DE102020106892B4 - Seal and its use as a rod or piston seal - Google Patents

Abstract

Seal comprising at least one first sealing area (1) and at least one first contact area (2), the first sealing area (1) and the first contact area (2) being arranged adjacent to one another in the axial direction (3) and one inside the other in the axial direction (3). are formed in a transitional manner, wherein the first sealing area (1) has a rotated first surface structure (4) with a first pitch (5) and the first contact area (2) has a rotated second surface structure (6) with a second pitch (7) and wherein the first slope (5) is smaller than the second slope (7), characterized in that on the side of the seal facing away from the first sealing area (1) and the first contact area (2) in the radial direction (10) in the radial direction (10) at least one second sealing area (11) with a turned third surface structure (12) on the inside or outside in the radial direction (10) and at least one second contact area (13) with a turned fourth surface Structure (14) are arranged, wherein the third surface structure (12) has a third slope (15), the fourth surface structure (14) has a fourth slope (16) and the third slope (15) is smaller than the fourth slope (16) is.

Description

technical field

The invention relates to a seal, comprising at least one first sealing area and at least one first contact area, the first sealing area and the first contact area being arranged adjacent to one another in the axial direction and merging into one another in the axial direction, the first sealing area having a rotated first surface structure with a first slope and the first contact area has a rotated second surface structure with a second slope and wherein the first slope is smaller than the second slope. The invention also relates to the use of the seal as a rod or piston seal.

State of the art

From the DE 21 13 557 A a sealing ring for reciprocating machine parts is known, which is used in particular for rods or pistons. The sealing ring has a sealing body made of elastic material, encompassing the machine part, the sealing surface of which is subdivided by ribs arranged one behind the other in the axial direction and running transversely to the axial direction.

A boundary surface of the ribs facing the axis encloses an angle of less than 30° with the axis in the unstressed state. With increasing distance from the medium to be sealed, the ribs enclose a larger angle with the common axis on their boundary surfaces facing the axis. In addition, the sealing edges of the ribs in the unstressed state have a clear diameter that is selected to be larger at the individual ribs as the distance from the medium to be sealed increases. A scraper is arranged on the face of the sealing body facing away from the medium.

Other seals are also known which are used as rod or piston seals. The sealing area and the contact area have a matching surface structure, with the matching surface structure being in the form of a thread as a result of production and having a constant pitch.

Presentation of the invention

The invention is based on the object of further developing a seal of the type mentioned at the outset in such a way that the inner peripheral surface and the outer peripheral surface of the seal are optimized with regard to their usage properties, in particular with regard to tightness and low friction, and that the usage properties of the respective areas are individualized in terms of function. In addition, uses of the seal should be mentioned.

This object is achieved according to the invention with the features of claim 1 and claim 6. The claims referring back directly or indirectly to claim 1 refer to advantageous configurations of the seal.

A seal is provided to solve the problem. on the side of the seal facing away from the first sealing area and the first contact area in the radial direction, at least one second sealing area with a rotated third surface structure and at least one second contact area with a rotated fourth surface structure are arranged in the radial direction inside or in the radial direction outside, wherein the third surface structure has a third slope, the fourth surface structure has a fourth slope and the third slope is smaller than the fourth slope.
The first sealing area and the first contact area accordingly have a surface structure that differs from one another, with the surface structures having gradients that differ from one another. Because the first slope of the first surface structure of the sealing area is smaller than the second slope of the second surface structure of the contact area, the sealing lip area has a smaller roughness and a higher tightness during the intended use of the seal, based on the contact area.
In contrast, the greater gradient of the second surface structure of the contact area causes greater roughness and less friction on the counter surface of the seal.

The first sealing area and the first contact area are optimized with regard to their respective functional properties by the design according to the invention. The sealing area brings about good sealing of the medium to be sealed, in particular good dynamic sealing during the intended use of the seal, and the first contact area touches the mating surface with as little friction as possible. The power loss of the seal is therefore low, as is the heat generation in the contact area.

The absolute size of the gradients depends on the application and depends on the sealing material from which the seal is made.

It is provided that on the side of the seal facing away from the first sealing area and the first contact area in the radial direction At least one second sealing area with a rotated third surface structure and at least one second contact area with a rotated fourth surface structure are arranged in the inner direction or in the radial direction on the outside, with the third surface structure having a third slope, the fourth surface structure having a fourth slope and the third slope being smaller than the fourth slope.
In such a case, the inner peripheral surface and the outer peripheral surface of the seal are each optimized with regard to their usage properties, in particular with regard to tightness and low friction.
The manufacture of the seal can be simplified in that the third surface structure with its third slope corresponds to the first surface structure with its first slope, just as the fourth surface structure and the fourth slope correspond to the second surface structure and the second slope. When producing such a seal, the two sealing areas and the two contact areas are rotated with one feed.

According to an advantageous embodiment, it can be provided that the ratio of the first gradient to the second gradient is 0.4 to 0.9. Such a ratio has proven itself well for most applications. Such a ratio ensures a good compromise between excellent sealing properties with the lowest possible leakage and the lowest possible friction of the seal in operation.

The first surface structure can have a first peak-to-valley height and the second surface structure can have a second peak-to-valley height. The ratio of the first peak-to-valley height to the second peak-to-valley height is preferably 0.6 to 0.8. The peak-to-valley height also depends on the particular circumstances of the application, for example on the viscosity of the medium to be sealed. The mentioned ratio of the peak-to-valley heights has the advantage that excellent sealing properties with the lowest possible leakage and the lowest possible friction are ensured.

