A submersible sewage pump

Abstract

The present invention relates to a submersible sewage pump, which comprises a casing, a gland, a bearing seat, a rotating shaft, a pump body and an impeller. The top end and the bottom end of the casing are respectively connected to the gland and the bearing seat. An annular flange is provided on the inner wall of the pump body, and the annular flange is located outside the rear baffle of the impeller to form an annular gap. A mechanical seal seat is arranged between the bearing seat and the impeller. The mechanical seal seat is nested on the rotating shaft and its top end is connected to the bearing seat. An annular retaining edge is arranged at the bottom end of the mechanical seal seat. The inner wall of the annular retaining edge and the rotating shaft form an installation space for arranging a second mechanical seal ring, and the end of the annular retaining edge and the impeller form a seal seat gap. Compared with the prior art, the present invention has the advantages of providing two protections for the mechanical seal ring, avoiding the influence of impurities, and improving the working stability and service life, etc.

Description

Technical Field

[0001] The present invention relates to a submersible pump structure, and more particularly to a submersible sewage pump. Background Art

[0002] Submersible sewage pumps are mainly used in municipal engineering, building construction, industrial sewage discharge and sewage treatment, etc., to pump sewage, wastewater and rainwater containing solids and long fibers. In the traditional structure of submersible sewage pumps, there is usually only one mechanical seal ring between the rotating shaft and the bearing seat in the pump body. After some long fiber bodies enter the pump body from the impeller outlet, they will entangle the mechanical seal ring, thus affecting the normal operation of the mechanical seal ring, resulting in water leakage in the oil chamber and even malfunction alarm. At the same time, in the traditional submersible sewage pump, the motor wiring is located in the upper cavity of the housing, and sufficient height space needs to be reserved for the connection of the cable during use, resulting in limited use scenarios and affected convenience. Summary of the Invention

[0003] The purpose of the present invention is to overcome the defects existing in the above-mentioned prior art and provide a submersible sewage pump.

[0004] The purpose of the present invention can be achieved by the following technical solutions:

[0005] A submersible sewage pump, comprising a housing, a gland, a bearing seat, a rotating shaft, a pump body and an impeller. The top and bottom ends of the housing are respectively connected to the gland and the bearing seat. The pump body is fixed below the bearing seat. The impeller is installed inside the pump body. The top end of the rotating shaft is connected to the gland, and the bottom end of the rotating shaft passes through the bearing seat and then is connected to the impeller. A first mechanical seal ring is provided between the rotating shaft and the bearing seat.

[0006] A circular flange is provided on the inner wall of the pump body. The circular flange is located outside the rear baffle of the impeller to form an annular gap. A mechanical seal seat is provided between the bearing seat and the impeller. The mechanical seal seat is nested on the rotating shaft and its top end is connected to the bearing seat. A circular retaining edge is provided at the bottom end of the mechanical seal seat. The inner wall of the circular retaining edge and the rotating shaft form an installation space. The end of the circular retaining edge and the impeller form a seal seat gap. A second mechanical seal ring is provided in the installation space. The second mechanical seal ring includes a moving ring and a static ring. The static ring is connected to the mechanical seal seat, and the moving ring is connected to the impeller.

[0007] Further, a convex edge is provided on the outer circle of the rear baffle of the impeller, and an annular gap is formed between the convex edge and the circular flange.

[0008] Further, the annular gap is 0.2 mm to 0.5 mm.

[0009] Further, a sealing baffle is fixed on the impeller, and a seal seat gap is formed between the end of the circular retaining edge and the sealing baffle.

[0010] Further, one side of the bearing housing is provided with an opening, at which an electrical connection block is arranged, and the cable inside the housing is arranged in the electrical connection block.

[0011] Further, a through hole is provided at the lower end of the bearing housing for the rotation shaft to pass through. An annular side plate is arranged at the outer ring of the through hole, and the end of the annular side plate is connected to the mechanical seal seat. The first mechanical seal ring is arranged at the through hole. Thus, the annular side plate, the first mechanical seal ring and the mechanical seal seat form a sealed oil chamber C.

[0012] Further, a horizontal oil pipe is provided on the bearing housing. One end of the oil pipe communicates with the sealed oil chamber C, and the other end forms an oil port on the outer wall of the bearing housing. A sealing plug is arranged at the oil port.

