Multiple seal screw pump

Abstract

The application discloses a multiple sealing screw pump, comprising an end plate, characterized in that the end plate is provided with a mounting hole, a shaft rod is rotatably mounted in the mounting hole, a shaft sealing element and an oil baffle are sleeved on the shaft rod, at least one sealing lip is arranged on the shaft sealing element, and the sealing lip cooperates with the shaft rod to realize sealing; a plurality of annular protrusions are arranged on the outer side wall of the oil baffle, a plurality of annular grooves are arranged on the inner side wall of the end plate, the annular protrusions cooperate with the annular grooves to form a labyrinth sealing structure, and the end plate is provided with an exhaust hole communicated with the labyrinth sealing structure. The shaft sealing element can cooperate with the labyrinth sealing mechanism to form multiple sealing in the screw pump, multiple sealing mechanisms cooperate with each other to provide more reliable sealing for the screw pump, so that the screw pump can stably run under harsh working conditions. The utility model can seal the screw pump multiple times, and has the advantages of high sealing performance and good stability.

Description

Technical Field

[0001] This application relates to the field of screw pump technology, and more particularly to a multi-seal screw pump. Background Technology

[0002] Screw pumps, commonly used in positive displacement fluid transfer, are widely applied in wastewater treatment, chemical transportation, and other technical fields due to their low pulsation and high self-priming capabilities. Screw pumps achieve fluid transport by axial propulsion through a closed chamber formed by the rotor and stator. The sealing mechanism, as a key component of the screw pump, directly determines the machine's operational reliability and service life. A reliable sealing structure not only effectively prevents internal media leakage and ensures external environmental safety but also maintains stable internal pressure within the pump chamber, thereby ensuring efficient media transport.

[0003] However, most screw pumps in the current technology use a single seal. If this single seal is damaged, the medium will leak directly without a backup seal, potentially causing safety accidents when transporting toxic, flammable, or explosive media. Furthermore, a single seal can only adapt to specific pressures and has weak pressure-bearing capacity. Under harsh operating conditions or when the operating environment of the screw pump changes, a single seal cannot meet the requirements. Therefore, it is necessary to improve the sealing structure of existing screw pumps. Utility Model Content

[0004] One objective of this application is to provide a multi-seal screw pump that can solve at least one of the defects in the aforementioned background art.

[0005] To achieve at least one of the above objectives, the technical solution adopted in this application is as follows: a multi-seal screw pump, including an end plate, a mounting hole provided on the end plate, a shaft rotatably mounted in the mounting hole, a shaft seal and an oil baffle ring sleeved on the shaft, the shaft seal having at least one sealing lip for sealing the shaft; the outer side wall of the oil baffle ring having multiple annular protrusions, the inner side wall of the end plate having multiple annular grooves, the annular protrusions cooperating with the annular grooves to form a labyrinth seal structure, and an exhaust hole communicating with the labyrinth seal structure provided on the end plate.

[0006] With the above configuration, multiple seals can be formed within the screw pump through the shaft seal and labyrinth seal mechanism. These multiple sealing mechanisms work together to provide a more reliable seal, ensuring stable operation under harsh conditions. Even if one seal fails, the remaining seals can maintain a high level of sealing, allowing the screw pump to continue operating. The sealing lip forms a physical sealing surface with the shaft, preventing media leakage. The oil baffle ring, similar to a rotating ring, rotates synchronously with the shaft. The end plate, similar to a stationary ring, has annular grooves and protrusions that are staggered to form a labyrinth gap. When the oil baffle ring and end plate rotate relative to each other, the throttling effect of the medium within the gap achieves a seal.

[0007] Preferably, there are two sealing lips, and the two sealing lips bend in opposite directions, with each sealing lip sealing one end of the shaft seal. This configuration allows for bidirectional sealing via the two sealing lips. When pressure in the sealing area fluctuates bidirectionally, the two oppositely bent sealing lips can simultaneously seal the medium on both sides, thereby enhancing the sealing reliability of the shaft seal.

