GB1589804A - Labyrinth seals - Google Patents
Labyrinth seals Download PDFInfo
- Publication number
- GB1589804A GB1589804A GB17516/78A GB1751678A GB1589804A GB 1589804 A GB1589804 A GB 1589804A GB 17516/78 A GB17516/78 A GB 17516/78A GB 1751678 A GB1751678 A GB 1751678A GB 1589804 A GB1589804 A GB 1589804A
- Authority
- GB
- United Kingdom
- Prior art keywords
- seal
- sealing gap
- outer ring
- ring
- inner ring
- 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
Links
- 238000007789 sealing Methods 0.000 claims description 54
- 239000007788 liquid Substances 0.000 claims description 32
- 230000013011 mating Effects 0.000 claims description 9
- 229920003023 plastic Polymers 0.000 claims description 9
- 239000004033 plastic Substances 0.000 claims description 9
- 230000001174 ascending effect Effects 0.000 claims description 8
- 239000002184 metal Substances 0.000 claims description 7
- 230000035515 penetration Effects 0.000 claims description 7
- 238000010438 heat treatment Methods 0.000 claims description 3
- 238000004519 manufacturing process Methods 0.000 claims description 3
- 238000001816 cooling Methods 0.000 claims description 2
- 230000000694 effects Effects 0.000 claims description 2
- 230000005489 elastic deformation Effects 0.000 claims description 2
- 239000007789 gas Substances 0.000 claims description 2
- 230000005484 gravity Effects 0.000 claims description 2
- 238000001746 injection moulding Methods 0.000 claims description 2
- 239000000463 material Substances 0.000 claims description 2
- TZRXHJWUDPFEEY-UHFFFAOYSA-N Pentaerythritol Tetranitrate Chemical compound [O-][N+](=O)OCC(CO[N+]([O-])=O)(CO[N+]([O-])=O)CO[N+]([O-])=O TZRXHJWUDPFEEY-UHFFFAOYSA-N 0.000 description 1
- 238000000034 method Methods 0.000 description 1
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
- F16J15/44—Free-space packings
- F16J15/447—Labyrinth packings
- F16J15/4472—Labyrinth packings with axial path
- F16J15/4474—Pre-assembled packings
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Sealing Using Fluids, Sealing Without Contact, And Removal Of Oil (AREA)
- Medicinal Preparation (AREA)
Description
(54) IMPROVEMENTS IN OR RELATING TO LABYRINTH
SEALS
(71) We, GEORG MULLER KUGELLA
GERFABRIK KG, a Kommanditgesellschaft organised and existing under the laws of the
Federal Republic of Germany, of Aussere
Bayreuther Strasse 230, 8500 Nurnberg, Germany do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention concerns improvements in or relating to seals, particularly so-called gap or labyrinth seals for providing a seal, for example, between a rotating shaft and a housing from which it protrudes.
Ready-to-fit gap or labyrinth seals consisting of an outer ring and a rotating inner ring are already known, which are shaped to engage one inside the other the adjacent surfaces being correspondingly shaped for mating engagement and uniformly designed, to form an approximately zigzag-shaped sealing gap. Such seals have the advantages that they can be used to seal shafts running at virtually any speed, because neither heating nor wear occurs since no contact takes place between the two rings. Such readytd-fit seals are also already known, in which the outer ring is provided in the central region of its shell with at least one radial passage. Such seals have the additional advantage of still being effective even when they are struck by a jet of liquid under high pressure, although it can happen that jets of liquid pentrate into the sealing gap.
The arrangement of the passage in the outer ring of these seals enables liquid which has penetrated into the gap to be swept away through the radial passage or passages and drained off again, so that, altogether, penetration of liquid into the sealed region is prevented.
All hitherto known labyrinth seals of the above-mentioned types have, however, the disadvantage that they do not guarantee reliable sealing under very high liquid stress and do not reliably prevent liquid from passing through the sealing gap.
The object of the present invention is to provide an improved gap or labyrinth seal.
