a rim seal for gas turbine engine comprising a wing extending into a buffer cavity with at least one set of protuberances including a first protuberance extending into the buffer cavity and a second protuberance extending from the wing into the buffer cavity, with the first and second protuberances being axially spaced from each other.

Abstract: A seal structure seals between a cover which closes an opening of a case for housing a part and the case by a sealing member. The cover is provided with an annular recessed portion attached to an end of a peripheral wall forming the opening of the case and a plurality of through-holes penetrating a bottom portion of the recessed portion and spaced apart from each other in a circumferential direction. The sealing member is formed integrally with the cover. The sealing member is integrally provided with a protrusion protruding from a bottom portion over an entire circumference in the recessed portion and an anchor portion engaged with each of the through-holes to fix the sealing member to the cover. Between at least the anchor portions in the recessed portion, a projecting portion for closing the gap between the protrusion and an inner wall of the recessed portion is provided.

Abstract: A slinger for a roller bearing seal includes (a) an inner section extending at least in a first direction parallel to a rotation axis of the slinger, encircling the rotation axis and forming a plurality of tabs configured to pressure fit the slinger onto a rotor of a roller bearing seal, (b) an outer section extending at least in the first direction at a greater distance than the inner section from the rotation axis and encircling the rotation axis, and (c) a middle section encircling the rotation axis and spanning between the inner section and the outer section, wherein the inner section, the middle section, and the outer section define respective portions of a single continuous part.

Abstract: A shaft seal assembly comprises a stator configured to engage a housing and a rotor positioned within the stator. The stator may include a main body, a stator inward radial projection extending radially inward from the stator main body, and a collection groove adjacent the stator inward radial projection. The rotor may include a rotor main body and a rotor axial projection extending from the rotor main body. The rotor axial projection may be positioned adjacent a distal end of the stator inward radial projection.

Abstract: A seal assembly and method of directing fluid flow away from a seal. The seal assembly comprises an inner seal member coupled to a rotatable shaft and an outer seal member which is either rotatable or static. The inner seal member has a plurality of knives spaced apart from each other and extending radially away from the shaft. The outer seal member has a rub surface disposed to abut a terminal edge of at least one of the plurality of knives to thereby form a seal. An outer knife of the plurality of knives of the inner seal member extends axially at an angle and is adapted to direct fluid flow away from the seal.

Abstract: A bearing assembly includes a housing having a flange at a first axial side and a bearing attachment section at a second axial side and a rolling-element bearing having inner and outer rings and a plurality of rolling elements. The rings are sealed on first and second axial sides by first and second seal disks, and the outer ring is pivotably mounted in the attachment section of the housing and the inner ring is configured to be mounted on a shaft. The assembly also includes a seal assembly configured to form a seal between the flange and the shaft at the first axial side of the housing, an end cover, an O-ring compressed between the second axial side of the housing and the end cover and at least one seal barrier between the seal assembly and the first seal disk and/or between the cover and the second seal disk.

Abstract: A line roller for guiding the fishing line onto a spool of a spinning reel for fishing includes a cylindrical guide member including a guide surface for guiding the fishing line on the outer perimeter, an axle bearing member that rotatably supports an inner perimeter surface of the guide member, a support member that supports the axle bearing member, and a grease holding unit that forms a space leading from the axle bearing member to the guide member and that holds a water-repellent grease in the space.

Abstract: Systems and methods for bearing housings are disclosed. A labyrinth seal bearing housing includes: a first seal element that is structured and arranged to be connected to a wall of a mixing vessel; a second seal element that is structured and arranged to be connected to a rotatable shaft; and a bearing support that is structured and arranged to be connected to the first seal element. The second seal element is configured to rotate relative to the first seal element and the bearing support. The first seal element and the second seal element are structured and arranged to create a tortuous flow path between an exterior and an interior of the mixing vessel.

Abstract: A line roller includes a cylindrical guide member including a guide surface on an outer perimeter for guiding a fishing line, an axle bearing member rotatably supporting an inner perimeter surface of the guide member, and a support member supporting the axle bearing member. The axle bearing member includes an inner ring supported by the support member, an outer ring integrally rotatable with the guide member, a rolling body disposed between the inner ring and the outer ring, and a grease holding unit holding water-repellent grease between the inner ring and the outer ring.

Abstract: A turbine arrangement and a gas turbine engine including a rim seal is configured with two cavities. The main fluid path, the two cavities, and a disc space are furthermore separated from another, but still in fluid communication with another, via three annular seal passages. The turbine arrangement also includes a plurality of cooling fluid injectors arranged underneath a radially inner vane platform. The rim seal is configured for an upstream guide vane and a downstream rotor blade.