[0013] Further, an oil-water probe is arranged on the side wall of the oil pipe.

[0014] Further, a handle frame is provided at the top end of the housing.

[0015] Further, a boss is provided on the side surface at the top end of the housing, and the end of the handle frame is connected to the boss by bolts.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The present invention provides two-stage protection for the mechanical seal ring. First, an annular gap is formed between the annular flange and the outer ring of the impeller to cut and crush long strip-shaped impurities, preventing them from winding around the mechanical seal ring. Then, a sealed seat gap B is formed between the annular edge of the mechanical seal seat and the impeller to grind and crush the cut impurities, preventing the impurities from affecting the second mechanical seal ring through the sealed seat gap B, making it not prone to failure and providing in-depth protection for the sealing structure.

[0018] 2. A convex edge is provided on the outer ring of the rear baffle of the impeller, improving the strength and wear resistance of the outer ring of the impeller and enhancing the reliability of cutting impurities.

[0019] 3. A sealing baffle is fixed on the impeller to prevent the impeller from being worn when the sealed seat gap B grinds impurities, providing protection for the impeller.

[0020] 4. The cable lead-out end of the motor is moved from the conventional top end to the side of the middle bearing housing, reducing the overall height dimension of the sewage pump, being less restricted by the environment and having a wider application range.

[0021] 5. The sealed oil chamber C is composed of an annular side plate and a mechanical seal seat, which can significantly reduce the volume of the sealed oil chamber C. Thus, less mechanical oil needs to be injected, saving oil. Moreover, the outer wall of the oil chamber is surrounded by the conveyed medium, which is beneficial to improving the cooling effect. Description of the Drawings

[0022] Figure 1 This is a schematic structural diagram of the present invention.

[0023] Figure 2 This is an enlarged schematic diagram of the sewage pump part.

[0024] Reference numerals: 1, housing; 101, boss; 2, gland; 3, bearing housing; 31, annular side plate; 4, rotating shaft; 5, pump body; 501, annular flange; 6, impeller; 601, rear baffle of impeller; 7, first mechanical seal ring; 8, mechanical seal seat; 801, annular rib; 9, second mechanical seal ring; 901, moving ring; 902, static ring; 10, sealing baffle; 11, terminal block; 12, oil pipe; 13, sealing plug; 14, oil-water probe; 15, handle frame; 16, stator coil; 17, rotor; 18, upper bearing; 19, lower bearing; 20, cable; A, annular gap; B, sealing seat gap; C, sealed oil chamber. Detailed implementation manners

[0025] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and detailed implementation manners and specific operation processes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0026] As Figure 1 shown, this embodiment provides a submersible sewage pump, which mainly includes a submersible motor part and a sewage pump part.

[0027] The submersible motor part includes a housing 1, a gland 2, a bearing housing 3, a rotating shaft 4, an upper bearing 18, a lower bearing 19, a handle frame 15, a stator coil 16, a rotor 17, a first mechanical seal ring 7 and a mechanical seal seat 8. The top and bottom of the housing 1 are respectively and hermetically connected to the gland 2 and the bearing housing 3 by bolts. The stator coil 16 of the motor is installed inside the housing 1, and the cable 20 on the stator coil 16 is led out from the lower end face of the stator coil 16. The upper bearing 18 is arranged on the gland 2, the lower bearing 19 is arranged on the bearing housing 3, the top end of the rotating shaft 4 is connected to the upper bearing 18, the bottom end is connected to the lower bearing 19 and passes through the bearing housing 3. The rotor 17 is arranged on the rotating shaft 4 and is located in the center of the stator coil 16. The first mechanical seal ring 7 is arranged at the connection between the rotating shaft 4 and the bearing housing 3.

[0028] The sewage pump part includes a pump body 5, an impeller 6 and a second mechanical seal ring 9. The pump body 5 is fixed below the bearing housing 3 by bolts, and the impeller 6 is installed inside the pump body 5. The rotating shaft 4 passing through the bearing housing 3 is connected to the impeller 6, and the mechanical seal seat 8 is nested on the rotating shaft 4 and is arranged between the impeller 6 and the bearing housing 3. A boss 101 is provided on the side near the gland 2 at the top end of the housing 1, and the end of the handle frame 15 is connected to the boss 101 here by bolts.

