A zirconium alloy mouth ring device for a centrifugal pump and its assembly method

Abstract

This application discloses a zirconium alloy mouth ring device and assembly method for centrifugal pumps, relating to the field of centrifugal pumps. The zirconium alloy mouth ring device for centrifugal pumps includes a first mouth ring and a second mouth ring. The outer wall of the first mouth ring mates with a mounting hole in the pump body or pump cover, and its outer wall is provided with a first interference fit portion and a first transition fit portion sequentially along the axial direction. The inner surface of the second mouth ring mates with the mounting journal of the impeller, and its inner surface is provided with a second interference fit portion and a second transition fit portion sequentially along the axial direction. The ratio of the axial length of the first interference fit portion to the first transition fit portion, and the ratio of the axial length of the second interference fit portion to the second transition fit portion, are both 1:1.5 to 1:2.5. This application corrects mouth ring deformation through interference fit and absorbs assembly errors through transition fit, solving the problem of assembly accuracy control caused by the inability to precision machine zirconium alloy mouth rings after heat treatment, and ensuring the uniformity and stability of the mouth ring operating clearance.

Description

Technical Field

[0001] This application relates to the field of centrifugal pump technology, and in particular to a zirconium alloy mouth ring device and assembly method for centrifugal pumps. Background Technology

[0002] The wear ring is a critical and vulnerable component in a centrifugal pump. It is typically a thin-walled annular structure, installed on the impeller, pump body, and pump cover, and its interaction forms the wear ring's operating clearance. This clearance is crucial to the efficiency and operational stability of the centrifugal pump: if the clearance is too large, it will lead to increased leakage, decreased efficiency, and difficulty in forming a liquid film, exacerbating vibration; if the clearance is too small, friction may occur due to machining errors in parts or shaft deflection, even leading to seizure.

[0003] Conventional ring fittings are mostly installed using clearance fits (such as H7 / h6). However, thin-walled rings are prone to elliptical deformation during machining, and the accumulation of machining and installation errors during assembly makes it difficult to simultaneously guarantee the designed clearance and geometric tolerances. For ring fittings made of special materials such as zirconium alloys, heat treatment is required at the finished product stage to improve surface hardness. After installation, the mating surfaces cannot be further finished, making it even more likely to cause problems such as clearance deviations and geometric tolerance discrepancies. Summary of the Invention

[0004] This application provides a zirconium alloy mouth ring device for a centrifugal pump and an assembly method thereof, which solves the problems mentioned in the background art.

[0005] In a first aspect, embodiments of this application provide a zirconium alloy mouth ring device for a centrifugal pump, including a first mouth ring mounted on a pump body or pump cover, and a second mouth ring cooperating with an impeller. The outer wall of the first mouth ring mates with a mounting hole provided on the pump body or pump cover, and its outer wall sequentially includes a first interference fit portion and a first transition fit portion along the axial direction. The mounting hole has corresponding sections that form a first interference fit with the first interference fit portion and a first transition fit with the first transition fit portion. The first interference fit is used to correct machining deformation of the first mouth ring during assembly and to achieve initial fixation. The first transition fit is used to accommodate the accumulation of machining and form / position errors between the first mouth ring and the pump body or pump cover, so as to determine the final positioning accuracy of the first mouth ring in the mounting hole. The second mouth ring... The inner bore surface of the second ring engages with a mounting journal mounted on the impeller. The inner bore surface sequentially includes a second interference fit portion and a second transition fit portion along the axial direction. The mounting journal has corresponding sections that form a second interference fit with the second interference fit portion and a second transition fit with the second transition fit portion. The second interference fit is used to correct machining deformation of the second ring during assembly and achieve initial fixation. The second transition fit is used to accommodate the accumulation of machining and form / position errors between the second ring and the impeller, thereby determining the final positioning accuracy of the second ring on the mounting journal. The ratio of the axial length of the first interference fit portion to the axial length of the first transition fit portion, and the ratio of the axial length of the second interference fit portion to the axial length of the second transition fit portion, are both between 1:1.5 and 1:2.5.

[0006] In conjunction with the first aspect, in one possible implementation, the cross-section of the first mouth ring is an L-shaped structure, including mutually perpendicular radial mounting portions and axial sealing portions. The inner hole formed by the axial sealing portion and the radial mounting portion forms an operating gap with the sealing surface of the second mouth ring.

