GB2261920A - A method of making a seal - Google Patents
A method of making a seal Download PDFInfo
- Publication number
- GB2261920A GB2261920A GB9125477A GB9125477A GB2261920A GB 2261920 A GB2261920 A GB 2261920A GB 9125477 A GB9125477 A GB 9125477A GB 9125477 A GB9125477 A GB 9125477A GB 2261920 A GB2261920 A GB 2261920A
- Authority
- GB
- United Kingdom
- Prior art keywords
- seal
- groove
- former
- blank
- relative motion
- 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.)
- Granted
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
- B29D99/00—Subject matter not provided for in other groups of this subclass
- B29D99/0053—Producing sealings
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21H—MAKING PARTICULAR METAL OBJECTS BY ROLLING, e.g. SCREWS, WHEELS, RINGS, BARRELS, BALLS
- B21H7/00—Making articles not provided for in the preceding groups, e.g. agricultural tools, dinner forks, knives, spoons
- B21H7/18—Making articles not provided for in the preceding groups, e.g. agricultural tools, dinner forks, knives, spoons grooved pins; Rolling grooves, e.g. oil grooves, in articles
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B26—HAND CUTTING TOOLS; CUTTING; SEVERING
- B26D—CUTTING; DETAILS COMMON TO MACHINES FOR PERFORATING, PUNCHING, CUTTING-OUT, STAMPING-OUT OR SEVERING
- B26D3/00—Cutting work characterised by the nature of the cut made; Apparatus therefor
- B26D3/08—Making a superficial cut in the surface of the work without removal of material, e.g. scoring, incising
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C59/00—Surface shaping of articles, e.g. embossing; Apparatus therefor
- B29C59/007—Forming single grooves or ribs, e.g. tear lines, weak spots
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C59/00—Surface shaping of articles, e.g. embossing; Apparatus therefor
- B29C59/02—Surface shaping of articles, e.g. embossing; Apparatus therefor by mechanical means, e.g. pressing
- B29C59/04—Surface shaping of articles, e.g. embossing; Apparatus therefor by mechanical means, e.g. pressing using rollers or endless belts
-
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
- B29L2031/00—Other particular articles
- B29L2031/26—Sealing devices, e.g. packaging for pistons or pipe joints
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Agronomy & Crop Science (AREA)
- Forests & Forestry (AREA)
- Sealing Devices (AREA)
- Sealing With Elastic Sealing Lips (AREA)
Abstract
A grooved seal is formed by pressing a groove former (6) into an end face (5) of a seal blank and causing relative motion between the blank and the former (6). The former (6) takes the form of a rotatably mounted wheel held in a holder (8) which is caused to rotate by the relative motion. The groove (10) is thus formed by a crushing action which imparts a fine surface texture on the groove (10).
Description
A METHOD OF MAKING A SEAL
This invention relates to a method of making a seal, in particular, a grooved seal.
Grooved seals are often used to form a seal about rotating shafts of machines. The grooves give an hydrodynamic effect which drives lubricant away from the seal. In the past these grooves have been machined into the seal material using a sharp cutting tool. However, the resultant grooves have had a coarse surface texture which retains a film of lubricant in the groove. Eventually, the retained oil burns onto the surface and the groove becomes choked and ineffective.
For some glass filled seal materials, the cutting tool is blunted after cutting grooves in a modest number of elements. If a blunt tool is used to cut further grooves, tearing and chipping can occur in the seal material producing a poor quality groove leading to premature failure.
Even whilst the tool is sharp, burring can occur requiring a further operation to be carried out to remove the burs.
It is an object of the invention to provide a method for forming a groove in a seal with a finer surface texture.
Accordingly the invention provides a method of making a grooved seal comprising the steps of providing a seal blank, providing a rotatably mounted groove former, pressing the former and seal blank into contact and causing relative motion of the former and seal blank to form a groove in the blank, the relative motion causing a rotational movement of the former.
By using a rotatably mounted groove former, the groove is formed by a crushing action in the material as opposed to a cutting action. The groove texture is, as a result, smoother and tearing and chipping is less likely to occur.
Preferably, the groove former is a wheel rotatably mounted in a holder.
The groove former will comprise a hard material of a cross section matching that of the required groove and, preferably, will comprise a tungsten carbide metal alloy.
A specific embodiment of the invention will now be described, by way of example only, with reference to the drawing in which:
Figures 1 to 4 show a method of making a seal in accordance with the invention; and
Figure 5 shows, in plan view, a seal groove forming tool in accordance with the invention.
