DE20101327U1 - sealing arrangement - Google Patents

Description

BOEHMERT & BOEHMERT

: . ~ LAW FIRM

Bbehmert & Boehmert · P.O.B. 43 02 54 · D-80732 Munich

German Patent and Trademark Office Zweibrückenstr. 12 " 80297 Munich

DR-INO."KARL BOEHMERT,PA(ls'99-l97j) DIPL-INOiALBERTBOEHMERT ₁ PA(ITO-TOJ) WILHELM J. K STAHLBERG, RA. Bremen DR-ING WALTERHOORMANN,PA ^: ,Bremen DlPL-PHYS: DR. HEINZ GODDAR, PA'. Moneten-DR-ING. ROLAND LIESEGANG.PA·.Some' WOLF-DIETER KUNTZE RA. Brauen. Äiicante DlPL-PHYS. ROBERTMÜNZHUBER, PA (IiU-ISM) DR. LUDWIG KOUKER, RAATBremen-DR! (CHEM.)ANDREAS WINKLER. PA'.Branen MICHAELA É&Igr;&Pgr;&EEacgr;-DIERIG, RA, Some · DIPL-PHYS. DR MARION TÖNHARDT, PA·. Düsseldorf "DR. ANDREAS EBERT-WEIDENFELLER, RA. Bremen DIPL-ING. EVA LIESEGANG, PA·. Manchen- -DRAXELNORDEMANN ₁ RABaUn DIPL-PHYS. DR.DOROTHEE WEBER-BRULS.PA·,Fnuikfun DIPL-PHYS. DR. STEFAN SCHOHE.PA·.Mönchen DR-ING. MATTHIAS PHILIPP,PA·.Bielefeld -DR. MARTIN WIRTZ, RA, Düsseldorf DR. DETMAR SCHAFER, RA, Bremen .

- DR. IAN BERND NORDEMANN, LLM, RA. Berlin

PA-Palentanvrall/Palcnt Attorney

RA - Rechtsanwmh/Attorney at Law -

·- -Kuropean Patent Attorney - -- - - -

—^&Dgr; - Bnmdenburg, zugdassen am OLG Brandenburg ■ ⁰ - Maine en Droit - · ""— .

All assigned ujt representation before the European M*rkenwm, My FTofewoiul Repm«i«Uiim it Uw Community TnoanutOfTke, Alicante ~

PROF. DR. WILHELM NORDEMANN, RA. BRB' DIPL-PHYS. EDUARD BAUMANN, PA·. HohenKrchen DR-ING. GERALD KLOPSCH, PA·, Doselctaf DIPL.-ING. HANS W. GROENING, PA!, Mönchen DIPL.-ING.SIEGFRIED SCWRMER, PA·, Bielefeld DIPL.-PHYS: LORENZ HANEWINKEL, PA·, Paderborn .DIPL-ING. DRIAN TÖNNIES, PA, RA, Kiel ■ DIPL-PHYS. CHRISTIAN BIEHL,PA·,Kiel -DIPL.-PHYS. DR-ING.UWEMANASSE ₁ PA",Bremen DR. CHRISTIAN CZYCHOWSKI, RA, BeHin DR. CARL-RICHARD HAARMANN, RA, Mönchen DIPL.-PHYS. DR. THOMAS L. BITTNER, PA", Berlin DR. VOLKER SCHMITZ, RA, Munich DIPL-PHYS. CHRISTIANW. APPELT, PA", Mönchen DR. ANKE NORDEMANN-SCHIFFEL, HA", Potato KERSTIN MAUCH, LLM., RA, Potsdam DIPL-BIOL. DR. JAN B. KRAUSS, P/t Munich IURGEN-ALBRECHT ₁ RA ₁ MOnChCn ANKE SIEBOLD, RA. Bremen .-'

m cooperation with/in cooperation with ■

DIPL-CHEM. ÖR..HANS ULRICH MAY. PA-, Mimcnei, _

Your sign
Your ref.

Your letter of Our sign
Our ref.

B30030(L)

_ Munich,

25: January 2001

Sealing technology G. Bruss GmbH & Go. KG - 22955 Hoisdorf

Seal arrangement

The invention relates to a sealing arrangement according to the preamble of claim 1.