[0008] Preferably, a wear-resistant ring is fixedly sleeved on the shaft, the shaft seal is sleeved with the wear-resistant ring, and the sealing lip is tightly fitted with the outer wall of the wear-resistant ring. This configuration allows the wear-resistant ring to act as a protective device between the shaft seal and the shaft. When the shaft rotates, it drives the wear-resistant ring to rotate synchronously. At this time, the sealing lip can only rub against the outer wall of the wear-resistant ring, thus preventing scratches on the shaft surface. When the wear-resistant ring is damaged, it can be replaced with a new one in a timely manner, further reducing the maintenance and repair costs of the screw pump.

[0009] Preferably, the wear ring is provided with perforations. These perforations create a pressure balance channel. During screw pump operation, some media may seep into the area between the two sealing lips through the tiny gap between the sealing lip and the wear ring, causing excessive pressure in that area. The perforations then act as a pressure relief mechanism, guiding some of the media to the shaft surface. Furthermore, some of the media flowing out of the perforations can also lubricate and cool the shaft and wear ring.

[0010] Preferably, a piston ring seat is fitted onto the shaft, and a piston ring is mounted on the piston ring seat. The piston ring fits tightly against the inner wall of the mounting hole. The piston ring seat and the oil baffle ring are located near both ends of the shaft seal, and a sealing mechanism is provided between the piston ring seat and the shaft. The piston ring seat and piston ring can further enhance the sealing effect of the screw pump, while the sealing mechanism can prevent internal media from leaking through the gap between the piston ring seat and the shaft.

[0011] Preferably, the sealing mechanism includes a sealing groove and a sealing ring. The sealing groove is located on the outer side of the shaft, and the sealing ring is installed in the sealing groove. The inner side of the piston ring seat presses the sealing ring tightly against the sealing groove. This configuration further improves the sealing effect of the piston ring seat through the sealing ring. When the sealing ring wears out, it can be replaced to ensure the sealing effect of the piston ring seat.

[0012] Preferably, the piston ring seat has multiple recesses, and the piston ring is positioned and fixed within these recesses. This configuration increases the number of piston rings installed, further improving the sealing effect of the screw pump; the recesses also limit the piston ring's position, preventing it from shifting.

[0013] Preferably, the end plate is provided with a through hole communicating with the shaft seal. The through hole is filled with buffer gas to form an air barrier sealing structure, which seals the medium inside the end plate. With this configuration, when the machine is running, the continuous injection of buffer gas into the through hole, in conjunction with the shaft seal, forms a continuous air film barrier at the sealing gap, preventing internal medium leakage and further improving the sealing effect of the screw pump.

[0014] Preferably, a bearing is sleeved on the shaft, the bearing abuts against the oil retaining ring, and a sealing ring is installed between the mating surfaces of the bearing and the mounting hole. This arrangement allows the bearing to be sealed within the mounting hole by the sealing ring, and the bearing can limit the position of the shaft, preventing angular deviation. If the shaft rotation becomes stuck, lubricating oil can be added to the bearing to make the rotation smoother.

[0015] Preferably, a pressure ring is installed on the end plate, the pressure ring abutting against the outer ring of the bearing, and a fixing member is fixedly installed on the shaft, the fixing member abutting against the inner ring of the bearing. This arrangement allows the pressure ring and the fixing member to respectively limit the movement of the outer and inner rings of the bearing, ensuring a more secure installation of the bearing within the mounting hole.

[0016] Compared with the prior art, the beneficial effects of this application are as follows: The shaft seal, in conjunction with a labyrinth seal mechanism, forms multiple seals within the screw pump. These multiple seals work together to provide a more reliable seal, ensuring stable operation under harsh conditions. Even if one seal fails, the others maintain a high level of sealing, allowing the pump to continue operating. The sealing lip forms a physical sealing surface upon contact with the wear ring, and both lips simultaneously provide bidirectional sealing to the shaft, further enhancing the seal's reliability.

[0017] The piston ring seat and gas barrier seal can further increase the number of sealing structures and improve the sealing effect of the screw pump. Continuously injecting buffer gas into the through-hole can work with the shaft seal to form a continuous gas film barrier at the sealing gap, preventing internal media leakage. The vent hole can discharge some of the gas from the labyrinth seal to the end plate, preventing excessive pressure in the sealing area. This invention has advantages such as high sealing performance and good stability. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall cross-sectional structure of the screw pump in this application.

[0019] Figure 2 for Figure 1 A magnified structural diagram of part A in the middle.

