Centrifugal pump with liquid flow direct impact prevention structure

Abstract

The utility model is specifically related to a centrifugal pump with liquid flow direct impact prevention structure, including pump shell and drive mechanism, the pump shell is provided with liquid inlet and liquid outlet respectively which are communicated with its inner chamber, the inner chamber of pump shell is fixed between liquid inlet and impeller component and is provided with the flow guide piece which is coaxial with liquid inlet, the flow guide piece includes umbrella head part, the end face of umbrella head part corresponding liquid inlet is provided with the umbrella shape curved surface which is convex to liquid inlet and is used for changing the flow direction of liquid inlet, the edge of umbrella shape curved surface is tangentially directed to the blade. After liquid inlet enters the inner chamber of pump shell through liquid inlet, the flow direction is changed by the umbrella shape curved surface of flow guide piece and is impacted to the blade, compared with the form that liquid inlet is vertically flowed to the center of impeller, the impact loss of liquid flow is reduced, the liquid inlet impact is effectively converted into the rotating force of impeller, so that the hydraulic efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of centrifugal pump technology, specifically to a centrifugal pump with a structure to prevent direct liquid flow. Background Technology

[0002] Centrifugal pumps work by using the rotation of an impeller to cause water to move centrifugally. They are commonly used in smart bathroom products, especially smart toilets. A centrifugal pump generally includes a drive mechanism and a pump casing. The pump casing has an inlet and an outlet that communicate with its internal cavity. Inside the pump casing, there is also an impeller assembly and a pump shaft. The pump shaft passes through the impeller assembly and is coaxial with it. The drive mechanism drives the impeller assembly to rotate around the pump shaft, causing the liquid flow to move centrifugally. The inlet liquid is thrown towards the outer edge of the impeller, generating a large scouring force, and then flows into the outlet through the flow channel of the pump casing.

[0003] In conventional centrifugal pumps, the liquid flows vertically towards the center of the impeller after entering the pump chamber through the inlet pipe, resulting in a significant loss of liquid flow force and making it impossible to effectively utilize the liquid flow force to form a scouring force. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings and deficiencies of the existing technology and to provide a centrifugal pump with a structure that prevents direct liquid flow.

[0005] The technical solution adopted by this utility model is as follows: A centrifugal pump with a structure to prevent direct liquid flow includes a pump casing and a drive mechanism. The pump casing is respectively provided with an inlet and an outlet communicating with its inner cavity. The inner cavity of the pump casing is provided with an impeller assembly and a pump shaft, both coaxial with the inlet. The impeller assembly includes a connecting rod and an impeller connected to the end of the connecting rod near the inlet. The impeller includes a hub and a plurality of blades arranged around the hub. The pump shaft passes through the center of the connecting rod, and the drive mechanism drives the impeller assembly to rotate around the pump shaft. A flow guide, coaxial with the inlet, is fixedly installed in the inner cavity of the pump casing between the inlet and the impeller assembly. The flow guide includes an umbrella head, the end face of which is convex to the inlet and has an umbrella-shaped curved surface for changing the direction of the inlet flow. The edge of the umbrella-shaped curved surface is tangentially directed towards the blade.

[0006] Preferably, the edge tangent of the umbrella-shaped curved surface is perpendicular to the edge streamline of the blade.

[0007] Preferably, the guide member further includes an upper shaft seat portion connected to the lower end of the umbrella head and located within the inner hole of the hub, with a gap between the inner hole of the hub and the upper shaft seat portion. The lower end of the upper shaft seat has a shaft seat hole at its center, and the upper end of the pump shaft passes through the shaft seat hole to form a fixed connection with the upper shaft seat.

[0008] Preferably, the umbrella head is coaxially arranged with the upper shaft seat, and the size of the umbrella head is larger than the size of the inner hole of the hub and covers it.

[0009] Preferably, the size of the umbrella head is not greater than the size of the wheel hub.