According to the invention there is provided a gap or labyrinth seal comprising an outer ring and an inner ring disposed therewithin, the mating faces of each ring being formed with a plurality of stepped mating annular grooves whereby to form a sealing gap of substantially zig-zag shape in axial section, the mating engagement of the stepped surfaces serving to prevent withdrawal of the inner ring from the outer, the circumference of the sealing gap at one end of the seal being greater than that at the other end, the zig-zag extending in a series of uniformly ascending steps and directly merging uniformly descending steps from one end of the rings to the other, and the outwardly ascending steps as seen from the lesser circumference end being of greater radial projection than the inwardly descending steps.
The seal must be fitted at the sealing region so that the end of the rings with the greater circumference of the sealing gap from the ring centre is adjacent the medium against which sealing is to be effected, and has the advantage of guaranteeing reliable sealing even under very high liquid stress.
The exact dimensioning of the narrow sealing gap required is possible by cutting or non-cutting manufacture of the inner and outer rings and, the arrangement of the sealing gap provides an especially effective seal against impinging liquids to the extent that this liquid is effectively a sealing medium when the seal is rotating. This surprising fact is explained as follows:
While the seal is in operation, liquid penetrates into the sealing gap in an amount which depends on the narrowness of the sealing gap, on the number and form of the zigzag-shaped steps and on the pressure and viscosity of the impinging liquid and which can be controlled according to these factors.
An equilibrium arises thereby in respect of the amount of penetration of the liquid, since penetration of the liquid is counteracted by the centrifugal force which forms a closed ring of liquid in the individual zigzag-shaped steps and, as a result of the different radial flank lengths of the sealing gap steps, prcssure components act against further penetration of liquid. The liquid thus flows back into the sealed space and, further, gases and vapours streaming through the scaling region are opposed by an advantageously effective, multi-step gastight barricr. As already mentioned, the narrowness and course of the sealing gap are selected in dependence on the viscosity and pressure of the liquid against which the seal must be effective.As the person skilled in the art knows the narrower the sealing gap is, the greater the pressure of the impinging liquid and the slower the rotation of the seal during operation. Thus, in contrast to the persuasive assumption that by the arrangement according to the invention of the sealing gap with a partial gradient from outside towards the space to be sealed, the penetration of liquid into the space to be sealed is facilitated under the action of gravity, in fact with the seal according to the invention the sealing action is substantially improved by this arrangement of the sealing gap in comparison with the conventional labyrinth seal with a substantially constant circumference of the zigzag-shaped sealing gap. It is advantageous, further, that at standstill the liquid which has penetrated into the seal flows back almost completely exclusively into the sealed space.
In an especially preferred embodiment of the present invention, the outer ring has an axial passage communicating with the sealing gap. which will, in use, be open towards the sealed space. By sealed space is meant the space on the side of the seal which contains the medium against which sealing is to be effected.
In the seal according to the invention the inner ring and outer ring can consist of metal or plastics, whereby the outer ring and inner ring can be manufactured in a non-cutting away, for example, by injection moulding or in a cutting way, for example, by turning. When metal rings are used, the inner ring and outer ring can be united by enlarging the outer ring by heating so that the inner ring can be inserted.
After cooling has taken placc, both rings are then connected together in a form-locking manner. When plastics are used, plastics are employed which enable the inner ring and outer ring to be united by elastic deformation. A combination of metal inner ring and elastically deformable plastics outer ring has proved especially successful.
Any person skilled in the art is capable of using suitable materials on the basis of the media against which sealing is to be effected. Within the scope of the present invention it is possible at once to make the outer ring of two semi circular parts which can be united into a closed ring by suitable plug connections or by a surrounding fixing ring. ln this way, it is possible to unite the inner ring and the outer ring without difficulty.
In order that the invention may be readily understood, certain embodiments thereof will now be described by way of example with reference to the accompanying drawings in which Figs. 1, 2 and 3 show in axial cross section three embodiments of seal in accordance with the invention.
