Backflow prevention structure of pump head

Abstract

The utility model provides an anti-backflow structure of a pump head, and belongs to the technical field of centrifugal pumps. The problem of how to avoid backflow is solved. In the backflow prevention structure of the pump head, the pump head comprises a shell internally provided with a water inlet channel, a water outlet channel and a mounting cavity, a centrifugal impeller internally provided with a centrifugal channel is rotationally connected into the mounting cavity, and the water inlet end of the centrifugal channel communicates with the water inlet channel; the backflow prevention structure is characterized in that the backflow prevention structure comprises a graphite ring, the graphite ring is positioned in the mounting cavity and arranged around the water outlet end of the water inlet channel, one end of the centrifugal impeller is used for being in transmission connection with a drive motor, and the other end of the centrifugal impeller is used for being in transmission connection with the drive motor. And the outer peripheral wall of the other end of the graphite ring is attached to the inner peripheral wall of the graphite ring. The backflow prevention structure of the pump head can effectively avoid backflow.

Description

Technical Field

[0001] The utility model belongs to the technical field of centrifugal pumps and relates to a backflow prevention structure of a pump head. Background Art

[0002] Centrifugal pump is one of the most widely used in today's life. Its working principle is roughly as follows: under the action of centrifugal force generated by the high-speed rotation of the centrifugal impeller, the pump head is an indispensable part of the centrifugal pump. It has an inlet channel, an outlet channel and an installation cavity connected to the two respectively. A centrifugal impeller fixedly connected to the motor drive shaft is rotatably connected in the installation cavity of the pump head. The centrifugal impeller has a centrifugal channel, and the inlet channel, centrifugal channel and outlet channel cooperate to form a complete water system.

[0003] When working, the motor drives the centrifugal impeller to rotate, so that the centrifugal impeller forms a negative pressure in the centrifugal channel under the action of centrifugal force. The negative pressure force draws water inward through the water inlet channel, and throws the water into the installation cavity through the rotation of the centrifugal impeller, so that the water pressure in the installation cavity continues to increase, and then the water in the installation cavity is pressed out through the water outlet channel, thereby completing the pumping work of the centrifugal pump.

[0004] However, there will be a certain gap between the centrifugal impeller rotatably connected in the installation cavity and the inner wall of the water inlet channel. When pumping water, due to the existence of negative pressure in the centrifugal channel, the pressure in the installation cavity is greater than the pressure in the water inlet channel. Therefore, part of the water in the installation cavity will flow back into the water inlet channel through the gap, seriously affecting the pumping efficiency of the water pump. Summary of the Invention

[0005] The purpose of the present invention is to solve the above problems in the existing technology and propose an anti-backflow structure for a pump head. The technical problem to be solved by the present invention is: how to avoid the occurrence of backflow.

[0006] The objectives of the present utility model can be achieved through the following technical solutions: a backflow prevention structure of a pump head, the pump head includes a shell with an inlet channel, a water outlet channel and an installation cavity provided inside, a centrifugal impeller with a centrifugal channel inside is rotatably connected in the installation cavity, the water inlet end of the centrifugal channel is connected to the water inlet channel, and the water outlet end of the centrifugal channel is connected to the water outlet channel through the installation cavity, and is characterized in that the backflow prevention structure includes a graphite ring, which is positioned in the installation cavity and arranged around the water outlet end of the water inlet channel, one end of the centrifugal impeller is used for transmission connection with the drive motor, and the outer peripheral wall of the other end is in contact with the inner peripheral wall of the graphite ring.

[0007] The working principle of the anti-backflow structure of this pump head is: when the motor in the centrifugal pump rotates, it drives the centrifugal impeller to rotate in the installation cavity through the drive shaft. It should be emphasized that the premise for the centrifugal pump to work and pump water is that the installation cavity and the inside of the water inlet channel are themselves in a state of being filled with water. At this time, as the centrifugal impeller rotates, the centrifugal channel in the centrifugal impeller generates negative pressure due to centrifugal force (the centrifugal impeller with a centrifugal channel is a conventional structure of the centrifugal pump in the prior art), so that water is sucked from the water inlet channel into the installation cavity through the existence of the negative pressure, so that the water pressure in the installation cavity increases and continuously presses the water outward through the water outlet channel. On this basis, the anti-backflow structure of this pump head is achieved by arranging a graphite ring circumferentially at the water outlet port of the water inlet channel in the installation cavity of the shell. The graphite ring seals the gap between the installation cavity and the water inlet channel, and makes the outer peripheral wall of one end of the centrifugal impeller located at the entrance of the centrifugal channel fit with the inner peripheral wall of the graphite ring, thereby effectively isolating the installation cavity and the water inlet channel, avoiding the backflow into the water inlet channel during the water extraction process. In addition, it is worth mentioning that the graphite ring itself is smooth and has a low friction coefficient, thereby reducing the wear and noise generated between the centrifugal impeller and the graphite ring when it is driven to rotate.