[0007] In conjunction with the first aspect, in one possible implementation, the height of the axial sealing portion is not less than half the width of the radial mounting portion.

[0008] In conjunction with the first aspect, in one possible implementation, a reverse spiral groove is formed on the axial sealing outer cylindrical surface of the second inlet ring; the longitudinal section of the reverse spiral groove is triangular, and its groove depth gradually increases from the impeller inlet end to the outlet end.

[0009] In conjunction with the first aspect, in one possible implementation, the zirconium alloy mouth ring device for the centrifugal pump further includes an anti-rotation component; the anti-rotation component passes through the first mouth ring and locks into the pump body or pump cover, and / or passes through the second mouth ring and locks into the impeller.

[0010] In conjunction with the first aspect, in one possible implementation, the anti-rotation component is a saddle screw.

[0011] In conjunction with the first aspect, in one possible implementation, the anti-rotation component is a profile-fitting structure disposed between the outer wall of the first ring and the mounting hole, and / or disposed between the inner wall of the second ring and the mounting journal, the profile-fitting structure being used to prevent relative rotation between the first ring and / or the second ring.

[0012] In conjunction with the first aspect, in one possible implementation, a gradient compensation structure is provided on the first and / or the second ring; the gradient compensation structure includes elastic grooves circumferentially distributed on the outer wall of the first ring and / or the inner surface of the second ring.

[0013] Secondly, embodiments of this application provide an assembly method for a zirconium alloy wear ring for a centrifugal pump, used for assembling a zirconium alloy wear ring device for a centrifugal pump as described in the first aspect or any possible implementation thereof, the method comprising the following steps: A first ring and a second ring are provided, wherein the outer wall of the first ring is provided with a first interference fit portion and a first transition fit portion arranged along the axial direction, and the inner surface of the second ring is provided with a second interference fit portion and a second transition fit portion arranged along the axial direction. The first ring is pressed into the mounting hole of the pump body or pump cover; wherein, firstly, the first interference fit is made with the corresponding section of the mounting hole to correct the deformation of the first ring and achieve its initial positioning; then, the first transition fit is made with the corresponding section of the mounting hole to absorb the error and determine the final positioning accuracy of the first ring. The second ring is fitted onto the mounting journal of the impeller; firstly, the second interference fit is made with the corresponding section of the mounting journal to correct the deformation of the second ring and achieve its initial positioning; then, the second transition fit is made with the corresponding section of the mounting journal to absorb errors and determine the final positioning accuracy of the second ring. The final positioning of the first and second rings creates an operational gap between them.

[0014] One or more technical solutions provided in the embodiments of this application have at least the following technical effects: This application provides a zirconium alloy mouth ring device for a centrifugal pump. A first interference fit is provided between the first mouth ring and the pump body / cover to correct machining deformation and achieve initial positioning, supplemented by a first transition fit to absorb the accumulation of machining and dimensional errors. Similarly, a second interference fit is provided between the second mouth ring and the impeller for deformation correction and positioning, and is further supplemented by a second transition fit to accommodate errors during assembly. Therefore, the first and second interference fits of this application correct elliptical deformation, restoring the first and second mouth rings to a circular shape, thus ensuring uniform and controllable operating clearance. The synergy between the first interference fit and the first transition fit, as well as the synergy between the second interference fit and the second transition fit, forms a dual precision guarantee of correction, positioning, and error absorption. This resolves the contradiction in assembly, preventing efficiency loss due to excessive operating clearance and avoiding the risk of frictional seizure due to insufficient operating clearance. Ultimately, even without the possibility of post-processing finishing, this application can still ensure that the mouth ring operating clearance and dimensional tolerances meet design requirements, improving the overall operating efficiency and reliability of the centrifugal pump. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of the zirconium alloy mouth ring device for centrifugal pumps provided in the embodiments of this application; Figure 2 A schematic diagram of the installation of the impeller and pump cover provided for an embodiment of this application; Figure 3 This is a schematic diagram of the structure of the mounting holes for the pump cover provided in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of the first opening ring provided in an embodiment of this application; Figure 5 for Figure 4 Enlarged view of a portion at point A; Figure 6 This is a schematic diagram of the structure of the second orifice ring provided in an embodiment of this application; Figure 7 for Figure 6 A magnified view of section B; Figure 8 This is a schematic diagram of the impeller structure provided in an embodiment of this application; Figure 9 The outer wall of the first ring provided in the embodiment of this application is a schematic diagram of a surface mating structure; Figure 10 The inner wall of the second ring provided in this embodiment is a schematic diagram of a surface-fitting structure.

