Space twisting impeller

Abstract

The utility model discloses a space twist impeller, relates to centrifugal pump technical field, concretely including impeller upper cover plate, blade and impeller lower cover plate, impeller upper cover plate and impeller lower cover plate pass through blade connection, impeller upper cover plate includes the one-piece front half part that is far away from blade and the rear half part that is connected with the blade, the impeller lower cover plate comprises a connecting part connected with the blades and a middle part located in the middle of the connecting part, the ends, close to the central axis of the front half part, of the blades are inlet ends, and the ends, away from the central axis of the front half part, of the blades are outlet ends. And a flow channel formed by the rear half part and the connecting part is in a gradual expansion form or a parallel state. The space twisting impeller has the advantages of an existing cylindrical straight blade and an existing space twisting impeller, has efficient hydraulic performance and efficient hydraulic efficiency, and can completely meet the requirement of the current high energy efficiency index; and good mold manufacturability is achieved, and mold stripping is simple and easy to implement.

Description

Technical Field

[0001] The utility model relates to the technical field of centrifugal pumps, in particular to a space-twisted impeller. Background Technique

[0002] As a type of centrifugal pump, canned motor pumps play a crucial role in national economic life. The impeller is the core power component of a centrifugal pump. The impeller blades do work on the medium transported in the inter-blade flow passage, throwing the medium out along the working surface of the blades, enabling the medium to obtain kinetic energy and potential energy, thereby achieving the purpose of transporting the medium. The geometric parameters, geometric shape, and size of the impeller directly determine the working efficiency of the centrifugal pump. There are various classification methods for impellers. Classified by the cover form of the impeller: mainly divided into open impellers, semi-open impellers, and closed impellers; classified by the structural form of the impeller blades: mainly divided into space-twisted blade impellers and cylindrical blade impellers; classified by the impeller material and forming process: mainly including stainless steel stamping impellers, plastic injection-molded impellers, gray cast iron cast impellers, etc.

[0003] Currently, in the canned motor pump market, closed plastic injection-molded impellers are the most widely used. There are mainly two corresponding blade forms for this kind of impeller: cylindrical straight blades and space-twisted impellers. In the most recent existing technology, this kind of impeller mainly consists of three parts: the upper impeller cover 001, the blades 002, and the lower impeller cover 003, as Figure 1 shown. In the impeller axial view, the upper impeller cover profile line 005 is a Bessel curve or an arc curve, and the lower impeller cover profile line 007 consists of a section of Bessel curve and another section of line segment, as Figure 2 shown. In Figure 2 , 008 is the impeller inlet edge, 009 is the impeller axis, and the inter-blade flow passage of the impeller presents a gradually decreasing contraction shape from the blade inlet edge 004 to the blade outlet edge 006. From the perspective of the profile line, the extension lines of the upper cover profile line 005 and the lower cover profile line 007 will intersect at a certain place outside the impeller, and the included angle after intersection is less than 90°.

[0004] Under the conditions of the prior art, for the canned motor pump field, the advantages of the cylindrical straight blade impeller are that the manufacturing process is simple, the blade injection mold is easy to demold, the mold cost is relatively low, and the production efficiency is high; its disadvantages are that the blade inlet angle cannot well follow the change of the liquid flow angle of the medium flow, so there must be positive and negative incidence angles, resulting in large hydraulic losses in the blade inter-channel, and it is difficult to achieve a very high hydraulic efficiency, and it is not suitable for applications in some scenarios with high efficiency requirements. The advantage of the space-twisted blade impeller is that its blade inlet angle can follow the change of the liquid flow angle of the medium flow, so the blade presents a space-twisted shape. The blade inlet impact loss of this type of blade is small, the inter-blade flow is uniform, the hydraulic loss in the inter-blade channel is small, and the achievable efficiency is very high, and high-efficiency hydraulic performance can be achieved. However, its disadvantage is that the production processability is poor, the processing is difficult, especially under the existing domestic manufacturing process level, the injection mold of this impeller is complex, the demolding is difficult, the mold cost is high, and the production efficiency is low. Even in some cases, the mold opening of the high-efficiency scheme cannot be realized due to process problems. The advantages of the impellers of the above two structural forms cannot be taken into account at the same time, and only choices can be made; based on this, the present application proposes a space-twisted impeller. Summary of the Utility Model

