Radial subdivision volute type heavy-station petrochemical process pump with impeller positioning structure
By using impeller nut with anti-rotating groove design and step key combined with mechanical seal in the centrifugal pump, the problems of insufficient structural strength and high cost in the prior art are solved, and impeller locking under complex working conditions is achieved Stability and cost-effectiveness.
Patent Information
- Application Number
- CN202421170673.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-27
- Publication Date
- 2025-01-14
- Estimated Expiration
- 2034-05-27
AI Technical Summary
The existing centrifugal pump impeller locking structure has problems such as insufficient structural strength and high parts processing costs under complex working conditions such as high temperature, high pressure, and strong vibration. It is impossible to prevent damage caused by loosening of the impeller by relying solely on impeller nut locking.
The impeller nut with an inner anti-rotation groove design is used to lock the impeller at a limit position, and is equipped with a step key and a mechanical seal. The step key is pressed by the moving ring of the mechanical seal to prevent the impeller nut from rotating and achieve the anti-rotation effect of the impeller.
It improves the applicability and structural strength of the centrifugal pump in complex working conditions, reduces the cost of parts processing, ensures the locking stability of the impeller nut, and avoids damage caused by loosening.
Smart Images
Figure CN222351014U_ABST
Abstract
Description
Technical Field
[0001] The utility model discloses a radially split volute type heavy-duty petrochemical process pump with an impeller positioning structure, which relates to the technical field of centrifugal pumps, and in particular to a centrifugal pump with a rotor structure in which an impeller nut is used to lock the impeller, and a mechanical seal is used to cooperate with the impeller nut to prevent loosening and position the impeller nut. Background Art
[0002] At present, there are two main types of centrifugal pump impeller locking structures in the industry:
[0003] The first method uses a retaining ring and a retaining ring sleeve to limit and fix the impeller. Although this method has a better anti-loosening effect, the installation of the retaining ring requires an annular groove to be opened on the shaft, which seriously affects the structural strength of the shaft. In addition, it has high precision requirements on the impeller hub length and the shaft retaining ring groove and other related matching dimensions, which increases the difficulty of part processing to a certain extent.
[0004] The second method only uses the impeller nut to limit and fix the impeller. Although the part structure is simple and the cost is low, it only relies on the locking torque of the impeller nut. Under long-term strong vibration conditions, once the impeller nut is loose, there is no anti-rotation structure, which will directly cause the impeller displacement and damage the centrifugal pump. It cannot be used in harsh working conditions such as high temperature, high pressure, and strong vibration.
[0005] In view of the problems existing in the above-mentioned prior art, it is very necessary to study and design a new radially split volute type heavy-duty petrochemical process pump with an impeller positioning structure to overcome the problems existing in the prior art. Summary of the invention
[0006] According to the above-mentioned prior art, the method of limiting and fixing the impeller with a retaining ring and a retaining ring sleeve will affect the structural strength of the centrifugal pump shaft and the parts processing cost is high. Only using the impeller nut to limit and fix the impeller cannot be applied to centrifugal pumps under complex working conditions. Technical problems such as the radially split volute type heavy-duty petrochemical process pump with an impeller positioning structure is solved. The utility model mainly adopts an impeller nut with an inner anti-rotation groove design to limit and lock the centrifugal pump impeller, and is matched with a stepped key and a mechanical seal to limit and position the impeller nut, which can achieve a simple structure, low parts processing cost, and can be used for locking and anti-rotation effects of the centrifugal pump impeller under various complex working conditions.
[0007] The technical means adopted by the utility model are as follows:
[0008] A radially split volute type heavy-duty petrochemical process pump with an impeller positioning structure, comprising: a shaft, an impeller, a shaft sleeve, an impeller nut and a mechanical seal; the impeller and the shaft sleeve are sleeved on the shaft, locked by the impeller nut, and then the mechanical seal is installed;
[0009] Further, a thin keyway is provided on the shaft;
[0010] Further, the rear end face of the impeller nut is provided with a high keyway;
[0011] Further, the stepped key is placed in the thin keyway, and its head is embedded in the tall keyway;
[0012] Furthermore, the mechanical seal encapsulates the step key in the thin keyway to prevent the step key from falling off.
[0013] Furthermore, a thin keyway is provided at the root of the threaded position where the shaft and the impeller nut cooperate.
[0014] Furthermore, the rear end surface of the impeller nut is provided with a plurality of semicircular high key grooves in a plum petal shape, which are used to fit with the head of the stepped key to ensure the anti-rotation effect of the impeller nut;
[0015] Furthermore, a high keyway is arranged from the tail end of the internal thread of the impeller nut to the end face of the impeller nut.