Abstract: A turbine arrangement and a gas turbine engine comprising a rim seal is configured with two cavities. The main fluid path, the two cavities, and a disc space are furthermore separated from another, but still in fluid communication with another, via three annular seal passages. A rim seal is configured for an upstream rotor blade and a downstream guide vane. The seal arrangement includes a trailing edge of the inner blade platform, a leading edge of the inner vane platform and a first annular cavity and a second annular cavity.

Abstract: A seal for a turbomachine is disclosed. The seal assembly includes a rotatable shaft having a stepped outer circumferential surface that defines one or more annular protrusions axially-spaced thereon. A seal is radially-offset from the rotatable shaft and has one or more annular recesses that extend radially-outward from the inner circumferential surface of the seal. A plurality of holes are defined in both the inner circumferential surface and the one or more annular recesses of the seal, the one or more annular recesses being axially-spaced from each other and configured to receive the one or more annular protrusions in an interlocking fit.

Abstract: A rolling-bearing sealing device includes: an outer ring fixed to a rotating sprocket housing; an inner ring fixed to a non-rotating motor housing; a plurality of rolling elements between the outer and the inner rings; a retainer holding the rolling elements; and an oil seal including a slinger and a seal lip and fixed to the inner ring, in which a radial lip of the oil seal is pressed against the outer ring or the sprocket housing, and in which the sprocket housing has an end face provided with a side plate fixed thereto, for sliding contact by a side lip extended axially from the oil seal.

Abstract: A vacuum pump which, among others, has a lubricated ball bearing for supporting a rotor shaft of a motor, a bearing holder for holding the lubricated ball bearing, a first labyrinth seal provided between a motor arrangement space and a bearing arrangement space, and a balance adjustment member installed at a position of the rotor shaft to face the bearing holder and used for balance adjustment of a rotating body. A second concave and convex part to be fitted to the first concave and convex part forming the first labyrinth seal. By reducing a gap of the bearing arrangement space, the space in which the oil vapor is filled is reduced. Therefore, a moving amount of the gas, and thus, the decrease in the base oil of the lubricant can be suppressed, thereby extending the lubricating life.

Abstract: The present application relates to a compression stage of a low-pressure compressor of an axial turbomachine, such as a turboprop. The stage includes a rotor with, on its outer surface, two lip seals, each forming a radial annular rib; and a stator which includes an annular row of stator blades extending substantially radially; and an inner shell whose radial cross section includes a central part connected to the inner tips of the blades, a lateral part extending from each side of the central part to one of the two lip seals, respectively, thus forming a rotor with the annular cavity. The shell and the rotor are configured so that the radial section of the annular cavity has a length L1 and a height H, the length L1 being greater than the height H, which initiates rotational movement of the air contained therein. The speed of the air reduces its pressure, which limits downstream to upstream leaks.

Abstract: A seal for use in a machine, such as a machine with rotating members, includes a labyrinth seal with multiple fins. The seal is slotted and is designed to limit fluid flow to the desired amount from the high pressure side of the seal to the low pressure side of the seal inside partially or exclusively radially extending cavities between two rotating members. The rotating members may operate at different speeds with a common axis of rotation. The seal remains effective when the rotating members move axially in relation to one another despite the fins having a component parallel to the axis of rotation.

Abstract: Provided is a turbine in which seal fins (15) are provided to a hub shroud (41) to protrude toward a bottom surface (33a) of an annular groove (33), small gaps (H) are formed between the tip ends of the seal fins and the bottom surface of the annular groove, and assuming that the axial distance between a first seal fin (15a) disposed on the front edge side of the hub shroud among the seal fins and a front edge (41a) of the hub shroud is (L) and the axial distance between the front edge of the hub shroud and an inside surface (33b) of the annular groove is (Bu), the first seal fin is disposed to satisfy L/Bu<0.3.

Abstract: A labyrinth seal including a stator and a non-contacting rotor, and annular elastomeric seals. The confronting surfaces of the stator and rotor define at least one interface passage, including a radially-outermost annular interface passage between an annular, outermost, radially-extending projection of the stator and an annular rearwardly-extending distal projection of the rotor that overlaps the radially-extending projection of the stator, the radially-outermost annular interface passage tapering outwardly and rearwardly at an acute angle relative to an axial reference line. The annular elastomeric seals are stationary with the stator during dynamic operation of the rotor, and are not contacted by a surface of the rotor during dynamic operation. The interface can also have two radially-disposed exclusion chambers, the outer exclusion chamber being defined in part by a radially-inboard projection of the rotor.

