Mechanical sealing structure and compressor
By setting up a displacement detection device in the mechanical seal structure, the axial movement distance between the moving ring and the static ring is detected, the problem of inconvenient wear detection of the moving ring is solved, accurate wear judgment and replacement timing are achieved, and cost waste is reduced.
Patent Information
- Application Number
- CN202421318548.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-11
- Publication Date
- 2025-02-14
- Estimated Expiration
- 2034-06-11
AI Technical Summary
The wear detection of mechanical sealing moving rings is inconvenient, and existing methods are prone to errors and misjudgment, resulting in waste of costs and delayed construction periods.
Design a mechanical seal structure, detect the axial movement distance of the moving ring relative to the static ring through a displacement detection device, and realize non-contact detection using magnetic signals or capacitive displacement sensors.
The wear condition is judged by the change of the axial movement distance of the moving ring, avoid misjudgment, ensure that the mechanical seal is replaced when the loss reaches the maximum value, and reduce waste.
Smart Images
Figure CN222479444U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of shaft sealing, in particular to a mechanical sealing structure and a compressor. Background Art
[0002] A mechanical seal is a device that is perpendicular to the end face of a rotating shaft and keeps the end face in contact and slides relative to each other with the help of elastic force or other forces to prevent fluid leakage. Mechanical seals are usually composed of static rings, dynamic rings, elastic elements and other components, and the dynamic rings will produce certain wear under high-speed operation of the machine. Therefore, in order to ensure the normal sealing operation of the machine, the mechanical seal needs to be replaced before failure. The current method of mechanical seal failure is usually based on the amount of liquid leakage at the mechanical seal, the degree of mechanical vibration, the sound and other abnormal conditions. Such methods are usually subjective judgments, which are prone to large errors and misjudgments, resulting in cost waste and delays in construction. Utility Model Content
[0003] In order to solve the problem that it is inconvenient to detect the wear of the dynamic ring of the mechanical seal, the utility model proposes a mechanical seal structure, which detects the axial movement distance of the dynamic ring relative to the static ring through a displacement detection device, thereby conveniently realizing the detection of the wear of the dynamic ring.
[0004] The technical solution adopted by the utility model is to design a mechanical sealing structure, comprising a static ring and a dynamic ring, wherein a displacement detection device is arranged between the dynamic ring and the static ring, and the displacement detection device detects the axial movement distance of the dynamic ring.
[0005] In some embodiments, the displacement detection device includes a marking member disposed on the moving ring for generating a marking signal and a sensitive member disposed on the stationary ring for detecting the marking signal.
[0006] In some embodiments, the marking element is a magnet, and the sensitive element is a magnetic sensitive element.
[0007] In some embodiments, the displacement detection device is a variable area capacitive displacement sensor, and the sensitive element of the capacitive displacement sensor is arranged on the static ring.
[0008] In some embodiments, an axial bracket is disposed on the dynamic ring, and a dynamic capacitor plate corresponding to the sensitive element is disposed on the axial bracket.
[0009] In some embodiments, the sensitive element includes a ring-shaped static capacitor plate fixedly sleeved on the surface of the static ring, the dynamic capacitor plate is ring-shaped, and the static capacitor plate is coaxially sleeved on the outside of the static capacitor plate.
[0010] In some embodiments, a retaining ring is provided on the bracket and is sleeved on the outside of the static ring. The retaining ring is located between the bracket and the dynamic capacitor plate. The retaining ring prevents the lubricating oil between the dynamic ring and the static ring from entering the side where the sensitive element is located.
[0011] In certain embodiments, a sleeve is provided on the other side of the retaining ring opposite to the bracket and is sleeved on the outside of the stationary ring, and the dynamic capacitor plate and the sensitive element are both located on the inner side of the sleeve.
[0012] In some embodiments, a baffle is provided on the stationary ring at the end of the sleeve, and an oil return groove is provided on the outer side of the baffle.
[0013] In certain embodiments, a stepped groove is provided on the stationary ring, and the inner diameter of the retaining ring extends into the stepped groove.
[0014] A compressor comprises the mechanical sealing structure.