Shaft seals - hereinafter also referred to as "dynamic seals" - basically have the task of preventing the ingress of dirt and the leakage of media to be sealed, such as lubricants, oils, etc., along the rotating shaft.

A known sealing arrangement is shown in the attached Figure 1, which shows a converter part a of an automatic transmission (not shown) which is connected on the drive side b to a

Franz-Joseph-Straße 38 · 0.-8080,1 ,Munich-&Rgr;.&Ogr;.&Bgr;. 43 02 54 .D-80732 Munich · Telephone+49-89-3840720- Fax+49-89-347010 ' ;

MUNICH - BREMEN - BERLIN!- DÖSiSlTdORF - FrVfrfiFUJlT- BJELEljiLLV PofSDAM -«BRANrjfeNBURO - KljjL -J ¹ AOf RBORN - HÖHENKIRCHEN - ALICANTE ··· ·■·· · *-- J- &idigr;*·&iacgr;.-··.· . . ....

' ; .···.··. httjf^'trtvwihoehniert.de ··; ;·· '••e-n»iUpo«tmaster@beeh(ntTt.de

&Ggr; BOEHMERT & BOEHMERr

Internal combustion engine (not shown) is flanged. On the output side c, a mechanical transmission (not shown) is provided, the gears of which are switched with the aid of a clutch or brake bands. In area I., the converter drive hollow shaft d is mounted in a plain bearing e, which is lubricated by a leakage oil flow generated by an oil pump f. The leakage oil flow, which is caused by the so-called side flow of the oil pump f, flows from the left-hand end face of the oil pump f via the gap g of the plain bearing e to a drain hole (not shown), from which the oil flows into an oil collecting container. A radial shaft seal j prevents the oil from leaking out of the space h to be sealed. . * ~ . . ..... ' ; " . :

With such a design, critical operating situations can arise if, as the service life and mileage of the gearbox increases, the plain bearing gap increases due to wear and tear, and an ever-increasing proportion of the oil volume required by the pump can leak through the plain bearing. The pressure in the system can thus drop so much that it is no longer sufficient to precisely hold the gears using the clutches or brake bands provided for this purpose, and the remaining amount of oil pumped is no longer sufficient to lubricate the gearbox and dissipate the frictional heat generated in it. The problems described occur quite generally with oil pumps, e.g. with vacuum pumps, "fuel pumps, pumps for power steering, pre-pumps for diesel injection pumps, etc."" _:

It is the object of the invention to create a sealing arrangement of the type described which, in addition to a good seal on the shaft, ensures a constant flow of medium to be sealed in the sealing chamber for supplying medium to a machine element, such as a bearing, a gear pair or the like, regardless of its state of use.

This problem is solved by claim 1.

Claim 13 solves this problem for use in the construction according to Fig. 1. The machine element is a plain bearing that is lubricated by the leakage oil flow of an oil pump.

. BOEHMERT & BOEHMERT

To keep this leakage oil flow constant even when the plain bearing wears out, the throttle valve connected upstream of the plain bearing acts in series with the bearing gap of the plain bearing -

additional flow resistance and thus keeps the leakage oil flow of the oil pump, which flows off via the plain bearing, unchanged almost regardless of the height of the bearing gap, so that sufficient lubrication is always ensured regardless of the state of wear. The throttle is dimensioned in such a way that the leakage oil flow hardly increases even if the bearing gap increases due to wear.; : " ;-_.,.

Advantageous embodiments of the invention are specified in the subclaims. -

A second dynamic seal can be provided as a throttle, or the sealing effect of which is designed according to the invention such that when a predetermined medium pressure or throughput is exceeded, medium can flow past the second dynamic seal to the outlet. ' . .. -.-/..

The use of a second seal as a throttle is advantageous because its placement next to the first seal requires only a minor structural change to the moritage area of the first seal that is already provided. . .

In particular, it is advantageous to form the seal and throttle as a structural unit, which in particular ensures quick and safe assembly of the sealing arrangement.

