Abstract: A robot joint including a first part and a second part arranged to have a relative movement in between, and a joint gap spacing the first part and the second part from each other, wherein the robot joint includes an inflatable seal accommodated in the joint gap to provide a fluid-tight sealing of the joint. The disclosure also relates to a robot including the robot joint, a system including the robot and a method for sealing a joint gap of a robot joint.

Abstract: A method of manufacturing a gas cylinder according to an embodiment of the present invention may include applying a sealant to at least a portion of inner surface of a hollow spindle; inserting a cylinder assembly contacting the inner surface of the spindle through an inlet of the spindle and forming a sealant film on an inner surface of the spindle by frictionally applying the sealant to the inner surface of the spindle; and hardening the sealant film to form a cured film cylinder in contact with the inner surface of the spindle.

Abstract: An industrial robot includes a robot control configured to execute a robot program and a robot arm having a plurality of links connected by joints. The joints are configured to automatically adjust the links relative to one another according to the robot program, wherein at least one of the joints is configured as a rotary joint that connects a first link of the plurality of links to an adjacent second link for rotation relative to one another. The first link comprises a shaft sealing ring that has a sealing lip formed from a PTFE material, and the second link has a shaft portion with a running surface formed from a PTFE material, on which the shaft sealing ring bears with its sealing lip in a sealing manner. A method for moving the robot arm in a clean room is also disclosed.

Abstract: A gas compressor with a drive power section engaging, through a seal assembly, a dual activating compressor section. The drive power section has a hydraulic drive cylinder, an upper hydraulic drive chamber, a lower hydraulic drive chamber, and a hydraulic drive piston. The dual activating compressor section has a compressor cylinder with an upper compression chamber and a lower compression chamber separated by a compressor piston, a first piston locator sensor, and a second piston locator sensor. The drive power section receives a hydraulic drive fluid and discharges spent hydraulic drive fluid. The dual activating compressor section is configured for receiving a source vapor or gas and discharging compressed vapors while the drive power section operates. The drive power section is movable between a first orientation and a second orientation.

Abstract: In a master cylinder, a piston seal provided in a circumferential groove includes an annular base section, an inner circumferential lip section protruding from an inner circumferential side of the base section to come into sliding contact with an outer circumferential surfaced of a piston, an outer circumferential lip section protruding from an outer circumferential side of the base section to abut the circumferential groove, and an intermediate protrusion section protruding from a portion between the inner circumferential lip section and the outer circumferential lip section of the base section to a position further forward than the outer circumferential lip section. At least one inner circumferential side groove extending in an axial direction and opened at a front end side of the intermediate protrusion section is formed in a surface of the inner circumferential lip section side of the intermediate protrusion section.

Abstract: Arrangements for promoting the restriction of fluid flow along a shaft via providing a deformable ring member in an annulus between the shaft and housing. In an initial general condition, the deformable ring member permits free fluid flow in a general direction along the shaft while in a second, constricted condition, the deformable ring closes or blocks a gap or clearance normally conducive to free fluid flow to thereby restrict fluid flow. An actuation medium, which can take any of a very wide variety of forms, preferably promotes constriction of the deformable ring member directly or indirectly.

Abstract: A sealing mechanism functioning as a separator between two spaces having different pressures or gases, includes: a housing; a shaft inserted into the housing; and a plurality of annular sealing members sealing a gap by contacting a part of the shaft or a radial outer surface of a rotary portion fixed to the shaft. The respective annular sealing members include materials having different material quality and are disposed at different positions in an axial direction parallel to a center axis of the shaft.

Abstract: A sealing system is between two components, which are translatorily movable relative to each other along a motional axis for sealing off a high-pressure side from a low-pressure side. The sealing system includes pressure relief elements. The use of such a sealing system produces an intermediate-space pressure cascade.

Abstract: A radial shaft seal is provided for sealing between high and low pressure sides in an annular space between a shaft and a static structural receiving part, wherein the shaft seal is rotationally symmetric and arranged coaxially to the shaft. A first sealing ring has an inner periphery bulging toward the low pressure side and forms a first sealing lip abutting the shaft. A spacer ring has first and second faces directed towards the high and low pressure sides, respectively. An elastic shaped part has an outer periphery abutting the second face of the spacer ring and an inner periphery bulging toward the high pressure side and abutting the first sealing lip. At least the spacer ring and elastic shaped part define a cavity subjected to the high pressure side or a control pressure which presses the first sealing lip against the shaft via the elastic shaped part.