[0015] Compared with the prior art, the utility model has the following beneficial effects:
[0016] In the utility model, a displacement detection device is provided between the moving ring and the stationary ring, and the displacement detection device detects the axial movement distance of the moving ring, so that the wear condition of the moving ring can be determined by the change of the axial movement distance of the moving ring.
[0017] Detection is performed through changes in magnetic signals, which facilitates non-contact detection. The pulse signal generated by the intersection of two different magnetic fields between the measuring point and the sensor is used to accurately measure the relative distance between the moving ring measuring point and the displacement sensor in the static ring. When the detection distance reaches the limit of the wear of the moving ring, an early warning will be generated to prompt the relevant operator to replace the mechanical seal. This ensures that the mechanical seal only needs to be replaced when the loss reaches the maximum value, avoiding inaccurate judgments through indirect methods such as oil leakage and human eye observation, which leads to the replacement of the mechanical seal in advance before failure, resulting in a lot of waste. During the operation of the compressor, the relative distance between the moving ring and the static ring can also be measured at fixed intervals to calculate the wear of the moving ring, which is used to determine whether there are abnormal problems during the operation of the compressor. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The present invention is described in detail below in conjunction with specific embodiments and drawings. In order to show details and facilitate understanding of its principles, it is not necessarily drawn to scale, and similar reference numerals may describe similar components in different views. The drawings generally illustrate the embodiments discussed herein by way of example and not limitation. Among them:
[0019] Figure 1 It is a schematic diagram of a mechanical seal structure arranged on the compressor input shaft.
[0020] Figure 2 yes Figure 1 An enlarged schematic diagram of point A.
[0021] Figure 3 The second embodiment Figure 1 An enlarged schematic diagram of point A.
[0022] Figure 4 yes Figure 3 An enlarged schematic diagram of point B.
[0023] Figure 5 yes Figure 3 An enlarged schematic diagram of point C.
[0024] Figure 6 This is a schematic diagram of the dynamic ring after wear.
[0025] In the figure, 1, static ring; 101, oil return groove; 102, stepped groove; 2, dynamic ring; 21, groove; 3, input shaft; 4, pressure-resistant shell; 5, magnet; 6, magnetic sensitive element; 7, dynamic capacitor plate; 8, connecting rod; 9, static capacitor plate; 10, retaining ring; 11, sleeve; 12, retaining body; 13, retaining cover; 14, lubricating oil inlet; 15, lubricating oil outlet. DETAILED DESCRIPTION
[0026] The following are specific embodiments of the present invention, and the technical solution of the present invention is further described in conjunction with the accompanying drawings, but the present invention is not limited to these embodiments, and the following embodiments do not limit the utility model involved in the claims. In addition, all combinations of the features described in the embodiments are not necessarily required for the solution of the utility model.
[0027] The principle and structure of the present utility model are described in detail below with reference to the accompanying drawings and embodiments.
[0028] Example
[0029] like Figure 1 , 2 As shown, the mechanical seal structure includes a stationary ring 1 and a dynamic ring 2, wherein a displacement detection device is provided between the dynamic ring 2 and the stationary ring 1, and the displacement detection device detects the axial movement distance of the dynamic ring 2. Since the preload spring has an axial thrust force on the dynamic ring toward the stationary ring, the dynamic ring has an axial preload force relative to the stationary ring. When a part of the surface of the dynamic ring in contact with the stationary ring is worn away, under the action of the preload force of the preload spring, the dynamic ring will move a certain distance in the axial direction toward the stationary ring. The distance is the thickness of the worn surface of the dynamic ring. In this way, the wear condition of the dynamic ring 2 can be judged by detecting the axial movement distance of the dynamic ring to the stationary ring, and the wear detection of the dynamic ring can be conveniently realized.