Further features, characteristics and advantages of the invention will become apparent from the following description of preferred embodiments with reference to the accompanying drawings, in which: ' "

Fig. 1 a known converter part of an automatic transmission; -

Fig.-2- a sealing arrangement according to the invention, which in the area I according to Fig. 1

.;:-.: is intended for assembly; - . -;- -

Fig. 3 shows a sealing arrangement according to the invention in a second preferred

~ embodiment; and " .:..:..:: ..■_'.. .·.·;.-.

BOEHMERT & BpEHMERT

Fig. 4 shows the sealing arrangement according to the invention in a third preferred embodiment.

driving form.-- _ .

The sealing arrangements shown in Figures 2 to 4 are intended as a replacement for the radial shaft seal in the construction according to Fig.!, \ ·-

The sealing arrangement 1 according to the invention according to Fig. 2 is seated on a shaft 3, the circumference of which is indicated by dashed lines. The sealing arrangement 1 comprises a first seal 5, which seals against the outside space B, an outlet 7 for the medium (not shown) to be sealed, in this case oil, and a throttle 9, which has a second seal 11.

The first seal 5, which can be designed similarly to the seal published in EP 0 711990"B:1, comprises a sealing element 13 made of PTFE-gasket, with a sealing lip 1-5, which prevents the medium from escaping from a sealing chamber section 17 into the outer space B. The sealing lip 15 of the sealing element 13, which is pressed against the shaft 3 in a spring-loaded manner, is arranged pointing into the sealing chamber section 17. The sealing element 3 is permanently attached to a support body 19, which is formed as a sleeve-like stiffening part made of plastic. . . :

A return structure which is effective in both or only one direction of rotation can be applied to the side of the sealing lip 15 which is in contact with the shaft and which conveys medium which has penetrated under the sealing lip back into the space 17 to be sealed. A return structure for sealing lips made of a PTFE compound which is only effective in one direction of rotation is described, for _example, in DE 43 07 964 C2. . . ~ &lgr;-.

The second seal 11 is designed almost the same as the first seal 5. The second seal 11 comprises a sealing element 21 made of PTFE compound which acts in the axial direction and is permanently attached to the carrier body 19, e.g. glued to it. The sealing lip 23 of the sealing element 21 which is in contact with the shaft 3 is arranged in a mirror image of the sealing lip 15 of the sealing element 13. ■-'--.

The support body 19 of the first and second seals 5, 11" is formed in one piece, with the outlet 7 being formed as a radial through-bore 25 ^: in the support body 19. The ^through-

- ■:_' - BÖEHMERT & BOEHMERT.

The through hole 25 is connected to a drain channel (not shown) which leads into a collecting container (not shown), such as a transmission oil sump,'" for the medium to be sealed.

A locking lever 27 of a locking device is arranged on the throttle-side region of the support body 19, preferably in one piece with the support body: The locking lever 27 interacts with a locking recess (not shown) which is made in a fixed component adjacent to the sealing arrangement 1. - - .

The functioning of the sealing lip 23 of the second seal 11 as a throttle 9 is explained below: .. .; : ..-. . ' r.

When the construction shown in Fig. 1 is in operation, oil collects in the sealing space section A to the right of the second seal 11, the hydrostatic pressure of which increases steadily with increasing bearing flow. The second seal 11 loses its sealing effect as soon as the oil pressure is sufficient to raise the sealing lip 23 of the seal 11 resting on the shaft 3 depending on the oil pressure (see the dashed position of the sealing lip 23 in Fig. 2). The oil can then flow into the intermediate sealing space 17 delimited by the first and second seals 5, 11 due to the pressure gradient between the intermediate space 17 and the sealing space A. The oil collecting in the intermediate space 17 can flow out unhindered via the through hole 25. ·..;.; ■ .": - - · " - -

The flexibility of the sealing lip 23 can be adjusted by incorporating a return-feeding structure (not shown) or concentric grooves or recesses. With these structural measures, the contact pressure of the sealing lip on the shaft 3 is reduced, so that even a lower medium pressure is sufficient to lift the sealing lip 23. Furthermore, the medium is held in the contact area of the sealing lip 23 by return-feeding structures, thus preventing the sealing lip from running dry. ..;...'·..

