An inner rotor driven dry-running magnetic pump

Abstract

The present invention relates to the technical field of pump equipment, and in particular to a magnetic pump that can run dry and is driven by an inner rotor. The inner magnetic rotor of the magnetic pump is set as an active component, and the outer magnetic rotor is set as a driven component. A compressed air channel is set on the shell so that the inner magnetic rotor is located in the compressed air channel. A cooling medium channel is set on a bracket close to the outer magnetic rotor, and the temperature of the bracket is cooled by the cooling medium. Therefore, when the magnetic pump runs dry, the compressed air can take away the eddy current heat of the isolation sleeve and the inner magnetic rotor, and the cooling medium can take away the eddy current heat of the outer magnetic rotor, thereby avoiding a sharp increase in the temperature of the magnetic pump during dry running, which may lead to demagnetization of the inner and outer magnetic rotors and damage to the pump body.

Description

Technical Field

[0001] The present invention relates to the technical field of pump equipment, in particular to a magnetic pump driven by an inner rotor and capable of dry operation. Background Art

[0002] At present, fully sealed, leak-free, corrosion-resistant magnetic drive centrifugal pumps (magnetic pumps) have become conventional equipment widely used in petrochemical, pharmaceutical energy, nuclear industry, environmental protection and other departments. They are widely used to transport various corrosive, flammable, explosive and toxic media.

[0003] A magnetic drive pump is a device that uses the magnetic transmission principle of internal and external magnetic rotors to drive the pump. It transmits the rotational power of the drive motor to the pump impeller through the magnetic contactless transmission of the internal and external magnetic rotors. Therefore, the drive part of the pump and the conveyed medium can be completely isolated by the isolation sleeve. Therefore, it is particularly suitable for conveying flammable, explosive, toxic, corrosive or precious liquids.

[0004] During the use of the magnetic pump, on the one hand, the inner magnetic rotor and the outer magnetic rotor will generate eddy heat due to the intersection of magnetic lines of force, and on the other hand, the friction between the rotating shaft and the bearing will also generate heat. In the existing solution, the drive motor drives the outer magnetic rotor, the impeller is connected to the inner magnetic rotor, and the inner magnetic rotor and the impeller are completely enclosed in an isolation sleeve. When the magnetic pump is operating normally, the conveyed medium fills the interior of the isolation sleeve, so the impeller, bearings and inner magnetic rotor are completely immersed in the conveyed medium. Therefore, the continuously conveyed medium can promptly remove the eddy heat generated by the inner and outer magnetic rotors and the friction heat of the bearings and the rotating shaft, thereby preventing the pump body from overheating. However, various sudden faults may occur during actual operation: for example, the medium inlet is blocked, no liquid enters, the pump is not shut down in time when unloading, etc., resulting in no medium being conveyed in the pump, and the magnetic pump continues to operate. At this time, the magnetic pump is in dry operation. Since there is no conveyed medium to remove the heat in time, it is very likely to cause the pump body temperature to rise sharply, and then cause the inner and outer magnetic rotors to demagnetize due to the temperature increase, causing damage to the magnetic pump.

[0005] Therefore, when the magnetic pump runs dry, how to effectively cool the pump body and ensure the smooth operation of the pump is an urgent problem to be solved. Summary of the Invention

[0006] In order to solve the above technical problems existing in the prior art, the present invention provides a magnetic pump that is driven by an inner rotor and can run dry.

[0007] The technical solution of the present invention to solve the above technical problems is as follows:

[0008] The present invention provides a dry-running magnetic pump driven by an inner rotor, comprising a pump body, an impeller, a driven shaft, a driving shaft, an outer magnetic rotor, a bracket, a spacer sleeve, an inner magnetic rotor, and a bearing housing; the pump body, bracket, and bearing housing are connected in sequence; a cavity is provided inside the pump body, the impeller and the driven shaft are both located in the cavity, one end of the driven shaft is connected to the impeller, and the other end is connected to the outer magnetic rotor; the driving shaft is disposed in the bearing housing, and one end of the driving shaft close to the driven shaft is connected to the inner magnetic rotor; the spacer sleeve is located between the outer magnetic rotor and the inner magnetic rotor, and the open end of the spacer sleeve is connected to the bearing housing;

[0009] The bearing housing is provided with a compressed air inlet and a compressed air outlet, and the compressed air enters the bearing housing to take away the eddy current heat generated by the inner magnetic rotor;

[0010] A cooling medium channel is also provided on the surface of the bracket, and the outer magnetic rotor is arranged close to the inner surface of the bracket.