Abstract: An adjustable seal and method for varying a radial distance between the adjustable seal and a rotor of a turbomachine are provided. The adjustable seal may include a first annular member defining a plurality of radial channels, and a second annular member defining a plurality of slots at least partially extending therethrough. The second annular member may be concentric with the first annular member and configured to rotate relative to the first annular member. The adjustable seal may also include a plurality of seal segments interposed between the first annular member and the second annular member. Each seal segment of the plurality of seal segments may be slidably disposed in a respective radial channel of the plurality of radial channels and may have an axial projection slidably disposed in a respective slot of the plurality of slots.

Abstract: A vehicle axle assembly includes a hub, which is mounted on a cylindrical axle body so that it can rotate about a central longitudinal axis, and an axially inner and an axially outer shaft sealing ring for indirect or direct sealing between the axle body and the hub. In order to enable an autonomous feed of pressure medium into a vehicle tire, the vehicle axle assembly includes an annular chamber that is formed between the two shaft sealing rings, the axle body and the hub, a first pressure medium line that extends through the axle body or one of the two shaft sealing rings and opens out into the annular chamber, and a second pressure medium line that extends out of the annular chamber through the hub and is designed to be connected to a wheel that is secured on the hub.

Abstract: A fluid machine has a housing and a rotating portion that rotates relative to and is at least partially disposed within the housing. The housing is coupled to a seal assembly comprising a plurality of seal channels having a plurality of seal rings. Each of the plurality of seal channels comprises a respective one of the plurality of seal rings.

Abstract: A pipe joint has a body, and an annular packing is mounted to the opening of the body into which a fluid tube is inserted. The packing is provided with: a body section having a substantially rectangular cross-sectional shape; and a seal section protruding in the radial direction from the inner peripheral surface of the body section. The seal section is formed at substantially the center of the body section in the widthwise direction thereof and is formed in a triangular cross-sectional shape tapering to the inner peripheral side. When the fluid tube is inserted in the opening, the seal section of the packing makes sliding contact with the outer peripheral surface of the fluid tube.

Abstract: An inner peripheral surface (10C) of an elastic seal (10) having a U-shaped cross section and made of rubber is supported by a guide ring (20) having a flat cross-sectional shape and made of synthetic resin.

Abstract: The invention provides a valve useful as a production valve in or connected to a production tree subsea, and other similar uses subsea or topside, the valve comprises a valve element, a valve element pressure housing, an actuator, a stem and a bonnet, the actuator is via the stem operatively arranged to close or open a fluid passageway through the valve element, the bonnet enclose the stem and is connected to the valve element pressure housing and seals are arranged between the stem and the bonnet for sealing against the pressure of the valve element pressure housing. The valve is distinctive in that the valve comprises at least one seal for sealing between stem and bonnet, the seal having identical inner sealing diameter against the stem and outer sealing against a single body or element of the bonnet.

Abstract: A seal for sealing a sealing surface 2 between a first machine part 1 having a seal accommodating structure, preferably a groove, and a second machine part 3, which defines the sealing surface 2 and can be moved relative to the first machine part 1. The seal seals a high-pressure area between the machine parts 1, 3 from a low-pressure area and has a retaining element 5 for positionally fixing the seal in the seal accommodating structure, and a sealing lip 6 which is formed on the retaining element 5 and is made from an elastomeric material having a sealing edge 7 formed at a free end of the sealing lip 6 for abutment on the sealing surface 2. The sealing lip 6 has a high-pressure surface area 10 bordering the high-pressure area, and a low-pressure surface area 11 bordering the low-pressure area.

Abstract: Due to increasingly strict requirements and regulations, it is becoming more and more important for piston compressors to reduce the amount of leakage of operating medium through the seal of the piston rod. Conventional seals comprising packing rings and/or packing ring combinations always have a certain amount of leakage, both during operation and when at standstill, which is why they are not usable for certain applications, or the complexity involved in such a seal increases considerably. A further problem involving the seals of piston rods relates to transverse movements by piston rods during which the sealing action of the seal must be maintained. Proposed is, therefore, a sealing arrangement according to the principle of a sealing medium barrier providing that the sealing elements 8, 9 are arranged in radial direction at a distance relative to the radial end of the recess 10 that receives the sealing elements 8, 9.