The embodiment shown in Figure 1 of a labyrinth seal consists of an inner ring 1 and an outer ring 2 which are separated from one another by the substantially zigzag-shaped sealing gap 3. The substantially zigzag-shaped sealing gap has at its opening 4 at the one end a smaller radial spacing r4 from the ring centre than at its opening 5 at the other end of the rings r5. In the embodiment shown in Figure 1 the zigzag-shaped sealing gap runs in a series of uniform ascending profile sections 6 and uniform descending profile sections 7 from one end of the seal to the other.The axial projections of the ascending profile sections 6 represent a broader ring face a6 than the axial projections a7 of the adjoining descending profile sections 7, looking in the direction of the course of the sealing gap from the end with smaller spacing of the sealing gap from the ring cenre r4 to the other margin side with larger spacing of the sealing gap from the ring centre r5.
The embodiment illustrated in Figure 2 of a labyrinth seal according to the invention has a radial passage 8 in the outer ring 2. This embodiment is especially suitable for very high liquid stress, since any liquid which has pentrated into the sealing gap and is not removed again by drainage under the action of centrifugal force can flow out of the sealed space. Apart from the case of high liquid stress this advantage is effective whenever the seal rotates at low speed, which is the case, for example, during starting and stopping. The embodiment shown in Figure 2 is, in practice, fitted so that the radial passage is located at the lowest point.
The embodiment of the seal shown in
Figure 3 has in the outer ring an axial discharge groove 9 communicating with the sealed space. In this embodiment no discharge groove is necessary in the housing in which the seal is fitted.
The labyrinth seals thus described are less expensive to manufacture than hitherto known seals of this kind and provide a better sealing effect.
WHAT WE CLAIM IS: 1. A gap or labyrinth seal comprising an outer ring and an inner ring disposed therewithin, the mating faces of each ring being formed with a plurality of stepped mating annular grooves whereby to form a sealing
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (4)
- **WARNING** start of CLMS field may overlap end of DESC **.gap steps, prcssure components act against further penetration of liquid. The liquid thus flows back into the sealed space and, further, gases and vapours streaming through the scaling region are opposed by an advantageously effective, multi-step gastight barricr. As already mentioned, the narrowness and course of the sealing gap are selected in dependence on the viscosity and pressure of the liquid against which the seal must be effective. As the person skilled in the art knows the narrower the sealing gap is, the greater the pressure of the impinging liquid and the slower the rotation of the seal during operation.Thus, in contrast to the persuasive assumption that by the arrangement according to the invention of the sealing gap with a partial gradient from outside towards the space to be sealed, the penetration of liquid into the space to be sealed is facilitated under the action of gravity, in fact with the seal according to the invention the sealing action is substantially improved by this arrangement of the sealing gap in comparison with the conventional labyrinth seal with a substantially constant circumference of the zigzag-shaped sealing gap. It is advantageous, further, that at standstill the liquid which has penetrated into the seal flows back almost completely exclusively into the sealed space.In an especially preferred embodiment of the present invention, the outer ring has an axial passage communicating with the sealing gap. which will, in use, be open towards the sealed space. By sealed space is meant the space on the side of the seal which contains the medium against which sealing is to be effected.In the seal according to the invention the inner ring and outer ring can consist of metal or plastics, whereby the outer ring and inner ring can be manufactured in a non-cutting away, for example, by injection moulding or in a cutting way, for example, by turning. When metal rings