The sealing arrangement 1 according to the invention ensures that the plain bearing e is supplied with a constant and appropriate oil flow from the oil pump f. Furthermore, excessive oil drainage and the risk of insufficient lubrication are avoided.

BOEHMERT &BOEHMERT..'■'. &Lgr;

other machine components requiring oil in the sealing chamber section A, e.g. the gear thread pairs of a gearbox, as well as the associated failure risks are reliably eliminated. . ,....-. ... "..;■ .„ t.

An outer casing 29 made of an elastomer is provided around the sleeve part of the support body 19 of the seal 5. The outer casing 29 is pressed into a housing bore (not shown) in the assembled state and prevents axial leakage of the draining medium into the external space B. The outer casing 29 is smooth or, as shown, provided with grooves and is extended radially in the direction of the shaft 3 following the profile of the support body 19 and runs into a non-contacting protective lip 31 made of the same elastomer .--'- -'"....■-..■-.' ._ . . v:- .·......■■. .. .: .'. .. --__:. y;.; .-. r·:™ . &igr;

In the embodiment of the sealing arrangement shown in Fig.3, identical or similar components are provided with identical reference numbers and an additional ^superscript ' and do not require any further explanation due to their identical or similar function. - - r .

In the case of the valve seat according to Fig. 3, the seal 5' has an elastomeric spring-loaded sealing lip 15'. The sealing lip 15' is provided with an annular groove into which an annular spiral spring 33 is inserted; which presses the sealing lip 15' radially against the circumference of the shaft y . - „">-_·...■';" · ,. "-. ^{r J} 7 "^7; -

A second seal "1" has a sealing element 2" with a sealing lip 23' which points into the sealing chamber section A'. When the oil pressure in the sealing chamber A' increases, the seal IV is pressed more strongly against the shaft 3' and, in contrast to the seal 11 according to Fig. 2, is not lifted off the shaft 3'. ",' . -

The support body 19' comprises two separate support body sections 35, 37," wherein the sealing lip 15' of the seal 5' is attached to the support body section 35 and the sealing element 21' of the second seal 11! is attached to the support body section 37. ■..:- . - . . ;

■■■"'#' ■·"·♦'· · · ■ · ■

_..-"■'.' BOEHMERT &BOEHMERT;

■-- .. ■■ '■ . ■ - ; ; -7- ■ · · ■■_.■.._-■■ -

The support body section 37 has a T-shaped, cylindrical shape in cross section, with the leg 39 pointing towards the first seal 5' being inserted into the sleeve-like support body section 35 of a seal 5'. The outer diameter of the leg 39 is smaller than the inner diameter of the part of the support body section 35 of the seal 5' that overlaps the leg 39. The leg section 41 of the support body section 37 opposite the leg 39 is partially surrounded by an elastomer seal 43 in order to prevent the medium to be sealed from leaking in the axial and radial direction on the outer surface of the support body section 37 from the space A ¹ to be sealed.

In order to achieve the desired throttling effect in the sealing arrangement 11' according to Fig. 3, the second seal 11' has an axial bore 45 in its supporting body section 37 radially outside the sealing element 21. This ensures an oil flow _from the sealing chamber section A' into the sealing chamber section or intermediate space 17'. As soon as a sufficient oil level or an adequate oil pressure level is reached in the space ^A1 , oil flows over the axial bore 45 to the sealing chamber section 17'. From there, the oil passes through at least one gap 47 located between the supporting body sections 35 and 37 into an oil sump. The gap 47 is formed in the elastomer material of the outer casing 29'.

In the embodiment of the sealing arrangement shown in Fig. 4, components which are identical or similar to the sealing arrangements according to Figs. 2 and 3 are provided with identical reference numbers and additional superscripts ", and do not require further explanation due to their identical or similar function.

The sealing arrangement ¹ ' according to Fig. 4 differs from that according to Fig. 3 in that the bore 45" is introduced in the curved region of the sealing element 21" adjoining the sealing lip 23", which is otherwise designed and arranged in the same way as the sealing element 21' of the embodiment according to Fig. 3.'

The 45" bore is dimensioned to achieve the desired throttling effect of the second 11" seal.

