Title of Invention

SEALING RING AND SEALING CONFIGURATION WITH SUCH A SEALING RING

Abstract

Sealing ring and sealing configuration with this type of sealing ring, whereby the sealing ring is essentially Z-shaped, comprising a radial fastening section (1) that is located on one side and a radial sealing lip (2) that is located on the other, which are connected to one another by a connection piece (3), whereby the connection piece (3) runs axially from fastening section (1) in the direction of a chamber (4) to be sealed to the sealing lip (2) and, whereby, the sealing lip (2) has a first sealing lip section (5) that, starting from the connection piece (3), extends axially against the chamber (4) to be sealed. Sealing lip (2) exhibits a second sealing lip section (6) that, starting from the connection piece (3), extends axially in the direction of the chamber (4) to be sealed. This type of sealing ring makes contact in a sealing manner under radial, elastic pre-load force only through its first sealing lip section (5) under radial, elastic pre-load force with the surface (10) to be sealed of a machine part (14) to be sealed.

Full Text

May 15th, 2007 Mattausch/BC Applicant: Carl Freudenberg KG, 69469 Weinheim SEALING RING AND SEALING CONFIGURATION WITH SUCH A SEALING RING DESCRIPTION TECHNICAL AREA The invention is with regard to a sealing ring that is basically Z-shaped, comprising a radial fastening section that is located on one side and a radial sealing lip that is located on the other, which are connected to one another by a connection piece, whereby the connection piece runs axially from the fastening section to the sealing lip in the direction of a chamber to be sealed and whereby the sealing lip has a sealing lip section that, starting from the connection piece, extends axially against the chamber to be sealed. PRIOR ART This type of sealing ring and sealing configuration that comprises such a sealing ring are established in DE 103 53 305 A1. The sealing ring has a fastening section that is held at a first machine part and a sealing lip that adjoins a second machine part in a sealing manner when the sealing ring is assembled and is curved towards the downstream face. The sealing ring is loaded by pressure within the chamber to be sealed in the direction of the machine part to be sealed in order to shape the sealing ring in such a manner that the sealing lip seals reliably even at a higher pressure within the chamber to be sealed and does not lift off from the surface to be sealed. With increasing medium pressure within the chamber to be sealed, the sealing lip is pressed proportionately firmly against the surface to be sealed of the machine part to be sealed, which ensures that the radial shaft sealing ring does not lift off from the surface to be sealed. The previously established sealing ring can be used as a radial shaft sealing ring, piston or rod sealing ring. The sealing lip of the previously established sealing ring is, moreover, flexible in the radial direction. The previously established sealing ring is preferably composed of polytetrafluoroethylene or can be manufactured from another suitable sealing material. PRESENTATION OF THE INVENTION The objective of the invention is to further improve on the sealing ring of the previously established type in such a manner that assembly of the sealing ring is further simplified and particularly that tilting of the sealing lip during assembly and when loading the sealing lip with excess pressure can be avoided. This objective is met in accordance with the invention by a sealing ring and a sealing configuration in accordance with Claims 1 and 8. The respective sub claims refer to advantageous designs. A sealing ring whose sealing lip has a second sealing lip section is provided to meet this objective, said sealing ring extending axially, starting from the connection piece, in the direction of the chamber to be sealed. The danger of the sealing lip tilting during assembly or when loading the sealing lip with excess pressure from the chamber to be sealed is practically ruled out due to the axial extension of the sealing lip, starting from the connection piece, in the form of a second sealing lip section against the first sealing lip section. The second sealing lip section cannot, in normal operating conditions, get axially deflected under the fastening section in the direction of the downstream face because too great a force would be required to deform the connection piece. Torque is exerted on the sealing lip in an axial manner against the chamber to be sealed when there is high excess pressure in the chamber to be sealed or during assembly and the second sealing lip section lies at the surface to be sealed of the machine part to be sealed in order to support the sealing lip and to prevent axial tilting in the direction of the downstream face. The ratio of the axial length of the first sealing lip section to the axial length of the second sealing lip section ranges preferably from 1 to 3, 2 being particularly preferred. In the case of current dimensions of the sealing ring, the second sealing lip section exhibits an axial length that amounts to approximately 0.8mm to 1.4mm. The axial length is, thereby, measured starting from the connection piece up to the axial front side of the second sealing lip section that axially faces the chamber to be sealed. The fastening section and the connection piece are connected to one another by an articulated transition area. The sealing lip and connection piece can pivot around this articulated transition area during radial deflection movements of the machine parts to be sealed and/or when loading the sealing ring with excess pressure from the chamber to be sealed. Due to the essentially Z-shaped design of the sealing ring, the same can result in comparably large radial deviating movements of the shaft to be sealed without leakages occurring between the sealing lip and the surface to be sealed. Only the first sealing lip section should preferably have a re-feed swirl for the medium to be sealed at that side that faces the surface to be sealed in the direction of the chamber to be sealed. The surface to be sealed of a machine