[0030] When the detection distance reaches the wear limit of the dynamic ring 2, an early warning will be generated to prompt the relevant operator to replace the mechanical seal. This ensures that the mechanical seal needs to be replaced only when the loss reaches the maximum value, avoiding inaccurate judgments through indirect methods such as oil leakage and human visual observation, which leads to the replacement of the mechanical seal before failure and causes a lot of waste. The relative distance between the dynamic ring 2 and the static ring 1 can also be measured at fixed intervals to calculate the wear of the dynamic ring 2, which is used to determine whether there are abnormal problems during the operation of the sealing structure.
[0031] The displacement detection device includes a marking member arranged on the moving ring 2 for generating a marking signal and a sensitive member arranged on the stationary ring 1 for detecting the marking signal. The marking member is arranged on the moving ring, so that the marking member moves accordingly following the axial movement of the moving ring. Since the sensitive member is arranged on the stationary ring, the sensitive member can determine the axial movement distance of the moving ring by detecting the change in the signal after the marking member moves relative to the axial movement thereof, thereby determining the axial wear condition of the moving ring.
[0032] For example, the marking part is a magnet 5, and the sensitive part is a magnetic sensitive element 6, and detection is performed through changes in magnetic signals. Magnets, such as permanent magnets, are small in size and are convenient to be set in the graphite end face of the moving ring. The change in the distance between the magnet and the magnetic sensitive element causes the change in the magnetic field strength detected by the magnetic sensitive element, thereby indirectly determining the moving distance of the moving ring through the change in the magnetic field strength, thereby realizing the detection of the wear of the moving ring. Using the magnetic field of the magnet as a detection signal ensures that the detection signal is not affected by surrounding objects such as graphite, nor does it affect the work of surrounding objects, so it is easy to realize non-contact detection, which is beneficial to detection and does not affect the normal operation of the equipment.
[0033] Embodiment 2
[0034] like Figure 3 , 4 As shown in , 5 and 6, different from the above embodiments, the displacement detection device is a variable area capacitive displacement sensor, and the sensitive element of the capacitive displacement sensor is arranged on the static ring 1. The capacitive displacement sensor can detect the change of the distance of the object relative to the sensitive element by using the capacitance change between the sensitive element and the detected object, for example, detecting the capacitance change of the end face of the moving ring relative to the sensitive element. This detection method is non-contact detection, which is suitable for detecting the distance between relatively rotating objects such as the moving ring and the static ring, and does not affect the relative rotation of the two. The capacitive displacement sensor detects displacement based on capacitance change, has high precision and sensitivity, and is convenient for accurate detection of wear.
[0035] The moving ring 2 is provided with an axial bracket, one end of which is connected to the moving ring 2, and the other end of which is provided with a dynamic capacitor plate 7 corresponding to the sensitive element. By providing a professional dynamic capacitor plate as a detection marker on the moving ring, the dynamic capacitor plate has a high standard and a stable signal, which is more conducive to the detection of the sensitive element and avoids the influence of the moving ring itself as a marker on the accuracy of the detection data.
[0036] The axial support of this embodiment is an axial connecting rod 8, so as to avoid affecting the lubricating oil from entering and exiting the contact surface between the moving ring 2 and the stationary ring 1. Since the dynamic capacitor plate needs to correspond to the capacitive sensitive element on one side of the stationary ring, the dynamic capacitor plate needs to be arranged on one side of the stationary ring, and the dynamic capacitor plate needs to be fixedly connected to the moving ring, so it is necessary to connect the moving ring and the dynamic capacitor plate through a bracket, and since the bracket is located radially outside the contact surface between the moving ring 2 and the stationary ring 1, if the bracket area is too large, it will block the external lubricating oil from entering and exiting between the moving ring 2 and the stationary ring 1. For this reason, this embodiment uses a connecting rod with a smaller cross-sectional area as the axial support connection, so as to avoid affecting the lubricating liquid from entering and exiting the contact surface between the moving ring 2 and the stationary ring 1.
