Sliding ring seal assembly with monitoring function and method thereof

Abstract

The invention relates to a slip ring seal device, comprising: a slip ring seal (2), the slip ring seal having a rotating slip ring (3) and a stationary slip ring (4), a sealing gap (5) being defined between the rotating slip ring and the stationary slip ring, wherein the rotating slip ring (3) has a first sliding surface (30) with a first information structure (6), wherein the stationary slip ring (4) has a second sliding surface (40) with a second information structure (7), wherein the first information structure (6) and the second information structure (7) at least partially overlap in an overlapping area (16); at least one sensor (8) for detecting sound and / or vibration generated by the first information structure (6) when moving past the second information structure (7); and an evaluation unit (10) configured to compare the detected sound and / or the detected vibration with a set value and output a comparison result.

Description

Technical Field

[0001] The present invention relates to a slide ring seal having a monitoring function by means of sound and / or vibration and a method for monitoring a slide ring seal. Background Art

[0002] Various designs of end-face slide ring seals are known from the prior art. During operation, for example, solid particles may enter between the sliding surfaces of the rotating and stationary slide rings and damage the sliding surfaces. This can reduce the airtightness of the slide ring seal, potentially leading to increased leakage. Such leaks can be detected, for example, in the recirculating barrier fluid, and the slide ring seal may need to be replaced. However, in practice, replacement of such slide ring seals requires a certain amount of time. This can result in long downtimes for the machine in which the slide ring seal is installed for sealing, and can be very frustrating for the machine operator. Summary of the Invention

[0003] Therefore, the object of the present invention is to provide a slide ring seal and a method for detecting wear and / or damage of a slide ring seal as early as possible and enabling the slide ring seal to be replaced early.

[0004] This object is achieved by a mechanical seal arrangement and a method having the features of claim 1 , the corresponding dependent claims indicating further preferred embodiments of the invention.

[0005] The slip-ring seal device according to the present invention, having the features of claim 1, offers the advantage of enabling early detection of any changes in the slip-ring seal. This allows a decision to be made regarding replacement of the slip-ring seal long before any actual failure of the slip-ring seal occurs. Consequently, a suitable slip-ring seal can be readily available and subsequently replaced during a brief downtime of the machine's operation by the machine user. This is achieved according to the present invention by a slip-ring seal device comprising a rotating slip ring and a stationary slip ring, with a sealing gap defined between the rotating and stationary slip rings. The rotating slip ring includes a first sliding surface having a first information structure, and the stationary slip ring includes a second sliding surface having a second information structure. The first and second information structures are arranged on the two sliding surfaces so as to at least partially overlap in an overlapping region. Overlapping in this context means that the first and second information structures are at least partially arranged at the same radial height in the radial direction. Preferably, the first and second information structures completely overlap. Furthermore, the slip-ring seal device includes at least one sensor for detecting sound and / or vibration generated by the first information structure moving past the second information structure. Because the information structures at the two sliding surfaces at least partially overlap, characteristic acoustic noises and / or vibrations are generated that can be detected by means of sensors. Furthermore, an evaluation unit is provided that is configured to compare the detected acoustic waves and / or detected vibrations with stored nominal values ​​and output a comparison result. Thus, by providing the information structures, it is possible to specifically detect (acoustic) waves and vibrations that change in the presence of wear and / or solid particles, or in the event of changes in other physical values ​​of the medium in the sealing gap (such as pressure, temperature, and / or density). Based on changes in the detected acoustic and / or detected vibrations, it is possible to infer the condition of the mechanical seal and, if necessary, to replace it.

[0006] Preferably, the first information structure and the second information structure comprise recesses defined in the sliding surfaces of the rotating slip ring and the stationary slip ring. The depth of the recess on the sliding surface of the rotating slip ring may be different from the depth of the information structure on the sliding surface of the stationary slip ring. In addition, the individual information structures in the sliding surface may themselves have different height profiles, such as a stepped height profile within the information structure or an arched or wavy height profile within the recess. Further preferably, a plurality of separate recesses are provided in the sliding surface forming the information structure.

