EP3234420A1

EP3234420A1 - Slide ring seal and method for producing a slide ring seal

Info

Publication number: EP3234420A1
Application number: EP15843080.1A
Authority: EP
Inventors: Thomas Schmitt; Franz Kneidl; Achim Dehnz; Stefan Weigl; Erich Weber
Original assignee: Netzsch Pumpen and Systeme GmbH
Current assignee: Netzsch Pumpen and Systeme GmbH
Priority date: 2014-12-18
Filing date: 2015-12-18
Publication date: 2017-10-25
Also published as: DE102014118987A1; CN107002884A; RU2017125465A; KR20170094437A; JP2018500519A; WO2016095893A1; RU2017125465A3

Abstract

The invention relates to a slide ring seal (1) comprising a housing arrangement (2), a sprung counter ring (3) and a slide ring (4) slidingly associated with the counter ring. The housing arrangement comprises a first movable housing element (5); and a second housing element (6) which can be locked in position. According to the invention, the housing arrangement consists at least partially of a plastic and/or a composite material. The invention further relates to a method for producing a slide ring seal.

Description

Mechanical seal and method of manufacture

Mechanical seal

The present invention relates to a mechanical seal and a method of manufacturing a mechanical seal according to the features of the preambles of

Claims 1 and 9.

State of the art

The invention relates to a mechanical seal. These are so-called dynamic seals for sealing rotating shafts against a side wall or the like, for example with respect to a machine housing. The main components of action are two components sliding on one another, in particular a spring-loaded sliding ring and an associated counter-ring. One of the two rings is rigidly arranged in a stationary housing element, the other ring is secured by means of anti-rotation pins or the like on the rotating shaft. The areas between the two rings are - depending on the type of

Mechanical seal - usually flat and usually made of carbon graphite, metal, ceramic, plastic or resin-bonded carbon.

US 2006/0061041 A1 discloses the structure of a mechanical seal comprising a sliding ring sealing sleeve, in which in particular resilient ring elements are arranged, and a sliding ring sealing housing or a retaining ring.

Conventionally, several superimposed sinusoidal springs are used for the suspension of the sliding ring, which are bounded by two metal rings. The metal rings are used in particular to support the sine springs sufficiently. Such a construction of the suspension is technically complicated due to the stratification of the sinusoidal springs, since the sinusoidal springs must be aligned correctly with respect to each other and must not rotate against each other. Furthermore, many items are required for such suspension, which must be mounted accordingly. The object of the invention is to produce a mechanical seal particularly cost. Another object of the invention is to make a mechanical seal technically easier, in particular using a smaller number of items.

The above object is achieved by a mechanical seal and a method for producing a mechanical seal, comprising the features in the claims 1 and 9. Further advantageous embodiments are described by the Unteransprücrv.

description

The invention relates to a mechanical seal with a spring-loaded mating ring and a sliding ring slidably mounted on the mating ring which are arranged in a housing arrangement. The housing arrangement comprises in particular a first movable housing element and a second stationary fixable housing element. The ring pair formed from the sprung counter ring and the sliding ring is arranged in the housing arrangement, wherein the sprung counter ring is arranged in particular on the second housing element, while the slidably arranged sliding ring is associated with the first movable housing element. Alternatively, the spring-loaded mating ring can be arranged on the first movable housing element and the sliding ring on the second static housing element.

The mechanical seal is used to seal a movable, in particular rotationally movable machine component relative to a stationary

Machine component used. According to one embodiment described here, the first movable housing element is attached to the sliding ring on a shaft, while the second housing element is arranged and fixed with the spring-loaded mating ring, for example in a shaft passage opening of the machine housing. The person skilled in the art can analogously transfer the features of the invention described below to a mechanical seal in which the spring-loaded counter-ring on the first

movable housing member and the sliding ring is arranged on the second static housing element. Other embodiments with a sprung sliding ring are also conceivable. According to the invention, it is provided that the housing arrangement consists at least partially of a plastic and / or a composite material. According to a preferred embodiment, the first movable housing element, which is also referred to as a mechanical seal sleeve, and / or the second stationary fixable housing element, which is also referred to as a mechanical seal housing, to manufacture at least partially made of a plastic and / or a composite material. In particular, it is provided to manufacture the first and / or the second housing element in each case as an injection molded part made of a plastic and / or a composite material, so that these preferably each completely made of plastic and / or a

Composite exist. As a composite material, in particular fiber-plastic composites or self-reinforced plastic composites are suitable. In particular, suitable materials or composite materials include

Glass fiber reinforced plastic (GRP), carbon fiber reinforced plastic (CFRP), aramid fiber reinforced plastic (AFK), natural fiber reinforced plastic (NFK).