[0010] Preferably, the pump housing is provided with a lower shaft seat for the lower end of the pump shaft to be inserted and fixedly connected. A bearing is provided between the inner circumference of the connecting rod and the outer circumference of the pump shaft. A first shim and a second shim are respectively provided between the upper and lower ends of the bearing and the guide member and the lower shaft seat. The distance between the lower end face of the umbrella head and the upper end face of the hub is D1. The distances between the bearing and the first shim and the second shim are D2 and D3 respectively, where D1 > D2 and D1 > D3.

[0011] Preferably, the flow guide is fixed to the inner wall of the pump housing via at least one connecting arm.

[0012] Preferably, the pump housing includes a volute and a motor housing with openings opposite to each other and connected, and the inlet, outlet, guide, and connecting arm are integrally formed on the volute.

[0013] The beneficial effects of this utility model are as follows: After the liquid enters the pump casing cavity through the inlet, the flow direction is changed by the umbrella-shaped curved surface of the guide and it flows towards the blades. Compared with the form of the liquid flowing vertically towards the center of the impeller, the impact force loss of the liquid flow is reduced, and the impact force of the liquid is effectively converted into the rotational force of the impeller, thereby improving the hydraulic efficiency; the dynamic balance of the impeller is enhanced, and vibration and noise are reduced. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, obtaining other drawings based on these drawings without creative effort still falls within the scope of this utility model.

[0015] Figure 1 This is a perspective structural diagram of an embodiment of the present utility model; Figure 2 This is a top view of an embodiment of the present utility model; Figure 3 for Figure 2 Sectional view of the structure at point AA; Figure 4 for Figure 3 Enlarged view of the structure at point B in the middle; In the figure, 1 is the pump casing; 3 is the pump shaft; 4 is the flow guide; 5 is the bearing; 6 is the first gasket; 7 is the second gasket; 8 is the connecting arm; 11 is the inlet; 12 is the outlet; 13 is the lower shaft seat; 21 is the connecting rod; 22 is the impeller; 41 is the umbrella head; 42 is the upper shaft seat; 101 is the volute; 102 is the motor housing; 221 is the blade; 222 is the hub; 411 is the umbrella-shaped curved surface; 421 is the shaft seat hole; 2211 is the edge streamline. Detailed Implementation

[0016] To make the objectives, technical solutions and advantages of this utility model clearer, the utility model will be described in further detail below with reference to the accompanying drawings.

[0017] It should be noted that all uses of "first" and "second" in the embodiments of this utility model are for the purpose of distinguishing two entities or parameters with the same name but different names. It is clear that "first" and "second" are only for the convenience of expression and should not be construed as limiting the embodiments of this utility model. Subsequent embodiments will not explain this in detail.

[0018] The directional and positional terms used in this utility model, such as "up," "down," "front," "back," "left," "right," "inner," "outer," "top," "bottom," and "side," are merely for reference to the accompanying drawings. Therefore, the directional and positional terms used are for the purpose of explaining and understanding this utility model, and not for limiting the scope of protection of this utility model.

[0019] like Figures 1 to 4 As shown in the illustration, a centrifugal pump with a direct-flow prevention structure is provided in an embodiment of this utility model. The pump includes a pump casing 1 and a drive mechanism. The pump casing 1 is provided with an inlet 11 and an outlet 12 communicating with its inner cavity. The inner cavity of the pump casing 1 is provided with an impeller assembly and a pump shaft 3, both coaxial with the inlet 11. The impeller assembly includes a connecting rod 21 and an impeller 22 connected to one end of the connecting rod 21 near the inlet 11. The impeller 22 includes a hub 222 and a plurality of blades 221 arranged around the hub 222. The pump shaft 3 passes through the center of the connecting rod 21, and the drive mechanism drives the impeller assembly to rotate around the pump shaft 3. A flow guide 4, coaxial with the inlet 11, is fixedly installed in the inner cavity of the pump housing 1 between the inlet 11 and the impeller assembly. The flow guide 4 includes an umbrella head 41. The end face of the umbrella head 41 corresponding to the inlet 11 is convex to the inlet 11 and is provided with an umbrella-shaped curved surface 411 for changing the direction of liquid flow. The edge of the umbrella-shaped curved surface 411 is tangentially directed towards the blade 221.

