Axial-force-free double-suction shield pump

Abstract

The utility model relates to the field of pumps, in particular to an axial-force-free double-suction shield pump which is of a symmetrical structure in the axial direction and comprises an outer shell and an inner shell coaxially arranged in the outer shell, and a flow guide cavity is formed between the inner shell and the outer shell so that media can flow. The main shaft is arranged in the inner shell and driven by the shielding motor to rotate, two bearings are arranged in the inner shell to support the two ends of the main shaft respectively, the main shaft is symmetrically provided with impellers on the two sides of the shielding motor, the pump inlet and the pump outlet are formed in the outer shell, and media sequentially pass through the pump inlet, the impellers and the flow guide cavity and then are discharged along the pump outlet. The pump outlet is evenly provided with rectifying plates which are fixed in an inserted mode in the circumferential direction, the plate faces on the two sides of each rectifying plate are a straight plate and an inclined plate respectively, and the plate faces of the straight plates are arranged in the radial direction of the pump outlet. According to the utility model, the axial force in the operation process of the shield pump is basically eliminated, and the service life of the pump under the working condition of high rotating speed is greatly prolonged.

Description

Technical Field

[0001] The utility model relates to the field of pumps, in particular to an axial force-free double-suction shielded pump. Background Art

[0002] A shielded pump is a type of pump body that connects a pump and a motor together. The motor rotor and the pump impeller are fixed on the same shaft, and a shield sleeve is used to separate the rotor assembly and the stator assembly. It has the advantages of high integration, small size, and no leakage. As described in the publication number "CN113404701A", the existing shielded pump includes a housing assembly, a stator assembly, an outer rotor assembly, and a hollow shaft. The stator assembly and the outer rotor assembly are both arranged in the housing assembly. It has a one-way flow channel and a small operating flow rate, which is not suitable for the requirements of a large-flow infusion system. If the operating flow rate of the shielded pump is to be increased, the axial force of the pump body will inevitably increase. When the axial force increases, the service life of the bearing will decrease rapidly when the pump runs at high speed, causing damage to the pump body, so it is urgent to solve the problem. Utility Model Content

[0003] In order to avoid and overcome the technical problems existing in the prior art, the utility model provides a double-suction shielded pump without axial force. The utility model basically eliminates the axial force during the operation of the shielded pump and greatly increases the service life of the pump under high speed conditions.

[0004] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0005] A double-suction shielded pump without axial force is symmetrically constructed along the axial direction, comprising an outer shell and an inner shell coaxially arranged inside the outer shell, a guide cavity being provided between the inner shell and the outer shell for medium flow; a main shaft is built into the inner shell and driven to rotate by a shielded motor, two sets of bearings are arranged in the inner shell to respectively support two ends of the main shaft, impellers are symmetrically installed on both sides of the shielded motor on the main shaft, a pump inlet and a pump outlet are provided on the outer shell, and the medium is discharged along the pump outlet after passing through the pump inlet, the impeller and the guide cavity in sequence; plug-in fixed rectifier plates are evenly installed at the pump outlet along the circumferential direction, the plate surfaces on both sides of the rectifier plates are straight plates and inclined plates respectively, and the plate surfaces of the straight plates are arranged radially along the pump outlet.

[0006] As a further solution of the utility model: pump inlets are symmetrically opened at both ends of the outer shell along the axial direction, a pump outlet is opened in the middle of the outer shell, two impellers are fixed at both ends of the main shaft, and the impeller inlet passes through the inner shell and is directly connected with the pump inlet, and impeller outlet flow channels are opened in the inner shell along the radial direction to be connected with the outlets of the corresponding impellers respectively, and the media at the two pump inlets pass through the impellers, the impeller outlet flow channels and the guide cavity in turn and then converge and discharge along the pump outlet.