[0037] The sensitive element includes a circular static capacitor plate 9 fixedly sleeved on the surface of the static ring 1, and the dynamic capacitor plate 7 is also circular. The static capacitor plate 9 is coaxially sleeved on the outside of the static capacitor plate 9, and the dynamic capacitor plate 7 and the static capacitor plate 9 constitute a capacitor. Since the dynamic ring needs to rotate relative to the static ring during the detection process, and the device only needs to detect the axial movement of the dynamic ring relative to the static ring, it is necessary to try to avoid the influence of the rotation of the dynamic ring relative to the static ring on the capacitance change. For this reason, the static capacitor plate and the dynamic capacitor plate are both coaxial circular rings, so that the dynamic capacitor plate is coaxially sleeved on the outside of the static capacitor plate to form a coaxial capacitor. When the dynamic capacitor plate moves axially relative to the static capacitor plate, the relative area of the dynamic capacitor plate and the static capacitor plate in the radial direction will change, thereby causing the capacitance to change. The axial movement change of the dynamic ring can be obtained by detecting the change, and the rotation of the dynamic capacitor plate relative to the static capacitor plate will not bring about a change in the relative area of the two, that is, it will not cause a change in capacitance.
[0038] When the moving ring 2 moves axially relative to the stationary ring 1, the dynamic capacitor plate 7 moves relative to the static capacitor plate 9, so that the relative area between the dynamic capacitor plate 7 and the static capacitor plate 9 changes, thereby changing the capacitance of the capacitor. By detecting the change in capacitance, the axial movement distance of the dynamic capacitor plate 7 relative to the static capacitor plate 9 can be calculated, and then the axial displacement change of the moving ring 2 relative to the stationary ring 1 can be obtained, that is, the dynamic capacitor plate 7 and the static capacitor plate 9 constitute a variable area capacitive displacement sensor.
[0039] The bracket is provided with a retaining ring 10 which is sleeved on the outside of the static ring 1. The retaining ring 10 is located between the bracket and the dynamic capacitor plate 7. The retaining ring 10 blocks the lubricating oil between the dynamic ring 2 and the static ring 1 from entering the side where the sensitive element is located, thereby preventing the oil from affecting the detection of the capacitive displacement sensor.
[0040] A sleeve 11 is provided on the other side of the retaining ring 10 opposite to the bracket and is sleeved on the outside of the static ring 1. The dynamic capacitor plate 7 and the sensitive element are both located on the inner side of the sleeve 11. The dynamic capacitor plate 7 is fixed on the inner wall of the sleeve 11, thereby further protecting the capacitive displacement sensor.
[0041] A baffle 12 is provided on the stationary ring 1 at the end of the sleeve 11, and an oil return groove 101 is provided on the outside of the baffle 12, so that the oil entering one side of the capacitive displacement sensor flows downward along the oil return groove 101 to avoid entering the sleeve 11. A baffle cover 13 is also provided on the end of the sleeve 11 and located on the outside of the baffle 12 to improve the oil-proof effect.
[0042] The stationary ring 1 is provided with a stepped groove 102, a lubricating oil inlet 14 facing downward is provided above the stepped groove 102, the dynamic ring 2 is provided with a groove 21, a lubricating oil outlet 15 facing upward is provided below the groove 21, and the inner diameter of the retaining ring 10 extends into the stepped groove 102, so as to facilitate the lubricating oil to enter the joint surface between the dynamic ring 2 and the stationary ring 1. The lubricating oil is kept constantly entering the joint surface between the dynamic ring 2 and the stationary ring 1 to provide lubrication for the relative rotation of the joint surface, which is conducive to reducing the friction between the dynamic ring and the stationary ring and reducing the wear rate of the surface of the dynamic ring.
[0043] The compressor includes the above-mentioned mechanical seal structure, wherein the dynamic ring 2 in the mechanical seal structure is assembled on the input shaft 3 of the screw compressor, and the static ring 1 in the mechanical seal is assembled on the mechanical seal cover plate or the pressure-resistant housing 4. When the input shaft 3 rotates, the dynamic ring 2 and the static ring 1 of the mechanical seal will form a friction pair to realize the dynamic sealing function. At the same time, with the friction between the dynamic ring 2 and the static ring 1, the dynamic ring 2 gradually generates friction loss. At this time, the pre-tightening spring of the dynamic ring 2 will push the dynamic ring 2 forward to ensure the effectiveness of the mechanical seal. A displacement detection device is arranged between the dynamic ring 2 and the static ring 1, and the displacement detection device detects the axial movement distance of the dynamic ring 2. By detecting the axial movement distance of the dynamic ring to the static ring, the wear condition of the dynamic ring 2 can be judged, and the detection of the wear of the dynamic ring can be conveniently realized.
