US3169695A - Radial seal for rotary mechanism - Google Patents

Radial seal for rotary mechanism Download PDF

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Publication number
US3169695A
US3169695A US243129A US24312962A US3169695A US 3169695 A US3169695 A US 3169695A US 243129 A US243129 A US 243129A US 24312962 A US24312962 A US 24312962A US 3169695 A US3169695 A US 3169695A
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US
United States
Prior art keywords
shoe
peripheral wall
seal strip
seal
head portion
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US243129A
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English (en)
Inventor
Wankel Felix
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Audi AG
Original Assignee
NSU Motorenwerke AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by NSU Motorenwerke AG filed Critical NSU Motorenwerke AG
Application granted granted Critical
Publication of US3169695A publication Critical patent/US3169695A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01C—ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES
    • F01C19/00—Sealing arrangements in rotary-piston machines or engines
    • F01C19/02—Radially-movable sealings for working fluids
    • F01C19/04—Radially-movable sealings for working fluids of rigid material
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01C—ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES
    • F01C19/00—Sealing arrangements in rotary-piston machines or engines
    • F01C19/02—Radially-movable sealings for working fluids

Definitions

  • This invention relates to a radial seal for rotary mechanisms such as rotary internal combustion engines, compressors, pumps and the like.
  • Rotary engines of this type generally comprise an outer body with axially spaced parallel end walls and a peripheral wall interconnecting the end walls and an inner body supported for relative rotation Within the outer body.
  • One of said bodies has grooves extending over the whole axial width of the inner body and accommodates seal strips which are movable in a direction towards the peripheral wall of the other body and serve to seal adjacent working chambers from each other.
  • said seal strips which can be arranged either within the inner body or rotor or within the outer body or housing, are urged against the peripheral wall of the other body i.e. against the inner surface of the housing peripheral wall or towards the outer peripheral wall or outer surface of the rotor, substantially by the gas pressure existing in one of the adjacent working chambers.
  • the pressure gas can enter the grooves accommodating the seal strips and acts on the bottom surface of the seal strips to urge them against the peripheral wall. This results in a comparatively high frictional force between the outer edge of the seal strip and the peripheral wall and this frictional force tends to rock the seal strip about an outer edge of its groove.
  • the seal strip performs a tilting movement with respect to the peripheral wall and such rocking motion can cause a jamming of the seal strip within its groove thus preventing free radial movement of the seal strip with consequent high wear of the edge of the seal strip and the risk of damaging the peripheral wall.
  • a shoe is arranged between each seal strip and the peripheral wall.
  • the shoe extends over the whole length of the seal strip and comprises a sliding surface for sliding along the peripheral wall. It is anchored within the body which accommodates the seal strip for tilting or pivotal motion about an axis parallel to the rotational axis of the inner body and the upper and lower surfaces of the shoe are exposed to the gas pressure existing within the adjacent working chamber.
  • the radial seal of the present invention operates in generally the same manner as the usual seals in which the seal strip is directly in contact with the peripheral wall.
  • the engagement of the sliding surface of the shoe with the peripheral wall is effected by the pressure gas entering the groove accommodating the seal strip. Consequently, the radial seal with the peripheral wall is effected, as heretofore, by the force acting on the seal strip.
  • a spring can be located underneath the seal strip to obtain the necessary contact pressure if there is no gas-pressure.
  • the shoe is arranged in such a way that it is trailed or dragged with respect to the direction of ro- 3,ih,695 Patented Feb. 16, 1965 tation of the inner body relative to the outer body in order to prevent the shoe from spreading between its anchorage and the peripheral wall.
  • the shoe can be made of a flexible material such as spring steel and in this case the shoe need not be hinged to the body as, due to its inherent flexibility, the shoe permits movement of the seal strip.
  • the shoe is arranged substantially parallel to the peripheral wall of the body accommodating the shoe so that only small tilting motions about its axis are necessary to keep the shoe in contact with the peripheral wall.
  • the direction of movement of the seal strip is preferably substantially perpendicular to a straight line interconnecting the tilting axis of the shoe with the contact point between the shoe and the seal strip.
  • the shoe can be made of several parts with one of said parts carrying the sliding surface and being preferably hinged to the other part that is tiltably anchored within the body.
  • the contact area between the sliding surface and the peripheral wall can be enlarged as the part carrying the sliding surface can tilt to adapt itself to the surface of the peripheral wall. In this way the pressure per unit of contact area between the sliding surface and the peripheral wall is decreased.