[0008] The inner wall of the installation cavity is provided with a stepped groove surrounding the outlet end of the water inlet channel. The backflow prevention structure further includes a mounting ring and a positioning ring. The positioning ring is clamped into the stepped groove, and the graphite ring is embedded in the mounting ring. The mounting ring is clamped into the positioning ring. To ensure stable installation of the graphite ring, an interference fit is generally used to embed it in the stepped groove. However, in reality, the hardness of the graphite ring itself is not as good as that of metal parts, and therefore it may break during actual installation. To avoid this, the present application first installs the graphite ring through the mounting ring structure, so that the mounting ring replaces the graphite ring in bearing force, thereby preventing the graphite ring from breaking during installation. Secondly, by pre-installing the positioning ring in the stepped groove, the radial dimension of the stepped groove is specifically reduced. The limiting portion of the mounting ring and the limiting portion of the positioning ring are interference fit, thereby ensuring the connection stability of the mounting ring and the graphite ring.

[0009] In the aforementioned pump head backflow prevention structure, the mounting ring includes a clamping portion arranged axially along the centrifugal impeller and a lifting portion arranged radially along the centrifugal impeller. The positioning ring includes a limiting portion arranged axially along the centrifugal impeller and an abutting portion arranged radially along the centrifugal impeller. The inner circumferential wall of the limiting portion is clamped to the outer circumferential wall of the clamping portion, and the outer circumferential wall of the limiting portion is clamped to the inner circumferential wall of the step groove. Thus, the mounting ring and the positioning ring cooperate to form an annular installation space, thereby ensuring stable installation of the graphite ring.

[0010] In the aforementioned anti-backflow structure of the pump head, the graphite ring abuts against the lifting portion, an elastic sealing ring is provided between the abutting portions, and the outer circumferential wall of the graphite ring fits closely against the inner circumferential wall of the clamping portion, thereby preventing the graphite ring from moving in the circumferential and axial directions of the centrifugal impeller.

[0011] In the anti-backflow structure of the pump head, a groove is formed on the outer edge of the top of the graphite ring along the circumferential direction, and the sealing ring is clamped in the groove to ensure the installation stability of the sealing ring.

[0012] In the aforementioned pump head backflow prevention structure, the sealing ring has a plurality of spherical protrusions along the circumference of its outer wall facing the abutment portion. These protrusions are spaced apart circumferentially along the sealing ring, and the sealing ring abuts against the inner side of the abutment portion via these protrusions. The sealing ring receives force locally via these protrusions, replacing the overall force applied by the transmission. This ensures a greater elastic deformation, thereby ensuring stable compression of the graphite ring.

[0013] Compared with the existing technology, the anti-backflow structure of this pump head has the following advantages: by installing a graphite ring around the water outlet end of the water inlet channel in the shell, one end of the centrifugal impeller is connected to the drive motor of the centrifugal pump, and the outer peripheral wall of the other end is in contact with the inner peripheral wall of the graphite ring. The gap between the installation cavity and the water inlet channel is sealed by the graphite ring, thereby preventing liquid backflow, and the surface of the graphite ring itself is smooth, which can prevent noise problems generated during operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a top view of the anti-backflow structure of this pump head.

[0015] Figure 2 yes Figure 1 Cross-sectional view taken along AA direction.

[0016] Figure 3 yes Figure 2 A partial enlarged view of point A in the middle.

[0017] Figure 4 This is an exploded view of the anti-backflow structure of this pump head.

[0018] Figure 5 It is a structural diagram of the sealing ring.

[0019] Figure 6 It is a structural diagram of the mounting ring.

[0020] Figure 7 It is a structural diagram of the positioning ring.

[0021] Figure 8 This is a bottom view of the pump head.