The material used can be processed very easily,

For example, thus inexpensive housing elements can be produced by injection molding, whereby the manufacturing cost compared to conventionally made of metal housing elements can be significantly reduced. Furthermore, the weight of such a mechanical seal is reduced.

According to one embodiment of the invention, the sliding ring in each case has first driver elements and the first movable housing element has in each case second driver elements for the first driver elements of the sliding ring, wherein the second driver elements engage in the first driver elements. By the operative connection of the first and second driving elements, the rotation of the shaft, on which the first housing element of the mechanical seal is fastened, is transmitted to the sliding ring, which has a contact surface with the spring-loaded mating ring.

Furthermore, it is provided that the mating ring in each case has third driver elements and that the second stationary fixable housing element in each case fourth

Has driving elements for the third driver elements of the mating ring, wherein the fourth driver elements engage in the third driver elements. Since the second housing element is fixedly attached to a stationary machine part, prevents the engagement of the third driver elements of the mating ring in the fourth driver elements of the second housing element in particular a transmission of the rotational movement of the sliding ring on the mating ring.

It is clear to the person skilled in the art that the driver elements can also be configured such that the first engage in the second and / or the third in the fourth driver elements.

Sliding ring and counter ring conventionally consist of silicon carbide (SiC) or a metal, for example of a steel material or the like. The first and / or the third driver elements of the sliding ring and counter ring are generally formed as recesses and thus also consist of silicon carbide (SiC) or a metallic material and thus have a first hardness.

Due to the at least partial formation of the housing elements

Plastic or other suitable composite material, at least due to the formation of the driver elements of the housing elements made of a plastic or other suitable composite material, these have a second, lower hardness, at least in the region of the driver elements.

According to one embodiment of the invention, the first housing element and / or the second housing element are each formed in one piece and comprise the driver elements as an integral part. In particular, the

Mitnehmerelemente thus not subsequently to the first and / or second

Housing element attached, but are formed at the same time in the production of the first and / or second housing element.

Conventionally, the entrainment of the sliding surfaces of the sliding ring and the counterring takes place by means of metallic cylinder pins arranged on the housing elements. Here it can always come to chipping the driver elements. This is in particular due to a high torque of the sliding surfaces of sliding and counter ring or by an abrupt start of the movable machine part in combination with cooperating first and second or third and fourth driver elements, each of which has a similar or comparable hardness. Since the second and fourth driving elements of the housing elements now consist of a plastic or other suitable composite material with a second, lower hardness, a material pairing is now given by two different material hardness, in particular results in a combination of hard hard first driver elements and soft second driver elements and hard third driver elements and soft fourth driver elements. This can be prevented in particular that the sliding surfaces of sliding and counter ring are damaged by excessive torque.

According to one embodiment of the invention, the second and fourth driver elements already pass through during the production of the housing elements

Injection molding directly injected with the housing elements. As already described, in particular the entire housing elements are each as

Injection molded part produced.

According to one embodiment of the invention is further provided that the suspension of the sliding ring is formed by a plurality of coil springs, that is, the suspension is designed as a kind of group suspension. In particular, the second housing element has specially designed receptacles or

Spring mounts for the coil springs on. The injection molding tool for producing the second housing element can be designed such that the spring receptacles are injected directly into the second housing element as indentations during the production of the second housing element by injection molding. In the spring housings coil springs are used whose outer diameter is approximately the inner diameter of the

Spring recordings corresponds, so that the coil springs are held positively and / or non-positively in the spring receptacles. A particular advantage of using

Spiral springs is that the force exerted on the sliding surfaces of the sliding and counter-ring force can be easily adjusted or adjusted if necessary.