[0007] As a further solution of the utility model: the shielded motor includes a rotor assembly coaxially fixed with the main shaft and a stator assembly coaxially arranged on the outer ring of the rotor assembly, and the stator assembly is fixed in the stator shielding sleeve of the inner shell; along the axial direction of the inner shell, the impeller, the bearing seat, the thrust plate and the rotor assembly are arranged in sequence, and the thrust plate cooperates with the bearing in the bearing seat to form a friction pair.

[0008] As a further solution of the utility model: there is a first gap between the bearing seat and the stator shielding sleeve, a second gap between the bearing and the thrust plate, a third gap between the bearing and the main shaft, and a fourth gap between the impeller outlet and the impeller outlet flow channel. The first gap, the second gap, the third gap and the fourth gap are connected in sequence to form a circulation flow channel. A circulation flow channel inlet connected to the first gap is opened on the inner shell, and the outlet of the circulation flow channel is connected to the impeller outlet flow channel.

[0009] As a further solution of the utility model: a symmetrically arranged pump inlet and pump outlet are radially opened in the middle of the outer shell, and an impeller inlet flow channel and an impeller outlet flow channel are radially opened in the inner shell, so as to be connected with the corresponding impeller inlet and outlet respectively. The medium at the pump inlet enters the guide cavity and then is divided, and passes through the impeller inlet flow channel, the impeller, the impeller outlet flow channel and the guide cavity in sequence, and then converges and is discharged along the pump outlet.

[0010] As a further solution of the utility model: the shielded motor includes a rotor assembly coaxially fixed with the main shaft and a stator assembly coaxially arranged on the outer ring of the rotor assembly, and the stator assembly is fixed in the stator shielding sleeve of the inner shell; along the axial direction of the inner shell, the bearing seat, the impeller, and the rotor assembly are arranged in sequence, and the two impellers and the rotor assembly are integrally injection molded.

[0011] As a further solution of the utility model: the outer shell and the inner shell are both provided with lead-in openings, and the motor lead wires of the shielded motor are led out to the outside of the pump body through the lead-in openings.

[0012] As a further solution of the utility model: a sealing ring is circumferentially arranged on the upper cover plate of the impeller, and a sealing ring is arranged at the contact surface between the sealing ring and the inner shell to prevent leakage of the medium.

[0013] As a further solution of the utility model: a flow guiding structure for rectifying is arranged in the flow guiding cavity, and at least two groups of flow guiding cavities are arranged and evenly distributed along the circumference of the shell.

[0014] As a further solution of the utility model: the angle between the inclined plate and the straight plate of the rectifier plate is 27.3° to 36.2°.

[0015] Compared with the prior art, the beneficial effects of the utility model are:

[0016] 1. The canned motor pump of the utility model is a horizontal double-inlet fully symmetrical layout. The power source and impeller and other components are built into the inner shell and the canned motor is located in the center of the pump body. When the impellers on both sides of the double-suction pump convey the same lift, the axial forces on both sides of the pump main shaft can be completely offset, so that the pump has no axial force when conveying the medium. It is suitable for high-speed working conditions and has a longer service life of the equipment, avoiding excessive axial force under high-speed operation to reduce the service life of the bearing or damage the pump body.

[0017] 2. All kinds of equipment of the utility model are integrated in the inner shell, and the lead wires are directly led out through the lead wire port. The overall structure is compact and the space utilization rate is extremely high. After the guide structure is installed in the guide cavity between the inner shell and the outer shell, there is no need for external volute and other water pressure chamber components, and the equipment has a high degree of integration.

[0018] 3. The utility model introduces a circulating flow channel in the pump body, which can cool the thrust plate and the bearing while conveying the medium, thereby avoiding excessive operating temperature. In another embodiment, the impeller and the rotor assembly can be integrally injection molded, which reduces the difficulty of pump body processing and reduces the size of the pump.

[0019] 4. The utility model has high conveying efficiency through the overall structure, and has the advantages of large flow and high efficiency of double-suction pump and no leakage and small size of shielded pump; the setting of the rectifying plate at the pump outlet makes the outlet medium flow more uniform and avoids turbulence. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the utility model.