[0020] With this design, after the liquid enters the pump casing cavity through the inlet, its flow direction is changed by the umbrella-shaped curved surface of the guide and it flows towards the blades. Compared with the form where the liquid flows vertically towards the center of the impeller, this reduces the impact force loss of the liquid flow and effectively converts the impact force of the liquid into the rotational force of the impeller, thereby improving hydraulic efficiency; it also enhances the dynamic balance of the impeller and reduces vibration and noise.

[0021] This embodiment is specifically a miniature centrifugal pump. The drive assembly includes a stator winding, a rotor magnet, and a drive circuit board. The rotor magnet is fixed around the outer periphery of the connecting rod. After being energized, the rotor is driven to rotate by magnetic force, which in turn drives the impeller assembly to rotate. There is no need for a mechanical seal, which reduces friction and wear and improves the reliability and life of the pump. At the same time, since there is no mechanical contact, the pump has low noise during operation, making it suitable for noise-sensitive application environments.

[0022] The edge tangent of the umbrella-shaped curved surface 411 is perpendicular to the edge streamline 2211 of the blade 221.

[0023] With this configuration, since the streamlined edge of the blades is where the impeller lever arm is longest, the torque generated by the liquid flow impact at this point is the greatest, resulting in higher angular acceleration and a more significant increase in rotational speed. This further reduces the impact force loss of the liquid flow, maximizing the conversion of the inlet impact force into the impeller's rotational power. The guide member 4 also includes an upper shaft seat 42 connected to the lower end of the umbrella head 41 and located inside the inner hole of the hub 222, with a gap between the inner hole of the hub 222 and the upper shaft seat 42. The lower end of the upper shaft seat 42 has a shaft seat hole 421 at its center, and the upper end of the pump shaft 3 passes through the shaft seat hole 421 to form a fixed connection with the upper shaft seat 42.

[0024] This design allows the umbrella head to act as a water barrier, preventing liquid from directly impacting the impeller hub gap and causing hydraulic loss.

[0025] The umbrella head 41 is coaxially arranged with the upper shaft seat 42, and the size of the umbrella head 41 is larger than the size of the inner hole of the hub 222 and forms a cover over it.

[0026] This setting ensures that the liquid flow directly into the gap between the hub and the pump shaft seat is completely blocked from the inlet.

[0027] The size of the umbrella head 41 is not greater than the size of the hub 222.

[0028] This design prevents the liquid flow from rushing directly into the gap between the hub and the pump shaft seat, without affecting the width of the blade inlet channel.

[0029] The pump housing 1 is provided with a lower shaft seat 13 for the lower end of the pump shaft 3 to be inserted and fixedly connected. A bearing 5 is provided between the inner circumference of the connecting rod 21 and the outer circumference of the pump shaft 3. A first gasket 6 and a second gasket 7 are respectively provided between the upper and lower ends of the bearing 5 and the guide member 4 and the lower shaft seat 13. The distance between the lower end face of the umbrella head 41 and the upper end face of the hub 222 is D1. The distances between the bearing 5 and the first gasket 6 and the second gasket 7 are D2 and D3 respectively, where D1 > D2 and D1 > D3.

[0030] This design prevents the umbrella head from colliding and rubbing against the hub when the impeller moves axially.

[0031] The flow guide 4 is fixed to the inner wall of the pump casing 1 by at least one connecting arm 8.

[0032] This embodiment specifically includes three configurations.

[0033] The pump housing 1 includes a volute 101 and a motor housing 102 with openings opposite to each other and connected. The inlet 11, outlet 12, guide 4, and connecting arm 8 are integrally formed on the volute 101.

