An axial flow reflux pump

Abstract

An axial flow reflux pump includes an inlet horn, a guide vane body, an impeller, and a motor shaft. The inlet horn is connected to the guide vane body to form an impeller chamber. A through hole is opened at the center of the guide vane body for the motor shaft to pass through. One end of the motor shaft passes through the through hole in the guide vane body and enters the impeller chamber. The impeller is located in the impeller chamber and has blades and a blade seat. One end of the blade seat is the motor shaft end, and the other end is a guide head end. The blade seat has a motor shaft cavity at the motor shaft end and a guide head cavity at the guide head end. The motor shaft extends into the motor shaft cavity and connects to the impeller. Several blades are provided on the outer wall of the guide head end. The guide head end gives the impeller a flow guiding structure and the ability to guide flow. No additional flow guiding structure needs to be installed, avoiding the situation where the overall streamline of the flow guiding structure is destroyed due to providing bolt installation positions, greatly simplifying the installation steps.

Description

Technical Field

[0001] This utility model belongs to the field of axial flow pump technology, specifically relating to an axial flow reflux pump. Background Technology

[0002] Axial flow pumps are a common type of pump. They rely on the force exerted by the blades of a rotating impeller on the liquid to transport it along the axial direction. They come in several types, including vertical, horizontal, inclined, and through-flow pumps, and are widely used in farmland irrigation, municipal water supply and drainage, water diversion projects, and power plant circulating water projects. Axial flow pumps mainly consist of a flow guide assembly, a power assembly, and a discharge assembly. They offer advantages such as large water delivery capacity, fast water delivery speed, and low energy consumption.

[0003] During operation, the impeller of an axial flow pump needs to be maintained and replaced regularly. The connection between the impeller and the guide shroud of axial flow pumps on the market is usually made by multiple bolts. In order to provide installation positions for the bolts, the streamline shape of the guide shroud will have a break. The liquid will form a vortex at the break, which will reduce the working efficiency of the axial flow pump. Furthermore, due to the increase in components, the steps to replace the impeller when it is damaged are more numerous, which increases the difficulty of maintenance.

[0004] For details, please refer to the Chinese utility model patent application CN202422610800.7, which discloses a dual-outlet vertical axial flow pump. This utility model has a guide cone installed separately on one side of the impeller. In order to provide a bolt mounting position, an installation groove is provided on the guide cone, which destroys the overall streamline of the guide cone, causing energy loss and reducing the overall working efficiency of the axial flow pump. In addition, due to the narrow installation position, when replacing the impeller, it is necessary to remove the inlet horn first before the impeller can be replaced, which makes the replacement process cumbersome and time-consuming. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide an axial flow reflux pump that addresses the shortcomings of the prior art.

[0006] To address the shortcomings of existing technologies, this utility model provides an axial flow reflux pump. To solve the aforementioned technical problems, the technical solution provided by this utility model is as follows: An axial flow reflux pump includes an inlet horn, a guide vane body, an impeller, and a motor shaft. The inlet horn and the guide vane body are connected to form an impeller chamber. A through hole is opened at the center of the guide vane body for the motor shaft to pass through. One end of the motor shaft passes through the through hole on the guide vane body and enters the impeller chamber. The impeller is located in the impeller chamber and has blades and a blade seat. One end of the blade seat is the motor shaft end, and the other end is the guide head end. A partition wall is provided between the motor shaft end and the guide head end. The blade seat has a motor shaft cavity at the motor shaft end and a guide head cavity at the guide head end. The motor shaft extends into the motor shaft cavity and connects to the impeller. Several blades are provided on the outer wall of the guide head end.

[0007] Furthermore, the axial flow reflux pump also includes a pump cover and a mechanical seal assembly. The pump cover is connected to the guide vane body to form a sealing chamber. The mechanical seal assembly is installed on the outer side wall of the sealing chamber where the motor shaft is located. One end of the mechanical seal assembly abuts against the pump cover, and the other end abuts against the guide vane body.

[0008] Furthermore, the axial flow reflux pump also includes a guide plug, which is installed at the guide head end of the impeller, so that the guide head cavity forms a closed space. Furthermore, a keyway is provided at the connection between the motor shaft and the impeller.

[0009] Furthermore, the shape of the guide head is conical.

[0010] Furthermore, the inlet horn and the guide vane are made of gray cast iron.

[0011] Furthermore, the blade adopts a backward-curved blade structure.

