Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16J—PISTONS; CYLINDERS; SEALINGS
  • F16J15/00—Sealings
  • F16J15/16—Sealings between relatively-moving surfaces
  • F16J15/34—Sealings between relatively-moving surfaces with slip-ring pressed against a more or less radial face on one member
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16J—PISTONS; CYLINDERS; SEALINGS
  • F16J15/00—Sealings
  • F16J15/16—Sealings between relatively-moving surfaces
  • F16J15/32—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings
  • F16J15/3204—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings with at least one lip
  • F16J15/3208—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings with at least one lip provided with tension elements, e.g. elastic rings
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16J—PISTONS; CYLINDERS; SEALINGS
  • F16J15/00—Sealings
  • F16J15/46—Sealings with packing ring expanded or pressed into place by fluid pressure, e.g. inflatable packings
  • F16J15/48—Sealings with packing ring expanded or pressed into place by fluid pressure, e.g. inflatable packings influenced by the pressure within the member to be sealed

Definitions

• the present invention relates to a seal, arranged between a radially inwardly facing outer boundary surface of an annular sealing gap and a radially outwardly facing inner boundary surface of the sealing gap.
• Seals for sealing annular gaps are required in technology, in particular in mechanical engineering, in a wide variety of geometrical and usage forms. A wide variety of designs of such seals are consequently known in the prior art - also as prepared standard components, even standardized.
• One of the simplest forms of known ring-shaped seals is the rubber O-ring.
• the so-called shaft sealing ring for example, a sealing element with a metal ring as the outer seat and a sealing lip made of rubber pointing radially inwards is much more complicated in construction.
• Such shaft locking rings are used, for example, to seal a gearbox housing from which a rotating shaft is guided.
• the metal ring sits in the bore of the housing through which the shaft is guided, and the sealing lip bears against a smooth, circular-cylindrical outer surface of the shaft.
• the contact area between the sealing lip and the shaft surface is reduced to a ring line around the shaft - in that the sealing lip tapers radially inwards to a geometrically sharp edge.
• This configuration allows high speeds of the shaft, for example gear oil which is located inside the housing and which exits the housing through the seal should be prevented, forms a lubricating film under the sealing lip.
• Dynamic pressure conditions in the area of the contact surface are then known to ensure that the oil does not penetrate under the sealing lip to the outside.
• felt rings are known for sealing annular gaps around a component that is not only rotating, but also translationally moved through the bore.
• seals are exposed to wear and tear and possible destruction, for example due to contamination or pressure - as seals against a moving component, but in particular also due to abrasion and fatigue, which generally also leads to the removal of the sealing element in the area of the contact surface and therefore on the one hand Relief of a pretensioning force with which the seal rests against a complementary component and, on the other hand, can even lead to the seal opening and opening.
• the wear of the seal limits its service life and, if the device whose seal is an element, the seal needs to be replaced, the seal must be replaced.
• the invention has for its object to provide a seal whose service life is extended.
• a seal for sealing an annular sealing gap has a sealing ring, a prestressing means and a pressure ring.
• the sealing ring has a sealing surface which bears tightly against a boundary surface of the sealing gap. According to the invention, this can be the radially inwardly facing outer boundary surface or the radially outwardly facing inner boundary surface of the sealing gap.
• a pressure surface of the sealing ring forms an intermediate space which is wedge-shaped in cross section on its side radially opposite the sealing surface.
• the pressure ring is biased against the surfaces forming the wedge-shaped space into the wedge-shaped tapering space, so that the pressure ring presses the space apart and thus presses the sealing ring with its sealing surface tightly against the (outer or inner) boundary surface of the sealing gap.
• the pressure ring can, for example, simply have a circular or rectangular cross section or cross-sectional portion and can, for example, simply be pressed into the wedge-shaped space by a spring ring as a pretensioning means, but a pressure ring with an essentially triangular cross section is preferred - in particular formed from an outer one Active surface in the form of a radially outwardly directed circular cylindrical surface and with an inner active surface in the form of a radially inwardly directed circular cone and with a biasing surface in the form of an axially directed annular surface against which the biasing means is biased.
• the prestressing means is preferably a fluid which is under pressure on one side of the seal and is in contact with the prestressing means by line connection - for example simply in the form of gap-shaped spaces which are not further sealed up to the sealing device according to the invention and its installation space.
• the biasing surface designed as an axially directed annular surface then reliably absorbs the pressure of the fluid and can transmit it to the active surfaces of the pressure ring, the biasing surface is preferably concave.
• an annular pressure chamber i.e. with a cross-section that is curved on the one hand according to the concave and on the other hand just according to the flat surface ).
• the sealing ring as a surface against which the inner effective area 'of the compression ring abuts a complementary, ie radially outwardly directed circular cone lateral surface - the sealing surface then accordingly on the radially opposite side of the sealing ring is thus designed to point radially inwards.
• the sealing surface according to the invention preferably has two radially projecting sealing lips which, for example, extend like a bead over the circumference of the sealing surface, depending on its orientation, either radially inwards or radially outwards. Between them, the two sealing lips preferably delimit a groove in the sealing ring, so that the cross section through the sealing lips and the groove is preferably delimited by a continuous wavy line, the cross section through the sealing lips and the groove each being circular (the lips being convex and the groove concave).