Abstract: A seal assembly for providing a seal between a pair of relatively rotatable components has; a first seal ring (30) mounted in sealing relationships, non-rotatably and for limited axial movement on a first of the components; a second seal (50) ring mounted in axially aligned relationship to the first seal ring, said second seal ring being mounted in sealing relationship, non-rotatably and for limited axial movement on a second of the components; first resilient means associated with the second seal ring urging it axially towards the first seal ring, second resilient means (40) acting on the first seal ring urging it away from the second seal ring to separate the first and second seal rings; and a centrifugal actuator (19) associated with the first seal ring, said centrifugal actuator comprising a radially extending chamber (38) between the first seal ring and the component associated therewith, said chamber being connected to a source of fluid, whereby when the components rotate relative to one another with fl

Abstract: An energized composite metal to metal seal. A sealing device includes a metal seal with a metal sealing surface facing radially outward, and another metal sealing surface facing radially inward; and a nonmetal seal including a nonmetal sealing surface positioned proximate one metal sealing surface and facing radially outward, and another nonmetal sealing surface positioned proximate the other metal sealing surface and facing radially inward. A method of sealing between a housing assembly and a closure member includes applying a pressure differential across the sealing device while the sealing device seals between the housing assembly and the closure member, and the pressure differential increasing contact pressure in a metal to metal seal between the housing assembly and a metal sealing surface on the metal seal, and increasing contact pressure in a metal to metal seal between the closure member and another metal sealing surface on the metal seal.

Abstract: A two-stage seal, such as a ring seal for use in a pressurized process fluid line, has a dynamic sealing member and a static sealing member. The dynamic sealing member is arranged to continuously sealingly engage against a seal surface that slides along the dynamic sealing member. The static sealing member is arranged to sealingly engage against the seal surface in response to an increased process fluid pressure within the process fluid line to increase static seal pressure against the seal surface. The static sealing member is also arranged to release from the seal surface to minimize friction with the seal surface when the process fluid pressure drops and/or in response to movement of the seal surface. The two-stage seal may be used in arrangements requiring both dynamic sealing and static sealing, such as in some process control valves. A process control valve having the two-stage seal is disclosed.

Abstract: A gas turbine engine turbine disk assembly includes a turbine disk, turbine blades, and pin seals. Each turbine blade includes a platform with a pressure side seal slot extending into a pressure side of the platform and a suction side seal slot extending into a suction side of the platform. The pressure side seal slot and the suction side seal slot are each angled between three and ten degrees in the radial direction relative to the axis of the turbine disk. The pin seal includes a cylindrical shape and is located within a seal slot formed from the pressure side seal slot and the suction side seal slot of adjacent turbine blades.

Abstract: A sealing device for a rotary feedthrough for receiving a rotating machine element whose outer side can be applied to another machine element, includes at least two sealing elements disposed in tandem in the axial direction of the machine element. Inner sides of the sealing elements are configured for forming an active sealing connection with the rotating machine element. At least one of the sealing elements can be pressurized with an additional force acting in the radial direction so that the force of compression acting on the rotating machine element for the at least one of the sealing elements can be adjusted relative to the force of compression acting on the rotating machine element due to at least one other sealing element.

Abstract: Tunable fluid end embodiments comprise a family, each family member comprising a pump housing with at least one installed tunable component chosen from: tunable valve assemblies, tunable valve seats, tunable radial arrays and/or tunable plunger seals. For example, a tunable valve assembly or tunable radial array selectively attenuates valve-generated vibration at its source, thus reducing the likelihood of fluid end failures associated with fatigue cracking and/or corrosion fatigue. Adding tunable valve seats and/or tunable plunger seals to a fluid end facilitates optimal damping and/or selective attenuation of vibration at one or more predetermined (and frequently localized) fluid end resonant frequencies. Thus, the likelihood of exciting destructive resonances in a pump's fluid end housing is further reduced.

Abstract: In combination with a body defining an annular space and a member received for rotation or linear movement within the annular space, an annular seal includes a first sealing member defining a first sealing portion disposed in constant engagement with a peripheral surface of the member during the rotation or the linear movement thereof, a second sealing member defining a second sealing portion disposed in constant engagement with the first sealing member and radially aligned only with the first sealing portion, and a fluid pressure directed at least onto the second sealing member, whereby the second sealing portion is configured to bias the first sealing portion into the constant engagement with the peripheral surface of the member.