[0021] Figure 2 It is a structural schematic diagram of another embodiment of the utility model.

[0022] In the figure:

[0023] 1. Shell; 11. Pump inlet; 12. Pump outlet; 13. Diversion chamber;

[0024] 14. Lead-in port; 141. Motor lead;

[0025] 2. Inner shell; 21. Impeller; 22. Bearing seat; 23. Bearing; 24. Thrust plate;

[0026] 25. Impeller outlet flow channel; 26. Circulation flow channel inlet; 27. Impeller inlet flow channel;

[0027] 3. Main shaft; 31. Rotor assembly; 32. Stator assembly; 33. Stator shielding sleeve. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0029] See also Figures 1-2 In an embodiment of the utility model, a double-suction shielded pump without axial force includes an inner shell 2 and an outer shell 1 coaxially sleeved outside the inner shell 2, a shielded motor is installed in the inner shell 2, a main shaft 3 is coaxially fixed in the inner shell 2, and two ends of the main shaft 3 are respectively supported by two sets of bearings 23.

[0030] The present application has the following two embodiments, both of which are symmetrical structures along the axial direction. A rotor assembly 31 and a stator assembly 32 are installed in the middle of the inner shell 2. The rotor assembly 31 is located in the inner ring of the stator assembly 32. The rotor assembly 31 is coaxially fixed with the main shaft 3, and the stator assembly 32 is fixed in the stator shielding sleeve 33 of the inner shell 2. The cavity of the inner shell 2 and the outer shell 1 constitutes a guide cavity 13, and the guide cavity 13 is connected to the pump outlet 12. The pump outlet 15 is evenly installed with plug-in fixed rectifier plates along the circumference, which are fixed by detachable fixing to facilitate the replacement of rectifier plates of different sizes. The plate surfaces on both sides of the rectifier plate are straight plates and inclined plates respectively. The plate surfaces of the straight plates are arranged radially along the pump outlet 15. The angle between the inclined plate and the straight plate of the rectifier plate is 27.3°~36.2°, preferably 32.5°.

[0031] In Example 1, two groups of pump inlets 11 are provided on the outer shell 1, and the two pump inlets 11 are respectively located on both sides of the outer shell 1 along the axial direction of the pump body. A group of pump outlets 12 are provided on the outer shell 1, and the pump outlets 12 are located in the middle of the outer shell 1 along the axial direction. Two groups of impellers 21 are installed on the inner shell 2, and the inlets of the impellers 21 penetrate the inner shell 2 and are directly connected with the pump inlets 11 on the outer shell 1. The impeller 21 and the inner shell 2 are coaxially rotatable, and the impeller 21 can be fixed to the end of the main shaft 3 by key transmission. An impeller outlet flow channel 25 is provided on the inner shell 2 in the radial direction, and the medium at the outlet of the impeller 21 is discharged into the guide cavity 13 along the impeller outlet flow channel 25, and the two media are discharged outward through the pump outlet 12 after converging.

[0032] Thrust plates 24 are installed on the main shaft 3 at both ends of the rotor assembly 31. In the direction away from the rotor assembly 31, the thrust plate 24, the bearing seat 22, and the impeller 21 are arranged in sequence, and the bearing 23 in the bearing seat 22 abuts against the thrust plate 24, thereby forming a friction pair.

[0033] In order to increase the cooling effect, a circulation channel is also provided in the pump body. The circulation channel includes a first gap between the bearing assembly 22 and the stator shield sleeve 33, a second gap between the bearing 23 and the thrust plate 24, a third gap between the bearing 23 and the main shaft 3, and a fourth gap between the impeller 21 outlet and the impeller outlet channel 25. The gaps are connected in sequence, and the medium is introduced into the first gap by providing a circulation channel inlet 26 on the inner shell 2. While conveying the medium, the medium can produce a self-cooling effect on the bearing 23, the thrust plate 24 and other components.

