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
  • F16J15/40—Sealings between relatively-moving surfaces by means of fluid
  • F16J15/406—Sealings between relatively-moving surfaces by means of fluid by at least one pump
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/08—Sealings
  • F04D29/10—Shaft sealings
  • F04D29/102—Shaft sealings especially adapted for elastic fluid pumps
• • 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
  • F16J15/002—Sealings comprising at least two sealings in succession
• • 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
  • F16J15/3232—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings with at least one lip having two or more lips

Definitions

• the present invention relates to the field of seals, in particular that of radial friction seals.
• the present invention relates more particularly to a sealing device for sealing between a casing and a shaft rotatably mounted in said casing, comprising first and second annular lip seals intended to be arranged side by side axially between the casing and the casing. 'tree.
• the adjectives "axial” and “radial” refer to the direction of the axis of rotation of the shaft.
• a pair of lip seals is used to seal a chamber by contact on the shaft.
• An object of the present invention is to provide a sealing device having a longer life than that of the prior art.
• the invention achieves its object by the fact that the sealing device according to the invention further comprises means for bringing a stream of pressurized gas into an annular cavity delimited by the first lip seal, the second lip seal and a outer surface of the shaft, such that during the rotation of said shaft, the gas flow is able to take off at least one of the two lip seals of the outer surface of the shaft to flow out of the cavity, said means for causing the flow of pressurized gas further comprise a diaphragm for limiting the flow of gas in case of damage to one of the annular lip seals.
• At least one of the two lip seals preferably both, take off from the outer surface of the shaft due to the flow of gas flow between the seals. lip and surface external of the shaft, as a result of which the friction between the shaft and the sealing device is advantageously eliminated.
• the sealing function is advantageously preserved thanks to the flow of gas flowing out of the cavity which tends to maintain the outer particles outside the cavity.
• the sealing device according to the present invention wears substantially less quickly than the device of the prior art which has the effect of increasing its service life.
• the diaphragm is disposed in this channel or at one of its ends.
• the gas flow rate is limited by the separation distance of the lips of the lip seals.
• the flow of gas is advantageously limited in the event of damage to one of the lip seals.
• the first lip seal has a first lip while the second lip seal has a second lip, and the first and second lips are intended to extend in the axial direction of the shaft while moving away. one from the other.
• the first and second lips that take off from the outer surface of the shaft during the flow of the gas flow out of the cavity.
• the means for bringing the flow of pressurized gas comprise a channel disposed between the first and second lip seals, said channel being connected to a source of pressurized gas.
• the channel extending radially between the two lip seals.
• the present invention also relates to a turbine engine for a helicopter comprising a housing and a shaft rotatably mounted in said housing, said turbine engine further comprising a sealing device according to the present invention.
• the turbine engine according to the invention further comprises a source of pressurized gas for supplying the means for bringing a flow of pressurized gas into the annular cavity.
• a source of pressurized air is a stream disposed at the outlet of the compression stage.
• FIG. 1 shows a detail of a turbine engine casing of a helicopter in which is mounted a rotary shaft, the turbine engine comprising a sealing device according to the present invention
• FIG. 2 shows a turbine engine equipped with a sealing device according to the present invention.
• FIG 1 there is shown a detail of a housing 10 of the speed reducer 11 of a turbine engine 52 for a flying machine, such as a helicopter, in which is mounted a sealing device 12 according to the invention.
• a shaft 14 having an axis of rotation A is rotatably mounted in the casing 10, in particular via a bearing 16.
• the housing 10 corresponds to the casing of the gearbox 11 of the turbine engine, that is to say that the end 18 of the shaft 14 on the bearing side is intended to be coupled to gears, while the opposite end 20 is a power take-off intended to be coupled to a shaft transmitting torque to the rotor of the helicopter.
• the PTO 20 is located outside the turbine engine 52 while the end 18 on the enclosure side 21 of the gear 11 is located inside the turbine engine 52.