Abstract: Tunable fluid end embodiments comprise a family, each family member comprising a pump housing with at least one installed tunable component chosen from: tunable valve assemblies, tunable valve seats, tunable radial arrays and/or tunable plunger seals. For example, a tunable valve assembly or tunable radial array selectively attenuates valve-generated vibration at its source, thus reducing the likelihood of fluid end failures associated with fatigue cracking and/or corrosion fatigue. Adding tunable valve seats and/or tunable plunger seals to a fluid end facilitates optimal damping and/or selective attenuation of vibration at one or more predetermined (and frequently localized) fluid end resonant frequencies. Thus, the likelihood of exciting destructive resonances in a pump's fluid end housing is further reduced.

Abstract: A sealing assembly for insertion between first and second mechanical elements subjected to offset positioning, including a reinforcement ring and at least one elastomeric sealing element in which the reinforcement ring is at least partially embedded, the sealing element including an annular membrane shaped as a truncated-cone sleeve and free from the reinforcement ring, which membrane obliquely extends to protrude from the reinforcement ring, towards a symmetry axis of the sealing assembly and ends with at least one annular sealing lip intended to slidingly cooperate with the first mechanical element; the membrane has, in radial direction, a relatively thin thickness, thinner than that of the at least one sealing lip, so as to be highly flexible, and a plurality of stiffening ribs formed with the membrane, which extend in the axial direction, parallel to one another, spaced apart from one another to form longitudinally extending radial projections on the membrane.

Abstract: An annular sealing device for a shaft and housing that can maintain sealing properties under fluid pressure load when creep occurs in a cut portion due to thermal expansion and the perimeter is shortened. The sealing device includes a seal ring unit configured to fit within an annular groove in the shaft, and has, on the side thereof where the outer periphery is located, a sliding surface on which the seal ring unit slides on the housing; and a lip portion on the inner periphery of the seal ring. The lip portion of tip is disposed on the side of the annular groove where a groove bottom thereof is located, in such a way that the tip thereof is deformable in a direction in which the tip increases the distance between the seal ring unit and the groove bottom of the annular groove when under pressure.

Abstract: A CPAP device includes a flow generator including an outlet, a humidifier including an inlet, and an adaptor connector between the outlet of the flow generator and the inlet of the humidifier. The connector includes a flexible and conformable sealing portion that is movable to accommodate misalignment.

Abstract: A sealing assembly for a shaft includes: a first sealing component; a first spring energizer associated with said first sealing component; an annular support member configured for supporting said first sealing component; a second sealing component; a second spring energizer associated with said second sealing component, said first and second sealing components each having a pair of seal lips, said pairs of seal lips facing each other, said first and second spring energizers each configured for energizing respectively said first and second sealing components, each said spring energizer being respectively between one said pair of seal lips, said annular support member being disposed about the shaft and positioned between said first and second sealing components and said first and second spring energizers, said annular support member including two outwardly facing protuberances each of which interfits with a respective said pair of seal lips.

Abstract: A radial shaft seal is provided for sealing between high and low pressure sides in an annular space between a shaft and a static structural receiving part, wherein the shaft seal is rotationally symmetric and arranged coaxially to the shaft. A first sealing ring has an inner periphery bulging toward the low pressure side and forms a first sealing lip abutting the shaft. A spacer ring has first and second faces directed towards the high and low pressure sides, respectively. An elastic shaped part has an outer periphery abutting the second face of the spacer ring and an inner periphery bulging toward the high pressure side and abutting the first sealing lip. At least the spacer ring and elastic shaped part define a cavity subjected to the high pressure side or a control pressure which presses the first sealing lip against the shaft via the elastic shaped part.

Abstract: A rotary seal arrangement has a rotatably mounted machine part and a machine part that forms a bearing for the rotatably mounted machine part. One of the machine parts forms a seal accommodating structure and the other one of the machine parts has a surface forming a sealing surface. At least one rotary seal is arranged in the seal accommodating structure. The rotary seal seals off a high-pressure area from a low-pressure area between the machine parts.

Abstract: [Object] To provide a sealing device, which is capable of keeping a higher sealability even when a fluid pressure is not applied and even just after starting of application of the fluid pressure, and which is capable of reducing a sliding resistance while keeping a sealability during operation where the fluid pressure is always applied thereto.

Abstract: An oil seal (1A) has an outer member (2) fitted to a crankcase (100), an inner member (3) integrally rotatably fitted to a crankshaft (101), and a first movable lip (4) disposed in the gap (G1) formed by the outer member (2) and the inner member (3). The first movable lip (4) is disposed such that it is not in contact with the outer member (2) when rotation of the crankshaft (101) is stopped and that it is displaced in the direction to approach the outer member (2), coming into contact with the outer member (2) to close the gap (G1).