Abstract: An oil deflector includes a segment array extending radially from a sleeve portion defining a longitudinal axis and configured for mounting on a shaft. The segment array includes a plurality of segments arranged circumferentially relative to the longitudinal axis and defines at least one oil diverting feature configured to create a pressure differential proximate the segment array or across a surface of the segment array during rotation of the oil deflector about the longitudinal axis. The segment array may define an oil diverting feature configured as a radially tapered peripheral surface, an axially inclined annular surface, at least one slot inclined relative to an annular surface of the array, and/or a combination of these configured to divert oil axially and/or radially from the oil deflector during rotation by the shaft in use.

Abstract: A seal assembly for sealing a stationary component and a rotating component including a seal tooth mating surface for mating with a seal tooth, the seal tooth mating surface including a plateau portion for sealingly receiving the seal tooth during a steady-state operation of the seal assembly and a first concave portion adjacent to the plateau portion for receiving the seal tooth with a clearance during a first non-steady-state operation of the seal assembly, wherein the seal tooth is coupled to one of the stationary component and the rotating component and the seal tooth mating surface is coupled to the other of the stationary component and the rotating component.

Abstract: A labyrinth sealing device is disclosed for use between a rotating shaft and a bearing housing. In some embodiments, an internal stator engages the housing and a rotor engages the shaft. A labyrinth pathway is defined between the rotor and stator to prevent the migration of lubricants and/or contaminants in either direction. The rotor acts as a running surface for the sealing element, but may also with a ground surface of the rotor to provide a pump that continuously draws lubricant away from the sealing lip toward a sump. In another embodiment, the stator and sealing element are combined as a single element formed from a sealing material. A recess in the sealing lip creates a pressure differential at the sealing surface and minimizes wear.

Abstract: In a system for contactlessly sealing a rotably mounted shaft from a housing, and a gear unit, oil is provided in the interior of the housing, the rotating shaft in particular projecting from the interior to the outer area, wherein a centrifugal disk is provided, which is connected to the shaft in torsionally fixed manner and has at least partially radially extending bores, which connect oil from a centrifugal chamber to a catch basin surrounding the centrifugal disk.

Abstract: A method and systems for a purged seal for an annular space are provided. The purged seal includes a first baffle element that extends from an inner surface of the annular space into the annular space at an oblique angle and a second baffle element that extends from an outer surface of the annular space above the first baffle element in a direction opposite gravity flow into the annular space wherein the second baffle element extends at an oblique angle. The system also includes a third baffle element that extends from the inner surface above the first baffle element in a direction of gravity flow into the annular space wherein the third baffle element extends into the annular space at an oblique angle with respect to the inner surface and wherein a distal end of the third baffle element is positioned proximate a distal end of the second baffle element.

Abstract: A seal ring for a rotatable shaft in a turbo machine includes a seal body configured for disposing around the shaft wherein a radial gap is defined between an inner surface of the seal body and the shaft. An upstream surface defined by the seal body extends from the inner surface, and an annular obstruction extends from the upstream surface of the seal body, wherein the obstruction is spaced away from the inner surface.

Abstract: A labyrinth seal system is disclosed, including a stationary component having a plurality of radially inwardly projecting, axially spaced teeth extending therefrom; and a rotor having a plurality of radially outwardly projecting, axially spaced protrusions, each protrusion having a low pressure side and a high pressure side, wherein the low pressure side of at least one protrusion extends farther in a radial direction than the high pressure side.

Abstract: An improved staggered seal assembly uses a static element and a rotating element to create a seal. The static element surrounds the rotating element and has at least one fin. The rotating element has at least one long fin and a set of shorter fins. A third component has a staggered fin. The fins create a leakage flow path which throttles the leakage across the seal from a high pressure zone into a low pressure zone.

Abstract: A main spindle device includes: a housing having an air supply passage; a spindle that is inserted into the housing and supported by a bearing so as to be able to rotate relative to the housing; and an air sealing member that is positioned between an outer circumferential surface of the spindle and the housing on a front side with respect to the bearing along a rotation axis of the spindle, has a substantially annular shape, and is detachably fixed to the housing with an inner circumferential surface of the air sealing member facing the outer circumferential surface of the spindle, wherein air supplied from the air supply source through the air supply passage is discharged into a gap between the outer circumferential surface of the spindle and the housing, thereby effecting non-contact air sealing at least between the inner circumferential surface of the air sealing member and the outer circumferential surface of the spindle.