Depending on which spring force is required, this can be adjusted by adjusting the number of coil springs used. For example, a lower spring force can be generated by reducing the number of coil springs. It is also possible, depending on the application, to use coil springs with appropriate spring hardness. Thus, for example, a higher spring force could be achieved by using coil springs of greater spring rate. Is advantageous Furthermore, this suspension requires no additional technical means, in particular no additional rings and pins or the like, to hold the coil springs in their respective position.

The mechanical seal of the invention is technically much easier to manufacture, as a conventionally known mechanical seal, in particular a mechanical seal, in which the counter-ring or the sliding ring is sprung over an array of sinusoidal springs. By injection molding, in which the

Mitnehmerelemente and the spring retainers are already integrated in at least one housing element, are no further post-processing steps to the

Housing elements necessary. These can be installed directly. The suspension of the mating ring or the sliding ring by a plurality of coil springs can be easily assembled, in particular in combination with the injection-molded spring mounts. In particular, no other components for fixing the

Spiral springs necessary and it must be paid during assembly not on a correct alignment of the spring elements, which simplifies the production effort. The use of a less hard material for the housing elements and the formation of the driving elements for sliding ring and counter ring of the same softer material as the housing elements also leads to a lower wear of the mechanical seal. The driver elements of the housing elements can

advantageously also be cast directly in the injection molding of the housing elements in this and do not have to be subsequently attached to this. All this has an advantageous effect on the production time and / or the production costs and / or the running costs.

figure description

In the following, embodiments of the invention and their advantages with reference to the accompanying figures will be explained in more detail. The proportions of the individual elements to one another in the figures do not always correspond to the actual size ratios, since some shapes are simplified and other shapes are shown enlarged in relation to other elements for better illustration. Figure 1 shows an exploded view of the components of a mechanical seal according to the prior art.

FIG. 2 shows a schematic partial representation of a mechanical seal housing of a mechanical seal according to the invention. Figure 3 shows a schematic partial view of a mechanical seal housing with the associated seal ring of a mechanical seal according to the invention.

For identical or equivalent elements of the invention, identical reference numerals are used. Furthermore, for the sake of clarity, only reference symbols are shown in the individual figures, which are required for the description of the respective figure. The illustrated embodiments merely represent examples of how the device according to the invention and / or the method according to the invention can be configured and do not represent a conclusive limitation.

Figure 1 shows an exploded view of the components of a mechanical seal 1 according to the prior art. A mechanical seal 1 has, in particular, a housing arrangement 2, in which a sprung counter-ring 3 and a sliding ring 4 are arranged. The housing assembly 2 comprises a movably formed housing element 5 and a stationary fixable housing element 6. The movably formed housing element 5 is also referred to as a mechanical seal sleeve, the stationary fixable housing element 6 is also referred to as a mechanical seal housing 15. The movably formed housing member 5 is assigned in the illustrated embodiment, the movable seal ring 4, while the stationary fixable housing member 6 of the spring-loaded mating ring 3 is assigned.

In particular, the spring-loaded mating ring 3 forms the standing surface and the sliding ring 4 forms the rotating surface of the mechanical seal 1. The housing elements 5, 6 are conventionally each made of metal.

For example, the housing elements by turning and more

produced metal-working steps or it is a metal blank made by investment casting, which is further processed, for example by drilling receptacles for driving pins for mating ring 3 and slide ring 4 in the metal blank and cylinder pins or the like are screwed as driving pins. The suspension 9 of the mating ring 3 is formed in particular by a plurality of sinusoidal springs 12, which are arranged between two metal rings 13-1, 13-2, which serve for the axial fixation of the suspension 9.

To achieve the desired sealing of a movable machine part with respect to a stationary machine part, the mechanical seal 1 comprises a

A plurality of sealing rings 14, which may have a different thickness depending on the respective requirements.