[0012] The beneficial effects of this utility model are: one end of the impeller is a flow guide head end, which enables the impeller itself to have a flow guide structure and the ability to guide flow. There is no need to install an additional flow guide structure, which avoids the situation where the overall streamline of the flow guide structure is destroyed due to the lack of a bolt installation position. In addition, the step of installing the flow guide structure is eliminated during assembly. Since the bolt installation position is designed inside the impeller, no additional installation operation space is required. When replacing the impeller, there is no need to disassemble the water inlet horn and the guide vane body. It is only necessary to install the impeller on the motor shaft, which greatly simplifies the installation steps. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the present invention;

[0014] Figure 2This is a magnified view of part A in the diagram;

[0015] Figure 3 This is a schematic diagram of the impeller in Example 1;

[0016] Figure 4 This is a cross-sectional view of the impeller in Example 1;

[0017] Figure 5 This is a top view of the impeller in Example 1;

[0018] Figure 6 This is a top view of the impeller in Example 2;

[0019] Figure 7 This is a top view of the connector in Example 2;

[0020] Figure 8 This is a half-sectional view of the connector in Example 2;

[0021] Figure 9 This is a partial exploded view of the impeller in Example 2. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings.

[0023] It should be noted that if any directional indication (such as up, down, left, right, front, back, top, bottom, inside, outside, vertical, horizontal, longitudinal, counterclockwise, clockwise, circumferential, radial, axial, etc.) is involved in the embodiments of this utility model, the directional indication is only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly. Example 1

[0024] See Figures 1 to 5This utility model provides an axial flow reflux pump, including an inlet horn 1, a guide vane 2, an impeller 3, a motor shaft 4, a pump cover 5, a mechanical seal assembly 6, and a flow guide plug 7. The inlet horn 1 and the guide vane 2 are bolted together to form an impeller chamber 11. The pump cover 5 and the guide vane 2 have through holes at their centers for the motor shaft 4 to pass through. One end of the motor shaft 4 enters from one side of the pump cover 5, passes through the through hole on the guide vane 2, and enters the impeller chamber 11. The impeller 3 includes blades 31 and a blade seat 32. The blade seat 32 has a plurality of blades 31. The guide plug 7 is threadedly connected to one end of the blade seat 32. The pump cover 5 and the guide vane body 2 are bolted together, forming a sealing chamber 51. The blades 31 and the blade seat 32 are designed as a single unit, with one end of the blade seat 32 being the motor shaft end 33 and the other end being the guide vane body 32. The flow head end 34 has a motor shaft cavity 36 inside the motor shaft end 33 and a flow head cavity 37 inside the flow head end 34. The motor shaft cavity 36 is used to connect the motor shaft 4 and the blade seat 32. A partition wall 35 is provided between the motor shaft end 33 and the flow head end 34. The partition wall 35 has bolt holes for bolts to pass through. The impeller 3 is connected to the motor shaft 4 by bolts. One end of the motor shaft 4 has a threaded hole. The bolt passes through the bolt hole in the impeller 3 to lock the impeller 3 onto the motor shaft 4, so that the impeller 3 can rotate with the motor shaft 4. For easy installation, the flow head end 34 is open. The flow guide plug 7 is connected to the opening so that the flow guide plug 7 and the outer wall of the blade seat 32 of the flow head end 34 form a complete streamline shape, so that the liquid will not rush into the flow head cavity 37 during flow, causing a decrease in the efficiency of the axial flow pump.

[0025] In this embodiment, the guide head 34 is cone-shaped. The cone-shaped guide head 34 can make the liquid evenly distributed to the blades 31, reducing local resistance and backflow problems. As part of the impeller 3, the guide head 34 eliminates the need to weld an additional guide shroud onto the impeller 3 for guiding the flow, which can reduce maintenance steps and reduce maintenance difficulty.

[0026] In this embodiment, a keyway 41 is provided at the connection between the motor shaft 4 and the impeller 3. The cooperation between the keyway 41 and the key prevents the impeller 3 from rotating circumferentially when subjected to water flow impact, thereby reducing the risk of bolt fastening failure.

[0027] In this embodiment, the mechanical seal assembly 6 is installed on the part of the motor shaft 4 located outside the sealing chamber 51. One end of the mechanical seal assembly 6 abuts against the pump cover 5, and the other end abuts against the guide vane body 2. When the axial flow reflux pump is working in some working environments, it is submerged in water. There is an assembly gap between the pump cover 5 and the guide vane body 2. When it is submerged in water for a long time, water will flow into the pump and cause damage to the motor. The mechanical seal assembly 6 can prevent such a situation from occurring.

[0028] Preferably, the inlet horn 1 and the guide vane 2 are made of gray cast iron, which has high tensile strength and wear resistance, can extend the working life of the entire pump body, and has good vibration reduction performance, which can effectively reduce mechanical vibration.