[0016] Further, the high step portion of the step key head has the same shape as the high key slot, and the high step portion is inserted into the high key slot;
[0017] Furthermore, the low step portion of the step key is placed in the thin keyway, and the height of the low step portion is not higher than the groove depth of the thin keyway; the low step portion is pressed by the dynamic ring of the mechanical seal, so that the step key is always stuck in the thin keyway to prevent falling off, thereby achieving the anti-rotation effect of the impeller nut.
[0018] Furthermore, the distance from the front end surface of the dynamic ring to the inner sealing ring of the dynamic ring is L, and L>the length of the low step portion to prevent the low step portion from damaging the sealing ring.
[0019] Furthermore, the distance between the front end face of the moving ring and the rear end face of the impeller nut is the minimum unilateral axial movement of the centrifugal pump rotor. The distance of the movement is A, A<the length of the low step portion, preventing the step key from falling off from the thin keyway.
[0020] Compared with the prior art, the utility model has the following advantages:
[0021] 1. The radially split volute type heavy-duty petrochemical process pump with a new impeller positioning structure provided by the utility model does not need to open an annular groove on the pump shaft compared with the clamping ring fixing impeller method, does not affect the strength of the shaft, and is more applicable to pumps in complex working conditions. In addition, the impeller nut with a stepped key is relatively simple in structure and has low requirements on parts precision, which reduces the processing cost to a certain extent, has higher reliability and saves costs at the same time;
[0022] 2. The utility model provides a new impeller positioning structure for a radially split volute heavy-duty petrochemical process pump. Compared with only using an impeller nut to fix the impeller, in addition to relying on the locking force of the impeller nut thread itself, under long-term strong vibration conditions, once the impeller nut is loosened, the anti-rotation structure of this patent can still be used to limit the rotation of the impeller nut, thereby ensuring the locking of the impeller and the normal operation of the centrifugal pump, thereby increasing the applicability of the centrifugal pump to complex working conditions.
[0023] In summary, the technical solution of the utility model solves the problems that the method of limiting and fixing the impeller with a retaining ring and a retaining ring sleeve in the prior art will affect the structural strength of the centrifugal pump shaft and the parts processing cost is high, and the impeller is limited and fixed only by an impeller nut, which cannot be applied to centrifugal pumps under complex working conditions. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.
[0025] Figure 1 It is a schematic diagram of the structure of the utility model;
[0026] Figure 2 For this utility model Figure 1 Part I: Amplification attempt;
[0027] Figure 3 This is a schematic diagram of the impeller nut structure of the utility model;
[0028] Figure 4 For this utility model Figure 3 AA view;
[0029] Figure 5 This is a schematic diagram of the step key structure of the utility model;
[0030] Figure 6 For this utility model Figure 5 Side view;
[0031] Figure 7 For this utility model Figure 5 Top view;
[0032] Figure 8 It is a schematic diagram of the assembly of the impeller nut, stepped key and mechanical seal of the utility model.
[0033] In the figure:
[0034] 1. Shaft 11, thin keyway;
[0035] 2. Impeller;
[0036] 3. Bushing;
[0037] 4. Impeller nut 41, high keyway;
[0038] 5. step key 51, high step portion 52, low step portion;
[0039] 6. Mechanical seal 61, dynamic ring 61, sealing ring. DETAILED DESCRIPTION
[0040] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.
[0041] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means a limitation on the utility model and its application or use. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.
[0042] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the utility model. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.
[0043] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values do not limit the scope of the utility model. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, so once a certain item is defined in one drawing, it does not need to be further discussed in subsequent drawings.
[0044] In the description of the present utility model, it needs to be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present utility model and simplifying the description. Unless otherwise stated, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present utility model: the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.
[0045] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below their position devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.
[0046] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the utility model.
[0047] like Figure 1 As shown, the utility model provides a radially split volute heavy-duty petrochemical process pump with a novel impeller positioning structure, comprising: a shaft 1, an impeller 2, a shaft sleeve 3, an impeller nut 4 and a mechanical seal 6; the impeller 2 and the shaft sleeve 3 are mounted on the shaft 1, locked by the impeller nut 4, and then the mechanical seal 6 is installed; a thin keyway 11 is provided on the shaft 1; a high keyway 41 is provided on the rear end face of the impeller nut 4; a stepped key 5 is placed in the thin keyway 11, and its head is embedded in the high keyway 41; the mechanical seal 6 encapsulates the stepped key 5 in the thin keyway 11 to prevent the stepped key 5 from falling off.