Figure 2 shows a schematic partial view of a fixed fixable

Housing member 6, in particular a mechanical seal housing 15 of a mechanical seal according to the invention and Figure 3 shows a schematic partial view of a mechanical seal housing 15 with the associated counter-ring 3 of a mechanical seal according to the invention. The preferably injection-molded

Mechanical seal housing 15 has in particular driver elements 8 and

Spring mounts 11 on. In particular, the injection molding tool used is designed such that the driver elements 8 and the spring retainers 11 are generated directly during injection molding and no further processing steps on

injection-molded mechanical seal housing 15 are necessary. In the spring housings 11 coil springs 10 are used. Subsequently, the counter-ring 3 is placed according to FIG. The counter ring 3 also has driver elements 7. In particular, these are formed as notches 16, so that the driver elements 8 of the

Gleitringdichtungsgehäuses 15 positively into the driver elements 7 of the

Counter ring 3 intervene. It can be provided that between the

Driver elements 7, 8 each a game is formed. According to a further embodiment, it is provided that the driver elements 8 of the

Mechanical seal housing 15 largely free of play positively and / or non-positively engage in the driver elements 7 of the mating ring 3.

The counter-ring 3 presses in the spring receptacles 11 of the

In particular, the entirety of all disposed between the mechanical seal housing 15 and the mating ring 3 coil springs 10, the suspension 9 of the mechanical seal according to the invention.

The invention has been described with reference to a preferred embodiment. However, it is conceivable for a person skilled in the art that modifications or Changes of the invention can be made without departing from the scope of the following claims.

LIST OF REFERENCES

1 mechanical seal

2 housing arrangement

3 counter ring

4 sliding ring

5 first housing element

6 second housing element

7 driver element

8 driver element

9 suspension

10 spiral spring

11 spring retainer

12 sine-wave spring

13 metal ring

14 sealing ring

15 mechanical seal housing

16 notch

Claims

claims

1. mechanical seal (1) comprising a housing assembly (2) in which a spring-loaded mating ring (3) and a sliding ring (4) slidably associated with the mating ring (3)

are arranged, the housing assembly (2) comprising a first movably formed housing element (5) and a second stationary fixable

Housing element (6), characterized in that the housing arrangement (2) consists at least partially of a plastic and / or a composite material.

Second mechanical seal (1) according to claim 1, wherein the first housing element (5) and / or the second housing element (6) made of a plastic and / or a

Composite exists.

3. mechanical seal (1) according to claim 1 or 2, wherein the sliding ring (4) each having first driver elements and wherein the first movable housing member (5) respectively second driver elements for the first driver elements of the sliding ring (4), wherein the second driver elements in engage the first driver elements.

4. The mechanical seal (1) according to claim 3, wherein the first housing element (5) and / or the second housing element (6) are each formed in one piece.

5. mechanical seal (1) according to one of the preceding claims, wherein the

Counterring (3) in each case third entrainment elements (7) and wherein the second stationary fixable housing element (6) in each case fourth entrainment elements f (8) for the third entrainment elements (7) of the counter ring (3), wherein the fourth entrainment elements (8) in engage the third driver elements (7).

6. The mechanical seal (1) according to one of claims 3 to 5, wherein the first and / or the third driver elements (7) consist of a first material having a first hardness and wherein the second and / or fourth driver elements (8) made of a plastic material and / or a composite material having a second hardness, wherein the first hardness is greater than the second hardness.

7. mechanical seal (1) according to one of the preceding claims, wherein a

Suspension (9) of the spring-loaded counter-ring (3) by a plurality of coil springs (10) is formed.

8. Mechanical seal (1) according to claim 7, wherein the second housing element (6).

Recordings (11) has formed for the coil springs (10).

9. A method for producing a mechanical seal (1) comprising a

Housing assembly (2), a spring-loaded mating ring (3) and a sliding ring (4) slidably associated with the mating ring (3), the housing assembly (2) comprising a first movably formed housing element (5) and a second stationary fixable housing element (6) in that the housing arrangement (2) is injection-molded at least partially from a plastic and / or a composite material.

10. The method of claim 9, wherein the first and / or the second housing member (5, 6) are each injection molded from a plastic and / or a composite material.

11. The method of claim 9 or 10, wherein between the counter-ring (4) and the associated second housing member (6) a plurality of coil springs (10) is arranged.

12. The method according to any one of claims 9 to 11, wherein the coil springs (10) in

Receivers (11) of the second housing element (6) are arranged, wherein the receptacles (11) during injection molding in the second housing element (6) are injected.

13. The method according to any one of claims 9 to 12, wherein the injection molding second and / or fourth driver elements (8) on the first and / or second

Housing element (5, 6) are formed.