[0017] Icons: 1-First inlet ring; 11-First interference fit; 12-First transition fit; 13-Radial mounting part; 14-Axial sealing part; 2-Pump cover; 21-Mounting hole; 3-Second inlet ring; 31-Inner bore surface; 311-Second interference fit; 312-Second transition fit; 4-Impeller; 41-Mounting journal; 5-Reverse spiral groove; 6-Anti-rotation component; 61-Seam bolt; 7-Pump body; 8-Elastic groove. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] In the description of the embodiments of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the embodiments of this application and for 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. Therefore, they should not be construed as limitations on this application. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0020] This application provides a zirconium alloy mouth ring device for a centrifugal pump, such as... Figures 1 to 10As shown. The zirconium alloy mouth ring device for the centrifugal pump includes a first mouth ring 1 mounted on the pump body 7 or pump cover 2, and a second mouth ring 3 that mates with the impeller 4. The outer wall of the first mouth ring 1 mates with a mounting hole 21 provided on the pump body 7 or pump cover 2. Its outer wall includes a first interference fit portion 11 and a first transition fit portion 12 in sequence along the axial direction. The mounting hole 21 has corresponding sections that form a first interference fit with the first interference fit portion 11 and a first transition fit with the first transition fit portion 12. The first interference fit is used to correct the machining deformation of the first mouth ring 1 during assembly and to achieve initial fixation. The first transition fit is used to accommodate the accumulation of machining and form and position errors between the first mouth ring 1 and the pump body 7 or pump cover 2, so as to determine the final positioning accuracy of the first mouth ring 1 in the mounting hole 21. The second mouth ring 3 mates with a mounting journal 41 provided on the impeller 4 through its inner bore surface 31. The inner bore surface 31 includes a second interference fit portion 311 and a second transition fit portion 312 in sequence along the axial direction. The mounting journal 41 has corresponding sections that form a second interference fit with the second interference fit portion 311 and a second transition fit with the second transition fit portion 312. The second interference fit is used to correct machining deformation of the second ring 3 during assembly and to achieve initial fixation. The second transition fit is used to accommodate the accumulation of machining and form / position errors between the second ring 3 and the impeller 4, thereby determining the final positioning accuracy of the second ring 3 on the mounting journal 41. The ratio of the axial length of the first interference fit portion 11 to the axial length of the first transition fit portion 12, and the ratio of the axial length of the second interference fit portion 311 to the axial length of the second transition fit portion 312, are both between 1:1.5 and 1:2.5.

[0021] In a preferred embodiment, the ratio of the axial lengths of the first interference fit portion 11 to the first transition fit portion 12, and the ratio of the axial lengths of the second interference fit portion 311 to the second transition fit portion 312, are both 1:2. This ratio ensures that the first interference fit portion 11 and the second interference fit portion 311 have sufficient axial length to provide adequate guiding and corrective forces during assembly, ensuring effective correction of the elliptical deformation of the thin-walled ring. Simultaneously, the transition fit portion retains ample axial space to accommodate the accumulation of machining errors and geometric tolerances, thereby achieving synergistic effects of interference correction and error absorption. This 1:2 length ratio achieves optimal clearance uniformity and geometric accuracy while ensuring assembly reliability.

[0022] This application provides a first interference fit 11 between the first retaining ring 1 and the pump body 7 or pump cover 2 to correct machining deformation and achieve initial positioning, while a first transition fit 12 is provided to absorb the accumulation of machining and form and position errors. Similarly, a second interference fit 311 is provided between the second retaining ring 3 and the impeller 4 for deformation correction and positioning, and a second transition fit 312 is used to further accommodate errors during assembly. Therefore, the first and second interference fits of this application correct elliptical deformation, restoring the first retaining ring 1 and the second retaining ring 3 to a circular shape, thus ensuring uniform and controllable clearance. The synergy between the first interference fit and the first transition fit, and the synergy between the second interference fit and the second transition fit, forms a dual precision guarantee of correction, positioning, and error absorption. This resolves the contradictions in assembly, preventing efficiency reduction caused by excessive clearance and avoiding the risk of frictional seizure caused by excessive clearance. Ultimately, even without the possibility of subsequent finishing, this application can still ensure that the retaining ring operating clearance and form and position tolerances meet design requirements, improving the overall operating efficiency and reliability of the centrifugal pump.