: -'- ;■·-·- BOEHMERT & BOEHMERT

The features disclosed in the above description, the figures and the claims can be important for the realization of the invention both individually and in any combination. _ - _: -

· · · - —...»
·· ·
• - ·
- ·"
• • - · ^ •—
-* *
• • · ··- — ·
■ - - · · :. ·-■ ····.- -
·- ·.' · * ·* -
· * ·· . · " -
- ■ *·.§· • •
• • •
-.· · * · · • ·

Claims (13)

1. Sealing arrangement with a first dynamic seal ( 5 , 5 ', 5 "), which seals against the escape of medium to be sealed from a sealing chamber ( 17 and A; 17 ' and A', 17 " and A") relative to a moving component, wherein an outlet for the medium to be sealed is provided in the sealing chamber, characterized in that a throttle ( 9 , 9 ', 9 ") acting depending on the medium pressure is connected upstream of the seal ( 5 , 5 ', 5 ") on the medium side and that the outlet ( 7 ; 47 ; 47 ") is provided between the seal ( 5 , 5 ', 5 ") and the throttle ( 9 , 9 ', 9 "). 2. Sealing arrangement according to claim 1, characterized in that the throttle ( 9 , 9 ', 9 ") is designed as a second dynamic seal ( 11 , 11 ', 11 ") which allows a medium flow towards the outlet ( 7 ). 3. Sealing arrangement according to claim 2, characterized in that the second seal ( 11 , 11 ', 11 ") has a sealing element ( 21 , 21 ', 21 ") with a sealing lip ( 23 , 23 ', 23 ") made of a polytetrafluoroethylene (PTFE) plastic compound, which is permanently attached to a support body ( 19 , 19 ', 19 "). 4. Sealing arrangement according to claim 3, characterized in that the sealing lip ( 23 ) of the second seal ( 11 ) is directed away from the medium side towards the first seal ( 5 ). 5. Sealing arrangement according to one of claims 2 or 3, characterized in that the throttle ( 9 ', 9 ") is designed as a through hole ( 45 , 45 ") formed in the sealing element ( 21 ") of the second seal ( 11 ") or in the supporting body ( 37 ) of the second seal ( 11 '). 6. Sealing arrangement according to one of claims 1 to 5, characterized in that the first seal ( 5 ) and the throttle ( 9 ) have a common supporting body ( 19 ) which encloses the outlet ( 7 ). 7. Sealing arrangement according to claim 6, characterized in that the drain ( 7 ) is designed as a passage ( 25 ) introduced into the common support body ( 19 ) which is connected to a medium drainage channel system. 8. Sealing arrangement according to one of claims 1 to 6, characterized in that the seal ( 5 ', 5 ") and the throttle ( 9 ', 9 ") each have a support body ( 35 , 35 ", 37 , 37 "), wherein the support bodies are coupled to one another and have the outlet ( 47 , 47 ") in their coupling region. 9. Sealing arrangement according to claim 8, characterized in that the support body ( 37 , 37 ") of the throttle ( 9 ') has an elastomeric static seal ( 43 , 43 "). 10. Sealing arrangement according to one of claims 3 to 9, characterized in that sealing aids are provided for the sealing lips ( 15 , 15 ', 15 ", 23 , 23 ', 23 ") of the dynamic seals ( 5 , 5 ', 5 ", 11 , 11 ', 11 "), in particular return devices or spiral grooves. 11. Sealing arrangement according to one of claims 3 to 9, characterized in that the sealing lip ( 23 ) of the seal ( 11 ) is provided with concentrically introduced grooves or recesses to increase the flexibility. 12. Sealing arrangement according to one of claims 3 to 10, characterized in that it is provided with a locking device for holding it on a fixed component. 13. Sealing arrangement with a first dynamic seal (S) which seals against the escape of oil to be sealed from a sealing chamber ( 17 and A; 17 ' and A; 17 " and A") relative to a shaft ( 3 ), wherein the leakage oil flow of an oil pump flows via the bearing gap of a plain bearing into a sealing chamber section ( 17 ) adjacent to the first seal ( 5 ), which contains an outlet ( 7 ; 47 ; 47 ") for the leakage oil flow, characterized in that a throttle ( 9 ) acting depending on the medium pressure is arranged between the plain bearing and the outlet ( 7 ).