[0011] The dry-running magnetic pump driven by the inner rotor provided by the present invention has the inner magnetic rotor set as the active driving part and the outer magnetic rotor set as the driven part, so that the outer magnetic rotor is close to the outer shell of the pump body, and a cooling medium channel is provided on the surface of the outer shell. Once dry running occurs, the temperature of the bracket can be kept at a low temperature under the action of the cooling medium, and the heat generated by the outer magnetic rotor close to the bracket can be promptly discharged. At the same time, compressed air is continuously passed through the bearing box where the inner magnetic rotor is located, and the flowing compressed air continuously carries away the eddy current heat generated on the inner magnetic rotor and the isolation sleeve. The two work together to ensure that the inner magnetic rotor and the outer magnetic rotor will not heat up rapidly, thereby avoiding the temperature increase in the pump due to heat generation; thereby ensuring the smooth operation of the pump.

[0012] On the basis of the above technical solution, the present invention can also make the following improvements:

[0013] Furthermore, the inner magnetic rotor is provided with a first blade.

[0014] The beneficial effect of adopting the above-mentioned further technical solution is that: on the one hand, the first blade drives the air flow disturbance as the inner magnetic rotor rotates, accelerating the heat exchange between the inner magnetic rotor and the compressed air. The air flow entering through the compressed air inlet flows into the chamber between the isolation sleeve and the inner magnetic rotor, and then is discharged through the compressed air outlet. On the other hand, the first blade itself also increases the heat exchange area of ​​the inner magnetic rotor, further improving the heat dissipation effect and taking away the heat.

[0015] Furthermore, the outer magnetic rotor is connected to the driven shaft via a connector, the connector includes a plurality of second blades spaced apart, the second blades include a first end and a second end, the first end is connected to the driven shaft, and the second end is connected to the outer magnetic rotor.

[0016] The beneficial effect of adopting the above-mentioned further technical solution is that the second blades on the connecting piece make the gas in the pump body cavity flow, thereby introducing the heat generated by the friction between the bearings in the pump body and the driven shaft into the external magnetic rotor, and then discharging it through the cooling medium on the outer surface of the bracket, thereby further reducing the temperature in the pump body and avoiding the bearing from heating up rapidly in the absence of medium lubrication.

[0017] Furthermore, it also includes a pressure sensor, which is used to measure the pressure in the cavity of the pump body that accommodates the external magnetic rotor. A pressure regulating device is provided at the compressed air inlet on the bearing housing. The pressure sensor is communicatively connected to the pressure regulating device. The pressure regulating device controls the pressure of the compressed air introduced into the bearing housing to maintain it near the pressure measured by the pressure sensor.

[0018] The beneficial effect of adopting the above further solution is to ensure that the pressures on the inner and outer sides of the isolation sleeve are substantially equal, thereby preventing the isolation sleeve itself from being subjected to excessive pressure, which would cause damage to the isolation sleeve.

[0019] Furthermore, cooling water flows through the cooling medium channel, and the cooling water can achieve temperature reduction at a low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A cross-sectional view of a magnetic pump according to embodiment 1 of the present invention is shown;

[0021] Figure 2 A schematic structural diagram of a second blade according to embodiment 2 of the present invention is shown;

[0022] Figure 3 Show Figure 2 Cross-section along AA direction;

[0023] Reference numerals:

[0024] 1. Pump body; 2. Impeller; 3. Pump cover; 4. Driven shaft; 5. Sliding bearing assembly; 6. Bushing; 7. Thrust bearing assembly; 8. Outer magnetic rotor; 9. Bracket; 10. Isolation sleeve; 11. Inner magnetic rotor; 12. Compressed air inlet; 13. Cooling medium channel; 14. Bearing housing; 15. Compressed air outlet; 16. First blade; 17. Second blade. DETAILED DESCRIPTION

[0025] The following is an explanation of the embodiments of the present invention by specific specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this invention are limited to this embodiment. On the contrary, the purpose of introducing the invention in conjunction with the embodiment is to cover other options or modifications that may be extended based on the claims of the present invention. In order to provide a deep understanding of the present invention, the following description will contain many specific details. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present invention, some specific details will be omitted in the description. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0026] Example 1:

[0027] A magnetic pump driven by an inner rotor and capable of dry operation, comprising a pump body 1, an impeller 2, a pump cover 3, a driven shaft 4, a sliding bearing assembly 5, a sleeve 6, a thrust bearing assembly 7, a driving shaft, an outer magnetic rotor 8, a bracket 9, a spacer sleeve 10, an inner magnetic rotor 11, and a bearing housing 14; the pump body 1, the bracket 9, and the bearing housing 14 are connected in sequence; a cavity is provided inside the pump body 1, the impeller 2 and the driven shaft 4 are both located in the cavity, one end of the driven shaft 4 is connected to the impeller 2, and the other end is connected to the outer magnetic rotor 8; the driving shaft is arranged in the bearing housing 14, and the end of the driving shaft close to the driven shaft 4 is connected to the inner magnetic rotor 11; the spacer sleeve 10 is located between the outer magnetic rotor 8 and the inner magnetic rotor 11, and the open end of the spacer sleeve 10 is connected to the bearing housing 14;

[0028] The bearing housing 14 is provided with a compressed air inlet 12 and a compressed air outlet 15. Compressed air enters the bearing housing 14 and takes away the eddy current heat generated by the inner magnetic rotor 11.