[0007] An information structure in the form of a recess is particularly easy and cost-effective to implement and allows for reliable detection of changes in the slip ring seal. For example, if small solid particles are present in the sealing gap between the two sliding surfaces of a stationary slip ring and a rotating slip ring, these particles preferably settle in the information structure in the form of a recess, thereby altering the sound and / or vibrations generated when the sliding surfaces slide past each other. This sound and / or vibration can then be detected by means of the sensor. The same applies, for example, if the density of the medium in the sealing gap changes, for example due to leakage of the product medium into the sealing gap.

[0008] Particularly preferably, the information structures are introduced into the sliding surface as rectangular recesses. These are very simple and cost-effective to produce and enable reliable sound and / or vibration detection.

[0009] Particularly preferably, the first information structure includes a first substructure and a second substructure, which are arranged on the sliding surface of the rotating slip ring at different heights in the radial direction of the slip ring. Further preferably, the second information structure includes a third substructure and a fourth substructure, which are arranged on the sliding surface of the stationary slip ring at different heights in the radial direction of the slip ring. In this case, the substructures are arranged such that, during rotation, the first substructure moves past the third substructure, and the second substructure moves past the third substructure.

[0010] For the most accurate detection of oscillations and / or vibrations, the sensor is preferably arranged directly on one of the slip rings, in particular on the stationary slip ring or the stationary component. Further preferably, the sensor is arranged directly on the rear side of one of the slip rings, in particular on the rear side of the stationary slip ring.

[0011] To ensure that the information structure does not significantly interfere with the sliding surface and, therefore, the sealing ability of the slip ring seal, the information structure is preferably arranged in a groove provided in the sliding surface. The groove is, for example, a spiral groove, which is used to enable the slip rings to disengage from each other as quickly as possible during machine startup. Alternatively, the information structure is arranged adjacent to the groove in the sliding surface.

[0012] According to a particularly preferred embodiment of the present invention, the information structures are arranged on the sliding surfaces of the rotating and stationary slip rings in such a way that a characteristic signal or melody is generated when the information structures move past one another. Thus, for example, a singing slip ring seal can be provided, and any changes in the slip ring or sliding surface can be reliably detected by a change in the characteristic signal or melody.

[0013] When the evaluation unit is preferably configured to determine the amplitude ratio of a plurality of amplitudes generated by the information structure, a particularly fast and simple way of performing the evaluation can be provided. This enables a rapid evaluation of the detected sound signal and / or vibration signal.

[0014] Preferably, the sensor for detecting sound and / or vibration is a structure-borne sound sensor or an acceleration sensor. The structure-borne sound sensor is preferably arranged on the housing or the fixed component.

[0015] The present invention also relates to a method for monitoring a slip ring seal comprising a rotating slip ring and a stationary slip ring, wherein at least one information structure is present on each sliding surface of the slip rings. During operation, the method comprises the steps of recording sound and / or vibration signals generated by the information structures as they move past one another, and comparing the recorded sound and / or vibration signals with stored sound and / or vibration signals to determine deviations.

[0016] Preferably, the state of the slide ring seal is derived from the recorded sound and / or vibration signals.

[0017] Furthermore, preferably, a maintenance message is issued when a predetermined deviation of the acoustic and / or vibration signal from a stored acoustic and / or vibration signal is detected. For example, this message can be sent directly to the manufacturer of the mechanical seal or the company responsible for maintenance, so that measures for a possible replacement of the mechanical seal can be initiated immediately.

[0018] In order to achieve the highest possible accuracy of the detected signals, the sound and / or vibration is preferably detected directly at one of the slip rings, in particular the stationary slip ring or the slip ring support. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0020] Figure 1 shows a schematic diagram of a slide ring seal device according to a first embodiment of the present invention,

[0021] Figure 2 Shown Figure 1 Schematic partial top view of the sliding surface of a rotating slip ring,

[0022] Figure 3 Shown Figure 1 Schematic partial plan view of the sliding surface of a stationary slip ring,

[0023] Figure 4 Shown is the representation represented by Figure 2 and Figure 3 The sound pressure generated by the information structure on the slip ring is plotted against time.

[0024] Figure 5 shows a schematic partial plan view of a sliding surface of a rotating slip ring according to a second embodiment of the present invention,

[0025] Figure 6 shows a schematic partial plan view of a sliding surface of a stationary slip ring according to a second embodiment of the invention,

[0026] Figure 7 shows a schematic top view of a sliding surface of a rotating slip ring according to a third embodiment of the present invention,

[0027] Figure 8 Shown along Figure 7 A schematic cross-sectional view taken along line VIII-VIII of , and

[0028] Figure 9 A schematic plan view showing a sliding surface of a rotating slip ring according to a fourth embodiment of the present invention is shown. DETAILED DESCRIPTION

[0029] Reference below Figures 1 to 4 A slide ring seal device 1 according to a first preferred embodiment of the present invention will be described in detail.