Abstract: A resin lip type seal has first and second inner peripheral seal lips and an outer peripheral seal lip slidably contacting an operation member and a fixed member. The second inner peripheral seal lip is formed in a plate-shape to extend obliquely in an inner peripheral direction toward a second sealed fluid side so that an inner peripheral side end portion slidably contacts with a shaft and an outer peripheral side end portion contacts with a tapered surface formed on a housing or an installation member of the housing, whereby contact surface pressure in the inner peripheral direction acts on the inner peripheral side end portion.

Abstract: A dust seal structure of an internal mixer including a casing having a mixing chamber defined therein, and a rotor rotating in the mixing chamber for kneading a material, which is charged into the mixing chamber to be kneaded there, comprises a ring-shaped cylinder fitted to a rotor shaft of the rotor and mounted on a peripheral edge of an opening portion of the casing through which the rotor shaft passes, the cylinder being located at the peripheral edge of the opening portion of the casing, and being adapted to urge a ring-shaped sealing member fitted on the rotor shaft in a direction of the rotor shaft to inhibit leakage of the kneading material from the mixing chamber.

Abstract: The invention pertains to a seal with at least one sealing lip that can be pressed against a surface to be sealed of a machine element to be sealed in the radial direction by means of an annular power transmission element. The power transmission element has an effective diameter that can be varied on both sides in the radial direction with the aid of an adjusting mechanism.

Abstract: Disclosed herein are a sealing member for a master cylinder and a master cylinder having the same. The master cylinder is configured such that a communication hole of a piston is rapidly brought into communication with an oil path toward an oil tank upon release of braking. This may minimize meaningless retracting movement of the piston and delay in a braking release operation. The sealing member for the master cylinder includes an outer wing part to come into contact with the cylinder body, and an inner wing part to come into contact with the outer surface of the piston.

Abstract: A sealing arrangement for the sealed leadthrough of rotating shafts (2) through housing bores of housings (1) comprises at least one lip seal (3, 8, 14, 15) with a sealing lip that faces toward the area normally under higher pressure. In order to extend substantially the area of application of sealing arrangements with lip seals and by doing so, to make use of the sealing arrangement to achieve its advantages of being more economical, more durable also at pressure peaks, easier to install, and easier to maintain, also at higher pressures and pressure fluctuations, the lip seal (3, 8, 14, 15) on the side (5) facing the area with higher pressure is under a constant pressure that is higher than the highest pressure occurring inside the housing (1), and a gap (7, 10) that throttles the outflow is provided between this area and the inside of the housing.

Abstract: Apparatus to enhance performance of sequentially-deployable lip seal assemblies. In certain embodiments, biasing members to ensure deployment of sequentially deployable lip seals include an o-ring mounted within a cartridge or housing of one or more yet-to-be-deployed lip seals, with the o-ring disposed immediately adjacent one of the lip seals. When a barrier member or deployment sleeve is interposed between the one or more yet-to-be-deployed lip seals and a shaft, such as a rotating and/or reciprocating shaft of a stuffing box, the o-ring biases the lip seal toward the outside diameter of the shaft. Upon movement of the barrier member or deployment sleeve to a position exposing the Hp seal to the shaft, the o-ring urges the lip seal into engagement with the outside diameter of the shaft. A pressurized fluid may be employed between the housing and the o-rings. Flush paths, multi-part housings, and baffle-type housings are also disclosed.

Abstract: A high-friction fluid seal used for high-friction sealing, comprising a fluid seal lip provided on the working fluid filling side to intercept a working fluid; and a dust lip provided on the working fluid non-filling side (the outer side) of the fluid seal lip to intercept dust coming from the outside, wherein the thickness of a working fluid film formed on the extension stroke by the dust lip is smaller than the thickness of a working fluid film formed on the extension stroke by the fluid seal lip.

Abstract: A sealing mechanism comprises a support member forming part of the semiconductor producing apparatus which has a vacuum chamber, a rotation shaft rotatably received in the support member, and at least three seal rings axially spaced apart from each other between the support member and the rotation shaft to form a first fluid chamber close to the atmosphere and a second fluid chamber close to the vacuum chamber. The first fluid chamber is vacuumized to have a first pressure, and the second fluid chamber is also vacuumized to have a second pressure which is lower than the first pressure. The first and second fluid chambers work together to enhance the sealing performance of the sealing mechanism.

