Lower pump shell for low-lift multi-stage pump and low-lift multi-stage pump

Abstract

The utility model relates to the field of submersible pumps, in particular to a lower pump shell for a low-lift multi-stage pump and the low-lift multi-stage pump. The lower pump shell comprises a mounting part suitable for being arranged between an outer cover and a base of a shell, and a first bolt hole is formed in the mounting part; the bearing part is fixedly connected with the mounting part and is suitable for bearing the guide vane; a limiting step is formed at the end, away from the mounting part, of the limiting part, and a first sealing ring suitable for abutting against the impeller is arranged in the limiting step; and the connecting part is connected with the mounting part and the bearing part, and the circumferential inner wall of the connecting part abuts against the circumferential outer wall of the guide vane. According to the lower pump shell for the low-lift multi-stage pump, the installation part is directly connected with the pump body in a sealing mode, the bearing part and the connecting part are matched to install and fix the guide vane, the limiting part assists in limiting and sealing the impeller, an original lower pump shell structure can be replaced, and the lower pump shell is suitable for the multi-stage pump without a water inlet section.

Description

Technical Field

[0001] The utility model relates to the field of submersible pumps, in particular to a lower pump casing for a low-lift multistage pump and the low-lift multistage pump. Background Art

[0002] A multistage submersible pump is a centrifugal pump that can be driven underwater by an electric motor. Depending on the number of impellers, multistage submersible pumps can be divided into low-lift submersible pumps, medium-lift submersible pumps, and high-lift submersible pumps.

[0003] Chinese invention patent application publication number CN108194372A discloses an amphibious vertical sand removal pump. This vertical sand removal pump comprises a cylindrical pump body with a water inlet at the bottom and a water outlet at the top. The pump body is sequentially equipped with a top cover, an upper bearing seat, a lower bearing seat, an inlet section, a lower pump casing, and a base. An axial-flow impeller is mounted at the end of the pump motor's rotating shaft, and an overflow pipe connected to the inlet section is located inside the water inlet. However, the lower pump casing of this sand removal pump is integrally formed with the base and fixedly connected to the inlet section by bolts, making it unsuitable for submersible pumps without an inlet section.

[0004] Therefore, this field needs a new technical solution to solve the above problems. Summary of the Invention

[0005] In order to improve or solve the technical problem that the lower pump casing and the base are integrally formed in the prior art and are not suitable for submersible pumps without an inlet section, the utility model provides a lower pump casing for a low-lift multi-stage pump that is directly sealed with the pump body and can be installed with fixed guide vanes. The lower pump casing includes: a mounting portion, suitable for being arranged between the outer cover and the base of the housing, and a first bolt hole is opened on the mounting portion; a first step groove and a second step groove are also formed on the mounting portion, and a first sealing ring is arranged in the first step groove; a supporting portion is fixedly connected to the mounting portion and is suitable for supporting the guide vane; a limiting portion is arranged at one end of the supporting portion away from the mounting portion, and a limited step is formed at one end of the limiting portion away from the mounting portion, and a first sealing ring suitable for abutting against the impeller is arranged in the limiting step; a connecting portion connects the mounting portion and the supporting portion, and the circumferential inner wall of the connecting portion abuts against the circumferential outer wall of the guide vane.

[0006] The utility model is used for the lower pump casing of a low-lift multi-stage pump, and includes a mounting portion, a supporting portion, a limiting portion, and a connecting portion. The mounting portion is fixedly connected to the pump body by bolts, and is used to install the lower pump casing on the pump body. A first sealing ring is arranged in the first step groove, which is used to enhance the sealing performance between the mounting portion and the casing; the supporting portion is located below the guide vane, which is used to support the guide vane; the circumferential inner wall of the connecting portion is against the circumferential outer wall of the guide vane, and cooperates with the supporting portion to install and fix the guide vane. A limited step is formed on the limiting portion, and a first sealing ring is arranged in the limiting step. The first sealing ring is against the impeller, and is used to limit and seal the lower end of the impeller. Through the above-mentioned arrangement, the utility model is used for the lower pump casing of a low-lift multi-stage pump, and the mounting portion directly forms a sealed connection with the pump body, the supporting portion and the connecting portion cooperate to install and fix the guide vane, and the limiting portion assists in limiting and sealing the impeller. It can replace the original lower pump casing structure and is suitable for multi-stage pumps without a water inlet section.