• the seal according to the invention can be used particularly advantageously for sealing an annular gap between an outer component with a bore and an inner component which moves through this bore in an oscillating manner.
• the sealing surface of the sealing ring points radially inwards and bears against the preferably circular-cylindrical outer surface of the inner component, which advantageously has the smoothest possible wall.
• This application is, for example, in the case of a piston, the piston rod of which is guided as an inner component to the outside through the piston housing as an outer component.
• the annular gap between them usually has to be sealed against a fluid which is in the piston as a pressure medium.
• this fluid which is at times - namely pulse-like - under pressure with each piston stroke during oscillating movement of the piston, can advance as a biasing means through gap spaces to the seat of the pressure ring and there (preferably via the biasing surface) the pressure ring into the wedge-shaped space between the sealing ring and the other of the surfaces of the sealing gap - which in this application is the radially inward-facing outer surface of the sealing gap in the outer component.
• the seal according to the invention advantageously has the effect that the abrasion of the pressure ring compensates for this abrasion by the fact that the sealing ring is "readjusted", so to speak, by the pressure force of the pressure ring, that is to say by the prestressing of the prestressing means applied by the pressure ring (in the example described last the fluid) is pressed against the complementary sealing gap surface.
• the fluid is transported as a lubricant to the sealing surface with each translational movement of the inner component out of the fluid, this advantageous effect can be further enhanced according to the invention by the fact that on the other side of the seal there is a change in the bore of the outer component there is also a fluid storage groove, which is formed there, for example, as an annular groove over the entire circumference.
• Fluid which may move further under the seal on the wetted surface of the inner component before the seal completely seals under the pre-tensioning of the fluid, can collect in it, which initially additionally promotes the sealing effect by this portion of the fluid not further is transported outside.
• the return stroke movement of the inner component transports fluid from this fluid storage groove back to the sealing surface, where the fluid favors the same (for example lubricating). the) effects that have already been described above for the lifting movement.
• the seal has a dimensionally stable core.
• This dimensionally stable core can e.g. B. from polyethylene (PE), polypropylene (PP) or poly-oxymethylene (POM).
• POM in particular is a widely used material in the sanitary sector because it is easy to process and has hydrophobic properties.
• the sealing ring can remain unchanged in its outer shape.
• the dimensionally stable core of the sealing ring can essentially correspond to the shape of the pressure ring, that is to say be wedge-shaped, and be enclosed by the sealing material in such a way that the outer shape of the seal remains unchanged.
• the dimensionally stable core can also essentially have the shape of the sealing ring and in turn be coated all around with the sealing material.
• the material thickness of the sealing material is then preferably approximately in the range from 2 to 3 mm.
• the seal according to the invention can be used according to the invention particularly advantageously in transport pistons in seawater desalination plants in which transport pistons convey seawater with relatively low piston stroke frequencies of approximately 0.1 Hz.
• the seal according to the invention can also be used advantageously in other pistons or pumps.
• Figures 3 and 4 show two configurations of a seal according to the invention with a dimensionally stable core.
• a seal 2 can be seen in FIG. 1, which has a sealing ring 4 and a pressure ring 6.
• the sealing ring 4 has a radially inwardly facing sealing surface 8 with a cross section in the form of a continuous wavy line.
• the wavy line as a cross section is created by two radially inwardly projecting sealing lips 10, which define a groove 12 between them in the sealing surface 8 of the sealing ring 4.
• the sealing surface 8 of the sealing ring 4 lies against a radially outwardly facing inner boundary surface 14 of a sealing gap 16 which is formed between an inner component 18 and an outer component 20.
• the inner component 18 is a piston rod, which moves in a bore 16 in a piston housing as an outer component 20, oscillating in the direction of the axis 22.
• the water 24, which is transported to the outside as a wetting of the piston rod 18 under the seal 2 can collect there and is also transported from there on the way back of the piston rod 18 into the area of the seal 2 and thereby favors the formation of a lubricating film in the area between the seal 2 and the boundary surfaces of the sealing gap (16) additionally.
• the radially inward-facing outer boundary surface 40 of the sealing gap 16 is the radially directed boundary surface of the seat 26, and it is in the shape of a circular cylinder; and the radially outward pressure surface of the sealing ring 4 is circular cone-shaped to form the wedge-shaped cross section of the intermediate space.
• the seal 6 adjusts itself automatically according to the invention after abrasion or other types of wear.
• the seal 2 'according to FIG. 2 differs in principle from the seal 2 according to FIG. 1 in that it is mounted in an inner component 18' (here a piston 18 '). Accordingly, its sealing surface 8 'faces radially outwards and bears against a radially inward-facing outer surface 40' of a sealing gap 16 '.
• the surface 40 'against which the sealing surface 8' of the seal 2 'rests is the radially inward-facing circular cylinder jacket surface of a cylinder 20' in which the piston 18 'moves back and forth.
• the seal described can also have a dimensionally stable core, which is preferably made of a plastic material.
• a dimensionally stable core is shown in FIG. 3.
• the dimensionally stable core 41 has the wedge-shaped shape of a pressure ring and is arranged inside the sealing ring 42.
• the dimensionally stable core 41 ' can also have the shape of the sealing ring 4 and can be coated with a sealing material 42', the coating 42 'preferably being 2 to 3 mm thick. The problem of excessive wear of the seal during operation is countered by these configurations.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Architecture (AREA)
• Fluid Mechanics (AREA)
• Sealing Devices (AREA)
• Materials For Medical Uses (AREA)
• Gasket Seals (AREA)
• Inks, Pencil-Leads, Or Crayons (AREA)
• Diaphragms And Bellows (AREA)
• Glass Compositions (AREA)
• Separation Using Semi-Permeable Membranes (AREA)