[0020] Figure 3 for Figure 1 A magnified structural diagram of part B in the middle section.

[0021] Figure 4 This is a schematic diagram of the wear-resistant ring in this application.

[0022] In the diagram: 1. End plate; 11. Mounting hole; 12. Annular groove; 13. Vent hole; 100. Shaft; 101. Sealing groove; 102. Fixing component; 2. Shaft seal; 21. Sealing lip; 200. Wear ring; 201. Perforation; 3. Oil retainer ring; 31. Annular protrusion; 300. Through hole; 4. Piston ring seat; 41. Recess; 5. Bearing; 6. Pressure ring. Detailed Implementation

[0023] The present application will be further described below with reference to specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0024] In the description of this application, it should be noted that the terms "center", "lateral", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., which indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and should not be construed as limiting the specific protection scope of this application.

[0025] It should be noted that the terms "first," "second," etc., in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0026] The terms “comprising” and “having”, and any variations thereof, in the specification and claims of this application are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0027] One aspect of this application provides a multi-seal screw pump, one preferred embodiment of which is, for example... Figure 1 , Figure 2 and Figure 3 As shown, the pump includes an end plate 1 with mounting holes 11. A shaft 100 is rotatably mounted in the mounting holes 11, and a shaft seal 2 and an oil baffle ring 3 are sleeved on the shaft 100. The shaft seal 2 has at least one sealing lip 21, and a wear-resistant ring 200 is fixedly mounted on the shaft 100. The shaft seal 2 and the wear-resistant ring 200 are sleeved together, and the sealing lip 21 directly contacts the outer wall of the wear-resistant ring 200 to form a physical sealing surface, thereby sealing the medium inside the screw pump. The side wall of the oil baffle ring 3 has multiple annular protrusions 31, and the inner wall of the end plate 1 has multiple annular grooves 12. The annular grooves 12 and the corresponding annular protrusions 31 approach each other and cooperate to form a labyrinth seal structure. The oil baffle ring 3, similar to a moving ring structure, rotates synchronously with the shaft 100, and the end plate 1, similar to a stationary ring, achieves sealing by utilizing the throttling effect of the medium in the gap when the oil baffle ring 3 and the end plate 1 rotate relative to each other.

[0028] It should be noted that in this application, the wear ring 200 is used as a protective device between the shaft seal 2 and the shaft 100. When the shaft 100 rotates, it drives the wear ring 200 to rotate synchronously. At this time, the sealing lip 21 can only rub against the outer wall of the wear ring 200, thereby avoiding scratches on the surface of the shaft 100. When the wear ring 200 is damaged, a new wear ring 200 can be replaced in time, which further reduces the maintenance and repair costs of the screw pump.

[0029] Furthermore, such as Figure 1 As shown, the end plate 1 is provided with multiple vent holes 13 that communicate with the labyrinth seal structure. One end of the vent hole 13 is connected to the annular groove 12, and the other end is connected to the outside. When the screw pump is working, if the pressure in the sealing area is too high, some high-pressure gas will enter the labyrinth seal and then flow to the outside through the vent hole 13 to ensure that the pressure in the sealing area is always at a normal level. When there is a small amount of leaking medium inside the labyrinth seal, it can be discharged through the vent hole 13 to avoid the medium accumulating inside the labyrinth seal and affecting the sealing effect.

[0030] Understandably, the shaft seal 2 can work with the labyrinth seal mechanism to form multiple seals inside the screw pump. The multiple sealing mechanisms work together to provide a more reliable seal for the screw pump, ensuring that the screw pump can operate stably under harsh conditions. When one of the sealing structures is damaged, the remaining sealing structures can still maintain a high level of sealing, ensuring that the screw pump can continue to work.

[0031] Specifically, such as Figure 3 As shown, there are two sealing lips 21, and the two sealing lips 21 bend in opposite directions. The two sealing lips 21 seal both ends of the shaft seal 2 respectively, thereby achieving bidirectional sealing of the shaft 100. When the pressure in the sealing area fluctuates bidirectionally, the two sealing lips 21 that bend in opposite directions can simultaneously seal the medium on both sides, thereby enhancing the sealing reliability of the shaft seal 2.

