Vortex pump with adjustable axial clearance between dynamic and static vortex plates

Abstract

The utility model discloses a vortex pump with an adjustable axial gap between a dynamic vortex plate and a static vortex plate. The vortex pump comprises a vortex plate pair, a driving assembly and a machine base. Wherein the scroll plate pair comprises a fixed scroll plate and a movable scroll plate which are conjugated in molded line, the driving assembly comprises an eccentric shaft, one end of the eccentric shaft is fixedly connected with the movable scroll plate through a bearing connecting piece, and the other end of the eccentric shaft is fixedly connected with a motor rotor; the shaft diameter part of the eccentric shaft is sleeved with the bearing connecting piece, an adjusting gasket is arranged on the side, close to a shaft shoulder of the eccentric shaft, of the bearing connecting piece, and the bearing connecting piece is axially fixed to the shaft diameter part of the eccentric shaft through an end pressing plate and a fastener. The machine base fixes the journal portion of the eccentric shaft through the fixing bearing set. According to the vortex pump, the eccentric shaft is indirectly connected with the dynamic vortex plate through the bearing connecting piece, the gap distance between the dynamic vortex plate and the static vortex plate is adjusted by increasing the adjusting shim according to the installation relation of the bearing connecting piece on the eccentric shaft, cost is low, operation is convenient, and the structure is stable.

Description

Technical Field

[0001] This application relates to the field of fluid machinery technology, and in particular to a vortex pump with adjustable axial clearance between the moving and stationary vortex discs. Background Technology

[0002] A scroll pump is a positive displacement mechanical device that compresses or transports fluid based on the meshing motion of a stationary and a moving scroll. It mainly consists of a stationary scroll, a moving scroll, an eccentric shaft, a drive assembly, and a base. Its working principle is as follows: the moving scroll, driven by the eccentric shaft, performs planar translational motion around the stationary scroll. The involute helical grooves, with conjugate profiles of both, form a continuous closed chamber. The periodic change in chamber volume achieves fluid intake, compression, and discharge. Due to its compact structure, stable operation, low noise, and high efficiency, scroll pumps are widely used in vacuum systems, refrigeration equipment, and gas compression.

[0003] However, the long-term reliability and performance stability of a scroll pump are highly dependent on the axial clearance control of the moving and stationary scrolls and the axial positioning accuracy of the eccentric shaft. Excessive clearance leads to increased internal leakage and decreased efficiency; insufficient clearance may cause scraping and wear between the moving and stationary scrolls, or even jamming and failure. Furthermore, under extreme vacuum conditions, the moving scroll may displace due to axial suction, exacerbating clearance fluctuations and further affecting the equipment's lifespan. In traditional designs, the axial clearance of the moving and stationary scrolls is often directly ensured through the machining accuracy of components, lacking an on-site adjustable mechanism. If assembly errors or long-term operation cause component wear, the clearance will deviate from the design range, making it difficult to restore to the ideal state easily, resulting in decreased pump efficiency or abnormal wear. For example, the scroll pump in the invention patent application number 201410737947.0 suffers from the aforementioned drawbacks. To address these issues, there is an urgent need for a scroll pump that can dynamically adjust the axial clearance between the moving and stationary scrolls, offering strong adaptability and ease of adjustment. Utility Model Content

[0004] The main objective of this application is to provide a vortex pump with adjustable axial clearance between the moving and stationary vortex plates, aiming to solve the technical problem of high cost in adjusting the clearance between the moving and stationary vortex plates in existing vortex pumps.

[0005] This application discloses a vortex pump with adjustable axial clearance between the dynamic and static vortex discs, comprising:

[0006] A scroll disk pair consists of a stationary scroll disk and a moving scroll disk with conjugate profiles.

[0007] A drive assembly includes an eccentric shaft, one end of which is fixedly connected to the moving scroll plate via a bearing connector, and the other end of which is fixedly connected to a motor rotor. The bearing connector is fitted onto the shaft diameter portion of the eccentric shaft, and an adjusting shim is provided on the shoulder side of the eccentric shaft. An end plate and fasteners provide axial fixation to the shaft diameter portion of the eccentric shaft.

[0008] The base, wherein the journal portion of the eccentric shaft is fixed by a fixed bearing assembly.