With reference to Figure 1, a cylindrical rod 1 formed of polytetrafluoroethylene, PTFE, filled with 5% glass and 5% MoS2 is removably mounted in a lathe chuck 2. The outside diameter and inside diameter of the rod has been formed in a previous lathing operation well known to those skilled in the art. The lathe chuck 2 rotates the cylindrical rod 1 about central longitudinal axis 3.
As the chuck 2 rotates, a groove forming tool 4 is brought into contact with a planar annular end face 5 of the rod 1 and then pressed axially into the material. Progressively, the tool 4 is moved radially inwards, towards the axis 3 from distance
X to distance Y from the axis 3.
As the tool 4 approaches Y, the pressure is gradually removed to form a helical groove centred on axis 3 with a gradual groove run out, that is to say, the depth of the groove gradually decreases as it approaches V.
As shown in Figure 2, the tool 4 comprises a tungsten carbide rolling wheel 6 rotatably mounted about an axle 7 in a wheel holder 8. The wheel 6 has a tapering edge 9 to form the desired crosssection of groove 10, as more clearly shown in
Figure 3.
The seal is completed by a parting operation in which a cutting tool 11 is brought radially inwards, starting from a point the desired thickness Z of the finished seal from the end face 5, towards the axis 3 as shown in Figure 4. To form the next seal the cut end face of the remaining stock is machined flat and true and the previously described operations repeated.
A preferred form of seal groove forming tool is shown in Figure 5 and it comprises a holder 12 having a selectively rotatable carriage 13 mounted by a stud 14 at one end. The carriage 13 is retained by the stud in a generally circular recess 15 in the holder 12. Rotatably mounted in the carriage 13 are four tungsten carbide wheels 16, 17, 18 and 19. When wheel 16 has worn, the carriage 13 is rotated clockwise until unused wheel 17 is in position for use. Likewise, wheel 17 may be replaced by wheel 18 and wheel 18 by wheel 19.
In a test of two seals 896-008-7280-00 formed according to the invention, the seals were used to seal a shaft running at 6,000 r.p.m. at 1200C.
The lubricant used was B.P. UF7 which after 400 hours did not leak past the seal. No signs of burnt oil were found on the seals after completion of the test.
A further test was carried out to examine whether or not the groove would recover from the crushing action of the former.
A completed seal was placed in an air oven at 2000C for a period of 24 hours. Examination of the seal showed that material recovery had been minimal.
Claims (5)
1. A method of making a grooved seal comprising the steps of providing a seal blank, providing a rotatably mounted groove former, pressing the former and seal blank into contact and causing relative motion of the former and seal blank to form a groove in the blank, the relative motion causing a rotational movement of the former.
2. A method substantially as hereinbefore described with reference to the drawings.
3. A seal groove forming tool comprising a rotatably mounted groove former to, in use, be pressed into a surface of a seal blank relative motion of the tool and blank causing rotational movement of the former.
4. A tool as claimed in claim 2, wherein the groove former comprises a tungsten carbide wheel.
5. A seal groove forming tool substantially as hereinbefore described with reference to the drawings.
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB9125477A GB2261920B (en) | 1991-11-29 | 1991-11-29 | A method of making a seal |
PCT/GB1992/002168 WO1993010964A1 (en) | 1991-11-29 | 1992-11-24 | A method of making a seal |
CN 92114162 CN1073386A (en) | 1991-11-29 | 1992-11-28 | The method of processing sealing |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB9125477A GB2261920B (en) | 1991-11-29 | 1991-11-29 | A method of making a seal |
Publications (3)
Publication Number | Publication Date |
---|---|
GB9125477D0 GB9125477D0 (en) | 1992-01-29 |
GB2261920A true GB2261920A (en) | 1993-06-02 |
GB2261920B GB2261920B (en) | 1995-04-26 |
Family
ID=10705481
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB9125477A Expired - Fee Related GB2261920B (en) | 1991-11-29 | 1991-11-29 | A method of making a seal |
Country Status (3)
Country | Link |
---|---|
CN (1) | CN1073386A (en) |
GB (1) | GB2261920B (en) |
WO (1) | WO1993010964A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1448920A2 (en) * | 2001-11-28 | 2004-08-25 | Federal-Mogul Corporation | Hydrodynamic seal and method of making the same |