[0030] If you can Figure 1 As can be seen in FIG, the slide ring seal arrangement 1 comprises a slide ring seal 2 with a center axis XX, a rotating slide ring 3 and a stationary slide ring 4. A sealing gap 5 is defined between the rotating slide ring 3 and the stationary slide ring 4.

[0031] The slide ring seal 2 seals the product area 12 from the atmosphere area 13 .

[0032] Figure 2 and Figure 3 The sliding surfaces of the rotating slip ring 3 and the stationary slip ring 4 are shown respectively. Figure 2 As can be seen in FIG, a first information structure 6 is arranged on the sliding surface 30 of the rotating slip ring 3. A second information structure 7 is arranged on the sliding surface 40 of the stationary slip ring 4. In this exemplary embodiment, three individual information structures 7a, 7b, 7c form the second information structure 7.

[0033] If you can Figure 2 and Figure 3 As can be seen further in FIG, the information structures 6, 7 are partially arranged at the same radial height on the sliding surfaces 30, 40.

[0034] If you can Figure 1 As can be seen in detail in FIG, this results in the information structures 6, 7 having an overlapping area 16 in the radial direction, the center of which is located on the radius R1. This ensures that during operation, when the rotating slip ring 3 rotates with the shaft 11, the information structures move past each other during the rotation.

[0035] If you can Figure 1As can be seen further in FIG, the information structures 6, 7 of this embodiment are rectangular recesses on the sliding surface. The depth of the recesses is preferably about 1 to 2 μm. The information structures arranged as recesses can have the same width or different widths. As can be seen from FIG. Figure 3 As can be seen in FIG, the information structures can also have different lengths in the radial direction.

[0036] When the first information structure 6 arranged on the rotating slip ring 3 slides during operation past the second information structure 7 consisting of three individual information structures, a characteristic sound signal is generated. Figure 4 is shown in the diagram.

[0037] Figure 4 A sound pressure curve 14 is shown for the sound pressure P in Pascals over the time t in seconds s. As can be seen from the diagram, a characteristic amplitude 15 results. Because the second information structure 7 comprises three different, individual information structures 71, 72, 73, the amplitude 15 has different heights.

[0038] like Figure 1 As shown, the sensor 8 is arranged directly on the rear side 41 of the stationary slip ring 4. The sensor 8 detects the sound and / or vibrations generated by the first information structure 6 and the second information structure 7 sliding past each other. The sensor 8 is connected to an evaluation unit 10, which is arranged on the housing 9 together with the stationary slip ring 4.

[0039] The evaluation unit 10 is configured to compare the detected sound signal and / or the detected vibration signal with stored target values ​​and output the comparison result. If the comparison shows a significant deviation between the set value and the actual value, the manufacturer of the slide ring seal or any company responsible for maintenance can react immediately.

[0040] Thus, it is possible to monitor the slide ring seal 1 in order to detect the risk of failure as early as possible and to take appropriate countermeasures, such as replacing the slide ring seal. In this context, monitoring can be very cost-effective and simple in design. In particular, the average gap height, i.e., the vertical distance, between the sliding surfaces of the slide rings 3 and 4 in the direction of the center axis XX can be determined in a simple manner. Thus, even when monitoring the slide ring seal during operation, it can be determined whether the sealing gap 5 changes, in particular as a so-called A-gap (i.e., the sealing gap 5 opens radially inward) or as a so-called V-gap (i.e., the sealing gap opens radially outward).

[0041] Furthermore, monitoring can be performed based on amplitude ratios, so that an absolute calibration of the signal levels can be dispensed with. Signals generated by the information structures 6, 7 can also be easily distinguished from other signals that may be present from other sources.

[0042] It should also be noted that sensors for detecting signals from the information structure, such as structure-borne sound sensors, may also already be present on the machine to be sealed and may be connected to the evaluation unit 10. Existing slip ring seals can also be retrofitted by installing a slip ring with an information structure.

