SLIDING RING SEAL ASSEMBLY WITH SENSOR

Description

[0001] The present invention relates to a mechanical seal arrangement with a sensor and a wireless transmission device for wireless transmission of information and / or signals and / or energy.

[0002] Mechanical seal assemblies are known in various designs from the state of the art. In order to detect a potential failure of a mechanical seal assembly as early as possible, various physical values ​​in the area of ​​the mechanical seal are recorded and monitored. Since mechanical seal assemblies often have to seal media with very high temperatures above 200°C or very aggressive media, the sensors used to record the physical values ​​must meet the highest requirements. Furthermore, a cable connection that connects the sensor to an evaluation unit or the like is also subjected to high loads. In particular, the seal rings of the mechanical seal assembly sometimes move several millimeters during operation, which places extreme stress on the cable connections.Furthermore, such a cable connection must be disconnected during maintenance, for example, and securely reconnected after maintenance. DE 10 2013 220 429 A1 discloses a mechanical seal assembly according to the preamble of claim 1. Furthermore, US Pat. No. 6,360,610 B1 discloses a mechanical seal assembly according to the preamble of claim 1, which implements sealing gap monitoring using ultrasound.

[0003] It is therefore an object of the present invention to provide a mechanical seal arrangement which enables a simplified possibility of detecting physical values ​​in the area of ​​the mechanical seal arrangement.

[0004] This object is achieved by a mechanical seal arrangement having the features of claim 1, the subclaims show preferred developments of the invention.

[0005] The mechanical seal assembly with the features of claim 1 has the advantage that wireless transmission of recorded physical values ​​in the form of signals is possible. In particular, a sensor can also be arranged on a rotating seal ring, which is not possible with a wired connection of the sensor. According to the invention, the mechanical seal assembly comprises at least one mechanical seal with a rotating and a stationary seal ring, which define a sealing gap between them. Furthermore, a sensor for detecting at least one physical value is provided, wherein the sensor is arranged on one of the seal rings. The sensor is arranged directly on the seal ring. A wireless transmission device is provided, which comprises a first transmitter-receiver device and a second transmitter-receiver device.The first transmitter-receiver device is arranged on the sensor, and the second transmitter-receiver device is arranged on a stationary component, for example, a housing of the mechanical seal assembly. The recorded values ​​are transmitted wirelessly between the first and second transmitter-receiver devices. This makes it possible for a sensor to be connected to an evaluation unit or the like without the cables normally required. In particular, a sensor can also be easily connected to a rotating seal ring and / or a component connected to the rotating seal ring, e.g., a seal ring carrier.

[0006] The wireless transmission device is also configured to transmit electrical energy to the sensor. This eliminates the need for the sensor to have its own power supply, but can be powered wirelessly via induction.

[0007] The sensor also includes an evaluation unit located directly on the sensor. This makes it possible to significantly reduce the amount of data to be transmitted, as the evaluation takes place directly at the sensor. This means that only a small amount of energy is required to transmit the data.

[0008] Furthermore, the physical values ​​that the sensor records are a structure-borne sound of the rotating seal ring and / or the stationary seal ring and a gap height of the sealing gap, i.e. a distance between the sliding surfaces of the rotating and stationary seal ring.

[0009] To enable the widest possible range of applications and versatility, the sensor is preferably a thin-film sensor. Thin-film sensors have a low profile and can be easily and securely attached to components, for example, by adhesive.

[0010] Particularly preferably, the sensor, the first transmitter-receiver device and the evaluation unit are a compact component.

[0011] According to a further preferred embodiment of the invention, the sensor is arranged on the mechanical seal in a region of the seal ring(s) facing away from the product. This ensures a certain degree of protection for the sensor, since the sensor does not come into direct contact with the product to be sealed, which can be very hot or very aggressive.

[0012] Further preferably, the sensor is arranged in a sensor receiving element connected to the sliding ring. The sensor receiving element can, for example, be an O-ring or a secondary seal of the sliding ring seal, or even a sliding ring carrier or the like.

[0013] To record a variety of different physical values, preferably several sensors are arranged on one of the seal rings of the mechanical seal, and / or one or more sensors are arranged on the rotating and stationary seal rings. Thus, physical values ​​can be recorded by both the rotating and stationary seal rings. Particularly preferably, one or all sensors are arranged directly on the seal ring.