[0007] Furthermore, a first weight-reducing groove is provided on the supporting portion.

[0008] Furthermore, the first weight-reducing grooves are arranged in a ring shape.

[0009] Furthermore, the limiting portion extends obliquely downward from one end of the supporting portion, and a second weight-reducing groove is provided on the limiting portion.

[0010] In order to improve or solve the technical problem in the prior art that the lower pump casing and the base are integrally formed and are not suitable for submersible pumps without water inlet sections, the utility model also provides a low-lift multi-stage pump. The low-lift multi-stage pump comprises: a pump body, including an outer cover and a base sealed with the outer cover; guide vanes installed in the pump body; an impeller rotatably installed in the pump body; an inlet connecting frame fixedly connected to the pump body; and a lower pump casing for a low-lift multi-stage pump as described in any of the above items, wherein the mounting portion of the lower pump casing forms a sealed fixed connection with the pump body; the supporting portion of the lower pump casing supports the guide vanes; the connecting portion of the lower pump casing abuts against the circumferential outer wall of the guide vanes; and the limiting portion of the lower pump casing abuts against the impeller through a first sealing ring.

[0011] Furthermore, it also includes a motor assembly installed in the pump body, the motor assembly includes a motor housing fixedly connected to the pump body, a stator installed in the motor housing, a rotor installed in the motor housing, a rotatable shaft installed in the motor housing, and an output wire structure connected to the motor housing and the pump body; the shaft and the impeller rotate synchronously through a keyway structure.

[0012] Furthermore, an upper bearing seat is arranged at the upper end of the motor housing, and a deep groove ball bearing matching the rotating shaft is arranged on the upper bearing seat; a lower bearing seat is arranged at the lower end of the motor housing, and an angular contact ball bearing matching the rotating shaft is arranged on the lower bearing seat.

[0013] In summary, compared with the prior art, the present invention has the following beneficial effects:

[0014] (1) The mounting portion is fixedly connected to the pump body by bolts and is used to mount the lower pump casing on the pump body; a first sealing ring is arranged in the first stepped groove to enhance the sealing performance between the mounting portion and the casing; the supporting portion is located below the guide vane and is used to support the guide vane; the circumferential inner wall of the connecting portion abuts against the circumferential outer wall of the guide vane, and the guide vane is fixedly mounted in cooperation with the supporting portion; a limited step is formed on the limiting portion, and a first sealing ring is arranged in the limiting step, and the first sealing ring abuts against the impeller to limit and seal the lower end of the impeller;

[0015] (2) By opening a first weight-reducing groove on the supporting portion and a second weight-reducing groove on the limiting portion, the weight of the lower pump casing is reduced, thereby enhancing the connection stability between the lower pump casing and the pump body. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The preferred embodiments of the present invention are described below with reference to the accompanying drawings, in which:

[0017] Figure 1 It is a schematic diagram of an embodiment of the low-lift multi-stage pump of the utility model;

[0018] Figure 2 This is a top view of an embodiment of the lower pump casing of the low-lift multi-stage pump of the utility model;

[0019] Figure 3 It is a cross-sectional view of an embodiment of the lower pump casing of the low-lift multi-stage pump of the utility model.

[0020] List of reference numerals: 1. lower pump casing; 11. mounting portion; 111. first bolt hole; 112. first stepped groove; 113. second stepped groove; 114. first sealing ring; 12. supporting portion; 121. first weight-reducing groove; 13. limiting portion; 131. limiting step; 132. first sealing ring; 133. second weight-reducing groove; 14. connecting portion; 2. pump body; 21. outer cover; 22. base; 3. motor Components; 31. Motor housing; 32. Stator; 33. Rotor; 34. Rotating shaft; 35. Outlet structure; 351. Outlet box; 352. Cable gland; 353. Cable pressure plate; 36. Upper bearing seat; 361. Terminal block; 362. Deep groove ball bearing; 4. Guide vane; 5. Impeller; 6. Lower bearing seat; 61. Angular contact ball bearing; 62. Mechanical seal; 63. Sealing chamber cover; 7. Water inlet connecting frame. DETAILED DESCRIPTION

[0021] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0022] It should be noted that in the description of this utility model, terms such as "upper," "lower," "left," "right," "inner," and "outer" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is merely for ease of description and does not indicate or imply that the device or component described must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, it should not be understood as limiting the utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance.