[0009] For example, in the vortex pump provided in at least one embodiment of this application, the bearing connector is provided with a pre-tightening elastic element on the side near the moving vortex, and the pre-tightening elastic element abuts against the end pressure plate.

[0010] For example, in the vortex pump provided in at least one embodiment of this application, the moving vortex and the stationary vortex are installed facing each other and meshing, and the top of the involute or helix of both the moving vortex and the stationary vortex are provided with sealing strips.

[0011] For example, in the vortex pump provided in at least one embodiment of this application, at least two balance blocks are disposed on the eccentric shaft, respectively disposed on the shoulder portion and the journal portion of the eccentric shaft.

[0012] For example, in the vortex pump provided in at least one embodiment of this application, the base is a cylindrical structure with openings at both ends, and the fixed bearing assembly includes two bearing units placed on the openings.

[0013] For example, in the vortex pump provided in at least one embodiment of this application, the bearing unit is a deep groove ball bearing or an angular contact bearing.

[0014] For example, in the vortex pump provided in at least one embodiment of this application, the base includes a bearing pressure plate and a locking nut on at least one side opening, respectively disposed on both axial sides of the bearing unit, for tightly connecting the eccentric shaft to the base.

[0015] For example, in the vortex pump provided in at least one embodiment of this application, the motor rotor is connected to the other end of the eccentric shaft via a pin connector and drives the eccentric shaft to rotate.

[0016] For example, in the vortex pump provided in at least one embodiment of this application, the bearing connector is a double-row angular contact bearing.

[0017] For example, in at least one embodiment of the vortex pump provided in this application, a corrugated compensator is further included, which is disposed in the circumferential direction of the eccentric shaft and whose two ends are respectively fixedly connected to the moving vortex and the base.

[0018] Compared with existing vortex pumps, this application has at least the following beneficial effects:

[0019] This application discloses a scroll pump that uses an adjusting shim on one side of the eccentric shaft shoulder, forming an axially fixed structure with an end plate and fasteners. This allows the axial clearance between the moving and stationary scrolls to be directly adjusted by increasing or decreasing the thickness of the adjusting shim. Compared to traditional passive compensation methods that rely on machining precision or replacing entire parts, this design allows for quick and low-cost adjustment of the clearance to the ideal range during assembly or maintenance, effectively avoiding clearance misalignment caused by machining errors, wear, or thermal deformation, and significantly improving pump operating efficiency and lifespan. Simultaneously, the adjusting shim is integrated into the assembly interface between the eccentric shaft diameter and the bearing connector, achieving overall fixation through axial locking of the end plate and fasteners. This structure eliminates the need for complex adjustment mechanisms or additional auxiliary components; clearance adjustment can be completed simply by replacing adjusting shims of different specifications, greatly simplifying assembly and maintenance processes. Furthermore, the modular design of the adjusting shim reduces spare parts management costs, making it particularly suitable for mass production and on-site maintenance scenarios.

[0020] The vortex pump of this application ensures the axial positioning accuracy between the eccentric shaft and the moving vortex by adjusting the shims, bearing connectors, and end pressure plates. By eliminating the influence of clearance fluctuations on the translational trajectory of the moving vortex, this structure can maintain the ideal contact state of the meshing surfaces of the moving and stationary vortices, reducing the risk of internal leakage or scraping caused by abnormal clearance, thereby improving the stability and reliability of the pump body under long-term high-load conditions. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0022] Figure 1 This is a cross-sectional structural diagram of an embodiment of the vortex pump of this application;

[0023] Reference numerals: 1. Stationary scroll; 2. Sealing strip; 3. Moving scroll; 4. Plug; 5. End pressure plate; 6. Wave spring; 7. Bearing connector; 8. Adjusting shim; 9. Bearing pressure plate; 10. Front bearing unit; 11. Locking nut; 12. Rear bearing unit; 13. Rubber ring; 14. Adaptive spring; 15. Pin connector; 16. Motor rotor; 17. Rear balance block; 18. Eccentric shaft; 19. Machine base; 20. Corrugated compensator; 21. Front balance block.