• the sealing device 12 comprises a first annular lip seal 24 and a second annular lip seal 26 which are arranged side by side between the casing 10 and the shaft 14 while being coaxial, it being understood that their common axis corresponds substantially to the axis A of the tree
• the annular lip seals 24, 26 are radial contact seals and are preferably made of elastomer.
• the first and second annular lip seals 24, 26 are preferably fixed on a sleeve 28 arranged axially in a bore 30 of the casing 10, the sleeve 28 itself being held integrally with the casing 10 between a flange 32 secured to the casing 10 and the landing 16.
• first and second annular lip seals 24, 26 respectively comprise a first lip 34 and a second lip 36 which extend in the axial direction of the shaft 14 while moving away from each other. one of the other.
• the lips 34 and 36 are shaped to have a first position, shown in dashed lines in FIG. 1, in which each of them comes into contact with the outer surface 22 of the shaft 14 in order to ensure the sealing the enclosure 21 of the gearbox 11.
• the lips 34, 36 are in their first position preferably when the shaft 14 does not rotate.
• the lips 34,36 in their first position, provide a static seal between the housing 10 and the shaft 14.
• the first lip 34 prevents the outer particles from entering the the enclosure 21, while the second lip 36 prevents the oil droplets from leaving the enclosure 21 of the gearbox 11.
• the lips 34 and 36 are able to be in a second position, represented in solid lines in the figure, in which position the lips 34, 36 take off from the outer surface 22 of the shaft 24.
• the lips 34 and 36 are in their second position when the shaft 14 rotates.
• an annular cavity 38 delimited by the first lip 34, the second lip 36 and the outer surface 22 of the shaft 14 is pressurized by means 40 to bring a stream of pressurized air F into said cavity 38.
• Said means comprise a channel 40 formed in a neck 42 of the sleeve 28, said neck 42 extending in a plane orthogonal to the axis A of the shaft 14 so that the channel 40 extending substantially radially.
• a first end 44 of the channel 40 opens into the annular cavity 38, while a second end 43 of the channel 40 opposite the first end 44 is connected to a connection 46 by the intermediate of a radial pipe 48 formed in the housing 10.
• the connector 46 is connected via a casing 45 to a pressure source which, in the present case, is a sampling point 49 disposed at the outlet of a compressor 50 of the turbine engine 52 as represented in FIG. 2.
• the gas corresponds in this case a fraction of air taken from the compressed air by the compressor 50.
• the gas flow F brought into the cavity 38 has a sufficient pressure to be able to take off the lips 34 and 36 of the outer surface 22 of the shaft 14.
• the gas flow F detaches the lips 34 and 36 from the outer surface 22 of the shaft 14 to flow out of the cavity 38.
• the stream of gas leaving the cavity 38 is preferably constituted by a first annular flow Fl flowing axially outwardly of the turbine engine 52 and a second annular flow F2 flowing axially inwardly of the enclosure 21, in a direction opposite to the first annular flow Fl.
• the first flow Fl prevents the outer particles from entering the enclosure 21 of the reducer
• the annular lip seals 24,26 wear substantially less because of the absence of friction during the rotation of the tree.
• the sealing device according to the invention has a longer life than those of the prior art.
• the sealing device according to the present invention further comprises a diaphragm D to limit the flow of pressurized gas in case of damage to one or other of the lips 34,36.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Sealing Using Fluids, Sealing Without Contact, And Removal Of Oil (AREA)
• Sealing Devices (AREA)
• Filling Or Discharging Of Gas Storage Vessels (AREA)
• Turbine Rotor Nozzle Sealing (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=38667008

Family Applications (1)

Country Status (10)

Families Citing this family (10)

Family Cites Families (7)

• 2007
  • 2007-03-27 FR FR0754050A patent/FR2914384B1/fr active Active
• 2008
  • 2008-03-27 JP JP2010500334A patent/JP2010522857A/ja not_active Withdrawn
  • 2008-03-27 EP EP08788058A patent/EP2140178A2/de not_active Withdrawn
  • 2008-03-27 CA CA002682004A patent/CA2682004A1/fr not_active Abandoned
  • 2008-03-27 CN CN200880010209A patent/CN101652590A/zh active Pending
  • 2008-03-27 BR BRPI0809521-3A2A patent/BRPI0809521A2/pt not_active Application Discontinuation
  • 2008-03-27 RU RU2009139645/06A patent/RU2009139645A/ru unknown
  • 2008-03-27 WO PCT/FR2008/050532 patent/WO2008132410A2/fr not_active Ceased
  • 2008-03-27 US US12/593,094 patent/US20100119368A1/en not_active Abandoned
• 2009
  • 2009-10-07 ZA ZA200906987A patent/ZA200906987B/xx unknown

Non-Patent Citations (1)

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