[0029] Preferably, the blade 31 adopts a backward-curved blade design. The bending direction of the blade outlet portion of the backward-curved blade is opposite to the impeller rotation direction, that is, the blade bends in the opposite direction of rotation. When viewed from the radial section of the impeller, the angle between the extended line of the outer side of the blade and the tangent of the rotation direction at that point is an acute angle. This geometric structure allows the liquid to accelerate more smoothly in the impeller and has a lower absolute velocity when leaving the impeller, reducing the loss of kinetic energy in subsequent stages due to friction or impact. In contrast, the absolute velocity at the outlet of the forward-curved blade is higher, which will cause greater friction or impact losses in the subsequent stages. Moreover, the high kinetic energy of the liquid is more likely to generate vortices, thus consuming energy. Therefore, the backward-curved blade is more suitable for axial flow pumps, which are suitable for liquid pumps with low head and high flow rate requirements. Compared with the forward-curved blade, the backward-curved blade has higher working efficiency and is less prone to vortex formation. Example 2

[0030] The specific implementation of this embodiment is largely the same as that of Embodiment 1, the difference being the structure of the impeller, see reference [link to previous document]. Figures 6 to 9The impeller in this embodiment includes blades 31, a blade seat 32, and a connector 38. The blades 31 and the blade seat 32 are designed to be separate and are connected by the connector 38. The connector 38 has a flange 381, a mating post 382, ​​and an adjustment hole 383. The flange 381 is perpendicularly connected to the mating post 382, ​​and the flange 381 has the adjustment hole 383. The blade seat 32 has a mounting hole 321 for connecting the connector 38. The mating post 382 on the connector 38 and the mounting hole 321 on the blade seat 32 are press-fitted, allowing the connector 38 to be connected to the blade seat 32. This design ensures a secure connection between the connector 38 and the blade seat 32, while also simplifying the assembly process. The blade 31 has several threaded holes 311 corresponding to the size of the adjustment hole 383. The connector 38 and the blade 31 are connected together by bolts. The tilt angle of the blade 31 can be adjusted by adjusting the position of the bolts passing through the adjustment hole 383, allowing the axial flow pump to adapt to more different operating conditions. Because the opening position of the adjustment hole 383 is fixed on the flange 381, the angle change is a fixed value when adjusting the tilt angle of the blade 31, preventing excessive deviation in the tilt angle adjustment due to manual adjustment.

[0031] The above description is only a preferred embodiment of the present utility model. Any technical solution that achieves the purpose of the present utility model by essentially the same means shall fall within the protection scope of the present utility model.

Claims

1. An axial flow reflux pump, characterized in that: The device includes an inlet horn (1), a guide vane body (2), an impeller (3), and a motor shaft (4). The inlet horn (1) and the guide vane body (2) are connected to form an impeller chamber (11). The guide vane body (2) has a through hole at its center for the motor shaft (4) to pass through. One end of the motor shaft (4) passes through the through hole on the guide vane body (2) and enters the impeller chamber (11). The impeller (3) is located in the impeller chamber (11). The impeller (3) is provided with blades (31) and blade seats (32). One end is a motor shaft end (33), and the other end is a guide head end (34). A partition wall (35) is provided between the motor shaft end (33) and the guide head end (34). The blade seat (32) has a motor shaft cavity (36) on the motor shaft end (33) and a guide head cavity (37) on the guide head end (34). The motor shaft (4) extends into the motor shaft cavity (36) and is connected to the impeller (3). Several blades (31) are provided on the outer wall of the guide head end (34).

2. The axial flow reflux pump according to claim 1, characterized in that: It also includes a pump cover (5) and a mechanical seal assembly (6). The pump cover (5) is connected to the guide vane body (2) to form a sealing chamber (51). The mechanical seal assembly (6) is installed on a portion of the outer wall of the sealing chamber (51) of the motor shaft (4). One end of the mechanical seal assembly (6) abuts against the pump cover (5) and the other end abuts against the guide vane body (2).

3. The axial flow reflux pump according to claim 1, characterized in that: It also includes a flow guide plug (7), which is installed on the flow guide head end (34) of the blade seat (32) to form a closed space in the flow guide head cavity (37).

4. An axial flow reflux pump according to claim 1, characterized in that: A keyway (41) is provided at the connection between the motor shaft (4) and the impeller (3).

5. An axial flow reflux pump according to claim 1, characterized in that: The shape of the guide head (34) is conical.

6. An axial flow reflux pump according to claim 1, characterized in that: The inlet horn (1) and the guide vane (2) are made of gray cast iron.

7. An axial flow reflux pump according to claim 1, characterized in that: The blade (31) adopts a backward-curved blade structure.

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