  • a hinged connection between both of said parts is not necessary if the part anchored in the body is made of a flexible material such as spring steel as in this case the flexibility of this part permits the part carrying the sliding surface to perform the necessary tilting movement.
  • FIG. 1 is a side view of a rotary internal combustion engine with one of the Walls removed so as to show the arrangement of the rotor in the housing and with portions illustrated in section so as to show the ports and the ignition means;
  • FIG. 2 is a detailed, enlarged view of the apex of the rotor showing the arrangement of the sealing strip and shoe;
  • FIG. 3 is a view in the direction of the arrows on the line 3-3 of FIG. 2;
  • FIGS. 4, 5, and 6 are detailed side sectional views of the apex portions of the rotors showing three modified arrangements of sealing strips and shoes;
  • FIG. 7 is a perspective view of the shoe shown in FIG.
  • FIGS. 8 and 9 are side elevational and perspective views respectively of the apex portions of rotors showing two further modified forms of sealing strips and shoes.
  • the rotary internal combustion engine comprises a housing having two axially spaced parallel end walls 1 and 2 and a peripheral wall 3 arranged therebetween.
  • the inner surface 4 of the peripheral wall 3 preferably has the shape of a twolobed epitrochoid.
  • a shaft 6 is journaled in the housing, said shaft having an eccentric portion 8 on which a three-pointed inner body or rotor It) is journaled.
  • the apices 12 of the rotor 19 slide along the inner peripheral surface 4 thereby forming three variable volume working chambers A, B, C.
  • the rotation of the rotor it is in direction of the arrow D.
  • Gearing (not shown) ensures a certain speed ratio between rotor 10 and shaft 6, said speed ratio being 1:3 .in the embodiment shown.
  • each rotor apex 12 carries a radial seal generally designated 2% in FIG. 1 for sealing engagement withthe inner peripheral wall 4.
  • each rotor end face carries axial fseals that consist of axially movable seal strips 22 extendmg between adjacent rotor 'apices 12 and being in sealing engagement with the radial seals 2% by way'of'axially mov able intermediatese'al bodies 24.
  • Each rotor apex 12 has a groove firs eriteiidi'n'g over the-whole axial width as the rotor and accommodating a seal strip 28 that is movable in a direction towards the inner peripheral wall 4.
  • a spring 46 is shown in detail in FIGS; 2 and 3.
  • this axis is formed by the edge 36 of recess 34.
  • An abutment 42 of rotor 10 that overlaps the end 44 of shoe 3t! prevents the ejection ofthe shoe frornthe recess 34, under centrifugal force.
  • the end 44 is inserted laterally into the recess 34 and is, therefore, axially movable with respect to the rotor 10. Because of this, on axial displacementof the rotor, no axial guidance of the rotor is performed by the shoes.
  • FIG. 2 it is assumed that the higher pressure is withinworking chamber C; This pressure acts on the upper surface of the shoe 3% and, therefore, tends to urge the sliding surface 32 away from the inner peripheral wall 4.
  • means are provided to ensure that the gas pressure can act also on the bottom surface of shoe 30, for instance by having the lateral edges 31 of -Sl'10e 30 tapered as shown in FIG. 3 so that pressure gas can stream underneath the shoe 30 through the wedgeshaped gaps between the edges 31 and the adjacent end walls 1,- 2 of the housing.
  • This pressure gas balances the pressure gas acting on the upper surface of the shoe.
  • the pressure gas flows into groove 26 beside and underneath the seal strip 28 and urges the strip against the opposite wall of groove 2s and in conjunction with spring 46 urgesit against shoe 30 which thereby is pressed against the-inner peripheral wall4. It is likewise possible to provide a separate spring acting directly on shoe 3%, such spring 61 being shown in dotted lines in FIG. 2.
  • a represents the area determined by the distance between the contact points 38 and 40
  • b represents the area determined by thehalf .of therseal strip 28
  • 0 represents the moment arm with respect to the tilting axis 36 of the gas pressure acting on area tr
  • .landfd represents The moment arm with respect to -4. .1 tilting axis 36 ofthe gas pressure acting on area b
  • the product of a and. c must be smaller than the product of b and d in order to maintain the sho e in contact with the inner peripheral surface 4-.
  • shoe 30 can also be provided withopenings 48 shown in FIG. 3 in'dottedzline. These openings 48 have the additional advantage thatthe heat-absorbing surface of the shoe is decreased.
  • V V v The directionQof movement of seal strip28 generally is perpendicular .to the straight line interconnecting the tilting axis 36 of shoe3l) with the contact spot 40 between the shoe and the seal strip'28. -.Therefore,' the forces that. a tend to tilt the shoe 3% radially towards the inner peripheral surface .4,.can act substantially in a radial direction of movement" of the seal strip only and cannot cause a rocking of the seal strip withinits groove 26. This can be favoredin the manner indicatedin FIG.
  • the seal strip 28 or 28" is urged againstthe opposite wall of-the groove and the pressure gasentering groove 26 can act on the bottom surface of the seal strip 28 or 28" thereby'urging seal strip 28 or 28" against the .shoe'30- or 30" and shoe 3% or 30 with its sliding surface 32 against the inner peripheral Wall 4.