[0029] AsFigure 2 As shown, an annular flange 501 is provided on the inner wall of the pump body 5. The annular flange 501 is located outside the outer ring of the impeller rear baffle 601 to form an annular gap A. The annular gap A is generally 0.2 mm to 0.5 mm, and 0.3 mm is preferably selected in this embodiment. The top end of the mechanical seal seat 8 is connected to the bearing seat 3, and an annular edge 801 is provided at the bottom end. The inner wall of the annular edge 801 and the rotating shaft 4 form an installation space, and a second mechanical seal ring 9 is arranged in the installation space. At the same time, a seal seat gap B is formed between the end of the annular edge 801 and the impeller 6. The second mechanical seal ring 9 itself includes a moving ring 901 and a stationary ring 902. The stationary ring 902 is connected to the mechanical seal seat 8, and the moving ring 901 is connected to the impeller 6. In this embodiment, the annular gap A and the seal seat gap B form two protections for the second mechanical seal ring 9, avoiding the direct influence of long fiber bodies or large solid particles in the medium on the second mechanical seal ring 9 and improving the reliability. The principle is as follows:

[0030] When the water pump is running normally, the impeller 6 rotates at a high speed, and the pump body 5 remains relatively stationary. When the fiber bodies or larger particles in the conveyed medium pass through the annular gap A, they will be shredded by the outer ring of the impeller 6 rotating at a high speed, ensuring that large impurities do not pass through the annular gap A, thus becoming the first protection for the second mechanical seal ring 9.

[0031] After the conveyed medium passes through the annular gap A, it may still carry some long fiber bodies. The seal seat gap B formed between the impeller 6 and the mechanical seal seat 8 becomes the second protection. During operation, the impeller 6 rotates at a high speed, and the mechanical seal seat 8 remains relatively stationary. The remaining fiber bodies are blocked outside the seal seat gap B and even ground into pieces, unable to touch the second mechanical seal ring 9.

[0032] Such as Figure 2As shown in the figure, a through hole is provided at the lower end of the bearing housing 3 for the rotation shaft 4 to pass through. An annular side plate 31 extending downward is provided on the outer circle of the through hole. The lower end of the annular side plate 31 is hermetically connected to the mechanical seal seat 8 by bolts. The first mechanical seal ring 7 is arranged at the through hole. The stationary ring of the first mechanical seal ring 7 is connected to the bearing housing 3, and its rotating ring is fixed in cooperation with the retaining ring structure on the rotation shaft 4. Thus, the annular side plate 31, the first mechanical seal ring 7 and the mechanical seal seat 8 form a sealed oil chamber C. Since the inner diameter of the annular side plate 31 is only slightly larger than the through hole, the space volume of the sealed oil chamber C is small, and only a small amount of mechanical oil can be injected, saving oil. Moreover, the outer wall of the oil chamber, that is, the outside of the annular side plate 31, is surrounded by the conveyed medium, which is beneficial to improving the cooling effect. A horizontal oil pipe 12 is also provided on the bearing housing 3. One end of the oil pipe 12 communicates with the sealed oil chamber C, and the other end forms an oil port on the outer wall of the bearing housing 3. This oil port is used to pour in mechanical oil, and a sealing plug 13 is provided at the oil port. At the same time, an oil-water probe 14 is provided on the side wall of the oil pipe 12. The oil-water probe 14 is used to detect whether there is water in the oil chamber. Detecting water indicates that the first mechanical seal ring 7 fails.

[0033] As Figure 1 shown, an opening is also provided on one side of the bearing housing 3, and a terminal block 11 is provided at this opening. The specific structure is as follows: threaded holes are machined on the end face of the opening. The side end face of the terminal block 11 fits with this opening and is hermetically installed on the side of the bearing housing 3 through bolts. The other opening end face of the terminal block 11 faces upward. The external cable and the opening end face of the terminal block 11 are hermetically connected by bolts. The cable 20 on the stator coil 16 passes through the opening on the side of the terminal block 11 and is connected to the external cable inside the terminal block 11. This structure moves the cable lead-out end of the motor part from the conventional top to the side of the middle bearing housing 3, reduces the overall height dimension of the sewage pump, is less restricted by the environment, and makes the applicable range wider.