[0043] It should also be noted that the first information structure 6 and the second information structure 7 can also be designed to generate sounds that are actually audible to the human ear. In this respect, it is also conceivable to generate certain melodies with the help of the information structure, so that in this way the changes can also be easily detected by the human ear.

[0044] Figure 5 and Figure 6 The slide ring seal device 1 according to the second embodiment of the present invention is shown. Figure 5 and Figure 6 As can be seen from FIG, the first information structure 6 configured on the rotating slip ring 3 includes a first substructure 61 and three second substructures 62, 63, and 64. Figure 6 As can be seen further in FIG, the stationary slip ring 4 has a second information structure 7 comprising three third substructures 71 , 72 , 73 and one fourth substructure 74 .

[0045] If you can Figure 5 and Figure 6 As can be seen in the figure, the areas of the first substructure 61 and the third substructures 71, 72, and 73 are arranged on the same first radius R1. The areas of the second substructures 62, 63, and 64 and the fourth substructure 74 are arranged on the same second radius R2. The second radius R2 is significantly smaller than the first radius R1. Therefore, the substructures arranged on the first radius R1 can generate a first acoustic signal and / or a first vibration signal, and the substructures arranged on the second radius R2 can generate a second acoustic signal and / or a vibration signal. This significantly improves monitoring accuracy and, in particular, enables reliable detection of the gap height of the sealing gap 5.

[0046] Figure 7 and Figure 8 The slide ring seal device according to the third embodiment of the present invention is shown. Figure 7 As can be seen in FIG, in the third exemplary embodiment, a first information structure 6 having three substructures 65, 66, 67 is shown on the rotating slip ring 3. Figure 8 As can be seen in the cross-sectional view of FIG, the three substructures 65, 66, 67 have different depths T1, T2 and T3 respectively.

[0047] Thus, in this embodiment, three substructures are integrated into the first information structure 6 formed as a recess. Figure 8The second information structure (not shown) on the stationary slip ring can be formed in the same manner as on the rotating slip ring 3, or can be formed by several separate recesses in the sliding surface of the stationary slip ring as in the aforementioned exemplary embodiment.

[0048] Figure 9 A slide ring seal according to a fourth embodiment of the present invention is shown. In this fourth exemplary embodiment, a plurality of grooves 17 are provided in the sliding surface. The grooves 17 have a depth of only a few micrometers, wherein a first information structure 6' is arranged in the groove 17 and a further first information structure 6" is arranged outside the groove 17 in the sliding surface 30 of the rotating slide ring. The information structures 6', 6" are in turn formed at different radii R1, R2 in order to reliably detect, in particular, the gap height of the sealing gap.

[0049] In other respects, this exemplary embodiment is similar to the aforementioned exemplary embodiment, so reference is made to the aforementioned description.

[0050] In general, it should be noted that for all embodiments, any combination of designs for the first information structure 6 and the second information structure 7 is possible. The first information structure 6 and the second information structure 7 formed as recesses can also have any geometric shape. For example, recesses with a continuously changing height profile can also be provided as the information structures 6 and 7. Furthermore, alternatively, in addition to rectangular information structures, square information structures, circular or elliptical information structures, or triangular information structures can also be provided.