[0023] In this embodiment, the cross-section of the first ring 1 is L-shaped, including a radially mounted portion 13 and an axially sealing portion 14 that are perpendicular to each other. The inner hole formed by the axially sealing portion 14 and the radially mounted portion 13 forms an operating gap with the sealing surface of the second ring 3.

[0024] It should be noted that the first inlet ring 1, installed on the pump cover 2 or pump body 7, is relatively large. To prevent significant deformation during processing, an L-shaped cross-section is adopted. This L-shaped cross-section structure has two advantages: First, it structurally enhances the rigidity of the thin-walled annular part, effectively suppressing deformation that may occur during processing and heat treatment. Second, under harsh conditions of high temperature and high pressure with a large pressure difference between the pump inlet and outlet, this structure can guide and confine the erosion energy carried by the medium leaking through the inlet ring mating part to the first inlet ring 1 itself. This locks the vulnerable part onto the replaceable first inlet ring 1, avoiding direct erosion of the pump body 7, pump cover 2, and other main pressure-bearing components by the high-temperature and high-pressure medium, thereby extending the overall service life of the centrifugal pump.

[0025] In this embodiment, the height of the axial sealing part 14 is not less than half the width of the radial mounting part 13, which enhances the structural rigidity of the L-shaped cross-section of the first ring 1, enabling the thin-walled annular part to effectively resist elliptical deformation and vibration under processing, heat treatment, and high-pressure operation conditions. At the same time, this proportional relationship ensures that the radial mounting part 13 has sufficient bearing area and bending section modulus, which can maintain the stability of the operating gap between the radial mounting part 13 and the sealing surface of the second ring 3 for a long time under high-speed rotation and fluid pulsation impact, preventing uneven gap or abnormal friction caused by local deformation. Thus, while ensuring the long-term alignment of the sealing pair, it avoids the efficiency reduction caused by increased leakage and eliminates the risk of frictional seizure caused by gap instability. Ultimately, it achieves effective protection for core pressure-bearing components such as the pump body 7 and pump cover 2, and extends the overall service life and operational reliability of the centrifugal pump under harsh operating conditions.

[0026] In this embodiment, a reverse spiral groove 5 is formed on the axial sealing outer cylindrical surface of the second ring 3. The longitudinal section of the reverse spiral groove 5 is triangular, and its depth gradually increases from the inlet end of the impeller 4 to the outlet end (e.g., from 0.2 mm to 0.8 mm). When the medium flows through the operating gap of the ring, the reverse spiral groove 5 can guide and impede the leaking fluid in the opposite direction to the mainstream leakage direction, forming a "dynamic sealing barrier," reducing leakage and improving the volumetric efficiency of the centrifugal pump. In addition, the surface of the second ring 3 is subjected to oxidation heat treatment to form a dense oxide layer with a hardness of HV350-450. This oxide layer significantly improves the wear resistance of the sealing surface, delays the increase in gap caused by wear, thereby extending the service life of the second ring 3 and reducing maintenance costs.

[0027] In this embodiment of the application, the zirconium alloy inlet ring device for the centrifugal pump further includes an anti-rotation component 6. The anti-rotation component 6 passes through the first inlet ring 1 and is locked into the pump body 7 or pump cover 2, and / or passes through the second inlet ring 3 and is locked into the impeller 4.

[0028] It should be noted that the anti-rotation component 6 structurally eliminates the possibility of relative circumferential rotation between the first inlet ring 1 and the pump body 7, pump cover 2, or between the second inlet ring 3 and the impeller 4. Its direct purpose is to prevent the first inlet ring 1 or the second inlet ring 3 from unexpectedly rotating during operation due to friction or other reasons, solving the so-called "ring running" problem in engineering. This design offers significant and dual technical benefits: First, it fundamentally eliminates the additional friction and wear caused by "ring running," avoiding the resulting rapid increase in clearance, uncontrolled leakage, or rapid component failure. Second, it effectively prevents scratches and damage to the mating surfaces of the pump body 7, pump cover 2, or impeller 4 during "ring running," thereby protecting these core pressure-bearing components.