[0022] In the figure, 1. shell; 11. water inlet channel; 12. water outlet channel; 13. mounting cavity; 131. step groove; 2. centrifugal impeller; 21. centrifugal channel; 3. graphite ring; 31. slot; 4. mounting ring; 41. clamping part; 42. lifting part; 5. positioning ring; 51. limiting part; 52. abutting part; 6. sealing ring; 61. spherical convex part. DETAILED DESCRIPTION

[0023] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0024] The anti-backflow structure of this pump head is mainly used in the field of centrifugal pumps. It should be explained first that the pump head includes a shell 1 with an inlet channel 11, an outlet channel 12 and a mounting cavity 13 provided inside. The shell 1 is installed on the pump body of the centrifugal pump by bolts in a detachable connection manner. The internal mounting body thereof has a centrifugal impeller 2, and a drive motor is installed in the pump body. The two are connected together in a transmission manner, and the centrifugal impeller 2 and the drive motor are both existing technologies. A centrifugal channel 21 is provided in the centrifugal impeller 2 (specifically, the inlet end of the centrifugal channel 21 is arranged along the axial direction of the centrifugal impeller 2, and the outlet end is arranged along the circumference of the centrifugal impeller 2. Of course, this is also existing technology. The centrifugal impeller 2 currently used in centrifugal pumps has a flow channel structure with this arrangement). When the motor drives the centrifugal impeller 2 to rotate, the centrifugal impeller 2 can generate centrifugal negative pressure in the centrifugal channel 21 when it is driven to rotate.

[0025] like Figure 1 and Figure 8 As shown, the water inlet end of the water inlet channel 11 and the water outlet end of the water outlet channel 12 are both arranged in the transverse direction. Figure 2 As shown, the outlet end of the water inlet channel 11 is arranged along the axial direction of the centrifugal impeller 2 and is connected to the installation cavity 13, and the water inlet end of the water outlet channel 12 is arranged along the circumferential direction of the centrifugal impeller 2 and is connected to the installation cavity 13. The centrifugal impeller 2 arranged in the installation cavity 13 is connected to the water outlet end of the water inlet channel 11 through the water inlet end of the centrifugal channel 21, and the water outlet end of the centrifugal channel 21 is connected to the installation cavity 13. When working, the rotating centrifugal impeller 2 will cause a centrifugal negative pressure to be formed in the centrifugal channel 21 by centrifugal force, so that the water inlet channel 11 is affected by the negative pressure in the centrifugal channel 21 to absorb water inward, so that the water flows into the centrifugal channel 21 through the water inlet channel 11 in turn, and the continuously rotating centrifugal impeller 2 can throw the water in the centrifugal channel 21 into the installation cavity 13 at high speed, so that the pressure in the installation cavity 13 gradually increases. As the subsequent water flow continues to enter, the water in the installation cavity 13 is discharged outward through the water outlet channel 12.

[0026] When performing the above operation, since the centrifugal impeller 2 needs to rotate at high speed, there cannot be substantial contact between it and the inside of the installation cavity 13 to avoid affecting its rotation speed, and at the same time, the metal friction noise caused by the rotation process is minimized as much as possible. Therefore, a certain gap is left between the installation cavity 13 and the water outlet end of the water inlet channel 11, and the rotating centrifugal impeller 2 will affect the pressure in the water inlet channel 11, which is specifically manifested as the pressure in the water inlet channel 11 is lower than the pressure in the installation cavity 13. Therefore, when the pressure in the installation cavity 13 is greater than a certain level, part of the water will flow back into the water inlet channel 11 from the gap between the two. This phenomenon will interfere with the water flow rate in the water inlet channel 11 and the centrifugal channel 21, and may cause the water pressure in the installation cavity 13 to be affected to a certain extent, which is not conducive to the pumping efficiency of the centrifugal pump.

[0027] like Figure 3-7 As shown, a step groove 131 is provided around the water inlet channel 11 at the water outlet port of the water inlet channel 11 in the installation cavity 13. The backflow prevention structure includes a graphite ring 3, a mounting ring 4 and a positioning ring 5. The positioning ring 5 is fixed in the step groove 131. Specifically, the positioning ring 5 includes a limiting portion 51 provided along the axial direction of the centrifugal impeller 2 and an abutting portion 52 provided along the radial direction of the centrifugal impeller 2. The positioning ring 5 is clamped by the outer wall of the clamping portion 41 and the circumferential inner wall of the step groove 131, so that the abutting portion The outer wall of 52 and the circumferential groove bottom wall of the step groove 131 are clamped, and the mounting ring 4 specifically includes a clamping portion 41 arranged along the axial direction of the centrifugal impeller 2 and a lifting portion 42 arranged along the radial direction of the centrifugal impeller 2. The graphite ring 3 is embedded in the mounting ring 4 and abuts against the side of the lifting portion 42 facing the water outlet end of the water inlet channel 11, and the outer circumferential wall of the graphite ring 3 and the inner side wall of the clamping portion 41 are in contact with each other. The mounting ring 4 is embedded in the positioning ring 5 and the outer circumferential wall of the clamping portion 41 and the inner circumferential wall of the limiting portion 51 are clamped, so that the graphite ring 3 It is limited between the mounting ring 4 and the positioning ring 5. In addition, a card groove 31 is opened along the circumferential direction on the outer edge of the graphite ring 3 facing the abutment portion 52. A sealing ring 6 made of elastic material (such as rubber, silicone) is clamped in the card groove 31. The surface of the sealing ring 6 facing the abutment portion 52 is formed with a plurality of spherical protrusions 61 arranged at intervals along the circumferential direction. When assembling, as the positioning ring 5 is inserted and extended, the sealing ring 6 can continuously press against the inner wall of the abutment portion 52 through the spherical protrusions 61, thereby passing through the sealing ring The elastic force generated by the deformation presses the graphite ring 3 against the lifting portion 42. The centrifugal impeller 2 is connected to the motor through its lower end, and the upper end is inserted into the mounting ring 4 so that the outer peripheral wall fits the inner peripheral wall of the graphite ring 3, so that the gap between the mounting cavity 13 and the water outlet end of the water inlet channel 11 is completely sealed, thereby preventing the centrifugal pump from backflowing when pumping water. In addition, the surface of the graphite ring 3 itself is smooth and the friction coefficient is low. Due to the low friction coefficient, the centrifugal impeller 2 will not generate excessive noise when rotating.

