Impeller axial force balancing structure

Abstract

The utility model discloses an impeller axial force balancing structure which comprises a pump shell and a main shaft installed in the pump shell, a plurality of impellers are installed on the main shaft, and a first interval and a second interval are formed between the impellers and the pump shell. The projection area of the second interval on a plane perpendicular to the main shaft is larger than the projection area of the first interval on the plane. A balance hole is omitted, an existing sealing structure is simplified, only one sealing ring is arranged on the back face of the impeller, the size of the second annular boss and the size of the second sealing ring on the back face of the impeller can be flexibly adjusted according to design requirements, and axial force is balanced by combining the characteristic that the pressure difference directions of all positions are different. Therefore, a better axial force balance effect is achieved, the structure is simplified, the hydraulic loss caused by the balance hole is avoided, and the hydraulic flow stability is enhanced.

Description

Technical Field

[0001] The utility model relates to the technical field of centrifugal pumps, in particular to an impeller axial force balancing structure. Background Art

[0002] The existing centrifugal pump impeller shaft will generate axial force in the axial direction under the action of the fluid medium, which will increase the wear of the bearing end face and thrust plate and other structures. Therefore, it is necessary to set an impeller axial force balancing structure. The current impeller axial force balancing structure mostly adopts the method of sealing ring plus balancing hole, as shown in the attached manual. Figure 1 As shown, in the existing structure, the spacing between the front and back sides of the impeller and the corresponding cavity in the pump housing forms a balancing chamber P3. The projected areas of the balancing chambers P3 on both sides, measured perpendicular to the impeller axis, are similar, thus exerting similar axial forces on the impeller. A balancing hole I is provided on the impeller, connecting the flow channel in the impeller with the balancing chamber P2 on the back side. The pressure of the fluid entering the balancing chamber P2 through balancing hole I balances the pressure of the fluid entering the flow channel, thereby balancing the axial force on the impeller. This structure requires three sealing rings II on the front and back sides of the impeller, as well as near the impeller axis, to seal P2 and P3. This structure is relatively complex, and the presence of balancing hole I can affect the stability of the hydraulic flow. The balancing holes on the impeller primarily function to reduce the axial force generated during operation by balancing the fluid pressure on both sides of the impeller. However, the structure is relatively complex. Furthermore, leakage through the balancing holes can impact the main flow entering the impeller, potentially disrupting normal flow conditions and reducing the efficiency and flow stability of the impeller. Utility Model Content

[0003] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide an impeller axial force balancing structure to solve the problems of the prior art such as complex structure and poor working stability.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows: an impeller axial force balancing structure includes a pump housing and a main shaft installed inside the pump housing, multiple impellers are installed on the main shaft, a cavity corresponding to the impeller is opened on the pump housing, and a spacing is formed between the impeller and the cavity wall to form a first spacing located on the front side of the impeller and a second spacing located on the back side of the impeller; a flow channel is provided inside the impeller, one end of the flow channel passes through the wheel surface of the impeller, and the other end passes through the front end face of the impeller along the axial direction of the main shaft, and a first annular boss is formed on the front end face of the impeller, and a first sealing ring is installed between the first annular boss and the pump housing; a second annular boss is formed on the back end face of the impeller, and the diameter of the second annular boss is smaller than the diameter of the first annular boss, and a second sealing ring is installed between the outer peripheral surface of the second annular boss and the pump housing, so that the projected area of the second spacing on a plane perpendicular to the main shaft is larger than the projected area of the first spacing on the plane.

[0005] As an optimization, there is a distance between the end surface of the second sealing ring close to one end of the impeller and the back end surface of the impeller.

[0006] Compared with the prior art, the utility model has the following advantages:

[0007] By eliminating the balancing hole and simplifying the existing sealing structure, there is only one sealing ring on the back of the impeller, and the size of the second annular boss and the second sealing ring on the back of the impeller can be flexibly adjusted according to design requirements. The axial force is balanced by combining the characteristics of different pressure difference directions at various locations, thereby achieving a better axial force balance effect, which not only simplifies the structure, but also avoids the hydraulic loss caused by the balancing hole and enhances the hydraulic flow stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a structural diagram of the existing structure;

[0009] Figure 2 It is a structural diagram of the utility model;

[0010] In the figure: 1 pump housing, 2 main shaft, 3 impeller, 4 first spacing, 5 second spacing, 6 flow channel, 7 first sealing ring, 8 second annular boss, 9 second sealing ring. DETAILED DESCRIPTION