[0014] The mechanical seal arrangement preferably comprises sensors that can record the following physical values: Temperature of the rotating and / or stationary seal ring and / or a fluid in the sealing gap between the seal rings, and / or acceleration of the rotating and / or stationary seal ring in the axial direction of the seal ring and / or radial direction of the seal ring, and / or surface wave propagation on the rotating and / or stationary seal ring, and / or strain and / or stress of the rotating and / or stationary seal ring.

[0015] The sensor of the mechanical seal assembly preferably has a toroidal shape and is particularly designed as a hollow cylinder or a torus. This ensures that the sensor's location on the seal ring does not result in any imbalance, meaning that the sensor does not impede the proper functioning of the mechanical seal assembly.

[0016] The mechanical seal assembly preferably further comprises a control unit configured to determine a failure probability of the mechanical seal assembly based on the detected physical values. Depending on the determined failure probability, maintenance of the mechanical seal assembly can then be ordered, for example, or components of the mechanical seal assembly can be replaced if necessary.

[0017] Preferred embodiments of the invention are described in detail below with reference to the accompanying drawings. In the drawing: Fig. 1 is a schematic sectional view of a mechanical seal arrangement according to a first embodiment of the invention, Fig. 2 is a schematic sectional view of a mechanical seal arrangement according to a second embodiment of the invention, Fig. 3 is a schematic sectional view of a mechanical seal arrangement according to a third embodiment of the invention, and Fig. 4 is a schematic plan view of a rotating seal ring of a mechanical seal arrangement according to a fourth embodiment of the invention.

[0018] The following is based on reference to Fig. 1 a mechanical seal arrangement 1 according to a first embodiment of the invention is described in detail.

[0019] As from Fig. 1 As can be seen, the mechanical seal arrangement 1 comprises a mechanical seal 2 with a rotating seal ring 3 and a stationary seal ring 4. A sealing gap 5 is defined between the rotating seal ring 3 and the stationary seal ring 4.

[0020] The mechanical seal 2 seals a product area 11 from an atmospheric area 12. The rotating seal ring 3 is fixed to a shaft 17 with a central axis XX by means of a seal ring carrier 13. The stationary seal ring 4 is arranged on a shaft sleeve 16, which is firmly connected to a housing 15.

[0021] A preloading element 14, which in this embodiment comprises a plurality of coil springs arranged along the circumference, preloads the stationary slide ring 4 against the rotating slide ring 3.

[0022] The mechanical seal assembly 1 further comprises a sensor 6, which is arranged on the stationary seal ring 4 on a rear side 41 of the seal ring. The sensor 6 detects at least one physical value, for example, temperature and / or pressure and / or structure-borne sound or the like.

[0023] An evaluation unit 8 is also arranged directly at the sensor 6. The evaluation unit 8 evaluates the physical values ​​recorded by the sensor 6 and enables a reduction in the data volume to be transmitted.

[0024] Furthermore, the mechanical seal assembly 1 comprises a wireless transmission device 7. The transmission device 7 comprises a first transmitter-receiver device 71 and a second transmitter-receiver device 72. As in Fig. 1 As indicated, the signals generated by the evaluation unit can be transmitted wirelessly from the transmitter-receiver device 71 to the second transmitter-receiver device 72. The second transmitter-receiver device 72 is connected to a control unit 10. This connection can also be wireless or, as shown in this exemplary embodiment, cost-effectively via cable. It should be noted that it is also possible for the control unit 10 to be arranged directly on the second transmitter-receiver device 72, so that a complex connection between the two components can be omitted.

[0025] The control unit 10 is configured to determine a failure probability of the mechanical seal 2 based on the transmitted data. For example, conclusions about wear of the mechanical seals can be drawn based on the physical values ​​recorded by the sensor 6.

[0026] As from Fig. 1 As can be seen, the sensor 6 in this exemplary embodiment is arranged in the product area 11. The product in the product area 11 can have a very high temperature, in particular higher than 200°C, and / or be an aggressive medium. Therefore, the sensor 6 must be protected depending on the medium to be sealed. In this exemplary embodiment, the sensor 6 and the evaluation unit 8 form a common assembly, which can, for example, have a common housing. The first transmitter-receiver device 71 is an antenna, which is arranged on the outside of the common housing.