[0032] In addition, in order to ensure that the sealing lip 21 can maintain a tight fit with the wear ring 200, the sealing lip 21 itself should be elastic, and the material of the sealing lip 21 includes, but is not limited to, rubber, so that the sealing lip 21 can apply a continuous pre-tightening force to the wear ring 200 through its own elasticity after assembly, so as to ensure the fit and sealing performance of the sealing lip 21.

[0033] It should be understood that during the operation of the screw pump, some of the medium will seep into the space between the two sealing lips 21 through the tiny gap between the sealing lip 21 and the wear ring 200, resulting in excessive pressure in the area between the two sealing lips 21, which in turn affects the sealing effect of the sealing lip 21.

[0034] In this embodiment, such as Figure 4 As shown, the wear ring 200 is provided with a perforation 201. The sealing lip 21 and the shaft 100 are connected through the perforation 201. The perforation 201 serves as a pressure balancing channel and can reduce pressure. When the pressure between the two sealing lips 21 is too high, some of the medium flows through the perforation 201 to the surface of the shaft 100, thereby reducing the pressure between the two sealing lips 21. In addition, some of the medium flowing out from the perforation 201 can also lubricate and cool the shaft 100 and the wear ring 200.

[0035] In this embodiment, as Figure 1 and Figure 3 As shown, a piston ring seat 4 is fitted onto the shaft 100, and a piston ring (not shown) is mounted on the piston ring seat 4. The piston ring fits tightly against the inner wall of the mounting hole 11 to seal the medium inside the piston pump. The piston ring seat 4 and the oil retainer ring 3 are located near the two ends of the shaft seal 2, and a sealing mechanism is provided between the piston ring seat 4 and the shaft 100. The piston ring seat 4 can serve as a third sealing structure for the screw pump to further enhance the sealing effect. The sealing mechanism can prevent the internal medium from leaking through the gap between the piston ring seat 4 and the shaft 100.

[0036] Specifically, such as Figure 3 As shown, the sealing mechanism includes a sealing groove 101 and a sealing ring. The sealing groove 101 is located on the outside of the shaft 100, and the sealing ring is installed inside the sealing groove 101. After the piston ring seat 4 is installed, the inner side of the piston ring seat 4 presses the sealing ring tightly against the sealing groove 101, thereby further improving the sealing effect of the piston ring seat 4. When the sealing ring is worn, the sealing effect of the piston ring seat 4 can be ensured by replacing the sealing ring.

[0037] Furthermore, such as Figure 3 As shown, the piston ring seat 4 is provided with multiple recesses 41, and a piston ring is installed in each recess 41. The piston ring itself is elastic. When the piston ring seat 4 enters the mounting hole 11, the piston ring can rely on its own elasticity to tightly fit with the inner wall of the mounting hole 11. The recesses 41 can also limit the piston ring to prevent the piston ring from shifting under pressure impact, thereby improving the sealing effect of the screw pump.

[0038] It should be noted that piston rings include, but are not limited to, materials with anti-slip and wear-resistant properties such as rubber and soft plastic. The specific number and size of the recesses 41 are not limited, and those skilled in the art can adjust them according to the actual situation, but it is necessary to ensure that the piston rings have sufficient elasticity to fit tightly with the mounting holes 11.

[0039] In this embodiment, as Figure 1 As shown, the end plate 1 is provided with a through hole 300 communicating with the shaft seal 2. The through hole 300 is filled with buffer gas to form an air barrier seal structure to seal the medium inside the end plate 1. As the fourth sealing structure of the screw pump, the air barrier seal, when the machine is running, can work with the shaft seal 2 to form a continuous air film barrier at the sealing gap by continuously filling the through hole 300 with buffer gas, thereby preventing internal medium leakage and further improving the sealing effect of the screw pump.

[0040] It should be noted that buffer gases include, but are not limited to, nitrogen. In addition, buffer gases should have properties such as being clean, dry, and stable.

[0041] In this embodiment, as Figure 1As shown, a bearing 5 is sleeved on the shaft 100. The end of the bearing 5 abuts against the end of the oil retainer ring 3. A sealing ring is provided between the mating surfaces of the bearing 5 and the mounting hole 11, allowing the bearing 5 to be sealed and installed in the mounting hole 11. The bearing 5 is inserted into the shaft 100 to limit the position of the shaft 100, preventing angular deviation. When the rotation of the shaft 100 becomes stuck, lubricating oil can be added to the bearing 5 to make the rotation of the shaft 100 smoother. In addition, the bearing 5 can also fix the angle of the oil retainer ring 3, preventing the oil retainer ring 3 from tilting and reducing the sealing effect of the labyrinth seal.