part to be sealed comes into contact only with the first sealing lip section in a sealing manner under radial, elastic pre-load force during use as specified. The second sealing lip section is designed as a supporting body and does not come into contact with the surface to be sealed in normal operating conditions during use as specified. The advantage here is that the sealing ring, according to the invention, can be operated with low friction. The medium to be sealed, which is located under the first sealing lip section and whose low friction run on the surface to be sealed ensures resultant low wear and tear, is pumped back through the re-feed swirl in the direction of the chamber to be sealed. The first and second sealing lip sections exhibit an essentially consistent radial thickness and are designed to merge axially without radial offset during use of the sealing ring as specified. The sealing ring is simple to manufacture due to the extensively constant thickness because material accumulation caused by varying thickness can be avoided. The connection piece and sealing lip can be composed of polytetrafluoroethylene or can be manufactured from another suitable sealing material. Apart from this, the invention is with regard to a sealing configuration comprising the previously described sealing ring, whereby the sealing ring comes into contact under radial elastic pre-load force, with the surface to be sealed of a machine part to be sealed only with its first sealing section. In the manufacture-related state of the radial shaft sealing ring, the sealing lip can form an open, acute angle with the surface to be sealed in the direction of the chamber to be sealed, said angle preferably amounting to 45°. This is an advantage with regard to simple assembly. The danger of damage to the sealing ring, especially to the sealing lip, during assembly is reduced to a minimum as a result of the acute angle mentioned. It is simple to assemble the sealing ring due to the acute-angled configuration of the sealing lip, for example, to slide the sealing ring onto a shaft to be sealed. The sealing lip extends axial and parallel to the surface to be sealed after assembly of the sealing ring. As already explained, the second sealing lip section does not come into contact with the surface to be sealed during use as specified in normal operation of the sealing ring. The second sealing lip section is located at a radial distance from and adjacent to the surface to be sealed, whereby the gap that is formed by the distance is of capillary-active narrowness. Static sealing of the sealing ring at test pressure is good in the case of this kind of configuration even if the re-feed swirl is not closed by a partition towards the downstream face. Low frictional relative mobility of the sealing ring on the surface to be sealed is ensured in each case by the gap. SHORT DESCRIPTION OF THE DRAWINGS The exemplary embodiments of a sealing configuration according to the invention with a sealing ring according to the invention is described below in greater detail by means of Figures 1 and 2 which are schematic illustrations respectively. Figure 1 presents a sealing ring in its manufacture-related shape before assembly. Figure 2 presents a sealing configuration in which the sealing ring is illustrated during use as specified. Figs. 3&4 respectively present a detail of the sealing ring according to the invention. An exemplary embodiment of the sealing ring according to the invention is illustrated in its manufacture-related state in Figure 1. Machine part 14, here a shaft to be sealed, is illustrated with dashes for clarification. Fastening section 1 is strengthened by a supporting body 18 made from a ductile material in the embodiment illustrated here. Connection piece 3 extends essentially parallel to the symmetric axis 19 that simultaneously forms the rotation axis of machine part 14 to be sealed. Sealing lip 2 comprises the first sealing lip section 5 and the second sealing lip section 6 that are connected to one another at their facing sides by connection piece 3. Sealing lip 2 forms an open acute angle 16 in the direction of the chamber 4 to be sealed together with surface 10 to be sealed that extends parallel to the symmetric axis 19, said angle amounting to between 30° and 45° in the embodiment illustrated. The largest diameter of the angled, employed sealing lip 2, viz. the diameter of the front side of the second sealing lip section 6 that axially faces the chamber 4 to be sealed, is considerably larger than the diameter of surface 10 to be sealed, so that assembly of the shaft in the assembly direction 15 can take place without any problem and the danger of damage to the sealing lip 2 and/or of tilting the sealing lip 2 in the direction of the downstream face 20 is reduced to a minimum. An exemplary embodiment of a sealing configuration with the sealing ring according to the invention from Figure 1 is illustrated in Figure 2. The sealing ring is essentially Z-shaped, whereby the radial, outer fastening section 1 and the radial inner sealing lip 2 are connected to one another by connection piece 3. Connection piece 3 runs axially from fastening section 1 in the direction of chamber 4 to be sealed towards sealing lip 2, whereby sealing lip 2, starting from connection piece 3, is divided into a first sealing lip section 5 extending axially in the direction of the downstream face 20 and a second sealing lip section 6 extending axially in the direction of chamber 4 to be sealed. Both sealing lip sections 5, 6 are designed as a single merging piece and made from the same material as the connection piece 3, whereby the ratio of the axial length 7 of the first sealing lip section 5 to the axial length 8 of the second sealing lip section 6 amounts to 2 in this embodiment. During deflection movements of fastening section 1 of the sealing ring relative to the machine part 14 to be sealed, the sealing lip 2 moves in a curve around the articulated transition area 9 that connects fastening section 1 and connection piece 3 to one another. As can be seen from the drawing, only the first sealing lip section 5 comes into contact with surface 10 to be sealed, whereby