[0027] It should also be noted that the wireless transmission device 7 is also capable of transmitting energy for the sensor 6 from the second transmitter-receiver device 72 via the first transmitter-receiver device 71. As a result, the sensor 6 does not need to have its own energy storage device, but can be supplied with electrical energy, for example, by induction. Alternatively or additionally, the sensor 6 can also have its own energy storage device.

[0028] Thus, the wireless transmission device 7 enables simple and reliable monitoring of the mechanical seal 2. The recorded data is evaluated in the evaluation unit 8 and then wirelessly transmitted to the second transmitter-receiver device 72, in which the data can be further evaluated or appropriate measures can be initiated, for example, a maintenance message for servicing the mechanical seal. The evaluation unit 8 arranged on the sensor 6 can significantly reduce the amount of raw data recorded by the sensor 6, thus enabling fast and energy-saving data transmission between the first and second transmitter-receiver devices 71, 72. The sensor 6 can be connected to the stationary seal ring 4, for example, by means of adhesive bonding. However, it should be noted that other alternative connection techniques for fixing the sensor 6 to the stationary seal ring 4 are also possible.

[0029] Energy transmission between the second transceiver device 72 and the first transceiver device 71 can be achieved, for example, via coils, which can also be printed. Energy transmission preferably occurs in a low frequency range ≤ 1 kHz. Since the transmission path from the rear side 41 of the stationary sliding ring 4 to the housing 15 is short and not interfered with by other components, especially metallic components, a very compact design is possible.

[0030] Fig. 2 shows a mechanical seal arrangement 1 according to a second exemplary embodiment of the invention. Identical or functionally identical parts are designated by the same reference numerals as in the first exemplary embodiment. In contrast to the first exemplary embodiment, the wireless transmission device 7 and the sensor 6 are arranged differently in the second exemplary embodiment. In the second exemplary embodiment, the sensor 6 is arranged on the rotating seal ring 3. The sensor 6 is arranged in the atmospheric region 12 so that the sensor 6 is not exposed to the medium to be sealed in the product region 11. This may eliminate the need for a protective device to protect the sensor 6 from an aggressive medium and / or high temperatures or the like. An evaluation unit 8 is again arranged on the sensor 6 in order to significantly reduce the amount of data to be transmitted.In this embodiment, the second transmitter-receiver device 72 is arranged on the shaft sleeve 16. This again provides a free wireless transmission path between the first and second transmitter-receiver devices 71, 72. Otherwise, this embodiment corresponds to the previous embodiment, so reference can be made to the description given there.

[0031] Fig. 3 shows a mechanical seal assembly 1 according to a third embodiment of the invention. Identical or functionally identical parts are again designated by the same reference numerals as in the previous embodiments.

[0032] In contrast to the previous embodiments, in the third embodiment, sensors 6 are arranged on both the stationary sliding ring 4 and the rotating sliding ring 3. One sensor 6 is arranged, as in the first embodiment, on a rear side 41 of the stationary sliding ring 4. In this embodiment, another sensor 6' is integrated into a sensor receiving element 9. In this embodiment, the sensor receiving element 9 is an O-ring arranged in a recess 18 in a sliding ring carrier 13. Both sensors 6 each have first transmitter-receiver devices 71, 71', which can wirelessly transmit data to a common second transmitter-receiver device 72. The second transmitter-receiver device 72 is connected to a control unit 10. Evaluation units 8, 8' are arranged directly on both sensors 6 in order to reduce the amount of data to be transmitted.

[0033] The sensor 6 arranged in the O-ring has a torodial shape, so that an imbalance, which could only occur with a sensor arranged at a specific point on the rotating part of the mechanical seal 2, can be avoided. The O-ring is positioned such that wireless data transmission is easily possible through the material of the O-ring and the mechanical seal carrier 13. The sensor 6 is completely enclosed by the O-ring. The wireless transmission device 7 is also capable of transmitting both signals and energy. Otherwise, this embodiment corresponds to the previous embodiment, so reference can be made to the description given there.