[0029] A cooling medium channel 13 is further provided on the surface of the bracket 9 , and cooling water flows through the cooling medium channel 13 . The outer magnetic rotor 8 is close to the inner surface of the bracket 9 .

[0030] The inner magnetic rotor 11 is provided with a first blade 16 , which is used to disturb the airflow, thereby disturbing the gas in the isolation sleeve 10 and better exchanging heat with the isolation sleeve 10 and the inner magnetic rotor 11 .

[0031] Example 2:

[0032] Different from Example 1, this example further adds the following features on the basis of Example 1:

[0033] The outer magnetic rotor 8 is connected to the driven shaft 4 via a connecting member, wherein the connecting member includes a plurality of second blades 17 arranged at intervals, and the second blade 17 includes a first end and a second end, wherein the first end is connected to the driven shaft 4, and the second end is connected to the outer magnetic rotor 8;

[0034] It also includes a pressure sensor, which is used to measure the pressure in the cavity of the pump body 1 that accommodates the external magnetic rotor 8. A pressure regulating device is provided at the compressed air inlet 12 on the bearing housing 14. The pressure sensor is communicatively connected to the pressure regulating device. The pressure regulating device controls the pressure of the compressed air introduced into the bearing housing 14 to maintain it near the pressure measured by the pressure sensor.

[0035] Compared with Example 1, this embodiment can better dissipate the friction heat between the bearing and the driven shaft 4. In addition, it can balance the pressure inside and outside the isolation sleeve 10, thus avoiding damage to the isolation sleeve 10 itself.

[0036] Example 3:

[0037] In this example, based on Example 2, the following technical features are further added:

[0038] It also includes a temperature sensor for sensing the temperature of the bracket 9; an electrically controlled valve is provided at the inlet of the cooling medium channel. When the temperature of the bracket 9 sensed by the temperature sensor is within the normal temperature range, such as below 200°C, the electrically controlled valve at the inlet of the cooling medium channel is closed. Once the bracket temperature is sensed to exceed 220°C, it is considered that the pump body has run dry, and the electrically controlled valve at the inlet of the cooling medium channel is immediately opened to cool the bracket 9 and trigger an alarm to remind staff to intervene. For magnetic pumps, as long as the temperature does not exceed 250°C, there is generally no problem.

[0039] In the solution of this embodiment, the cooling medium does not need to run continuously, and dry running of the magnetic pump is not a normal working state, so a large amount of energy can be saved by starting it through the temperature sensor.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A magnetic pump driven by an inner rotor and capable of dry operation, characterized in that: The invention comprises a pump body (1), an impeller (2), a driven shaft (4), a driving shaft, an outer magnetic rotor (8), a bracket (9), an isolating sleeve (10), an inner magnetic rotor (11), and a bearing housing (14); the pump body (1), the bracket (9), and the bearing housing (14) are connected in sequence; a cavity is provided inside the pump body (1), the impeller (2) and the driven shaft (4) are both located in the cavity, one end of the driven shaft (4) is connected to the impeller (2), and the other end is connected to the outer magnetic rotor (8); the driving shaft is arranged in the bearing housing (14), and one end of the driving shaft close to the driven shaft (4) is connected to the inner magnetic rotor (11); the isolating sleeve (10) is located between the outer magnetic rotor (8) and the inner magnetic rotor (11), and the open end of the isolating sleeve (10) is connected to the bearing housing (14); The bearing housing (14) is provided with a compressed air inlet (12) and a compressed air outlet (15), and the compressed air enters the bearing housing (14) and takes away the eddy current heat generated by the inner magnetic rotor (11); The outer surface of the bracket (9) is further provided with a cooling medium channel (13), and the outer magnetic rotor (8) is arranged close to the inner surface of the bracket (9); The invention also includes a pressure sensor, which is used to measure the pressure in the cavity of the pump body (1) accommodating the outer magnetic rotor (8). A pressure regulating device is provided at the compressed air inlet (12) on the bearing housing (14). The pressure sensor is communicatively connected to the pressure regulating device. The pressure regulating device controls the pressure of the compressed air introduced into the bearing housing (14) to be maintained near the pressure measured by the pressure sensor.

2. The inner rotor driven dry-running magnetic pump according to claim 1, characterized in that: The inner magnetic rotor (11) is provided with a first blade (16).

3. The inner rotor driven dry-running magnetic pump according to claim 2, characterized in that: The outer magnetic rotor (8) is connected to the driven shaft (4) via a connecting member, wherein the connecting member includes a plurality of second blades (17) arranged at intervals, and the second blades (17) include a first end and a second end, wherein the first end is connected to the driven shaft (4), and the second end is connected to the outer magnetic rotor (8).

4. The inner rotor driven dry-running magnetic pump according to claim 2, characterized in that: Cooling water flows through the cooling medium channel (13).

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