[0029] In this embodiment, the anti-rotation component 6 is a saddle screw 61. The saddle screw 61 is locked onto the pump body 7, pump cover 2, or impeller 4 through its threaded section, and its head or smooth section presses across the preset hole or groove of the first ring 1 or the second ring 3, achieving anti-rotation connection through mechanical constraint. In this embodiment, the outer wall of the first ring 1 and the inner wall of the second ring 3 are both cylindrical surfaces.

[0030] In the embodiments of this application, such as Figure 9 and Figure 10 As shown, the anti-rotation component 6 is a surface-fitting structure disposed between the outer wall of the first ring 1 and the mounting hole 21, and / or between the inner wall of the second ring 3 and the mounting journal 41, used to prevent relative rotation of the rings. Simultaneously, the first ring 1 and / or the second ring 3 are also provided with a gradient compensation structure, which includes elastic grooves 8 evenly distributed circumferentially on the outer wall of the first ring 1 and / or the inner hole surface 31 of the second ring 3; the groove width of the elastic grooves 8 is 0.5 mm, and the depth is 1 / 3 of the wall thickness of the corresponding first ring 1 or second ring 3, distributed circumferentially at 30° intervals. The elastic grooves 8 impart elastic deformation capability to the corresponding first ring 1 or second ring 3, forming temperature adaptive compensation. Taking zirconium alloy and Hastelloy as examples, the two have significantly different coefficients of thermal expansion, with zirconium alloy having a coefficient of approximately 5.8 × 10⁻⁶. / ℃, Hastelloy approximately 10.6× / ℃: During assembly at room temperature, the elastic groove 8 is slightly compressed, which does not affect the correction function; under high temperature conditions, the elastic groove 8 is released to compensate for the expansion difference and maintain the stability of the gap; under low temperature conditions, the elastic groove 8 contracts in the opposite direction to avoid excessive gap. This solves the problem of thermal expansion mismatch between different materials and expands the range of working conditions that can be adapted.

[0031] Furthermore, the preferred surface mating structure is a triangular key structure.

[0032] This application provides an assembly method for a zirconium alloy mouth ring for a centrifugal pump, the method comprising the following steps: A first ring 1 and a second ring 3 are provided, wherein the outer wall of the first ring 1 is provided with a first interference fit portion 11 and a first transition fit portion 12 arranged along the axial direction, and the inner hole surface 31 of the second ring 3 is provided with a second interference fit portion 311 and a second transition fit portion 312 arranged along the axial direction.

[0033] The first ring 1 is pressed into the mounting hole 21 of the pump body 7 or pump cover 2. First, the first interference fit 11 is applied to the corresponding section of the mounting hole 21 to correct the deformation of the first ring 1 and achieve initial positioning. During the pressing of the first interference fit 11, the axis of the first ring 1 is kept aligned with the axis of the mounting hole 21, and the pressing force is controlled within the range of 1.5kN to 2kN. However, for the first ring 1 with an interference amount exceeding 0.2mm, it needs to be cooled in liquid nitrogen for 10 minutes before pressing. Then, the first transition fit 12 is applied to the corresponding section of the mounting hole 21 to absorb errors and determine the final positioning accuracy of the first ring 1. During the pressing of the first transition fit 12, it is pressed in at a constant speed of 1mm / s. After pressing, it is left to stand at room temperature for at least 8 hours to release assembly stress and stabilize its shape and position.

[0034] The second ring 3 is fitted onto the mounting journal 41 of the impeller 4. First, the second interference fit 311 is applied to the corresponding section of the mounting journal 41 to correct any deformation of the second ring 3 and achieve initial positioning. During the pressing of the second interference fit 311, the axis of the second ring 3 is kept aligned with the axial direction of the mounting journal 41 of the impeller 4. The pressing force is controlled within the range of 1.5kN to 2kN. However, for the second ring 3 with an interference fit exceeding 0.2mm, it needs to be heated to 150℃~200℃ and kept at a uniform temperature before pressing. Then, the second transition fit 312 is applied to the corresponding section of the mounting journal 41 to absorb errors and determine the final positioning accuracy of the second ring 3. Similarly, the second transition fit 312 is pressed in at a constant speed of 1mm / s. After pressing, the ring is left to stand at room temperature for at least 8 hours to release assembly stress and stabilize its shape and position. The final positioning of the first ring 1 and the second ring 3 creates an operating gap between them.