are used, the inner ring and outer ring can be united by enlarging the outer ring by heating so that the inner ring can be inserted.After cooling has taken placc, both rings are then connected together in a form-locking manner. When plastics are used, plastics are employed which enable the inner ring and outer ring to be united by elastic deformation. A combination of metal inner ring and elastically deformable plastics outer ring has proved especially successful.Any person skilled in the art is capable of using suitable materials on the basis of the media against which sealing is to be effected. Within the scope of the present invention it is possible at once to make the outer ring of two semi circular parts which can be united into a closed ring by suitable plug connections or by a surrounding fixing ring. ln this way, it is possible to unite the inner ring and the outer ring without difficulty.In order that the invention may be readily understood, certain embodiments thereof will now be described by way of example with reference to the accompanying drawings in which Figs. 1, 2 and 3 show in axial cross section three embodiments of seal in accordance with the invention.The embodiment shown in Figure 1 of a labyrinth seal consists of an inner ring 1 and an outer ring 2 which are separated from one another by the substantially zigzag-shaped sealing gap 3. The substantially zigzag-shaped sealing gap has at its opening 4 at the one end a smaller radial spacing r4 from the ring centre than at its opening 5 at the other end of the rings r5. In the embodiment shown in Figure 1 the zigzag-shaped sealing gap runs in a series of uniform ascending profile sections 6 and uniform descending profile sections 7 from one end of the seal to the other.The axial projections of the ascending profile sections 6 represent a broader ring face a6 than the axial projections a7 of the adjoining descending profile sections 7, looking in the direction of the course of the sealing gap from the end with smaller spacing of the sealing gap from the ring cenre r4 to the other margin side with larger spacing of the sealing gap from the ring centre r5.The embodiment illustrated in Figure 2 of a labyrinth seal according to the invention has a radial passage 8 in the outer ring 2. This embodiment is especially suitable for very high liquid stress, since any liquid which has pentrated into the sealing gap and is not removed again by drainage under the action of centrifugal force can flow out of the sealed space. Apart from the case of high liquid stress this advantage is effective whenever the seal rotates at low speed, which is the case, for example, during starting and stopping. The embodiment shown in Figure 2 is, in practice, fitted so that the radial passage is located at the lowest point.The embodiment of the seal shown in Figure 3 has in the outer ring an axial discharge groove 9 communicating with the sealed space. In this embodiment no discharge groove is necessary in the housing in which the seal is fitted.The labyrinth seals thus described are less expensive to manufacture than hitherto known seals of this kind and provide a better sealing effect.WHAT WE CLAIM IS: 1. A gap or labyrinth seal comprising an outer ring and an inner ring disposed therewithin, the mating faces of each ring being formed with a plurality of stepped mating annular grooves whereby to form a sealinggap of substantially zig-zag shape in axial section, the mating engagement of the stepped surfaces serving to prevent withdrawal of the inner ring from the outer, the circumference of the sealing gap at one end of the seal being greaer than that at the other end, the zig-zag extending in a series of uniformly ascending steps and directly merging uniformly descending steps from one end of the rings to the other, and the outwardly ascending steps as seen from the lesser circumference end being of greater radial projection than the inwardly descending steps.
- 2. A seal according to claim 1, in which the outer ring has an axial discharge passage communicating with the sealing gap.
- 3. A seal according to claim 1 or 2, in which the outer ring consists of elastically deformable plastics and the inner ring consists of metal.