[0005] The utility model provides a space-twisted impeller, which has the advantages of the above two forms of impellers: it has high-efficiency hydraulic performance and can fully meet the requirements of current high-energy efficiency indicators; it has good mold processability, and the demolding is simple and easy, solving the problem that the advantages of the impellers of the above two structural forms in the above background technology cannot be taken into account at the same time and only choices can be made.

[0006] The utility model provides the following technical solution: a space-twisted impeller, including an impeller upper cover plate, blades and an impeller lower cover plate. The impeller upper cover plate and the impeller lower cover plate are connected by the blades. The impeller upper cover plate includes a front half part far from the blades and a rear half part connected to the blades that are integrally formed. The impeller lower cover plate includes a connecting part connected to the blades and an intermediate part located in the middle of the connecting part. One end of the blade adjacent to the central axis of the front half part is the inlet end, and the end of the blade far from the central axis of the front half part is the outlet end. Along the fluid flow direction, the flow channel formed by the rear half part and the connecting part presents a gradually expanding form or a parallel state;

[0007] In the impeller axial view, the upper cover plate profile line of the impeller upper cover plate includes line segment one and line segment two, and line segment one is parallel to the axis of rotation of the space-twisted impeller; the lower cover plate profile line of the impeller lower cover plate includes line segment three and line segment four, and line segment four is perpendicular to the axis of rotation of the space-twisted impeller, and line segment one and line segment three present a gradually expanding form or a parallel state. The blade inlet edge of the blade is located in a parallel or gradually expanding flow channel, and the position of the blade inlet edge cannot exceed the intersection point of the upper cover plate profile line and the lower cover plate profile line.

[0008] Preferably, the first line segment, the second line segment, the third line segment, and the fourth line segment are all straight line segments.

[0009] Preferably, the first line segment and the second line segment intersect at point A, the third line segment and the fourth line segment intersect at point B, and the two end points of the blade inlet edge of the space-twisted impeller do not exceed point A and point B respectively.

[0010] Preferably, the blade inlet edge is located in a parallel or gradually expanding flow channel. The cavity between the blade outlet edge and the blade inlet edge of the space-twisted impeller is the inter-blade flow channel of the space-twisted impeller. And the inter-blade flow channel presents an expanding shape that gradually increases from the blade inlet edge to the blade outlet edge. Its lower limit value lies in that the first line segment is parallel to the third line segment.

[0011] Preferably, the blade is a straight blade.

[0012] Compared with the prior art, the present utility model has the following beneficial effects:

[0013] 1. The space-twisted impeller combines the advantages of the existing cylindrical straight blade and the existing space-twisted impeller: it has high hydraulic performance and high hydraulic efficiency, and can fully meet the requirements of current high energy efficiency indicators; it has good mold processability, and the demolding is simple and easy.

[0014] 2. The space-twisted impeller, through the settings of the upper cover plate of the impeller, the lower cover plate of the impeller, and the blade, reduces the processing difficulty of the space-twisted impeller, making the solution of the present application have good mold processability. And through the setting of the inter-blade flow channel, the blade inlet angle can change with the change of the liquid flow angle of the medium flow. The hydraulic loss of the inter-blade flow channel is small, and the achievable efficiency is very high. It can achieve high hydraulic performance and hydraulic efficiency, so that the space-twisted impeller combines the advantages of the existing cylindrical straight blade and the existing space-twisted impeller. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic diagram of a blade impeller in the prior art;

[0016] Figure 2 is Figure 1 the axial plane schematic diagram of the impeller;

[0017] Figure 3 is the front schematic diagram of the structure of the present utility model;

[0018] Figure 4 is the Figure 3 axial plane schematic diagram of the impeller of the present utility model;

[0019] Figure 5 is the performance and efficiency comparison of the embodiment of the impeller of the solution of the present application with a conventional cylindrical impeller and a conventional space-twisted impeller.