[0028] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope defined by the appended claims.

[0029] Although this document frequently uses terms such as pump head 1, water inlet channel 11, water outlet channel 12, mounting cavity 13, stepped groove 131, centrifugal impeller 2, centrifugal channel 21, graphite ring 3, clamping groove 31, mounting ring 4, clamping portion 41, lifting portion 42, positioning ring 5, limiting portion 51, abutting portion 52, sealing ring 6, and spherical protrusion 61, the use of other terms is not excluded. These terms are used only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional limitations is contrary to the spirit of the present invention.

Claims

1. A backflow prevention structure for a pump head, the pump head comprising a housing (1) with an inlet channel (11), an outlet channel (12) and an installation cavity (13) provided therein, a centrifugal impeller (2) having a centrifugal channel (21) rotatably connected in the installation cavity (13), the inlet end of the centrifugal channel (21) being in communication with the inlet channel (11), the outlet end of the centrifugal channel (21) being in communication with the outlet channel (12) via the installation cavity (13), characterized in that: The backflow prevention structure comprises a graphite ring (3), which is positioned in the installation cavity (13) and arranged around the water outlet end of the water inlet channel (11); one end of the centrifugal impeller (2) is used for transmission connection with the drive motor, and the outer peripheral wall of the other end is in contact with the inner peripheral wall of the graphite ring (3).

2. The anti-backflow structure of the pump head according to claim 1, characterized in that: A stepped groove (131) is provided on the inner wall of the installation cavity (13) and is arranged around the water outlet end of the water inlet channel (11). The backflow prevention structure further comprises a mounting ring (4) and a positioning ring (5). The positioning ring (5) is clamped in the stepped groove (131). The graphite ring (3) is embedded in the mounting ring (4), and the mounting ring (4) is clamped in the positioning ring (5).

3. The anti-backflow structure of the pump head according to claim 2, characterized in that: The mounting ring (4) comprises a clamping portion (41) arranged along the axial direction of the centrifugal impeller (2) and a lifting portion (42) arranged along the radial direction of the centrifugal impeller (2); the positioning ring (5) comprises a limiting portion (51) arranged along the axial direction of the centrifugal impeller (2) and a supporting portion (52) arranged along the radial direction of the centrifugal impeller (2); the inner peripheral wall of the limiting portion (51) is clamped with the outer peripheral wall of the clamping portion (41), and the outer peripheral wall of the limiting portion (51) is clamped with the inner peripheral wall of the step groove (131).

4. The anti-backflow structure of the pump head according to claim 3, characterized in that: The graphite ring (3) abuts against the supporting portion (42), and an elastic sealing ring (6) is provided between the abutting portion (52), and the outer peripheral wall of the graphite ring (3) and the inner peripheral wall of the clamping portion (41) are in contact with each other.

5. The anti-backflow structure of the pump head according to claim 4, characterized in that: A clamping groove (31) is provided on the outer edge of the top of the graphite ring (3) along the circumferential direction, and the sealing ring (6) is clamped in the clamping groove (31).

6. The anti-backflow structure of the pump head according to claim 4 or 5, characterized in that: The sealing ring (6) has a plurality of spherical protrusions (61) along the circumferential direction on the outer wall facing the abutting portion (52), and the plurality of spherical protrusions (61) are arranged at intervals along the circumferential direction of the sealing ring (6), and the sealing ring (6) is tightly abutted against the inner side surface of the abutting portion (52) through the plurality of spherical protrusions (61).

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