[0035] Specifically, after pressing the first ring 1 into the mounting hole 21, and / or after pressing the second ring 3 into the mounting journal 41, the step of installing the anti-rotation member 6 is also included.

[0036] Furthermore, the fit tolerances for both the first and second interference fits are U7 / h6, and the fit tolerances for both the first and second transition fits are K7 / h6. Extensive testing has verified that, considering the inability to precision machine zirconium alloy rings after heat treatment, to correct the deformation of thin-walled rings of different sizes, the tolerance zone of the hole needs to be U7 to provide sufficient interference correction force; while to absorb machining errors in the base component, the tolerance zone of the hole needs to be K7 to provide the necessary error tolerance space.

[0037] Through this specific tolerance fit design, the first ring 1 and the second ring 3 can achieve graded positioning and error compensation during assembly: the interference fit of U7 / h6 first provides sufficient radial correction force, effectively eliminating the elliptical deformation of the first ring 1 and the second ring 3 caused by heat treatment, ensuring that they return to a circular shape and achieve initial positioning. Subsequently, the transition fit of K7 / h6, while maintaining centering, accommodates dimensional and geometrical errors generated during part machining and assembly, avoiding excessive assembly stress or local interference.

[0038] Ultimately, the operating clearance formed by the assembly of the first ring 1 and the second ring 3 is selected and controlled according to the minimum operating clearance specified in Table 6 of API 610-2021 standard. The above tolerance fit and clearance setting achieve a dual effect in terms of process: firstly, it ensures that the operating clearance of the rings meets the minimum leakage requirements, while providing compensation space for shaft deflection and thermal expansion; secondly, under conditions where precision machining is not possible after assembly, standardized assembly processes stably guarantee the accuracy of the sealing clearance and operational reliability, making it suitable for high-speed, high-pressure differential operating conditions, and improving the energy efficiency and service life of the centrifugal pump.

[0039] Furthermore, the device also features the characteristic of preventing the first retaining ring 1 and the second retaining ring 3 from axially detaching along the corresponding mounting parts. To achieve reliable anti-detachment while ensuring assembly accuracy, its mounting process employs a unique stepped assembly method of first interference fit and then transition fit. When pressing the first retaining ring 1 into the mounting hole 21 of the pump body 7 or pump cover 2, and when fitting the second retaining ring 3 onto the mounting journal 41 of the impeller 4, in the initial stage, the tight fit between the interference fit and the corresponding mounting surface, through the smooth pressing force applied by a non-metallic tool, effectively corrects the deformation of the first retaining ring 1 and the second retaining ring 3 and achieves initial fixation by friction, forming a mechanical barrier to prevent axial detachment.

[0040] The various embodiments in this specification are described in a progressive manner. For the same or similar parts between the various embodiments, please refer to each other. Each embodiment focuses on describing the differences from other embodiments.

[0041] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of this application.

Claims

1. A zirconium alloy ring device for a centrifugal pump, comprising a first ring (1) mounted on a pump body (7) or a pump cover (2), and a second ring (3) cooperating with an impeller (4), characterized in that, The outer wall of the first mouth ring (1) is fitted with a mounting hole (21) provided on the pump body (7) or pump cover (2). The outer wall of the first mouth ring (1) includes a first interference fit part (11) and a first transition fit part (12) in sequence along the axial direction. The mounting hole (21) has a corresponding section that forms a first interference fit with the first interference fit part (11) and a first transition fit with the first transition fit part (12). The first interference fit is used to correct the machining deformation of the first mouth ring (1) during assembly and to achieve initial fixation. The first transition fit is used to accommodate the accumulation of part machining and form and position errors between the first mouth ring (1) and the pump body (7) or pump cover (2) to determine the final positioning accuracy of the first mouth ring (1) in the mounting hole (21). The second ring (3) engages with the mounting journal (41) on the impeller (4) through its inner bore surface (31). The inner bore surface (31) includes, in sequence along the axial direction, a second interference fit portion (311) and a second transition fit portion (312). The mounting journal (41) has corresponding sections that form a second interference fit with the second interference fit portion (311) and a second transition fit with the second transition fit portion (312). The second interference fit is used to correct the machining deformation of the second ring (3) during assembly and to achieve initial fixation. The second transition fit is used to accommodate the accumulation of machining and form and position errors between the second ring (3) and the impeller (4) to determine the final positioning accuracy of the second ring (3) on the mounting journal (41). The ratio of the axial length of the first interference fit portion (11) to the first transition fit portion (12), and the ratio of the axial length of the second interference fit portion (311) to the second transition fit portion (312) are both 1:1.5 to 1:2.