  • the gas pressure also acts on the front face of shoe 36 or 30' and tends to'shift the shoe 3.0 or 30'" to .theright against the action of the frictional forces. Thisis possible until the end 440i shoe 30 and 30' abuts againstwall 52 of recess 34.
  • the wall 52 formsa corner 54 that covacts with theacute end 44 of the shoe. Thiscorner 54, therefore, forms in thiscase .the tilting axis for shoe 30. i i
  • Sthe anchoring of shoe 3% is effected by screwsi that project through bores 58 of shoe 30. These bores have adiarneter larger than the diameter of the screws 56 and, therefore, enable the necessary tilting movement of shoe 30.
  • the shoe 30" is made of a flexible material e.g. spring steel and one of its ends is fixed to the inner body 10; For this purpose this end of the. shoe is slotted to form lugs 60, 62 that are bent at different angles. The lugs are inserted laterally in correspondinggrooves:64, 66 within the inner body 10.
  • the shoe 30 can perform the necessary tilting movements to have its sliding surfacein continuous contact withthe inner'peripheralwall'4;
  • the shoe is formed in such arnanner that it has an'initial tension towards the inner peripheral wall.
  • the sliding surface 32" can be made of another material that has better antifriction; properties than spring steel.
  • the shoe 30" can also be fastened byother means to'the rotor 19,
  • FIG. 8 differs from that one of FIGS; 6 and 7 only by the fact that the sliding surface is formed by a separate part 65 which is connected to a second part 67 made offlexible material and fastened to the inner body 10 in the same manner as the shoe 39" in FIG.
  • the sliding surface has two crestsqGS that areparallel to the axis of-ro-tation of rotor wand that slide along the inner pcripheral'wall 4.
  • part 65 has a groove 70 circular in cross section for accommodating the correspondingly shaped end 72 of part 67'.
  • the other end '74 of part 67' is also circular in cross section and engages the corresponding groove 76 of inner body 10.
  • Naturally other hinge connections could also be used.
  • a rotary mechanism having an improved radial seal comprising an outer body having axially spaced parallel end Walls, a peripheral wall interconnecting the end walls and an inner body mounted within the outer body for rotation relative to the outer body, said inner body having a plurality of circumferentially spaced grooves extending over the whole axial width of the inner body, seal strips mounted in said grooves and extending between the end walls of the outer body and movable in a direction towards the peripheral Wall of the outer body, and a shoe arranged between each seal strip and the peripheral wall, said shoe including a head portion and a body portion with the head portion extending over the whole axial length of said seal strip and having a radially outer surface for sliding along the peripheral wall and a radially inner surface for engagement with said seal strip thereby to provide adjacent chambers on opposite sides of said shoe, said chambers being sealed from each other by the engagement of the radially outer surface of the head portion of said shoe with the peripheral Wall and the engagement of the radially inner surface of the head portion of the shoe with said seal
  • a rotary mechanism as claimed in claim 1 in which the body portion of said shoe is mounted adjacent its leading edge and the head portion of said shoe is in trailing relation with respect to the direction of rotation of the inner body relative to the outer body.
  • a rotary mechanism as claimed in claim 1 in which the body portion of said shoe is inserted in a recess formed in the inner body.
  • a rotary mechanism as claimed in claim 1 in which the direction of movement of the seal strip is substantially perpendicular to the straight line interconnecting the tilting axis of the shoe with the contact point between the radially inner surface of the head portion of said shoe and the seal strip.
  • a rotary mechanism as claimed in claim 1 in which a spherical contact surface is provided between the head portion of said shoe and seal strip.
  • a rotary mechanism as set forth in claim 1 in which the head portion of said sliding surface of the shoe is kept in contact with the peripheral wall by the forces acting on the seal strip.
  • a rotary mechanism as set forth in claim 1 in which a spring is provided to urge the shoe against the peripheral wall.
  • a rotary mechanism having an improved radial seal comprising an outer body having axially spaced parallel end walls and a peripheral wall interconnecting the end walls, and an inner body mounted within the outer body for rotation relative to the outer body, one of said bodies having a plurality of circumferentially spaced grooves extending over the whole axial width of the inner body, seal strips mounted in said grooves and movable in a direction towards the peripheral wall of the other body, a shoe arranged between each seal strip and the peripheral wall, said shoe extending over the whole axial length of said seal strip and comprising a sliding surface for sliding along the peripheral wall to thereby provide adjacent chambers on opposite sides of said shoe, said chambers being sealed from each other by the engagement of the shoe with the peripheral Wall and the engagement of the shoe with said seal strip, said shoe Ibeing anchored within that body accommodating the seal strip for tilting motion about an axis parallel to the rotational axis of the inner body, the radially outer surface and the radially inner surface of the shoe being exposed to the gas pressure existing within the adjacent