[0034] In Embodiment 2, only one set of pump inlet 11 and one set of pump outlet 12 are provided on the outer shell 1, and both the pump inlet 11 and the pump outlet 12 are located in the middle of the outer shell 1 and are arranged symmetrically along the radial direction. The impeller 21 is built into the inner shell 2, and an impeller inlet flow channel 27 and an impeller outlet flow channel 25 are provided in the inner shell 2 along the radial direction, thereby communicating with the inlet and outlet of the impeller 21 respectively. After the medium enters the guide cavity 13 along the pump inlet 11, it is evenly divided into two sets of impeller inlet flow channels 27, and after being transported by the two sets of impellers 21, it is discharged from the impeller outlet flow channel 25, and after converging in the guide cavity 13, it is discharged to the outside through the pump outlet 12.

[0035] Different from the first embodiment, the rotor assembly 31 , the impeller 21 and the bearing assembly 22 are arranged in sequence in a direction away from the rotor assembly 31 , and the rotor assembly 31 and the impeller 21 are preferably integrally injection molded.

[0036] In order to avoid leakage, a sealing ring is provided on the upper cover plate of the impeller 21 along the circumferential direction, and a sealing ring is provided on the contact surface between the sealing ring and the inner shell 2 to avoid leakage when the medium is sucked in.

[0037] In both embodiments, to facilitate the introduction of wires, a lead-in port 14 may be provided on the outer shell 1 and the inner shell 2, and the motor lead 141 of the shielded motor is led out of the pump body through the lead-in port 14. The lead-in port 14 is preferably located in the same radial plane of the pump as the pump outlet 12, so as to avoid the lead-in port affecting the axial balance of the pump.

[0038] In order to make the medium flow more uniform and avoid turbulence, a guide structure can be added in the guide cavity 13 along the medium flow direction to improve the uniformity of the medium flow, reduce the energy loss of medium transportation, and improve the transportation efficiency.

[0039] The basic principles of the present application are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present application are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present application. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, not for limitation, and the above details do not limit the present application to being implemented by adopting the above specific details.

[0040] The block diagrams of the devices, apparatuses, equipment, and systems involved in this application are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagram. As will be appreciated by those skilled in the art, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open words, referring to "including but not limited to", and can be used interchangeably with them. The words "or" and "and" used here refer to the words "and / or" and can be used interchangeably with them, unless the context clearly indicates otherwise. The words "such as" used here refer to the phrase "such as but not limited to", and can be used interchangeably with them.

Claims

1. A double-suction canned motor pump without axial force, characterized in that: The double-suction canned motor pump is symmetrically constructed along the axial direction, comprising an outer shell (1) and an inner shell (2) coaxially arranged inside the outer shell (1); a flow guide cavity (13) is provided between the inner shell (2) and the outer shell (1) for medium flow; a main shaft (3) is built into the inner shell (2) and driven to rotate by a canned motor; two sets of bearings (23) are arranged in the inner shell (2) to respectively support two ends of the main shaft (3); an impeller (21) is symmetrically mounted on both sides of the canned motor on the main shaft (3); a pump inlet (11) and a pump outlet (12) are provided on the outer shell (1); the medium passes through the pump inlet (11), the impeller (21) and the flow guide cavity (13) in sequence and is discharged along the pump outlet (12); a plug-in fixed rectifier plate is evenly installed at the pump outlet (12) along the circumferential direction; the plate surfaces on both sides of the rectifier plate are a straight plate and an inclined plate respectively, and the plate surface of the straight plate is arranged along the radial direction of the pump outlet.