US7938405B2 (en) | 2005-04-22 | 2011-05-10 | Vr-Dichtungen Gmbh | Radial shaft sealing ring |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1522722A (en) * | 1975-02-04 | 1978-08-31 | Federal Mogul Corp | Method of making sealing elements |
US4243235A (en) * | 1979-07-02 | 1981-01-06 | The Mather Company | Composite polytetrafluoroethylene and elastomer lip seal |
US4542573A (en) * | 1984-09-28 | 1985-09-24 | The Fluorocarbon Company | Method of producing a hydrodynamic seal |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1988738A (en) * | 1931-05-25 | 1935-01-22 | Charles E Johnson | Process of making piston rings |
FR1421558A (en) * | 1964-11-05 | 1965-12-17 | New process for modifying the outer shape of a plastic object and the internal tensions in this object | |
US3735615A (en) * | 1970-05-19 | 1973-05-29 | J Shneider | Method of making grooves on surface of articles and device for its realization |
US3857156A (en) * | 1973-12-19 | 1974-12-31 | Federal Mogul Corp | Method of making tetrafluoroethylene sealing elements with hydrodynamic action |
DE2421936B2 (en) * | 1974-05-07 | 1976-06-10 | Speidel-Kunststoffwerk Kg, 7404 Ofterdingen | PROCESS FOR JOINT-TO-JOINT JOINT OF THE EDGES OF SPATIAL CURVED SHELL ELEMENTS MADE OF GLASS FIBER REINFORCED PLASTIC AND DEVICE FOR THEM |
US4385429A (en) * | 1979-07-18 | 1983-05-31 | Dynetics, Inc. | Method of manufacturing a clutch plate |
US4450614A (en) * | 1982-02-19 | 1984-05-29 | Microdot Inc. | Method of making a polytetrafluoroethylene hydrodynamic seal |
US5048382A (en) * | 1989-08-23 | 1991-09-17 | Mar Don Corporation | Method for making elastomeric sealing device |
-
1991
- 1991-11-29 GB GB9125477A patent/GB2261920B/en not_active Expired - Fee Related
-
1992
- 1992-11-24 WO PCT/GB1992/002168 patent/WO1993010964A1/en active Application Filing
- 1992-11-28 CN CN 92114162 patent/CN1073386A/en active Pending
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1522722A (en) * | 1975-02-04 | 1978-08-31 | Federal Mogul Corp | Method of making sealing elements |
US4243235A (en) * | 1979-07-02 | 1981-01-06 | The Mather Company | Composite polytetrafluoroethylene and elastomer lip seal |
US4542573A (en) * | 1984-09-28 | 1985-09-24 | The Fluorocarbon Company | Method of producing a hydrodynamic seal |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1448920A2 (en) * | 2001-11-28 | 2004-08-25 | Federal-Mogul Corporation | Hydrodynamic seal and method of making the same |
EP1448920A4 (en) * | 2001-11-28 | 2006-06-14 | Federal Mogul Corp | Hydrodynamic seal and method of making the same |
US7938405B2 (en) | 2005-04-22 | 2011-05-10 | Vr-Dichtungen Gmbh | Radial shaft sealing ring |
Also Published As
Publication number | Publication date |
---|---|
GB2261920B (en) | 1995-04-26 |
WO1993010964A1 (en) | 1993-06-10 |
GB9125477D0 (en) | 1992-01-29 |
CN1073386A (en) | 1993-06-23 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4126064A (en) | Preparation of annular blanks from tube stock | |
US3435502A (en) | Piston ring and method of manufacture thereof | |
US2105896A (en) | Method and means for honing gears, and for truing the honing means | |
US4611509A (en) | Method of manufacturing a dental root canal cutting tool and apparatus therefor | |
US3994251A (en) | Apparatus and method for trimming and deburring the edges of cylindrical metal bodies | |
US3952179A (en) | Rotary cutting die and method for its production | |
US3905283A (en) | Improved rotary cutting die | |
US4744277A (en) | Method and device for cutting pipe lengths | |
EP1330339B1 (en) | Method and apparatus for making a cutting tool having a plurality of margins | |
GB2261920A (en) | A method of making a seal | |
EP1322448B1 (en) | Method and apparatus for making a cutting tool having a flute | |
US2232843A (en) | Method and means for burnishing spherical seats | |
JPH01130822A (en) | Method for working surface of metallic pipe | |
US1944380A (en) | Method of and means for bushing openings | |
US3691898A (en) | Edge burr removal apparatus | |
US3293988A (en) | Method and apparatus for broaching gears | |
GB2195928A (en) | Method of cutting a surface of a work-piece | |
US4398078A (en) | Finishing of annular articles | |
US1118784A (en) | Manufacture of piston-packings. | |
EP0316105A1 (en) | Endmill | |
JPS60232857A (en) | High-speed profile milling method and device for rotatory symmetric workpiece | |
JP4431244B2 (en) | Method for machining dynamic pressure generating groove in hydrodynamic bearing | |
US1881652A (en) | Method of making alpha ring joint | |
GB2072069A (en) | Method and machine for finishing a worm screw thread | |
RU2100179C1 (en) | Method of shaping grinding wheel |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20001129 |