[0023] Furthermore, it should be noted that, in the description of this utility model, unless otherwise expressly specified or limited, the terms "installed," "set," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0024] In order to improve or solve the technical problem in the prior art that the lower pump casing and the base are integrally formed and are not suitable for submersible pumps without an inlet section, the utility model provides a lower pump casing for a low-lift multi-stage pump. The lower pump casing includes: a mounting portion 11, which is suitable for being arranged between the outer cover 21 and the base 22 of the casing, and a first bolt hole 111 is opened on the mounting portion 11; a first step groove 112 and a second step groove 113 are also formed on the mounting portion 11, and a first sealing ring 114 is arranged in the first step groove 112; a supporting portion 12 is fixedly connected with the mounting portion 11, and is suitable for supporting the guide vane 4; a limiting portion 13 is arranged at one end of the supporting portion 12 away from the mounting portion 11, and a limited step 131 is formed at the end of the limiting portion 13 away from the mounting portion 11, and a first sealing ring 132 suitable for abutting against the impeller 5 is arranged in the limiting step 131; a connecting portion 14 connects the mounting portion 11 and the supporting portion 12, and the circumferential inner wall of the connecting portion 14 abuts against the circumferential outer wall of the guide vane 4.

[0025] Figure 1 This is a schematic diagram of an embodiment of the low-lift multi-stage pump of the utility model. Figure 2 This is a top view of an embodiment of the lower pump casing of a low-lift multi-stage pump of the utility model. Figure 3 This is a cross-sectional view of an embodiment of the lower pump casing of the low-lift multi-stage pump of the present invention. Figure 1 、 Figure 2 and Figure 3As shown, in one or more embodiments, the lower pump casing of the utility model for a low-lift multi-stage pump includes a mounting portion 11 , a supporting portion 12 , a limiting portion 13 and a connecting portion 14 .

[0026] Continue to see Figure 1 、 Figure 2 and Figure 3 In one or more embodiments, the mounting portion 11 is roughly annular. A first bolt hole 111 is provided on the mounting portion 11, and a plurality of first bolt holes 111 are evenly and spaced apart along the circumference of the mounting portion 11. Exemplarily, there are 12 first bolt holes 111, and the 12 first bolt holes 111 are spaced apart. Specifically, the mounting portion 11 and the pump body 2 are fixedly connected by bolts that match the first bolt holes 111. Furthermore, a first step groove 112 and a second step groove 113 arranged in a stepped manner are provided at the top of the mounting portion 11. A first sealing ring 114 is arranged in the first step groove 112 to enhance the sealing performance of the mounting portion 11 and the pump body 2. The second step groove 113 matches the water inlet connecting frame 7 and is used to enhance the connection stability of the mounting portion 11, the pump body 2 and the water inlet connecting frame 7.

[0027] Continue to see Figure 1 、 Figure 2 and Figure 3 , one end of the connecting portion 14 is connected to the mounting portion 11, and the other end is connected to the supporting portion 12. In one or more embodiments, the connecting portion 14 is roughly cylindrical, and the circumferential inner wall of the connecting portion 14 is suitable for abutting against the circumferential outer wall of the guide vane 4. Further, the supporting portion 12 is connected to the bottom end of the connecting portion 14. The supporting portion 12 is roughly annular, and the diameter of the supporting portion 12 matches the diameter of the guide vane 4. Further, a first weight-reducing groove 121 is provided on the supporting portion 12. Specifically, the first weight-reducing groove 121 is arranged in an annular shape. Alternatively, the first weight-reducing groove 121 can be arranged uniformly and spaced along the circumference of the supporting portion 12. Further, the limiting portion 13 is arranged at one end of the supporting portion 12 away from the mounting portion 11. Specifically, the limiting portion 13 extends obliquely downward from one end of the supporting portion 12. That is, the limiting portion 13 extends toward the center and downward to adapt to the position of the impeller 5. Furthermore, a limiting step 131 is formed at the end of the limiting portion 13 away from the mounting portion 11, and a first sealing ring 132 is disposed within the limiting step 131. The first sealing ring 132 is adapted to abut against the circumferential wall of the impeller 5, thereby providing both sealing and limiting functions. Furthermore, a second weight-reducing groove 133 is defined in the limiting portion 13. It will be appreciated that the lower pump casing 1 of the present invention can be used in both single-stage and multi-stage pumps.