Priority Applications (12)

Applications Claiming Priority (2)

Publications (1)

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ID=7670990

Family Applications (1)

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Cited By (3)

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Citations (9)

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• 2001
  • 2001-01-19 DE DE10102161A patent/DE10102161B4/de not_active Expired - Fee Related
• 2002
  • 2002-01-11 PT PT02703543T patent/PT1356221E/pt unknown
  • 2002-01-11 DE DE50206379T patent/DE50206379D1/de not_active Expired - Lifetime
  • 2002-01-11 ES ES02703543T patent/ES2259699T3/es not_active Expired - Lifetime
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  • 2002-01-11 WO PCT/EP2002/000206 patent/WO2002057668A1/de not_active Ceased
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  • 2002-01-11 CN CNA028036832A patent/CN1486407A/zh active Pending
  • 2002-01-11 EP EP02703543A patent/EP1356221B1/de not_active Expired - Lifetime
  • 2002-01-11 AU AU2002237265A patent/AU2002237265B2/en not_active Ceased
  • 2002-01-11 AT AT02703543T patent/ATE323251T1/de active
• 2003
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  • 2003-07-18 NO NO20033262A patent/NO20033262L/no unknown
• 2006
  • 2006-07-05 CY CY20061100928T patent/CY1105304T1/el unknown

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