Abstract: A stepped labyrinth seal having a plurality of teeth forming gaps between a stationary honeycomb member, where the cavities formed between adjacent teeth include a plurality of vortex flow generating strips on the wall of the cavity that redirect the leakage flow from a gap back toward the gap and in a direction toward the gap in order to limit the leakage flow through the gap. The vortex generating strips extend along the cavity floor and up the sides of the teeth forming the cavity. The strips slope downward from the downstream tooth toward the upstream tooth in the direction of rotation, and with a curvature in the direction of rotation. The stepped labyrinth seal is intended for use in a gas turbine engine having a plurality of stages in the turbine, with the labyrinth seal being used to seal the gap between rotating blades and the honeycomb surface on the stationary casing.

Abstract: A shaft seal reduces leakage between a rotating shaft such as a rotor and a stator. The shaft seal or shingle seal includes a plurality of compliant-plate members attached to the stator in facing relation. The compliant-plate members define a sealing ring between the stator and the rotating shaft. Each of the compliant-plate members includes a plurality of shingles, where adjacent compliant-plate members are disposed relative to each other such that the shingles are at least partially staggered in a direction of axial leakage.

Abstract: The invention relates to a rotary seal that comprises first (7, 8) and second (7, 8) parts mobile relative to each other about a rotation axis (A). The first and second mobile parts (7, 8) each include an interface area (30) having a plurality of protruding and recessed members with complementary shapes, the protruding and recessed members of one part (7, 8) engaging the protruding and recessed members of the other part (7, 8) in order to define decompression chambers with an increasing volume, the interface areas being located at a distance from each other without any friction between them.

Abstract: A seal assembly for a compressor includes a static member fixedly disposed within a compressor casing and having an end surface and a rotatable separator coupled with a compressor shaft and spaced from the static member. The separator has an axial end with a radial end surface located adjacent to the static member end surface such that a clearance space is defined therebetween. The separator has a plurality of openings extending inwardly from the end surface and spaced about the shaft axis such that land surface sections are defined on the end surface. The land surface sections or/and the openings are configured to prevent fluid flow radially inwardly through the clearance space. The static member has two annular walls receiving an end portion of the separator, with annular ridges providing labyrinth seals disposed against inner and outer surfaces of the separator, and an annular deflector with an angled deflector surface.

Abstract: A sealing assembly is provided. The sealing assembly includes a foil disposed circumferentially around a rotating component and configured to provide primary sealing to the rotating component between high pressure and low pressure sides and a spring system disposed adjacent to the foil. The spring system includes a plurality of features to facilitate foil surface to follow excursions of the rotating component, wherein the plurality of features provide secondary sealing from the high pressure to the low pressure sides between the foil and a stationary component.

Abstract: A stepped labyrinth seal for a turbomachine, the seal having a stepped portion with a redirecting groove formed thereon to redirect a leakage flow through the gap in substantially a reverse direction and onto a surface of the finger such that the dynamic pressure of the leakage flow is not substantially reduced and the static pressure increased. The cavity formed between adjacent fingers has a flow guiding surface that maintains the dynamic pressure of the flow, thereby keeping the flow at high velocity and low static pressure.

Abstract: A shaft seal serves to reduce leakage between a rotating shaft and a static shell. The shaft seal includes a plurality of compliant plate members, each having a root and a tip. The compliant plate members are secured to the static shell at their root in facing relation. The tips of the compliant plate members define a sealing ring between the static shell and the rotating shaft. An axial flow resistance member is disposed within the compliant plate members and serves as a barrier to axial leakage flow between the compliant plate members.

Abstract: A controlled leakage seal assembly having a first stationary portion adapted to be connected in substantially fluid-tight relation to a source of drilling fluid and a second portion adapted to be connected in substantially fluid-tight relation to a rotary portion including a washpipe. The seal includes a first housing and a stack of radially inwardly extending, spaced apart annular stators, and a second seal housing and stack of spaced apart radially outwardly extending annular rotors interleaved with one another. The seal assembly, a cartridge, permits the first and second housings to rotate relative to each other in substantially fluid-tight relation except for the drilling fluid entering an outlet region at greatly reduced pressure. In a preferred embodiment, the seal is held by a sleeve that permits the cartridge to be removed and replaced while the fluid connections to the sleeve remains.