[0024] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0027] In this utility model, unless otherwise explicitly specified and limited, the terms "connection," "fixing," etc., should be interpreted broadly. For example, "fixing" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0028] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0029] This application provides a scroll pump with adjustable axial clearance between the stationary and moving scrolls. The scroll pump includes a scroll plate pair, a drive assembly, and a base. Specifically, the scroll plate pair includes a stationary scroll and a moving scroll with conjugate profiles. The drive assembly includes an eccentric shaft, one end of which is fixedly connected to the moving scroll via a bearing connector, and the other end of which is fixedly connected to a motor rotor. The bearing connector is fitted onto the shaft diameter portion of the eccentric shaft, and an adjusting shim is provided on the shoulder side of the eccentric shaft. An end plate and fasteners are used to axially fix the eccentric shaft in the shaft diameter portion. The base fixes the journal portion of the eccentric shaft via a fixed bearing assembly.

[0030] like Figure 1 The diagram illustrates one implementation of the vortex pump of this application. From right to left, the vortex pump comprises a fixed stationary vortex disk 1, a moving vortex disk 3 that mates with the stationary vortex disk 1, and a drive assembly mounted on the moving vortex disk 3. The drive assembly is an eccentric shaft 18. One end of the eccentric shaft 18 is mounted on the moving vortex disk 3 via a bearing connector 7, driving the moving vortex disk 3 to rotate. The other end of the eccentric shaft 18 is fixedly connected to a motor rotor 16, which drives the rotation to provide power input to the vortex pump. The bearing connector 7 is installed on the shaft diameter portion of the eccentric shaft 18, and the pump base 19 fixes the journal portion of the eccentric shaft 18 via a fixed bearing assembly.

[0031] It should be noted that the eccentric shaft 18 consists of a journal, a shoulder, and a shaft diameter. The journal, i.e., the bearing portion, is the part where the eccentric shaft 18 contacts the fixed bearing, used to support the eccentric shaft 18 and ensure its stability during rotation. The shaft diameter is the main working part of the eccentric shaft 18, used to transmit torque and realize the conversion of mechanical motion. The shoulder is the transition part between the journal and the shaft diameter, usually in the shape of a rounded corner or chamfer. In this application, the eccentric shaft 18 is used for clear distinction. Figure 1 In the scheme, the part connected to the moving scroll 3 by the bearing connector 7 is the shaft diameter, and the part fixed by the base 19 is the journal. All the following embodiments can be understood in this way, and will not be described again.

[0032] More specifically, the connection and fixation between the eccentric shaft 18 and the moving scroll 3 via the bearing connector 7 is achieved through the following structure: Figure 1 As shown, the profiles of the shaft diameter portion and the shoulder portion of the eccentric shaft 18 are different, with obvious steps. A bearing connector 7 is fitted onto the shaft diameter portion of the eccentric shaft 18, and the right side of the bearing connector 7 near the shoulder portion abuts against the adjusting shim 8. The adjusting shim 8 can be selected as needed to change the axial position of the moving scroll 3 relative to the stationary scroll 1. On the left side, on one hand, the outer contour is tightly connected to the screw hole on the moving scroll 3 by threaded parts, such as screws and bolts, thereby fixing it. On the other hand, at the end of the eccentric shaft 18, a pressure plate is installed and fixed to the corresponding screw hole by screws and bolts, so that the bearing connector 7 is directly or indirectly restricted by the pressure plate and cannot be removed from the eccentric shaft 18.

[0033] In the embodiments of this application, the stationary volute 1 remains fixed in position during engineering operations. To adjust the gap between the moving volute 3 and the stationary volute 1, the relative position of the moving volute 3 needs to be adjusted. The aforementioned structure first locks the bearing connector 7 to the moving volute 3, ensuring that they remain in a fixed relative position as a single component during operation. Furthermore, during the process of installing the bearing connector 7 onto the eccentric shaft 18 and connecting the moving volute 3 to the eccentric shaft 18, adjusting shims 8 are added to the eccentric shaft 18 to allow for minor axial adjustments to the moving volute 3, i.e., adjusting the gap between the moving volute 3 and the stationary volute 1. Compared to vortex pumps that rely on machining precision or complete component replacement, the structure of this application offers greater cost and operational advantages in adjusting the gap between the moving volute 3 and the stationary volute 1. The same purpose and effect can be achieved through the assembly and adjustment of some parts.