[0051] Reference Signs List

[0052] 1 Slide ring seal

[0053] 2 Slide ring seals

[0054] 3 Rotating slip rings

[0055] 4 Stationary slip rings

[0056] 5 Sealing gap

[0057] 6, 6', 6″ First Information Structure

[0058] 7 Second Information Structure

[0059] 7a, 7b, 7c Single information structure

[0060] 8 Sensors

[0061] 9 Housing

[0062] 10 evaluation units

[0063] 11 Axis

[0064] 12 Product Area

[0065] 13 Atmosphere Zone

[0066] 14 Sound pressure curve

[0067] 15 Amplitude

[0068] 16 Overlapping Area

[0069] 17 grooves

[0070] 30 Sliding surface of rotating slip ring

[0071] 40 Sliding surface of stationary slip ring

[0072] 41 Rear side of stationary slip ring

[0073] 61 First substructure

[0074] 62, 63, 64 Second substructure

[0075] 65, 66, 67 have substructures of different depths

[0076] 71, 72, 73 Third substructure

[0077] 74 Fourth substructure

[0078] R1 first radius

[0079] R2 Second radius

[0080] T1 First Depth

[0081] T2 Second Depth

[0082] T3 Third Depth

[0083] XX Axial direction / center axis of the mechanical seal

Claims

1. A sliding ring sealing device, comprising: A slip ring seal (2), comprising a rotating slip ring (3) and a stationary slip ring (4), with a sealing gap (5) defined between the rotating slip ring and the stationary slip ring, wherein the rotating slip ring (3) comprises a first sliding surface (30) having a first information structure (6), wherein the stationary slip ring (4) comprises a second sliding surface (40) having a second information structure (7), wherein the first information structure (6) and the second information structure (7) at least partially overlap in an overlapping region (16), at least one sensor (8) for detecting sounds and / or vibrations generated by the first information structure (6) when it moves past the second information structure (7), An evaluation unit (10) configured to compare the detected sound and / or the detected vibration with a set value and output a comparison result, wherein based on a change in the detected sound and / or the detected vibration, a condition of the slide ring seal is deduced and its replacement is arranged.

2. The slide-ring seal device according to claim 1, wherein the first information structure (6) and the second information structure (7) comprise recesses defined in the first sliding surface (30) and the second sliding surface (40). The slide ring seal device according to claim 2 , wherein the recess is a rectangular recess.

4. The slip ring sealing device according to claim 1 or 2, wherein the first information structure (6) includes a first substructure (61) and a second substructure (62, 63, 64), the first substructure and the second substructure are arranged at different heights in the radial direction on the first sliding surface of the rotating slip ring (3), and the second information structure (7) includes a third substructure (71, 72, 73) and a fourth substructure (74), the third substructure and the fourth substructure are arranged at different heights in the radial direction on the second sliding surface of the stationary slip ring (4), so that the first substructure and the third substructure have an overlapping area (16) on a first radius R1, and the second substructure and the fourth substructure have an overlapping area (16) on a second radius R2.

5. The slip ring sealing device according to claim 1 or 2, wherein the sensor (8) is directly arranged on one of the rotating slip ring (3) and the stationary slip ring (4).

6. The slip ring seal device according to claim 5, wherein the sensor (8) is directly arranged on the rear side (41) of the stationary slip ring (4) or on a slip ring bracket.

7. The sliding ring seal device according to claim 1 or 2, wherein at least one of the first sliding surface (30) and the second sliding surface (40) includes a groove (17) provided in the sliding surface, wherein the first information structure and / or the second information structure is configured in the groove (17).

8. The slide ring seal device according to claim 1 or 2, wherein: During operation, a characteristic signal or melody is generated by the first information structure (6) as it moves past the second information structure (7).

9. The slide ring seal device according to claim 1 or 2, wherein the evaluation unit (10) is configured to determine an amplitude ratio of a plurality of amplitudes generated by the first information structure (6) or the second information structure (7).

10. The slide ring seal according to claim 1 or 2, wherein the sensor (8) is a structure-borne sound sensor or an acceleration sensor. 11 . The slide ring seal device according to claim 1 , wherein the sensor is a structure-borne noise sensor arranged on a housing or a stationary component.

12. A method for monitoring a slip ring seal (2), the slip ring seal comprising a rotating slip ring (3) and a stationary slip ring (4), a first information structure (6) being arranged on a first sliding surface (30) of the rotating slip ring (3), and a second information structure (7) being arranged on a second sliding surface (40) of the stationary slip ring (4), wherein the first information structure (6) and the second information structure (7) at least partially overlap in an overlapping region (16), wherein: During operation, a sound signal and / or a vibration signal generated by the first information structure (6) when it moves past the second information structure (7) is detected by at least one sensor (8), and the detected sound signal and / or vibration signal is compared with a sound signal and / or vibration signal stored in the evaluation unit (10) by an evaluation unit (10) and a comparison result is output by the evaluation unit (10), wherein based on a change in the detected sound signal and / or the vibration signal, a condition of the slide ring seal is inferred and its replacement is arranged.

13. The method according to claim 12, wherein a message is outputted if there is any predetermined deviation between the detected sound signal and / or the vibration signal and the stored sound signal and / or the vibration signal. 14 . The method according to claim 12 , wherein the sound signal and / or the vibration signal is directly detected at the rotating slip ring, the stationary slip ring or a slip ring support.

15. The method according to claim 14, wherein the sound signal and / or the vibration signal is detected directly at the stationary slip ring.

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