[0034] Fig. 4 shows a stationary seal ring 4 of a mechanical seal assembly 1 according to a fourth embodiment of the invention in plan view. As can be seen from Fig. 4As can be seen, the mechanical seal assembly 1 has three sensors 6, which are arranged at equal distances from one another in the circumferential direction along the circumference of the stationary seal ring 4. The three sensors 6 can detect the same physical values ​​or, preferably, different physical values. For example, the three sensors can detect the temperature, a vibration path of the stationary seal ring 4, and the structure-borne noise occurring at the stationary seal ring 4. It should be noted that, of course, further sensors can be arranged on the stationary seal ring 4 and / or on the rotating seal ring 3.

[0035] As can be seen from the described exemplary embodiments, according to the invention, data and / or energy can be transmitted wirelessly from and to sliding rings 3, 4 of a mechanical seal 2. This enables the use of sensors 6, in particular with media with difficult environmental conditions, for example high temperatures above 200°C and / or high pressures and / or with very aggressive media. The sensors 6 can, for example, be designed as thin-film sensors. This means they are lightweight and can be arranged in a wide variety of positions on the mechanical seal 2. Particularly preferably, the sensors are arranged in an area on the mechanical seal 2 facing away from the product. More preferably, evaluation units 8 are arranged directly on the sensors, so that the amount of data to be transmitted can be significantly reduced. List of reference symbols

[0036] 1 Mechanical seal assembly 2 Seal ring 3 Rotating seal ring 4 Stationary seal ring 5 Sealing gap 6, 6 Sensor 7 Wireless transmission device 8, 8 Evaluation unit 9 Sensor receiving element 10 Control unit 11 Product area 12 Atmosphere area 13 Seal ring carrier 14 Preload element 15 Housing 16 Shaft sleeve 17 Shaft 18 Recess 41 Rear of the stationary seal ring 71, 71 First transmitter-receiver device 72 Second transmitter-receiver device X-X Center axis of the shaft 17

Claims

1. A mechanical seal arrangement, comprising: - at least one sliding ring seal (2) with a rotating sliding ring (3) and a stationary sliding ring (4), which define a sealing gap (5) therebetween, and - at least one sensor (6) for detecting at least one physical value, wherein the sensor (6) is arranged at one of the sliding rings or a component connected to the sliding ring, and - a wireless transmission device (7) with a first transmitter-receiver device (71), which is arranged at the sensor (6), and a second transmitter-receiver device (72), which is arranged at a stationary component, wherein a transmission of data and electrical energy by induction to the sensor between the first and second transmitter-receiver devices (71, 72) is performed wirelessly, and - an evaluation unit (8), characterised in that the evaluation unit is arranged directly at the sensor (6) and is configured to reduce amounts of data to be transmitted, - wherein multiple sensors (6) are arranged at one of the sliding rings, and - wherein the physical values, which the sensors record, is a structure-borne sound of the rotating sliding ring (3) and / or of the stationary sliding ring (4) and is a gap height of the sealing gap between the rotating and the stationary sliding ring.

2. The mechanical seal arrangement according to any of the preceding claims, wherein the sensor (6) is a thin-film sensor.

3. The mechanical seal arrangement according to any of the preceding claims, wherein the sensor (6) is arranged at a region of the sliding ring seal facing away from product.

4. The mechanical seal arrangement according to any of the preceding claims, wherein the sensor (6) is arranged in a sensor receiving element (9) connected to the sliding ring, wherein the sensor receiving element (9) is an O-ring or is a secondary seal of the sliding ring seal or is a sliding ring carrier (13).

5. The mechanical seal arrangement according to any of the preceding claims, wherein the physical values, which the sensors record, are further selected from: - a temperature of the rotating sealing ring and / or the stationary sealing ring and / or a fluid located in the sealing gap (5), and / or - an acceleration of the rotating sealing ring (3) and / or the stationary sealing ring (2) in axial direction and / or radial direction and / or in circumferential direction, and / or - a surface wave propagation at the rotating sliding ring (3) and / or at the stationary sliding ring (4), and / or - a positive and / or negative expansion of the rotating sliding ring and / or the stationary sliding ring.

6. The mechanical seal arrangement according to any of the preceding claims, wherein the sensor (6) comprises a toroidal shape.

7. The mechanical seal arrangement according to any of the preceding claims, further comprising a control unit (10), which is configured to determine a failure probability of the mechanical seal arrangement based on the detected physical value and / or the detected physical values.