[0048] like Figure 1 As shown, a thin keyway 11 is formed on the shaft 1 at the root of the locking thread of the impeller nut 4 for accommodating the stepped key 5 .
[0049] like Figure 2 As shown, the impeller nut 4 has a semicircular high key groove 41 from the inner thread tail end to the end face, and the groove is distributed in a petal-like circumference for clamping the high step portion 51 of the stepped key 5 to ensure the anti-rotation effect.
[0050] like Figure 3 As shown, the stepped key 5 is designed as a stepped thin key, the high step portion 51 at the head is used to be inserted into the high keyway 41 of the impeller nut 4, and the remaining low step portion 52 is used to be placed in the thin keyway 11 on the shaft 1 and ensure that it is not higher than the sealing shaft diameter of the shaft 1. The low step portion 52 is pressed by the dynamic ring 61 of the mechanical seal 6, so that the stepped key 5 is always stuck in the thin keyway 11 of the shaft 1 to prevent falling off, thereby achieving the anti-rotation effect of the impeller nut 4.
[0051] like Figure 4 As shown, the mechanical seal 6 needs to stipulate that the distance from its dynamic ring 61 to the bottom surface of the sealing cavity is the maximum axial movement A of the rotor on one side, and no sealing parts such as O-rings are allowed in the stepped keyway area on the inner side of the dynamic ring, because it is necessary to ensure that the dynamic ring of the mechanical seal can press the stepped key 5 while preventing the stepped key 5 from damaging the sealing parts of the mechanical seal 6.
[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the utility model.
Claims
1. A radially split volute type heavy-duty petrochemical process pump with an impeller positioning structure, comprising: A shaft (1), an impeller (2), a shaft sleeve (3), an impeller nut (4), a stepped key (5) and a mechanical seal (6); the impeller (2) and the shaft sleeve (3) are mounted on the shaft (1), locked by the impeller nut (4), and then the mechanical seal (6) is installed; the characteristics are: The shaft (1) is provided with a thin keyway (11); The rear end surface of the impeller nut (4) is provided with a high keyway (41); The stepped key (5) is placed in the thin keyway (11), and its head is embedded in the high keyway (41); The mechanical seal (6) encapsulates the stepped key (5) in the thin keyway (11) to prevent the stepped key (5) from falling off.
2. The radially split volute type heavy-duty petrochemical process pump with an impeller positioning structure according to claim 1, characterized in that: The thin keyway (11) is provided at the root of the threaded position where the shaft (1) and the impeller nut (4) meet.
3. The radially split volute type heavy-duty petrochemical process pump with an impeller positioning structure according to claim 1, characterized in that: The rear end surface of the impeller nut (4) is provided with a plurality of semicircular high key grooves (41) distributed in a plum petal shape, which are used to be engaged with the head of the stepped key (5) to ensure the anti-rotation effect of the impeller nut (4); The high keyway (41) is arranged between the tail end of the internal thread of the impeller nut (4) and the end face of the impeller nut (4).
4. The radially split volute type heavy-duty petrochemical process pump with an impeller positioning structure according to claim 1, characterized in that: The high step portion (51) at the head of the stepped key (5) has the same shape as the high key slot (41), and the high step portion (51) is inserted into the high key slot (41); The low step portion (52) of the step key (5) is placed in the thin key groove (11), and the height of the low step portion is not higher than the groove depth of the thin key groove (11); the low step portion (52) is pressed by the movable ring (61) of the mechanical seal (6), so that the step key (5) is always stuck in the thin key groove (11) to prevent it from falling off, thereby achieving an anti-rotation effect of the impeller nut (4).
5. The radially split volute type heavy-duty petrochemical process pump with an impeller positioning structure according to claim 4, characterized in that: The distance from the front end surface of the moving ring (61) to the inner sealing ring (62) of the moving ring (61) is L, and L is greater than the length of the low step portion (52), so as to prevent the low step portion (52) from damaging the sealing ring (62).
6. The radially split volute type heavy-duty petrochemical process pump with an impeller positioning structure according to claim 4, characterized in that: The distance between the front end surface of the moving ring (61) and the rear end surface of the impeller nut (4) is the minimum unilateral axial movement of the centrifugal pump rotor. The distance of the movement is A, and A is less than the length of the low step portion (52), thereby preventing the step key (5) from falling out of the thin keyway (11).