The first sealing area and the first contact area are both arranged on the outside in the radial direction or on the inside in the radial direction. If the first sealing area and the first contact area are both arranged on the outside in the radial direction, the seal is a piston seal. The seal is then arranged in a radially outwardly open groove of the piston which encloses the outer circumference of a piston and seals dynamically with respect to a counter surface which forms part of a housing which encloses the piston on the outer circumference. The piston reciprocates axially within a bore in the housing and is sealed to the housing.

If, on the other hand, the sealing area and the first contact area are both arranged in the radial direction inside the seal, the seal is used as a rod seal. The component to be sealed is a rod to be sealed, translationally movable back and forth. The rod is surrounded on the outer circumference by a housing, the housing comprising an installation groove for the seal, which is open radially inwards.

The first sealing area and the first contact area are in contact with the mating surface of the rod to be sealed.

The seal described above can be used as a rod or piston seal. In any case, the machine elements to be sealed against one another, which together with the seal form part of a sealing arrangement, can be moved back and forth in a translatory manner in the axial direction.

character list

Two exemplary embodiments of the seal according to the invention will follow with reference to FIG 1 and 2 described in more detail.

• 1 ein erstes Ausführungsbeispiel der Dichtung, das als Stangendichtung ausgebildet ist, mit Details der Dichtung,
• 2 ein zweites Ausführungsbeispiel, das als Kolbendichtung ausgebildet ist, mit Details der Dichtung.

These each show a schematic representation:

• 1 a first embodiment of the seal, which is designed as a rod seal, with details of the seal,
• 2 a second embodiment, formed as a piston seal, with details of the seal.

implementation of the invention

In the 1 and 2 a sealing arrangement is shown in each case. In addition, details of the corresponding seal are shown in each case.

The sealing arrangement comprises two machine elements 17, 18 to be sealed against each other, of which the first machine element 17 in 1 through a rod and in 2 is formed by a piston. In contrast, the second machine element 18 is formed by a housing which encloses the first machine element 17 on the outer circumference.

In 1 the counter surface of the sealing ring is formed by the surface of the first machine element 17 to be sealed, here the rod det, in 2 through the second machine element 18, here the inner wall of a housing.

In the exemplary embodiments shown, the seal comprises two sealing areas 1, 11 and two contact areas 2, 13, with the first sealing area 1 and the first contact area 2 being dynamically stressed, while the second sealing area 11 and the second contact area 13 are more statically stressed.

The first sealing area 1 and the first contact area 2 are arranged adjacent to one another in the axial direction 3 and are designed to merge into one another in the axial direction 3 . The first sealing area 1 and the first contact area 2 each have a turned surface structure 4, 6, with the first surface structure 4 of the first sealing area 1 having the first slope 5 and the second surface structure 6 of the first contact area 2 having the second slope 7. The first gradient 5 is smaller than the second gradient 7. As a result, the first sealing area touches the counter surface particularly tightly. In contrast, the first contact region 2 touches the mating surface with particularly little friction.

In the exemplary embodiments shown here, the second sealing area 11 and the second contact area 13 also have different surface structures 12, 14 with different gradients 15, 16. Although the second sealing area 11 and the second contact area 13 are more statically sealing, the different surface structures are 12, 14 is nevertheless advantageous because the second sealing area 11 and the second contact area 13 are also sealed by pressurization in 1 in the machine element 18, in 2 undergoes a movement in the machine element 17 . As a result, the second sealing area 11 touches the machine element 18 ( 1 ) or machine element 17 ( 2 ) particularly dense. The second contact area 13 touches machine element 18 ( 1 ) or machine element 17 ( 2 ) on the other hand particularly low-friction.

Claims (6)

Seal comprising at least one first sealing area (1) and at least one first contact area (2), the first sealing area (1) and the first contact area (2) being arranged adjacent to one another in the axial direction (3) and one inside the other in the axial direction (3). are formed in a transitional manner, wherein the first sealing area (1) has a rotated first surface structure (4) with a first slope (5) and the first contact area (2) has a rotated second surface structure (6) with a second slope (7) and wherein the first slope (5) is smaller than the second slope (7), characterized in that on the side of the seal facing away from the first sealing area (1) and the first contact area (2) in the radial direction (10) in the radial direction (10) at least one second sealing area (11) with a turned third surface structure (12) on the inside or outside in the radial direction (10) and at least one second contact area (13) with a turned fourth surface n structure (14) are arranged, wherein the third surface structure (12) has a third slope (15), the fourth surface structure (14) has a fourth slope (16) and the third slope (15) is smaller than the fourth slope (16) is. seal after claim 1 , characterized in that the ratio of the first gradient (5) to the second gradient (7) is 0.4 to 0.9. seal after claim 1 , characterized in that the first surface structure (4) has a first peak-to-valley height (8) and the second surface structure (6) has a second peak-to-valley height (9). seal after claim 3 , characterized in that the ratio of the first peak-to-valley height (8) to the second peak-to-valley height (9) is 0.6 to 0.8. seal after claim 1 , characterized in that the first sealing area (1) and the first contact area (2) are both arranged in the radial direction (10) on the outside or in the radial direction (10) on the inside of the seal. Use of a seal according to any one of Claims 1 until 5 as a rod or piston seal.

Images