[0020] In the figure: 1. Upper cover plate of the impeller; 2. Blade; 3. Lower cover plate of the impeller; 4. Front half part; 004. Leading edge of the blade; 5. Rear half part; 005a. Line segment one; 005b. Line segment two; 6. Connecting part; 006. Trailing edge of the blade; 7. Middle part; 007a. Line segment three; 007b. Line segment four; 009. Axis of rotation of the space-twisted impeller. Specific embodiments

[0021] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0022] Referring to the attached drawings of the specification Figure 3 , the present invention provides a space-twisted impeller, which includes an upper cover plate 1 of the impeller, a blade 2, and a lower cover plate 3 of the impeller. The upper cover plate 1 of the impeller is connected to the lower cover plate 3 of the impeller through the blade 2. The upper cover plate 1 of the impeller includes a front half part 4 far from the blade 2 and a rear half part 5 connected to the blade 2, which are integrally formed. The lower cover plate 3 of the impeller includes a connecting part 6 connected to the blade 2 and a middle part 7 located in the middle of the connecting part 6. As Figure 1 shown in the state, both the front half part 4 and the middle part 7 are in a vertical state. One end of the blade 2 adjacent to the central axis of the front half part 4 is the inlet end, and the end of the blade 2 far from the central axis of the front half part 4 is the outlet end. That is, the front half part 4 is the inlet end of the space-twisted impeller, and the side of the cavity formed by the rear half part 5 and the connecting part 6 far from the blade 2 is the outlet end of the space-twisted impeller. Along the fluid flow direction, the flow channel formed by the rear half part 5 and the connecting part 6 presents a gradually expanding form or a parallel state.

[0023] Through the above description, it can be seen that this impeller can achieve that the blade inlet angle can follow the change of the liquid flow angle of the medium by relying on the flow channel presenting a gradually expanding form or a parallel state, and can achieve high hydraulic performance and hydraulic efficiency. Therefore, there is no requirement for the shape of the blade 2 in the present application solution. The blade 2 can be a straight blade, which reduces the processing difficulty of this impeller and makes the space-twisted impeller have good die processability and simple mold release.

[0024] In the impeller axial plane diagram, as Figure 4As shown in the figure, the upper cover profile line of the upper cover plate 1 of the impeller includes line segment 005a and line segment 005b. Line segment 005a is parallel to the axis 009 of the rotating shaft of the space-twisted impeller; the lower cover profile line of the lower cover plate 3 of the impeller includes line segment 007a and line segment 007b. Line segment 007b is perpendicular to the axis 009 of the rotating shaft of the space-twisted impeller. Line segment 005a, line segment 005b, line segment 007a, and line segment 007b are all straight line segments.

[0025] Line segment 005a and line segment 005b intersect at point A, and line segment 007a and line segment 007b intersect at point B. The two endpoints of the blade inlet edge 004 of the space-twisted impeller do not exceed point A and point B respectively. The blade inlet edge 004 is located in a parallel or gradually expanding flow channel. The cavity between the blade outlet edge 006 and the blade inlet edge 004 of the space-twisted impeller is the inter-blade flow channel of the space-twisted impeller. And the inter-blade flow channel presents an expanding shape that gets larger from the blade inlet edge 004 to the blade outlet edge 006. Its lower limit value lies in that line segment 005a is parallel to line segment 007a.

[0026] From the above description, it can be seen that when this space-twisted impeller is in use, the blade inlet angle can change with the change of the liquid flow angle of the medium flow. The hydraulic loss of the inter-blade flow channel is small, and the achievable efficiency is very high. It can achieve high hydraulic performance and hydraulic efficiency, and improve the adaptability of this space-twisted impeller.

