Dry-running magnetic drive pump driven by inner rotor

Abstract

The invention relates to the technical field of pump equipment, in particular to a magnetic drive pump driven by an inner rotor and capable of dry running, the inner magnetic rotor of the magnetic drive pump is arranged as a driving part, an outer magnetic rotor is arranged as a driven part, a compressed air channel is arranged on a shell, and the inner magnetic rotor is located in the compressed air channel; the cooling medium channel is arranged on the bracket close to the outer magnetic rotor, and the temperature of the bracket is cooled through the cooling medium, so that under the condition that the magnetic drive pump rotates dry, vortex heat of the isolation sleeve and the inner magnetic rotor can be taken away based on compressed air, and vortex heat of the outer magnetic rotor can be taken away based on the cooling medium; and the conditions of demagnetization of the inner and outer magnetic rotors and damage to the pump body caused by sharp temperature rise of the magnetic drive pump during dry rotation are avoided.

Description

Technical Field

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

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

[0003] A magnetic drive pump is a device that uses the magnetic transmission principle of an inner and outer magnetic rotor to drive the pump. It transmits the rotational power of the drive motor to the pump impeller through the magnetic contactless transmission of the inner and outer magnetic rotors, thereby achieving complete isolation between the driving part of the pump and the transported medium through an isolation sleeve. Therefore, it is particularly suitable for transporting 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 scheme, the driving 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 the isolation sleeve. When the magnetic pump is operating normally, the conveyed medium fills the inside of the isolation sleeve, so the impeller, the bearing and the inner magnetic rotor are completely immersed in the conveyed medium. Therefore, the continuously conveyed medium can take away the eddy heat generated by the inner and outer magnetic rotors and the friction heat of the bearings and the rotating shaft in time to avoid excessive temperature of the pump body. However, various sudden faults may occur during actual operation: for example, the medium inlet is blocked, no liquid enters, the pump is not turned off in time when unloading, etc., resulting in no medium being conveyed in the pump, and the magnetic pump continues to run. At this time, the magnetic pump is in dry operation. Since there is no conveying medium to take away 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 increase in temperature, 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 driven by an inner rotor and capable of dry operation.

[0007] The technical solution of the present invention to solve the above technical problems is as follows: The present invention provides a magnetic pump driven by an inner rotor and capable of dry operation, 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, the bracket, and the 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 arranged 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; 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; 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.

[0008] The inner rotor driven dry-running magnetic pump provided by the present invention has the inner magnetic rotor as an active driving part and the outer magnetic rotor as a driven part, so that the outer magnetic rotor can be 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, so that 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 takes 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 sharply, thereby avoiding the temperature increase in the pump due to the generation of heat; thereby ensuring the smooth operation of the pump.

[0009] On the basis of the above technical solution, the present invention can also make the following improvements: Furthermore, the inner magnetic rotor is provided with a first blade.

[0010] 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, accelerates the heat exchange between the inner magnetic rotor and the compressed air, and 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 improves the heat dissipation effect, and takes away the heat.

[0011] Furthermore, the outer magnetic rotor is connected to the driven shaft via a connecting member, the connecting member includes a plurality of second blades arranged at intervals, the second blade includes 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.

[0012] 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.

[0013] 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.

[0014] 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, thereby causing damage to the isolation sleeve.

[0015] 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

[0016] Figure 1 A cross-sectional view of a magnetic pump according to Embodiment 1 of the present invention is shown; Figure 2 A schematic diagram showing the structure of a second blade in Embodiment 2 of the present invention is shown; Figure 3 Show Figure 2 Section view along AA direction; Reference numerals: 1. Pump body; 2. Impeller; 3. Pump cover; 4. Driven shaft; 5. Sliding bearing assembly; 6. Bushing; 7. Thrust bearing assembly; 8. External magnetic rotor; 9. Bracket; 10. Isolation sleeve; 11. Internal 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

[0017] The following specific embodiments illustrate the implementation of the present invention, and 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 implementation. On the contrary, the purpose of introducing the invention in conjunction with the implementation is to cover other options or modifications that may extend based on the claims of the present invention. In order to provide a deep understanding of the present invention, the following description will include 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.

[0018] Embodiment 1: 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 one 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; 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. A cooling medium channel 13 is also 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 .

[0019] The inner magnetic rotor 11 is provided with a first blade 16 , which is used to disturb the airflow, so as to disturb the gas in the isolation sleeve 10 , so as to better exchange heat with the isolation sleeve 10 and the inner magnetic rotor 11 .

[0020] Embodiment 2: Different from Example 1, in this example, the following features are further added on the basis of Example 1: The outer magnetic rotor 8 is connected to the driven shaft 4 through a connecting member, the connecting member includes a plurality of second blades 17 arranged at intervals, the second blade 17 includes a first end and a second end, the first end is connected to the driven shaft 4, and the second end is connected to the outer magnetic rotor 8; 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.

[0021] Compared with Embodiment 1, this embodiment can better dissipate the friction heat between the bearing and the driven shaft 4, and can also balance the pressure on the inner and outer sides of the isolation sleeve 10, thereby avoiding damage to the isolation sleeve 10 itself.

[0022] Embodiment 3: In this example, based on Example 2, the following technical features are further added: It also includes a temperature sensor, which is used to sense the temperature of the bracket 9; an electric control 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 electric control valve at the inlet of the cooling medium channel is in a closed state. Once the bracket temperature is sensed to exceed 220°C, it is considered that the pump body has run dry, and the electric control valve at the inlet of the cooling medium channel is immediately opened to cool the bracket 9, and at the same time, an alarm message is triggered to remind the staff to intervene. For magnetic pumps, there is generally no problem as long as it does not exceed 250°C.

[0023] 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 through the temperature sensor.

[0024] 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 principle of the present invention should be included in the protection scope 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), 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 one 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); 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) to carry away eddy current heat generated by the inner magnetic rotor (11); The outer surface of the bracket (9) is also provided with a cooling medium channel (13), and the outer magnetic rotor (8) is arranged close to the inner surface of the bracket (9).

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 external magnetic rotor (8) is connected to the driven shaft (4) via a connecting member, the connecting member comprising a plurality of second blades (17) arranged at intervals, the second blades (17) comprising a first end and a second end, the first end being connected to the driven shaft (4), and the second end being connected to the external magnetic rotor (8).

4. The inner rotor driven dry-running magnetic pump according to claim 3, characterized in that: It also includes a pressure sensor, which is used to measure the pressure in the cavity of the pump body (1) accommodating 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 be maintained near the pressure measured by the pressure sensor.

5. 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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