DE102018201141A1 - Broken slide ring and mechanical seal with such sliding ring - Google Patents

Abstract

The invention relates to a split seal ring of a mechanical seal assembly, comprising a base body (5) made of a carbon comprising base material, a diamond coating (6) which is applied to the base body (5) and provides a sliding surface (9) of the sliding ring, and at least two break points (33, 34) which divide the sliding ring perpendicular to the sliding surface (9) in sliding ring parts (31, 32), wherein in the assembled state of the sliding ring parts a gap-free sliding surface (9) is present.

Description

The invention relates to a broken sliding ring of a mechanical seal assembly and a mechanical seal assembly with a broken sliding ring.

Mechanical seal assemblies are known in the prior art in various configurations and typically include annular closed stationary and rotating slip rings. However, there are applications in which either a mounting of a closed ring is no longer possible, for example in an exchange of damaged sliding rings in a mounted unit, or in applications where a large diameter of a shaft must be sealed. Here, so-called split slip rings may be used, in which the annular slip rings are divided in the axial direction of the slip rings, that is, perpendicular to the sliding surface. This results in two sliding ring halves, which can be mounted, for example in a pump from the side of the shaft and must not be pushed onto the shaft. Such split slip rings have heretofore been used only in uncoated slip rings since, when splitting the slip rings, there is a risk that the coating will be released from the base body at the split location, resulting in recesses on the slide surface in the assembled state. However, such slip rings can not fulfill any meaningful sealing tasks or have only an extremely short life.

It is therefore an object of the present invention to provide a split seal ring of a mechanical seal, which can be designed in a simple and inexpensive construction as a coated slide ring. It is another object of the invention to provide a mechanical seal assembly having such a split sliding ring with coating.

This object is achieved by a split sliding ring with the features of claim 1 and a mechanical seal assembly with the features of claim 10. The dependent claims each show preferred embodiments of the invention.

The broken-split sliding ring according to the invention with the features of claim 1, on the other hand, has the advantage that a diamond-coated sliding ring can be divided. Here, the slip ring comprises a carbon-containing base material and a diamond coating on the base material and at least two break points which divide the slip ring in the axial direction, that is, divide perpendicular to the sliding surface. In the assembled state of the thus generated, broken Gleitringteile the sliding surface of the composite seal ring is thereby gap-free. That Due to the undefined fracture points it is achieved that, during assembly, an exact matching of the sliding ring parts at the break points becomes possible, so that a gap-free sliding surface is provided which is provided by the diamond coating. The break points have a geometrically random, designed by the fracture surface, the two fracture surfaces can be re-assembled exactly together, so that a gap-free sliding surface is obtained.

Preferably, there is a chemical bond between the carbonaceous base material and the diamond of the diamond coating. By chemically bonding the base material to the diamond coating, it is possible to prevent diamond parts from breaking out of the diamond coating at the point of breakage, which could lead to a gap in the sliding surface. As a result of the carbon in the base material, crystallization points on the surface of the base material result for the diamond coating, so that chemical bonds between growing diamond and the base material are present.

The diamond coating comprises particularly elongated diamond crystals, which are arranged substantially perpendicular to the sliding surface. The elongated diamond crystals ensure that the undefined break point of the slip ring in the region of the diamond coating extends along a crystal boundary of the diamond crystals, so that breakage of parts of the diamond coating is avoided and it is ensured that no part of the diamond coating separates from the base material. As a result, a secure and gap-free composition of the sliding ring parts, in particular in the region of the diamond coating which forms the sliding surface, can be made possible. Alternatively, the base material comprises WC and is in particular made exclusively of WC.

The base material preferably comprises SiC and is more preferably exclusively made of SiC. When the base material of the main body of the slip ring is entirely made of SiC, particularly good chemical bonding between the base material and the diamond coating can be ensured.

More preferably, a maximum first breakage width in the composite slip ring in the diamond coating is less than a maximum breakage width in the composite slip ring in the base material. This can ensure that the undefined break point in the base material in the assembled state again a safe Hold and secure connection of the sliding ring parts allows, while in the diamond coating only a very narrow maximum breaking width is present, whereby the risk of a gap on the sliding surface of the sliding ring is minimized.