5.

2. The zirconium alloy mouth ring device for centrifugal pumps according to claim 1, characterized in that, The first mouth ring (1) has an L-shaped cross-section, including a radial mounting part (13) and an axial sealing part (14) that are perpendicular to each other. The inner hole formed by the axial sealing part (14) and the radial mounting part (13) forms an operating gap with the sealing surface of the second mouth ring (3).

3. The zirconium alloy mouth ring device for centrifugal pumps according to claim 2, characterized in that, The height of the axial sealing part (14) is not less than half the width of the radial mounting part (13).

4. The zirconium alloy mouth ring device for centrifugal pumps according to claim 1, characterized in that, The second inlet ring (3) has a reverse spiral groove (5) on its axial sealing outer cylindrical surface; the longitudinal section of the reverse spiral groove (5) is triangular, and its groove depth gradually increases from the inlet end of the impeller (4) to the outlet end.

5. The zirconium alloy mouth ring device for centrifugal pumps according to claim 1, characterized in that, It also includes an anti-rotation component (6); the anti-rotation component (6) passes through the first inlet ring (1) and is locked into the pump body (7) or pump cover (2), and / or passes through the second inlet ring (3) and is locked into the impeller (4).

6. The zirconium alloy mouth ring device for centrifugal pumps according to claim 5, characterized in that, The anti-rotation component (6) is a saddle screw (61).

7. The zirconium alloy mouth ring device for centrifugal pumps according to claim 5, characterized in that, The anti-rotation component (6) is a surface-fitting structure disposed between the outer wall of the first mouth ring (1) and the mounting hole (21), and / or disposed between the inner wall of the second mouth ring (3) and the mounting journal (41). The surface-fitting structure is used to prevent the first mouth ring (1) and / or the second mouth ring (3) from rotating relative to each other.

8. The zirconium alloy mouth ring device for a centrifugal pump according to claim 7, characterized in that, The first ring (1) and / or the second ring (3) are provided with gradient compensation structures; the gradient compensation structures include elastic grooves (8) that are circumferentially distributed on the outer wall of the first ring (1) and / or the inner hole surface (31) of the second ring (3).

9. A method for assembling a zirconium alloy wear ring for a centrifugal pump, used for assembling a zirconium alloy wear ring device for a centrifugal pump as described in any one of claims 1 to 8, characterized in that, Includes the following steps: A first ring (1) and a second ring (3) are provided, wherein the outer wall of the first ring (1) is provided with a first interference fit part (11) and a first transition fit part (12) arranged in the axial direction, and the inner hole surface (31) of the second ring (3) is provided with a second interference fit part (311) and a second transition fit part (312) arranged in the axial direction. The first ring (1) is pressed into the mounting hole (21) of the pump body (7) or pump cover (2); wherein, firstly, the first interference fit part (11) is made to the corresponding section of the mounting hole (21) to correct the deformation of the first ring (1) and achieve its initial positioning; then, the first transition fit part (12) is made to the corresponding section of the mounting hole (21) to absorb the error and determine the final positioning accuracy of the first ring (1); The second ring (3) is fitted onto the mounting journal (41) of the impeller (4); firstly, the second interference fit part (311) is used to make a second interference fit with the corresponding section of the mounting journal (41) to correct the deformation of the second ring (3) and achieve its initial positioning; then, the second transition fit part (312) is used to make a second transition fit with the corresponding section of the mounting journal (41) to absorb errors and determine the final positioning accuracy of the second ring (3); The first ring (1) and the second ring (3) are finally positioned to form an operating gap between them.

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