2. The axial force-free double-suction canned motor pump according to claim 1, characterized in that: The outer shell (1) is symmetrically provided with pump inlets (11) at both ends along the axial direction, and a pump outlet (12) is provided in the middle of the outer shell (1). Two impellers (21) are fixed at both ends of the main shaft (3), and the inlets of the impellers (21) penetrate the inner shell (2) and are directly connected to the pump inlet (11). Impeller outlet flow channels (25) are radially provided in the inner shell (2) and are respectively connected to the outlets of the corresponding impellers (21). The media at the two pump inlets (11) pass through the impellers (21), the impeller outlet flow channels (25) and the guide chamber (13) in sequence and then converge and are discharged along the pump outlet (12).

3. The axial force-free double-suction canned motor pump according to claim 2, characterized in that: The canned motor comprises a rotor assembly (31) coaxially fixed with a main shaft (3) and a stator assembly (32) coaxially arranged on the outer ring of the rotor assembly (31); the stator assembly (32) is fixed in a stator shielding sleeve (33) of an inner shell (2); along the axial direction of the inner shell (2), an impeller (21), a bearing seat (22), a thrust plate (24) and a rotor assembly (31) are arranged in sequence; the thrust plate (24) cooperates with a bearing (23) in the bearing seat (22) to form a friction pair.

4. The axial force-free double-suction canned motor pump according to claim 3, characterized in that: There is a first gap between the bearing seat (22) and the stator shielding sleeve (33), a second gap between the bearing (23) and the thrust plate (24), a third gap between the bearing (23) and the main shaft (3), and a fourth gap between the outlet of the impeller (21) and the impeller outlet flow channel (25). The first gap, the second gap, the third gap and the fourth gap are connected in sequence to form a circulation flow channel. A circulation flow channel inlet (26) connected to the first gap is provided on the inner shell (2), and the outlet of the circulation flow channel is connected to the impeller outlet flow channel (25).

5. The axial force-free double-suction canned motor pump according to claim 1, characterized in that: A pump inlet (11) and a pump outlet (12) are symmetrically arranged in the radial direction in the middle of the outer shell (1), and an impeller inlet flow channel (27) and an impeller outlet flow channel (25) are radially opened in the inner shell (2), so as to be connected with the corresponding impeller (21) inlet and outlet respectively. The medium at the pump inlet (11) enters the guide cavity (13) and then flows separately, and then passes through the impeller inlet flow channel (27), the impeller (21), the impeller outlet flow channel (25) and the guide cavity (13) in sequence, and then converges and is discharged along the pump outlet (12).

6. The axial force-free double-suction canned motor pump according to claim 5, characterized in that: The shielded motor comprises a rotor assembly (31) coaxially fixed with a main shaft (3) and a stator assembly (32) coaxially arranged on the outer ring of the rotor assembly (31); the stator assembly (32) is fixed in a stator shielding sleeve (33) of an inner shell (2); along the axial direction of the inner shell (2), the bearing seat (22), the impeller (21), and the rotor assembly (31) are arranged in sequence, and the two impellers (21) and the rotor assembly (31) are integrally injection molded.

7. The axial force-free double-suction canned motor pump according to any one of claims 1 to 6, characterized in that: The outer shell (1) and the inner shell (2) are both provided with lead-in openings (14), and the motor lead wires (141) of the shielded motor are led out to the outside of the pump body through the lead-in openings (14).

8. The axial force-free double-suction canned motor pump according to any one of claims 1 to 6, characterized in that: A sealing ring is provided on the upper cover plate of the impeller (21) in the circumferential direction, and a sealing ring is provided at the contact surface between the sealing ring and the inner shell (2) to prevent leakage of the medium.

9. The axial force-free double-suction canned motor pump according to any one of claims 1 to 6, characterized in that: A flow guiding structure for rectifying flow is arranged in the flow guiding cavity (13), and at least two groups of flow guiding cavities (13) are arranged and are evenly distributed along the circumference of the housing (1).

10. The axial force-free double-suction canned motor pump according to any one of claims 1 to 6, characterized in that: The angle between the inclined plate and the straight plate of the rectifier plate is 27.3° to 36.2°.

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