[0034] In another embodiment, a sealing baffle 10 is fixed on the impeller 6, and a sealing seat gap B is formed between the end of the annular rib 801 and the sealing baffle 10. This structure prevents the impeller 6 from being worn when the sealing seat gap B grinds impurities, and protects the impeller 6.

[0035] In yet another embodiment, a convex edge can be provided on the outer circle of the rear baffle 601 of the impeller, and an annular gap A is formed between the convex edge and the annular flange 501. The convex edge structure can improve the strength and wear resistance of the outer circle of the impeller 6 and improve the reliability of cutting impurities.

[0036] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations based on the concept of the present invention without creative efforts. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field based on the concept of the present invention through logical analysis, reasoning, or limited experiments on the basis of the prior art should fall within the protection scope determined by the claims.

Claims

1. A submersible sewage pump, comprising a housing (1), a gland (2), a bearing housing (3), a rotating shaft (4), a pump body (5) and an impeller (6). The top and bottom ends of the housing (1) are respectively connected to the gland (2) and the bearing housing (3). The pump body (5) is fixed below the bearing housing (3). The impeller (6) is installed inside the pump body (5). The top end of the rotating shaft (4) is connected to the gland (2), and the bottom end of the rotating shaft (4) passes through the bearing housing (3) and then is connected to the impeller (6). A first mechanical seal ring (7) is provided between the rotating shaft (4) and the bearing housing (3). It is characterized in that: An annular flange (501) is provided on the inner wall of the pump body (5), and the annular flange (501) is located outside the rear baffle (601) of the impeller to form an annular gap (A); A mechanical seal seat (8) is provided between the bearing housing (3) and the impeller (6). The mechanical seal seat (8) is nested on the rotating shaft (4) and its top end is connected to the bearing housing (3). An annular edge (801) is provided at the bottom end of the mechanical seal seat (8). The inner wall of the annular edge (801) and the rotating shaft (4) form an installation space, and the end of the annular edge (801) and the impeller (6) form a seal seat gap (B). A second mechanical seal ring (9) is provided in the installation space. The second mechanical seal ring (9) includes a moving ring (901) and a stationary ring (902). The stationary ring (902) is connected to the mechanical seal seat (8), and the moving ring (901) is connected to the impeller (6); A through hole is provided at the lower end of the bearing housing (3) for the rotating shaft (4) to pass through. An annular side plate (31) is provided at the outer circle of the through hole. The end of the annular side plate (31) is connected to the mechanical seal seat (8). The first mechanical seal ring (7) is provided at the through hole. Thus, the annular side plate (31), the first mechanical seal ring (7) and the mechanical seal seat (8) form a sealed oil chamber C; Outside the annular side plate (31), it is surrounded by the medium to be conveyed.

2. The submersible sewage pump according to claim 1, characterized in that, A convex edge is provided on the outer circle of the rear baffle (601) of the impeller, and an annular gap (A) is formed between the convex edge and the annular flange (501).

3. A submersible sewage pump according to claim 1 or 2, characterized in that, The annular gap (A) is 0.2 mm to 0.5 mm.

4. A submersible sewage pump according to claim 1, characterized in that, A seal baffle (10) is fixed on the impeller (6), and a seal seat gap (B) is formed between the end of the annular edge (801) and the seal baffle (10).

5. A submersible sewage pump according to claim 1, characterized in that, An opening is provided on one side of the bearing housing (3), and a terminal block (11) is provided at the opening. The cable (20) in the housing (1) is arranged in the terminal block (11).

6. The submersible sewage pump according to claim 1, characterized in that, A horizontal oil pipe (12) is provided on the bearing housing (3). One end of the oil pipe (12) communicates with the sealed oil chamber C, and the other end forms an oil port on the outer wall of the bearing housing (3). A seal plug (13) is provided at the oil port.

7. A submersible sewage pump according to claim 6, characterized in that, An oil-water probe (14) is provided on the side wall of the oil pipe (12).

8. A submersible sewage pump according to claim 1, characterized in that, A handle frame (15) is provided at the top end of the housing (1).

9. A submersible sewage pump according to claim 8, characterized in that, A convex platform (101) is provided on the side surface of the top end of the housing (1), and the end of the handle frame (15) is connected to the convex platform (101) by bolts.

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