[0034] Preferably, the bearing connector 7 of this application is a double-row angular contact bearing, which has good axial stability and is not prone to angular misalignment that affects transmission efficiency.

[0035] In another embodiment of this application, based on the structure of the bearing connector 7 described above, a pre-tightening elastic element is further provided on the side of the bearing connector 7 near the moving scroll 3, and the pre-tightening elastic element abuts against the end pressure plate 5.

[0036] Specifically, in the aforementioned embodiment, the side of the bearing connector 7 closest to the moving scroll 3 directly abuts against the end pressure plate 5 to form a limiting and fixed position. During the operation of the vortex pump, when the moving scroll 3 and the stationary scroll 1 reach a state of ultimate vacuum, the moving scroll 3 will be subjected to negative pressure and move towards the stationary scroll 1, forming an adsorption. Based on the structural relationship between the moving scroll 3, the bearing connector 7, and the eccentric shaft 18, this phenomenon will cause the eccentric shaft 18 to move axially, thus affecting the working efficiency and service life of the equipment. In this embodiment, by adding a pre-tightening elastic element, such as a wave spring 6, between the bearing connector 7 and the end pressure plate 5, a buffer layer is formed between the bearing connector 7 and the end pressure plate 5. When the moving scroll 3 drives the bearing connector 7 to move towards the stationary scroll 1, the energy stored in the compressed spring can buffer the movement, or the pre-tightening force of the spring can counteract this "adsorption," thereby ensuring that the gap between the moving and stationary scrolls 1 remains unchanged, preventing the eccentric shaft 18 from being affected and causing axial movement, reducing bearing wear, and benefiting the normal operation and service life of the turbine pump.

[0037] In some embodiments of this application, the moving scroll 3 and the stationary scroll 1 are installed facing each other and meshing, and the top of the involute or helix of both the moving scroll 3 and the stationary scroll 1 are provided with sealing strips 2.

[0038] In the combination of moving and stationary scroll plates 1 installed face to face, the sealing strip 2 is used to fill the axial gap between the moving scroll plate 3 and the stationary scroll plate 1 and to ensure that the moving and stationary scroll plates 1 do not scrape each other due to contact.

[0039] In addition, it is possible that an opening is provided at the center of the moving scroll 3 to facilitate the installation of the bearing connector 7 and the end pressure plate 5, so that this part can also be sealed by the plug 4.

[0040] In some embodiments of this application, at least two balance blocks are disposed on the eccentric shaft 18, respectively disposed on the shoulder portion and the journal portion of the eccentric shaft 18.

[0041] The shoulder and journal portions of the eccentric shaft 18 are respectively equipped with a front balance block 21 and a rear balance block 17. The front balance block 21 is fixed to the shoulder of the eccentric shaft 18 by bolts, while the rear balance block 17 is installed on the journal portion near the motor rotor 16. The two balance blocks are symmetrically distributed based on the rotation center of the eccentric shaft 18, and the inertial torque generated during the operation of the eccentric shaft 18 is offset by mass balancing, thereby significantly reducing vibration and noise, improving the smoothness of pump operation and bearing life.

[0042] In some embodiments of this application, the base 19 has a cylindrical structure with openings at both ends, and the fixed bearing assembly includes two bearing units placed on the openings.

[0043] The base 19 adopts a cylindrical structure with openings at both ends. Fixed bearing assemblies consisting of a front bearing unit 10 and a rear bearing unit 12 are respectively installed at the openings on both sides. The outer rings of the front bearing unit 10 and the rear bearing unit 12 are embedded into the inner wall of the opening of the base 19 by interference fit, and the inner rings are tightly fitted with the journal of the eccentric shaft 18 to form a stable double support structure.

[0044] It is possible that rubber rings 13 are also provided at the mounting positions of the front bearing unit 10 and the rear bearing unit 12 on the eccentric shaft 18. The rubber rings 13 can increase friction to ensure that the inner rings of the bearings of the two bearing units do not rotate relative to the eccentric shaft 18.