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Sealing Devices (AREA)
  • Applications Or Details Of Rotary Compressors (AREA)
US243129A 1961-12-09 1962-12-07 Radial seal for rotary mechanism Expired - Lifetime US3169695A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEN20934A DE1151994B (de) 1961-12-09 1961-12-09 Radialdichtung fuer Rotationskolbenmaschinen

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US3169695A true US3169695A (en) 1965-02-16

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US243129A Expired - Lifetime US3169695A (en) 1961-12-09 1962-12-07 Radial seal for rotary mechanism

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US (1) US3169695A (de)
AT (1) AT245864B (de)
CH (1) CH401612A (de)
DE (1) DE1151994B (de)
FR (1) FR1340143A (de)
GB (1) GB1020537A (de)
OA (1) OA01061A (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3326455A (en) * 1965-05-14 1967-06-20 Gen Motors Corp Sealing means for rotary mechanisms
US3456626A (en) * 1968-03-08 1969-07-22 Curtiss Wright Corp Compensated seal structure
US3740175A (en) * 1972-02-29 1973-06-19 Gen Motors Corp Rotary machine apex seal

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2606082A1 (de) * 1976-02-16 1977-08-25 Otto Eckerle Hochdruck-zahnradpumpe oder -motor
CH638866A5 (de) * 1979-03-27 1983-10-14 Wankel Felix Abdichtung am umfang eines laeufers einer rotationskolbenmaschine.

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US49070A (en) * 1865-08-01 Improvement in rotary engines
US84280A (en) * 1868-11-24 Improvement in rotary steam-engines
US105796A (en) * 1870-07-26 Will aed m
US501864A (en) * 1893-07-18 boenina
US803406A (en) * 1905-05-18 1905-10-31 Thomas Davis Rotary engine.
US1033748A (en) * 1907-11-09 1912-07-23 Edward K Standish Rotary explosion-engine.
US1453683A (en) * 1919-11-28 1923-05-01 Kochendarfer Sirius Edward Rotary engine
US2135760A (en) * 1934-09-15 1938-11-08 Moore Raymond John Francis Rotary engine and pump

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1922477A (en) * 1929-06-18 1933-08-15 Flind Herbert Charteris Construction of motive power engines and pumps

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US49070A (en) * 1865-08-01 Improvement in rotary engines
US84280A (en) * 1868-11-24 Improvement in rotary steam-engines
US105796A (en) * 1870-07-26 Will aed m
US501864A (en) * 1893-07-18 boenina
US803406A (en) * 1905-05-18 1905-10-31 Thomas Davis Rotary engine.
US1033748A (en) * 1907-11-09 1912-07-23 Edward K Standish Rotary explosion-engine.
US1453683A (en) * 1919-11-28 1923-05-01 Kochendarfer Sirius Edward Rotary engine
US2135760A (en) * 1934-09-15 1938-11-08 Moore Raymond John Francis Rotary engine and pump

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3326455A (en) * 1965-05-14 1967-06-20 Gen Motors Corp Sealing means for rotary mechanisms
US3456626A (en) * 1968-03-08 1969-07-22 Curtiss Wright Corp Compensated seal structure
US3740175A (en) * 1972-02-29 1973-06-19 Gen Motors Corp Rotary machine apex seal

Also Published As

Publication number Publication date
GB1020537A (en) 1966-02-23
OA01061A (fr) 1968-08-07
DE1151994B (de) 1963-07-25
AT245864B (de) 1966-03-25
CH401612A (de) 1965-10-31
FR1340143A (fr) 1963-10-11

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