[0044] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described, or replace them in similar ways, without departing from the spirit of the present invention or exceeding the scope defined by the appended claims.
[0045] Although some terms are used more frequently in this article, the possibility of using other terms is not excluded. These terms are used only to more conveniently describe and explain the essence of the utility model; interpreting them as any additional restrictions is contrary to the spirit of the utility model. The execution order of actions, steps, etc. in the devices and methods shown in the specification and the drawings can be implemented in any order as long as there is no special explicit limitation on the order and the output of the previous processing is not used in the subsequent processing. Similar sequential terms (for example, "first", "next", "secondly", "again", "then", etc.) used for the convenience of description do not mean that they must be implemented in such an order.
[0046] Those skilled in the art should understand that all directional references (for example, above, below, upward, up, downward, down, top, bottom, left, right, vertical, horizontal, etc.) are used descriptively in the drawings to facilitate the reader's understanding, and do not represent limitations (for example, on position, orientation or use, etc.) on the scope of the present invention as defined by the appended claims. They are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the referred device or element must have a specific orientation or be constructed and operated in a specific orientation. The directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.
[0047] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.
[0048] In addition, some vague terms (e.g., substantially, certain, generally, etc.) may refer to slight inaccuracies or slight deviations of conditions, quantities, values, or dimensions, some of which are within the manufacturing deviation or tolerance range. It should be noted that the use of words such as "first" and "second" to define components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above words have no special meanings and therefore cannot be understood as limiting the scope of protection of this application.
Claims
1. A mechanical seal structure, including a stationary ring and a dynamic ring, characterized in that: A displacement detection device is provided between the dynamic ring and the static ring, and the displacement detection device detects the axial movement distance of the dynamic ring.
2. The mechanical seal structure according to claim 1, characterized in that: The displacement detection device includes a marking component arranged on the moving ring for generating a marking signal and a sensitive component arranged on the stationary ring for detecting the marking signal.
3. The mechanical seal structure according to claim 2, characterized in that: The marking element is a magnet, and the sensitive element is a magnetic sensitive element.
4. The mechanical seal structure according to claim 1, characterized in that: The displacement detection device is a variable area capacitive displacement sensor, and the sensitive element of the capacitive displacement sensor is arranged on the static ring.
5. The mechanical seal structure according to claim 4, characterized in that: An axial bracket is arranged on the dynamic ring, and a dynamic capacitor plate corresponding to the sensitive element is arranged on the axial bracket.
6. The mechanical seal structure according to claim 5, characterized in that: The sensitive element comprises a circular static capacitor plate fixedly sleeved on the surface of the static ring, the dynamic capacitor plate is circular, and the static capacitor plate is coaxially sleeved on the outside of the static capacitor plate.
7. The mechanical seal structure according to claim 5, characterized in that: The bracket is provided with a retaining ring sleeved on the outside of the static ring, the retaining ring is located between the bracket and the dynamic capacitor plate, and the retaining ring prevents the lubricating oil between the dynamic ring and the static ring from entering the side where the sensitive element is located.
8. The mechanical seal structure according to claim 7, characterized in that: A sleeve is provided on the other side of the retaining ring opposite to the bracket and is sleeved on the outside of the static ring. The dynamic capacitor plate and the sensitive element are both located on the inner side of the sleeve.
9. The mechanical sealing structure according to claim 8, characterized in that: A baffle body is arranged on the stationary ring at the end of the sleeve, and an oil return groove is arranged on the outer side of the baffle body.
10. The mechanical seal structure according to claim 7, characterized in that: The stationary ring is provided with a stepped groove, and the inner diameter of the retaining ring extends into the stepped groove.
11. A compressor, characterized in that Comprising the mechanical sealing structure according to any one of claims 1 to 10.