[0034] This setting improves the convenience of production and processing.

[0035] The above-disclosed embodiments are merely preferred embodiments of the present utility model and should not be construed as limiting the scope of the present utility model. Therefore, any equivalent variations made in accordance with the claims of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A centrifugal pump with a structure to prevent direct liquid flow, comprising a pump casing (1) and a drive mechanism, wherein the pump casing (1) is provided with an inlet (11) and an outlet (12) communicating with its inner cavity, and the inner cavity of the pump casing (1) is provided with an impeller assembly and a pump shaft (3) coaxial with the inlet (11), the impeller assembly comprising a connecting rod (21) and an impeller (22) connected to one end of the connecting rod (21) near the inlet (11), the impeller (22) comprising a hub (222) and a plurality of blades (221) arranged around the hub (222), the pump shaft (3) passing through the center of the connecting rod (21), and the drive mechanism driving the impeller assembly to rotate around the pump shaft (3), characterized in that: A guide (4) coaxial with the inlet (11) is fixedly provided in the inner cavity of the pump housing (1) between the inlet (11) and the impeller assembly. The guide (4) includes an umbrella head (41). The end face of the umbrella head (41) corresponding to the inlet (11) is convex to the inlet (11) and is provided with an umbrella-shaped curved surface (411) for changing the direction of liquid flow. The edge of the umbrella-shaped curved surface (411) is tangentially pointing towards the blade (221).

2. A centrifugal pump with a structure to prevent direct liquid flow as described in claim 1, characterized in that: The edge tangent of the umbrella-shaped curved surface (411) is perpendicular to the edge streamline (2211) of the blade (221).

3. A centrifugal pump with a structure to prevent direct liquid flow as described in claim 1, characterized in that: The guide (4) also includes an upper shaft seat (42) connected to the lower end of the umbrella head (41) and located in the inner hole of the hub (222), with a gap between the inner hole of the hub (222) and the upper shaft seat (42). The lower end of the upper shaft seat (42) has a shaft seat hole (421), and the upper end of the pump shaft (3) passes through the shaft seat hole (421) to form a fixed connection with the upper shaft seat (42).

4. A centrifugal pump with a structure to prevent direct liquid flow as described in claim 3, characterized in that: The umbrella head (41) is coaxially arranged with the upper shaft seat (42), and the size of the umbrella head (41) is larger than the size of the inner hole of the hub (222) and forms a cover over it.

5. A centrifugal pump with a structure to prevent direct liquid flow as described in claim 3, characterized in that: The size of the umbrella head (41) is not greater than the size of the hub (222).

6. A centrifugal pump with a structure to prevent direct liquid flow as described in claim 3, characterized in that: The pump casing (1) is provided with a lower shaft seat (13) into which the lower end of the pump shaft (3) is inserted and fixedly connected. A bearing (5) is provided between the inner circumference of the connecting rod (21) and the outer circumference of the pump shaft (3). A first gasket (6) and a second gasket (7) are respectively provided between the upper and lower ends of the bearing (5) and the guide (4) and the lower shaft seat (13). The distance between the lower end face of the umbrella head (41) and the upper end face of the hub (222) is D1. The distances between the bearing (5) and the first gasket (6) and the second gasket (7) are D2 and D3 respectively, where D1 > D2 and D1 > D3.

7. A centrifugal pump with a structure for preventing direct liquid flow as described in any one of claims 1-6, characterized in that: The flow guide (4) is fixed to the inner wall of the pump housing (1) by at least one connecting arm (8).

8. A centrifugal pump with a structure to prevent direct liquid flow as described in claim 7, characterized in that: The pump housing (1) includes a volute (101) and a motor housing (102) with openings facing each other and connected. The inlet (11), outlet (12), guide (4), and connecting arm (8) are integrally formed on the volute (101).

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