[0027] Figure 5 This is a comparison of the performance and efficiency of the impeller embodiment of the solution of this application with a conventional cylindrical impeller and a conventional space-twisted impeller. From the comparison results, it can be seen that the impeller of the solution of this application has good mold processability while also having excellent hydraulic performance and high hydraulic efficiency.

[0028] In summary: When this space-twisted impeller is in use, the blade inlet angle can change with the change of the liquid flow angle of the medium flow. The hydraulic loss of the inter-blade flow channel is small, and the achievable efficiency is very high. It can achieve high hydraulic performance and hydraulic efficiency, and improve the adaptability of this space-twisted impeller. Moreover, the setting of the upper cover plate 1 of the impeller and the lower cover plate 3 of the impeller makes this space-twisted impeller have mold processability and is easy to process and produce.

[0029] All the standard parts used in this utility model can be purchased from the market. The special-shaped parts can be customized according to the description in the specification and the drawings. The specific connection methods of each part all adopt the conventional means such as bolts, rivets, welding, etc. that are mature in the prior art. The machinery, parts and equipment all adopt the conventional models in the prior art, which will not be elaborated here. The content not described in detail in this specification belongs to the prior art well-known to those skilled in the art. Although the embodiments of the present utility model have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present utility model. The scope of the present utility model is defined by the appended claims and their equivalents.

Claims

1. A spatially distorted impeller, comprising an impeller upper cover plate (1), blades (2) and an impeller lower cover plate (3), characterized in that: The impeller upper cover plate (1) is connected to the impeller lower cover plate (3) via the blade (2); the impeller upper cover plate (1) comprises an integrally formed front half portion (4) away from the blade (2) and a rear half portion (5) connected to the blade (2); the impeller lower cover plate (3) comprises a connecting portion (6) connected to the blade (2) and an intermediate portion (7) located in the middle of the connecting portion (6); an end of the blade (2) adjacent to the central axis of the front half portion (4) is an inlet end, and an end of the blade (2) away from the central axis of the front half portion (4) is an outlet end; and along the flow direction of the fluid, the flow channel formed by the rear half portion (5) and the connecting portion (6) is in a gradually expanding form or in a parallel state; In the impeller axial plane view, the upper cover plate profile of the impeller upper cover plate (1) includes line segment one (005a) and line segment two (005b), and the line segment one (005a) is parallel to the axis (009) of the rotation axis of the space-distorted impeller; the lower cover plate profile of the impeller lower cover plate (3) includes line segment three (007a) and line segment four (007b), and the line segment four (007b) is perpendicular to the axis (009) of the rotation axis of the space-distorted impeller, and the line segment one (005a) and the line segment three (007a) are in a gradually expanding form or in a parallel state, and the blade inlet edge (004) of the blade (2) is located in a parallel or gradually expanding flow channel, and the position of the blade inlet edge (004) cannot exceed the intersection of the upper cover plate profile line and the lower cover plate profile line.

2. A spatially distorted impeller according to claim 1, characterized in that: The line segment one (005a), the line segment two (005b), the line segment three (007a) and the line segment four (007b) are all straight line segments.

3. A spatially distorted impeller according to claim 2, characterized in that: The line segment one (005a) and the line segment two (005b) intersect at point A, the line segment three (007a) and the line segment four (007b) intersect at point B, and the two endpoints of the blade inlet edge (004) of the space-distorted impeller do not exceed point A and point B respectively.

4. A spatially distorted impeller according to claim 3, characterized in that: The blade inlet edge (004) is located in a parallel or gradually expanding flow channel, and the cavity between the blade outlet edge (006) of the spatially distorted impeller and the blade inlet edge (004) is the inter-blade flow channel of the spatially distorted impeller, and the inter-blade flow channel presents an expanding shape from small to large from the blade inlet edge (004) to the blade outlet edge (006), and its lower limit value is that the line segment one (005a) is parallel to the line segment three (007a).

5. The spatially distorted impeller according to claim 3, characterized in that: The blades (2) are straight blades.

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