first sealing lip section 5 exhibits a re-feed swirl 11 at that side that faces surface 10 to be sealed in a radial manner in order to return medium 12 found in this area in the direction of chamber 4 to be sealed, during use as specified. In doing so, the direction of the re-feed swirl 4 complies with the rotational direction of the machine part 14 to be sealed. It is also, in general, possible to design the re-feed swirl 11 as an interchangeable swirl and thereby seal, independent of the rotation direction of the machine part 14 to be sealed. First 5 and second 6 sealing lip sections in the embodiment illustrated here are designed to be correspondingly thick 13 and merge without radial offset/without erratic direction change. Second sealing lip section 6 borders surface 10 to be sealed with a radial distance, whereby the distance forms gap 17. Contact between sealing lip 2 and surface 10 to be sealed takes place only in the region of the partitions that form the re-feed swirl 11 so that low frictional relative mobility of sealing lip 2 on the surface 10 to be sealed is ensured. The advantage to be highlighted is that in the case of over-compression within chamber 4 to be sealed, not only the radial outer surface of connection piece 3 is effective for application of force through the sealing lip on the surface 10 to be sealed but also the radial external surface of the second sealing lip section 6. During the usual pressure tests before commissioning the sealing configuration i.e., when correct assembly of the sealing ring is checked by loading chamber 4 to be sealed with excess pressure or even during use as specified when excess pressures/pressure peaks occur within the chamber 4 to be sealed, the danger that the sealing lip 2 will tilt around the articulated transition area 9 in the downstream face 20 direction is practically ruled out by the second sealing lip section 6. This type of excess pressure is illustrated by arrows 21. Re-feed swirl 11 is generally to be understood as re-feed structure. The re-feed swirl 11 is axially restricted in such a manner that, independent of the position of machine part 14 to be sealed, a defined region of sealing lip 2 comes into contact with the machine part 14 and between two and two and a half circumferential narrow channels of the re-feed swirl 11 are adjacent to the surface 10 to be sealed. The part of sealing lip 2 that comes into adjacent contact with surface 10 to be sealed, can exhibit a structure that optimises static sealing characteristics to such an extent that a lower application force is required and a redundant line contact emerges due to the structure. It is particularly preferred that the structure have a triangular shape. Figure 3 illustrates the end of the first sealing lip section 5 that axially faces the downstream face 20, whereby this front side together with the machine part 14 to be sealed borders an annular gap, in which fluid pressing outwards is held. :igure 4 presents another embodiment of the front side shown in Figure 3, whereby the end of sealing lip 2 that faces the downstream face 20 exhibits a beading that, lying close to the surface 10, surrounds the same and thereby prevents impurities from entering from the downstream face 20 in the direction of the chamber 4 to be sealed. PATENT CLAIMS 1. Sealing ring that is essentially Z-shaped, comprising a radial fastening section (1) that is located on one side and a radial sealing lip (2) that is located on the other, which are connected to one another by a connection piece (3), whereby, the connection piece (3) runs axially from the fastening section (1) in the direction of a chamber (4) to be sealed to the sealing lip (2) and, whereby, the sealing lip (2) has a first sealing lip section (5) that, starting from the connection piece (3), extends axially against the chamber (4) to be sealed, characterised in that, the sealing lip (2) has a second sealing lip section (6) that extends axially in the direction of the chamber (4) to be sealed. 2. Sealing ring according to Claim 1, characterised in that, the ratio of the axial length (7) of the first sealing lip section (5) to the axial length (8) of the second sealing lip section (6) ranges from 1 to 3. 3. Sealing ring according to Claim 2, characterised in that, the ratio amounts to 2. 4. Sealing ring according to one of Claims 1 to 3, characterised in that, the fastening section (1) and connection piece (3) are connected to one another by an articulated transition area (9). 5. Sealing ring according to one of Claims 1 to 4, characterised in that, only the first sealing lip section (5) exhibits a re-feed swirl (11) for the medium (12) to be sealed at that side that faces the surface (10) to be sealed in the direction of the chamber (4) to be sealed. 6. Sealing ring according to one of Claims 1 to 5, characterised in that, the first (5) and second (6) sealing lip sections exhibit an essentially consistent radial thickness (13) and are designed to merge axially without radial offset during use of the sealing ring as specified. 7. Sealing ring according to one of Claims 1 to 6, characterised in that, the connection piece (3) and sealing lip (2) are made from a polymer sealing material. 8. Sealing configuration comprising a sealing ring according to one of Claims 1 to 7, said ring coming into contact in a sealing manner with the surface (10) to be sealed of a machine part (14) to be sealed under radial, elastic pre-load force only with its first sealing lip section (5) under radial, elastic pre-load force. 9. Sealing configuration according to Claim 8, characterised in that, the sealing lip (2) in a manufacture-related state of the sealing ring can enclose an open, acute angle (16) together with surface (10) to be sealed in the direction of the chamber (4) to be sealed against assembly direction (15) of machine part (14) to be sealed. 10. Sealing configuration according to Claim 9, characterised in that, the angle (16) amounts to 45°. 11. Sealing configuration according to one of Claims 8 to 10, characterised in that, the second sealing lip section (6) is located with a radial distance adjacent to the surface (10) to be sealed and that the gap (17) formed