[0011] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0012] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the utility model for protection, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0013] It should be noted that similar reference numerals and letters denote similar items in the following figures. Therefore, once an item is defined in one figure, it does not require further definition or explanation in subsequent figures. In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the figures, or the orientations or positional relationships in which the inventive product is typically placed when in use. These terms are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation, and are therefore not to be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third," etc., are used solely to distinguish descriptions and are not to be construed as indicating or implying relative importance. Furthermore, terms such as "horizontal" and "vertical" do not imply that a component must be absolutely horizontal or overhanging, but rather may be slightly tilted. For example, "horizontal" simply refers to a direction that is more horizontal than "vertical," and does not imply that the structure must be completely horizontal, but rather may be slightly tilted. In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0014] Example 1: See Figure 2 ,

[0015] The present application provides an impeller axial force balancing structure, comprising a pump housing 1 and a main shaft 2 installed inside the pump housing 1, a plurality of impellers 3 installed on the main shaft 2, a cavity corresponding to the impeller 3 is opened on the pump housing 1, and a spacing is formed between the impeller 3 and the cavity wall to form a first spacing 4 located on the front of the impeller 3 and a second spacing 5 located on the back of the impeller 3; a flow channel 6 is provided inside the impeller 3, one end of the flow channel 6 passes through the wheel surface of the impeller 3, and the other end passes through the front end face of the impeller 3 along the axial direction of the main shaft 2, and forms a first annular boss on the front end face of the impeller 3, and a first sealing ring is installed between the first annular boss and the pump housing 1 7. The back end face of the impeller 3 is formed with a second annular boss 8 coaxial with the main shaft 2. The diameter of the second annular boss 8 is smaller than that of the first annular boss. A second sealing ring 9 is installed between the outer circumference of the second annular boss 8 and the pump housing 1, so that the projected area of the second spacing 5 on a plane perpendicular to the main shaft 2 is greater than the projected area of the first spacing 4 on the same plane. In this way, by simplifying the structure of the impeller 3 and eliminating the balancing hole, the back of the impeller 3 is formed into a simple second annular boss 8 structure. This only requires one sealing ring on each of the front and back sides, resulting in a simpler structure and easier installation. It also eliminates the impact of the balancing hole on the hydraulic flow. In this way, the balancing cavity formed by the first spacing 4 on the front side of the impeller 3 has a smaller projected area on a plane perpendicular to the main shaft 2, resulting in a smaller axial force on the impeller 3. However, the balancing cavity formed by the second spacing 5 on the back side has a larger projected area on a plane perpendicular to the main shaft 2, resulting in a larger axial force on the impeller 3. Therefore, the axial force generated by the hydraulic pressure in the flow channel 6 can be balanced, thereby achieving axial force balance. The specific diameters of the second annular boss 8 and the second sealing ring 9 need to be designed according to the hydraulic characteristics, the structural features of the impeller 3, the structure of the pump housing 1, etc., to ensure that the axial forces exerted on the impeller 3 by the fluid on both sides of the impeller 3 are balanced.

[0016] In addition, there is a gap between the end face of the second sealing ring 9 close to the impeller 3 and the back end face of the impeller 3, which further increases the projected area of the second gap 5 on the plane perpendicular to the main shaft 2, making the design more flexible and improving the balancing effect.

[0017] In summary, this application eliminates the balancing hole and simplifies the existing sealing structure so that there is only one sealing ring on the back of the impeller. The size of the second annular boss and the second sealing ring on the back of the impeller can be flexibly adjusted according to design requirements. The axial force is balanced by combining the characteristics of different pressure difference directions at various locations, thereby achieving a better axial force balance effect. It not only simplifies the structure, but also avoids the hydraulic loss caused by the balancing hole and enhances the hydraulic flow stability.

[0018] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the technical solution. Ordinary technicians in this field should understand that those modifications or equivalent replacements of the technical solution of the present invention that do not depart from the purpose and scope of the technical solution of the present invention should be included in the scope of the claims of the present invention.

Claims

1. An impeller axial force balancing structure, comprising a pump housing and a main shaft installed inside the pump housing, a plurality of impellers installed on the main shaft, a cavity corresponding to the impeller is opened on the pump housing, and a spacing is formed between the impeller and the cavity wall to form a first spacing located on the front side of the impeller and a second spacing located on the back side of the impeller; a first annular boss is formed on the front end face of the impeller, and a first sealing ring is installed between the first annular boss and the pump housing; a flow channel is provided inside the impeller, one end of the flow channel passes through the wheel surface of the impeller, and the other end is bent and passes through the front end face of the impeller along the axial direction of the main shaft, characterized in that A second annular boss coaxial with the main shaft is formed on the back end face of the impeller, and the diameter of the second annular boss is smaller than the diameter of the first annular boss, and a second sealing ring is installed between the outer peripheral surface of the second annular boss and the pump casing, so that the projected area of the second spacing on the plane perpendicular to the main shaft is larger than the projected area of the first spacing on the same plane.

2. The impeller axial force balancing structure according to claim 1, characterized in that: There is a distance between the end surface of the second sealing ring close to one end of the impeller and the back end surface of the impeller.

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