Preferably, a maximum rupture width in the diamond coating is in a range of less than or equal to 10 .mu.m and in particular less than or equal to 5 .mu.m.

More preferably, the split seal ring is divided into exactly two sliding ring parts. Thus, there are only two break points, so that an assembly of the split sliding ring is relatively easy again.

The two undefined break points of the sliding ring are particularly preferably 180 ° opposite each other or in a range of ± 10 ° around 180 °.

Particularly preferably, the thickness of the diamond layer is less than or equal to 20 μm and greater than or equal to 4 μm. This ensures that there is a relatively long crystal boundary between adjacent diamond crystals in the diamond coating, which is substantially perpendicular to the sliding surface. This allows a safe breakup of the diamond coating along the crystal boundary of the diamond crystals.

Preferably, a gap-free body is present in the assembled state of the sliding ring parts.

Preferably, a ratio of the first fracture width in the diamond layer to the second fracture width in the base material is less than or equal to 1: 5.

Furthermore, the present invention relates to a mechanical seal assembly, comprising at least one split seal ring according to any one of the preceding claims and more preferably, both the rotary seal ring and the stationary seal ring are each formed as a split seal rings.

• 1 eine schematische Draufsicht auf einen geteilten Gleitring im zusammengesetzten Zustand gemäß einem bevorzugten Ausführungsbeispiel der Erfindung,
• 2 eine schematische, nicht maßstabsgetreue Schnittansicht entlang der Linie II-II von 1, und
• 3 eine Gleitringdichtungsanordnung mit einem geteilten Gleitring gemäß 1.

Hereinafter, a preferred embodiment of the invention will be described in detail with reference to the accompanying drawings. In the drawing is:

• 1 a schematic plan view of a split seal ring in the assembled state according to a preferred embodiment of the invention,
• 2 a schematic, not to scale section along the line II-II from 1 , and
• 3 a mechanical seal assembly with a split seal according to 1 ,

The following is with reference to the 1 to 3 a split slip ring 3 and a mechanical seal assembly 1 described in detail with such a sliding ring.

The mechanical seal assembly is described in detail in FIG 3 and includes a rotating seal ring 2 and a stationary slip ring 3 , which between them a sealing gap 4 limit. The mechanical seal assembly 1 wrote a product page 20 from an atmosphere side 21 from. The rotating seal ring 2 is via an annular driver element 19 with a wave 10 connected. The stationary seal ring 3 is on a housing 11 arranged. There are also O-rings 12 . 13 on the slip rings 2 . 3 arranged to seal to the shaft 10 or to the housing 11 display.

In this embodiment, the stationary seal ring 3 the broken-split slip ring and in detail in the 1 and 2 shown.

How out 1 it can be seen, is the stationary seal ring 3 in two sliding ring parts 31 and 32 divided. This results between the two Gleitringteilen 31 . 32 a first undefined breakpoint 33 and a second undefined breakpoint 34 , That is, the slip rings are not divided by a machining process, such as cutting, but by applying force to a closed sliding ring produced. This results in the undefined break points 33 . 34 , The advantage of the undefined fracture points is that during assembly, the fracture points again fit exactly into each other, since no parts of the slide ring fall off when breaking. The break points thus have a fracture surface, which can be composed exactly to a closed seal ring again.

How out 1 it can be seen, are the first undefined break point 33 and the second undefined breakpoint 34 facing each other by 180 °. This is the sliding ring 3 in exactly two sliding ring parts 31 . 32 divided.

As in 2 shown, the slip ring comprises 3 a basic body 5 and a coating 6 , The main body 5 is made exclusively of SiC (silicon carbide) or alternatively exclusively of WC (tungsten carbide). The coating 6 is a diamond coating.

Here is between the diamond coating and the main body 5 a chemical bond 14 educated.

How out 2 It can also be seen which the assembled state of the broken-split sliding ring 3 indicates is a first fraction width 15 in the field of coating 6 significantly smaller than a second fracture width 16 in the area of the basic body 5 , In particular, the first fracture width in the diamond coating is in a range of less than or equal to 5 μm.