[0042] Furthermore, such as Figure 1 As shown, a pressure ring 6 is installed on the end plate 1. The outer contour of the pressure ring 6 is larger than the contour of the mounting hole 11. The inner contour of the pressure ring 6 extends into the mounting hole 11 and abuts against the inner ring of the bearing 5. A fixing member 102 is fixedly installed on the shaft. The fixing member 102 abuts against the inner ring of the bearing 5. The pressure ring 6 and the fixing member 102 can simultaneously limit the inner and outer rings of the bearing 5 to ensure that the bearing 5 can be more securely installed in the mounting hole 11.

[0043] The basic principles, main features, and advantages of this application have been described above. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely the principles of this application. Various changes and modifications can be made to this application without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection claimed by this application is defined by the appended claims and their equivalents.

Claims

1. A multi-seal screw pump, comprising an end plate (1), characterized in that, The end plate (1) is provided with a mounting hole (11), and a shaft (100) is rotatably installed in the mounting hole (11). A shaft seal (2) and an oil baffle ring (3) are sleeved on the shaft (100). The shaft seal (2) is provided with at least one sealing lip (21), and the sealing lip (21) cooperates with the shaft (100) to seal. The outer side wall of the oil baffle ring (3) is provided with multiple annular protrusions (31), and the inner side wall of the end plate (1) is provided with multiple annular grooves (12). The annular protrusions (31) cooperate with the annular grooves (12) to form a labyrinth seal structure. The end plate (1) is provided with an exhaust hole (13) that communicates with the labyrinth seal structure.

2. The multi-seal screw pump as described in claim 1, characterized in that, The number of sealing lips (21) is two, and the two sealing lips (21) are bent in opposite directions. The two sealing lips (21) respectively seal both ends of the shaft seal (2).

3. The multi-seal screw pump as described in claim 1, characterized in that, A wear-resistant ring (200) is fixedly sleeved on the shaft (100), the shaft seal (2) is sleeved with the wear-resistant ring (200), and the sealing lip (21) is tightly fitted with the outer wall of the wear-resistant ring (200).

4. The multi-seal screw pump as described in claim 3, characterized in that, The wear-resistant ring (200) is provided with a perforation (201).

5. The multi-seal screw pump as described in claim 1, characterized in that, A piston ring seat (4) is sleeved on the shaft (100), and a piston ring is installed on the piston ring seat (4). The piston ring is tightly fitted with the inner wall of the mounting hole (11). The piston ring seat (4) and the oil baffle ring (3) are respectively close to the two ends of the shaft seal (2). A sealing mechanism is provided between the piston ring seat (4) and the shaft (100).

6. The multi-seal screw pump as described in claim 5, characterized in that, The sealing mechanism includes a sealing groove (101) and a sealing ring. The sealing groove (101) is located on the outside of the shaft (100), and the sealing ring is installed in the sealing groove (101). The inner side of the piston ring seat (4) presses the sealing ring tightly against the sealing groove (101).

7. The multi-seal screw pump as described in claim 5, characterized in that, The piston ring seat (4) is provided with a plurality of recesses (41), and the piston ring is limited and installed in the recesses (41).

8. The multi-seal screw pump as described in claim 1, characterized in that, The end plate (1) is provided with a through hole (300) communicating with the shaft seal (2). The through hole (300) is filled with buffer gas to form an air barrier sealing structure. The air barrier sealing structure is used to seal the medium inside the end plate (1).

9. The multi-seal screw pump as described in claim 1, characterized in that, A bearing (5) is sleeved on the shaft (100), the bearing (5) abuts against the oil baffle ring (3), and a sealing ring is installed between the mating surfaces of the bearing (5) and the mounting hole (11).

10. The multi-seal screw pump as described in claim 9, characterized in that, A pressure ring (6) is installed on the end plate (1), and part of the pressure ring (6) abuts against the outer ring of the bearing (5). A fixing member (102) is fixedly installed on the shaft (100), and the fixing member (102) abuts against the inner ring of the bearing (5).

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