Documents:

1182-CHE-2008 EXAMINATION REPORT REPLY RECEIVED 19-08-2013.pdf

1182-CHE-2008 FORM-3 19-08-2013.pdf

1182-CHE-2008 AMENDED CLAIMS 19-08-2013.pdf

1182-CHE-2008 CORRESPONDENCE OTHERS 23-05-2014.pdf

1182-CHE-2008 CORRESPONDENCE OTHERS 18-06-2013.pdf

1182-CHE-2008 CORRESPONDENCE OTHERS 27-06-2014.pdf

1182-CHE-2008 FORM-1 23-05-2014.pdf

1182-CHE-2008 FORM-3 13-10-2014.pdf

1182-che-2008 abstract.pdf

1182-che-2008 claims.pdf

1182-CHE-2008 CORRESPONDENCE OTHERS 13-10-2014.pdf

1182-CHE-2008 CORRESPONDENCE OTHERS 30-07-2014.pdf

1182-che-2008 correspondences-others.pdf

1182-che-2008 description (complete).pdf

1182-che-2008 drawings.pdf

1182-che-2008 form-1.pdf

1182-che-2008 form-18.pdf

1182-che-2008 form-3.pdf

1182-che-2008 form-5.pdf

1182-CHE-2008-Petition for POR.pdf