[0028] In order to improve or solve the technical problem in the prior art that the lower pump casing and the base are integrally formed and are not suitable for multi-stage pumps without water inlet sections, the present invention provides a low-lift multi-stage pump. The low-lift multi-stage pump comprises a pump body 2, including an outer cover 21 and a base 22 sealed with the outer cover 21; a guide vane 4 mounted in the pump body 2; an impeller 5 rotatably mounted in the pump body 2; an inlet connecting frame 7 fixedly connected to the pump body 2; and a lower pump casing 1 for a low-lift multi-stage pump according to any of the above items, wherein the mounting portion 11 of the lower pump casing 1 forms a sealed fixed connection with the pump body 2; the supporting portion 12 of the lower pump casing 1 supports the guide vane 4; the connecting portion 14 of the lower pump casing 1 abuts against the circumferential outer wall of the guide vane 4; and the limiting portion 13 of the lower pump casing 1 abuts against the impeller 5 via a first sealing ring 132.

[0029] Continue to see Figure 1 、 Figure 2 and Figure 3 In one or more embodiments, the low-lift multi-stage pump of the present invention includes a pump body 2, a motor assembly 3, a water inlet connecting frame 7, a lower pump casing 1, guide vanes 4 and an impeller 5.

[0030] Continue to see Figure 1 、 Figure 2 and Figure 3 In one or more embodiments, the pump body 2 includes an outer cover 21 and a base 22 detachably connected to the outer cover 21. A drain port is provided on the outer cover 21 and is located at the top of the outer cover 21. Furthermore, a through hole is provided at the top of the outer cover 21 for extending a cable.

[0031] Continue to participate Figure 1 、 Figure 2 and Figure 3In one or more embodiments, the motor assembly 3 includes a motor housing 31 fixedly connected to the pump body 2, a stator 32 installed in the motor housing 31, a rotor 33 installed in the motor housing 31, a rotating shaft 34 rotatably installed in the motor housing 31, and an outlet structure 35 connected to the motor housing 31 and the pump body 2. Specifically, the upper end of the motor housing 31 is connected to an upper bearing seat 36, and the upper bearing seat 36 is fixedly connected to the motor housing 31 by bolts and spring washers. A terminal 361 and a deep groove ball bearing 362 are arranged on the upper bearing seat 36, and the deep groove ball bearing 362 is installed in the upper bearing seat 36 by an upper bearing retaining ring. One end of the rotating shaft 34 is rotatably arranged in the deep groove ball bearing 362. Furthermore, the lower end of the motor housing 31 is connected to a lower bearing seat 6, and the lower bearing seat 6 is sealed and fixedly connected to the motor housing 31 by an O-ring and bolts. An angular contact ball bearing 61 is arranged on the lower bearing seat 6 and is mounted within the lower bearing seat 6 via a lower bearing gland. One end of the rotating shaft 34 passes through the angular contact ball bearing 61 and rotates synchronously with the impeller 5 via a keyway structure. Furthermore, a mechanical seal 62 is arranged between the lower bearing seat 6 and the rotating shaft 34. Below the lower bearing seat 6, a sealing chamber cover 63 is arranged to house the mechanical seal 62. The sealing chamber cover 63 is securely connected to the lower bearing seat 6 via an O-ring and bolts. Furthermore, the outlet structure 35 includes an outlet box 351, a cable gland 352 securely connected to the outlet box 351, and a cable pressure plate 353 mounted on the gland 352. Specifically, the outlet box 351 is securely connected to the upper bearing seat 36 via bolts and a sealing ring. The cable gland 352 is securely connected to the outlet box 351 via bolts. The cable pressing plate 353 presses the cable pressing sleeve 352, thereby fixing the cable in the cable pressing sleeve 352. Furthermore, the end of the cable pressing sleeve 352 away from the outlet box 351 is in a trumpet shape.