Abstract: A sealing device includes an inner race, an outer race capped on and rotatable relatively to the inner race, a rubber oil seal mounted between the inner race and the outer race, a lubricating oil received between the inner race and the outer race, radiation holes formed in the outer race, and a spoiler provided between the inner race and the outer race for causing convection of the lubricating oil to lower the temperature of the lubricating oil upon rotation of the outer race relatively to the inner race.

Abstract: A sealing mechanism comprises a support member forming part of the semiconductor producing apparatus which has a vacuum chamber, a rotation shaft rotatably received in the support member, and at least three seal rings axially spaced apart from each other between the support member and the rotation shaft to form a first fluid chamber close to the atmosphere and a second fluid chamber close to the vacuum chamber. The first fluid chamber is vacuumized to have a first pressure, and the second fluid chamber is also vacuumized to have a second pressure which is lower than the first pressure. The first and second fluid chambers work together to enhance the sealing performance of the sealing mechanism.

Abstract: A hydrodynamic PTFE seal for a rotating part including a first portion supported by a flexible, elastomeric member and a second portion extending from the first portion past the elastomeric member along the rotating part. The second or trailing portion of the seal is concentrically disposed about the rotating part. The first portion of the seal attached to the elastomeric member is also concentrically disposed around the rotating part. The seal can also include a living hinge portion disposed between the first and second portions. The first portion, the second portion and the living hinge portion can jointly define a continuous sealing surface.

Abstract: A shaft sealing module is proposed for sealing a shaft which extends driving rotationally from a normal pressure chamber into a high vacuum chamber. It is essential for the shaft sealing module according to the invention that the dynamic seal of the shaft takes place not on the shaft itself but on a bushing mounted rotatably in a housing through which is guided a shaft and which is held on the shaft in friction connection, statically sealed, by elastic rings so that the bushing rotates with the shaft. The dynamic seal between the bushing and the housing is achieved by several radial shaft sealing rings which are preferably arranged so that between them is provided a prevacuum chamber with intermediate evacuation so that a two-stage dynamic seal is provided, where the prevacuum acts on the static seal between the bushing and the shaft in the sense of a gas penetration barrier towards the high vacuum chamber.

Abstract: A method of providing variable pumping rate from a piston type pump at a constant drive speed, comprising providing a connecting rod connected to the throw of a crankshaft on one end and to a connecting pin on the other end, constraining said connecting pin to move reciprocally generally in a first direction when said crankshaft rotates, a piston connected to said connecting pin which is mounted in a head and moves reciprocally in a second direction, and varying the angle between said first direction and said second direction to vary the volume being pumped by said pump.

Abstract: A seal for a hydraulic cylinder rod is provided. The seal includes a main body that defines an opening therein. The seal includes an inner surface and an outer surface. A first radial face having a generally planar surface extends from the inner surface to the outer surface. A second radial face having a groove disposed therein also extends from the inner surface to the outer surface. The groove defines an inner lip adjacent the inner surface and an outer lip adjacent the outer surface. The seal also includes a relief feature in the outer surface of the main body. The relief feature extends from the first radial face towards the second radial face.

Abstract: A shaft sealing assembly seals a rotary shaft of a refrigerant compressor with a first sealing member, which is a lip seal. The first sealing member has a hollow portion. As the pressure in the interior space of the compressor housing increases, an outer wall surrounding the hollow portion is elastically deformed. Accordingly, a lip portion of the first sealing member receives a tension that weakens a force pressing the lip portion against the rotary shaft. Therefore, the sealing assembly improves the durability of the lip portion and maintains a satisfactory property of the lip portion to follow displacement of the rotary shaft at the same time.

Abstract: A rotation shaft seal disposed between a housing and a rotation shaft, and provided with a seal member of rubber having a lip end portion which extends as to diminish in diameter to a fluid storing chamber side, wherein the lip end portion has a contact portion which contacts a surface of the rotation shaft and an end face which is facing the rotation shaft, and a concave portion, generating a component of force in diameter direction to raise the lip end portion outward in the diameter direction when receiving pressure in the fluid storing chamber, is formed on the end face.

Abstract: A rock bit seal in which the shape of the retainer lip (which restrains the seal from axial motion in response to pressure differentials) is optimized, with respect to the as-deformed shape of the seal in place, to achieve a preload stress which is everywhere nonzero. Preferably the ratio of maximum to minimum stress in the as-installed condition is kept to a small ratio, e.g. less than 2:1.