How out 2 Further, the diamond crystals are 60 essentially perpendicular to the sliding surface 9 trained and range from the chemical bond 14 at the base body 5 to the sliding surface 9 , How farther 2 it can be seen that the fracture in the diamond coating is along the crystal boundary 61 between two adjacent diamond crystals 60 , In contrast, the rupture in the area of the main body is much wider and extends along the grain boundaries of SiC grains 50 in the silicon carbide. This results in the wider second fracture width 16 , The second breakage width 16 is about 50 microns.

By the chemical bond 14 between the diamond coating and the base body 5 from SiC is thus avoided, that diamond crystals 60 especially in the area of the break point from the main body 5 to solve. This can, as in 2 shown schematically, in the assembled state of the split sliding ring 3 despite the two fracture surfaces of the fractures 33 . 34 a gap-free sliding surface 9 to be obtained. Due to the breaking process of the sliding ring thus neither in the diamond coating 6 still in the body 5 Components of these two elements broken out, so that when assembling the undefined fracture surfaces fit together again exactly.

Thus, the stationary slip ring 3 in this embodiment in the axial direction XX divided, with at least two break points 33 . 34 are present, which, however, in the assembled state of the sliding ring a gap-free sliding surface 9 form. This allows the split seal ring to have a long life. The split slip ring is preferably used in large sliding ring diameter applications, ie, in particular greater than 150 mm. In particular, both the rotating and the stationary sliding ring can be provided as a split sliding ring, so that particularly preferably an exchange of damaged mechanical seals is possible without causing the entire machine must be disassembled to push the slip rings over a shaft. The split slip rings can be placed radially from the side of the shaft and joined together at the undefined break points.

LIST OF REFERENCE NUMBERS

1

The mechanical seal assembly

2

rotating seal ring

3

stationary sliding ring / split sliding ring

4

sealing gap

5

body

6

diamond coating

9

sliding surface

10

wave

11

casing

12

O-ring

13

O-ring

14

chemical compound

15

first breakage width

16

second breakage width

19

takeaway

20

product page

21

atmospheric side

31

first sliding ring part

32

second sliding ring part

33

first undefined breakpoint

34

second undefined break point

50

SiC grain

60

diamond crystal

61

Diamond crystal boundary

X X

Axial direction of the split sliding ring

Claims (13)

Split slip ring of a mechanical seal assembly, comprising: a base body (5) made of a base material comprising carbon, - A diamond coating (6) which is applied to the base body (5) and a sliding surface (9) of the sliding ring provides, and - at least two break points (33, 34) which divide the sliding ring perpendicular to the sliding surface (9) into sliding ring parts (31, 32), - In the assembled state of the sliding ring parts a gap-free sliding surface (9) is present. Slip ring after Claim 1 , wherein a chemical bond (14) between the carbon comprehensive base material and the diamond coating (6) is formed. Sliding ring according to one of the preceding claims, wherein the diamond coating comprises elongated diamond crystals (60), which is aligned substantially perpendicular to the sliding surface (9). Sliding ring according to one of the preceding claims, wherein the base material comprising carbon is SiC or WC. Sliding ring according to one of the preceding claims, wherein in the assembled state of the sliding ring, a maximum first breaking width (15) in the diamond coating (6) is smaller than a maximum second breaking width (16) in the base material of the base body (5). Slip ring after Claim 5 wherein a maximum first rupture width (15) in the diamond coating (6) is less than or equal to 10 μm. Sliding ring according to one of the preceding claims, wherein the sliding ring is exactly divided into a first sliding ring part (31) and a second sliding ring part (32). Sliding ring according to one of the preceding claims, wherein the first and second break points (33, 34) face each other by 180 °. Sliding ring according to one of the preceding claims, wherein a thickness of the diamond coating (6) is less than or equal to 20 microns and greater than or equal to 4 microns. Sliding ring according to one of the preceding claims, wherein in the assembled state of the sliding ring parts (31, 32) a gap-free base body (5) is present. Sliding ring according to one of the preceding claims, wherein a ratio of the first breaking width (15) in the diamond layer to the second breaking width (16) in the base material is less than or equal to 1: 5. A mechanical seal assembly comprising a split seal ring according to any one of the preceding claims. Mechanical seal arrangement according to Claim 12 , wherein a rotating seal ring and / or a stationary seal ring is formed as a split slip ring.

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