[0032] Continue to participate Figure 1 、 Figure 2 and Figure 3 In one or more embodiments, the mounting portion 11 of the lower pump casing 1 is arranged between the outer cover 21 and the base 22, and is fixedly connected to the outer cover 21 and the base 22 by bolts. Specifically, the water inlet connecting frame 7 is arranged between the lower pump casing 1 and the outer cover 21, and the outer cover 21, the water inlet connecting frame 7, the lower pump casing 1 and the base 22 are arranged in sequence and fixedly connected by bolts. Furthermore, the circumferential inner wall of the connecting portion 14 abuts against the circumferential outer wall of the guide vane 4, and the water inlet connecting frame 7 abuts against the circumferential inner wall and the upper side wall of the guide vane 4, thereby fixing the guide vane 4. The water inlet connecting frame 7 abuts against the outer circumferential wall of the upper end of the impeller 5, and the limiting portion 13 abuts against the outer circumferential wall of the lower end of the impeller 5, thereby sealing and limiting the impeller 5.

[0033] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is clearly not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and such changes or substitutions will fall within the scope of protection of the present invention.

Claims

1. A lower pump casing for a low-lift multistage pump, characterized in that: include: The mounting portion (11) is adapted to be arranged between the outer cover (21) and the base (22) of the housing, and a first bolt hole (111) is formed on the mounting portion (11); a first stepped groove (112) and a second stepped groove (113) are also formed on the mounting portion (11), and a first sealing ring (114) is arranged in the first stepped groove (112); A supporting portion (12) is fixedly connected to the mounting portion (11) and is suitable for supporting the guide vane (4); A limiting portion (13) is arranged at one end of the supporting portion (12) away from the mounting portion (11), and a limiting step (131) is formed at the end of the limiting portion (13) away from the mounting portion (11), wherein a first sealing ring (132) suitable for abutting against the impeller (5) is arranged in the limiting step (131); A connecting portion (14) connects the mounting portion (11) and the supporting portion (12), and a circumferential inner wall of the connecting portion (14) abuts against a circumferential outer wall of the guide vane (4).

2. The lower pump casing for a low-lift multistage pump according to claim 1, characterized in that: A first weight-reducing groove (121) is provided on the supporting portion (12).

3. The lower pump casing for a low-lift multistage pump according to claim 2, characterized in that: The first weight-reducing grooves (121) are arranged in a ring shape.

4. The lower pump casing for a low-lift multistage pump according to claim 1, characterized in that: The limiting portion (13) extends obliquely downward from one end of the supporting portion (12), and a second weight-reducing groove (133) is provided on the limiting portion (13).

5. A low-lift multistage pump, characterized in that: include: A pump body (2) comprising an outer cover (21) and a base (22) sealed with the outer cover (21); a guide vane (4) mounted in the pump body (2); an impeller (5) rotatably mounted in the pump body (2); A water inlet connecting frame (7) is fixedly connected to the pump body (2); and The lower pump casing (1) for a low-lift multistage pump according to any one of claims 1 to 4, wherein the mounting portion (11) of the lower pump casing (1) forms a sealed fixed connection with the pump body (2); the supporting portion (12) of the lower pump casing (1) supports the guide vane (4); the connecting portion (14) of the lower pump casing (1) abuts against the circumferential outer wall of the guide vane (4); and the limiting portion (13) of the lower pump casing (1) abuts against the impeller (5) through a first sealing ring (132).

6. The low-lift multistage pump according to claim 5, characterized in that: The invention also includes a motor assembly (3) installed in the pump body (2), wherein the motor assembly (3) includes a motor housing (31) fixedly connected to the pump body (2), a stator (32) installed in the motor housing (31), a rotor (33) installed in the motor housing (31), a rotating shaft (34) rotatably installed in the motor housing (31), and an outlet structure (35) connected to the motor housing (31) and the pump body (2); the rotating shaft (34) and the impeller (5) rotate synchronously through a keyway structure.

7. The low-lift multistage pump according to claim 6, characterized in that: An upper bearing seat (36) is arranged at the upper end of the motor housing (31), and a deep groove ball bearing (362) matching the rotating shaft (34) is arranged on the upper bearing seat (36); a lower bearing seat (6) is arranged at the lower end of the motor housing (31), and an angular contact ball bearing (61) matching the rotating shaft (34) is arranged on the lower bearing seat (6).

Images