- 4. Gap or labyrinth seals substantially as hereinbefore described with reference to the accompanying drawings.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2720135A DE2720135C3 (en) | 1977-05-05 | 1977-05-05 | Gap or labyrinth seal |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1589804A true GB1589804A (en) | 1981-05-20 |
Family
ID=6008103
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB17516/78A Expired GB1589804A (en) | 1977-05-05 | 1978-05-03 | Labyrinth seals |
Country Status (7)
| Country | Link |
|---|---|
| JP (2) | JPS53140449A (en) |
| BR (1) | BR7802804A (en) |
| DE (1) | DE2720135C3 (en) |
| ES (1) | ES469449A1 (en) |
| FR (1) | FR2389814A1 (en) |
| GB (1) | GB1589804A (en) |
| IT (2) | IT7821668V0 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114856885A (en) * | 2022-06-20 | 2022-08-05 | 南方电网调峰调频发电有限公司检修试验分公司 | Step type sealing structure and water turbine |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS55145852A (en) * | 1979-05-01 | 1980-11-13 | Fukuda Koeki Kk | Rotary seal |
| SU1131477A3 (en) * | 1979-05-02 | 1984-12-23 | Пшедсембиорство Вдражаня И Уповшэхняня Постэмпу Тэхничнэго И Организацыйнэго "Постэор" (Инопредприятие) | Labyrinth system for sealing bearing |
| US4386786A (en) * | 1982-02-08 | 1983-06-07 | Merck & Co., Inc. | Adjustable pump seal with tapered conical members |
| DE3326299A1 (en) * | 1983-07-21 | 1985-02-07 | MTU Motoren- und Turbinen-Union München GmbH, 8000 München | GAP TRAINING BETWEEN A FIXED AND A TURNING PART |
| US5735530A (en) * | 1993-05-21 | 1998-04-07 | Jm Clipper Corporation | Seal device |
| DE10011063A1 (en) * | 2000-03-07 | 2001-09-27 | Daimler Chrysler Ag | Labyrinth seal for shaft of electric motor is made up of two sections, outer section having annular components which form conical seal gaps with surface of other component |
| DE10242679A1 (en) * | 2002-09-14 | 2004-04-22 | Adolf Thies Gmbh + Co Kg | Arrangement with a labyrinth seal between two components which can be rotated relative to one another, in particular a rotational anemometer |
| DE202013101140U1 (en) * | 2013-03-17 | 2014-06-18 | Paul Müller GmbH & Co. KG Unternehmensbeteiligungen | sealing element |
| DE102021121903A1 (en) | 2021-08-24 | 2023-03-02 | Schaeffler Technologies AG & Co. KG | Electric final drive train and method of manufacturing an electric final drive train |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1008061B (en) * | 1954-04-27 | 1957-05-09 | Walter Pankratz | Shaft seal, in connection with roller bearings |
| JPS5085753A (en) * | 1973-12-07 | 1975-07-10 | ||
| DE2411004A1 (en) * | 1974-03-07 | 1975-09-18 | Hutzenlaub Ernst | ROTARY PISTON MACHINE WORKING WITH HOT DEPOSIT FORMING GASES OR DAMPER |
-
1977
- 1977-05-05 DE DE2720135A patent/DE2720135C3/en not_active Expired
-
1978
- 1978-04-28 IT IT7821668U patent/IT7821668V0/en unknown
- 1978-04-28 IT IT22815/78A patent/IT1095340B/en active
- 1978-05-03 GB GB17516/78A patent/GB1589804A/en not_active Expired
- 1978-05-03 FR FR7813101A patent/FR2389814A1/fr active Pending
- 1978-05-04 BR BR7802804A patent/BR7802804A/en unknown
- 1978-05-04 ES ES469449A patent/ES469449A1/en not_active Expired
- 1978-05-04 JP JP5282578A patent/JPS53140449A/en active Pending
-
1980
- 1980-03-21 JP JP1980035937U patent/JPS55137758U/ja active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114856885A (en) * | 2022-06-20 | 2022-08-05 | 南方电网调峰调频发电有限公司检修试验分公司 | Step type sealing structure and water turbine |
| CN114856885B (en) * | 2022-06-20 | 2024-03-29 | 南方电网调峰调频发电有限公司检修试验分公司 | Step type sealing structure and water turbine |
Also Published As
| Publication number | Publication date |
|---|---|
| IT1095340B (en) | 1985-08-10 |
| JPS55137758U (en) | 1980-10-01 |
| BR7802804A (en) | 1978-12-12 |
| DE2720135A1 (en) | 1978-11-09 |
| DE2720135C3 (en) | 1980-09-25 |
| ES469449A1 (en) | 1979-10-01 |
| IT7821668V0 (en) | 1978-04-28 |
| FR2389814A1 (en) | 1978-12-01 |
| DE2720135B2 (en) | 1980-02-07 |
| IT7822815A0 (en) | 1978-04-28 |
| JPS53140449A (en) | 1978-12-07 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed [section 19, patents act 1949] | ||
| 732 | Registration of transactions, instruments or events in the register (sect. 32/1977) | ||
| PCNP | Patent ceased through non-payment of renewal fee |