[0045] Furthermore, the front bearing unit 10 and the rear bearing unit 12 are deep groove ball bearings or angular contact bearings. Deep groove ball bearings are suitable for working conditions where radial loads are dominant, while angular contact bearings, through their contact angle design, can simultaneously withstand combined radial and axial loads.

[0046] In some embodiments of this application, at least one side opening of the base 19 further includes a bearing pressure plate 9 and a locking nut 11, respectively disposed on both axial sides of the bearing unit, for tightly connecting the eccentric shaft 18 to the base 19.

[0047] At least one opening on the base 19, the bearing pressure plate 9 and the locking nut 11 abut against the axial sides of the bearing unit (such as the front bearing unit 10). The bearing pressure plate 9 is fixed to the base 19 by bolts, and the locking nut 11 is tightened onto the threaded section of the eccentric shaft 18 to form an axial limit on the inner ring of the bearing and prevent the bearing from moving.

[0048] In some embodiments of this application, the motor rotor 16 is connected to the other end of the eccentric shaft 18 via a pin connector 15 and drives the eccentric shaft 18 to rotate. The pin connection structure has both high rigidity and shear resistance, ensuring that the motor power is efficiently transmitted to the eccentric shaft 18, avoiding the loosening or wear problems that may occur with key connections, and improving transmission reliability.

[0049] In particular, to prevent the parts from changing size due to thermal expansion and to maintain the adaptive relative position of the motor rotor 16 and the motor stator, an adaptive spring 13 is installed at the connection position between the motor rotor 16 and the eccentric shaft 18.

[0050] For example, in at least one embodiment of the vortex pump provided in this application, a bellows compensator 20 is also included, which is disposed in the circumferential direction of the eccentric shaft 18, and its two ends are fixedly connected to the moving vortex 3 and the base 19 respectively by bolts or other means. The bellows compensator 20 absorbs the axial displacement caused by thermal expansion or load fluctuation through elastic deformation, avoids stress concentration caused by rigid connection, and maintains the geometric accuracy of the translational motion of the moving vortex 3 to prevent abnormal wear.

[0051] The above description is merely an optional embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the inventive concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A scroll pump with adjustable axial gap between orbiting scroll and fixed scroll, characterized in that, include: A scroll disk pair consists of a stationary scroll disk and a moving scroll disk with conjugate profiles. The drive assembly includes an eccentric shaft, one end of which is fixedly connected to the moving scroll via a bearing connector, and the other end of which is fixedly connected to the motor rotor. The bearing connector is fitted onto the shaft diameter portion of the eccentric shaft, and an adjusting shim is provided on the shoulder side of the eccentric shaft. The shaft diameter portion of the eccentric shaft is axially fixed by an end plate and fasteners. as well as The base, wherein the journal portion of the eccentric shaft is fixed by a fixed bearing assembly.

2. The scroll pump of claim 1, wherein, The bearing connector has a preload elastic element on the side near the moving scroll, and the preload elastic element abuts against the end pressure plate.

3. The scroll pump of claim 1, wherein, The moving scroll and the stationary scroll are installed facing each other and meshing, and the top of the involute or helix of both the moving scroll and the stationary scroll are equipped with sealing strips.

4. The scroll pump of claim 1, wherein, At least two balance blocks are disposed on the eccentric shaft, respectively located on the shoulder portion and the journal portion of the eccentric shaft.

5. The scroll pump of claim 1, wherein, The base is a cylindrical structure with openings at both ends, and the fixed bearing assembly includes two bearing units placed on the openings.

6. The scroll pump of claim 5, wherein, The bearing unit is a deep groove ball bearing or an angular contact bearing.

7. The scroll pump of claim 5, wherein, The machine base also includes a bearing pressure plate and a locking nut on at least one side opening, respectively disposed on both axial sides of the bearing unit, for tightly connecting the eccentric shaft to the machine base.

8. The scroll pump of claim 1, wherein, The motor rotor is connected to the other end of the eccentric shaft via a pin connector and drives the eccentric shaft to rotate.

9. The scroll pump of claim 1, wherein, The bearing connector is a double-row angular contact bearing.

10. The scroll pump of claim 1, wherein, It also includes a corrugated compensator, which is disposed in the circumferential direction of the eccentric shaft and whose two ends are fixedly connected to the moving scroll and the base, respectively.

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