High-durability multi-stage shielding electric pump

Abstract

The invention discloses a high-durability multi-stage shielding electric pump in the technical field of shielding electric pumps, which comprises a pump body and a pump cover, the pump body is provided with an inlet pipe, an outlet pipe and a connecting flange plate, and after the pump body compresses a space guide vane, the pump body is fixed on the pump cover by utilizing a pump body fixing screw through the connecting flange plate; a rotor shaft is installed in the pump cover through a front bearing and a rear bearing, the circumferential side of the rotor shaft is sleeved with a thrust plate, the thrust plate is fixed to the rotor shaft through a limiting plate, the thrust plate and the rotor shaft form a self-adjusting movable joint through a spherical surface, and a wedge-shaped water film is formed by the thrust plate and the thrust surface of the front bearing when the thrust plate rotates at a high speed. The thrust plate and the shaft which are in opposite grinding with the bearing are of a spherical joint self-adjusting structure, a wedge-shaped water film can be formed between the thrust plate and the thrust bearing along with rotation of the shaft, the safe lubricating and supporting effects of the water-lubricated bearing can be guaranteed, bearing abrasion is reduced, and the running durability of the pump is effectively improved.

Description

Technical Field

[0001] The invention relates to a high-durability multi-stage canned electric pump, belonging to the technical field of canned electric pumps. Background Art

[0002] The canned motor pump is a power device used for conveying. The equipment is mainly composed of pump body, impeller, stator, rotor, front and rear bearings and thrust plate and other parts. The stator and rotor are isolated by non-magnetic corrosion-resistant thin-walled sleeves, and the rotor is supported by front and rear bearings and immersed in the conveying medium, so no dynamic seal is required to prevent the conveyed medium from leaking out.

[0003] The existence of axial force in the shielded electric pump will cause accelerated wear of the bearings, resulting in the pump being unable to run smoothly for a long time, reducing the service life and overall performance of the electric pump, and even endangering the safety of the operator in severe cases. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a high-durability multi-stage canned electric pump that can ensure the safe lubrication and support of water-lubricated bearings, reduce bearing wear, and effectively improve the operating durability of the pump.

[0005] To achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0006] In the first aspect, the present invention provides a high-durability multi-stage shielded electric pump, including a pump body and a pump cover, the pump body is provided with an inlet pipe, an outlet pipe and a connecting flange, and after the pump body is pressed against the space guide vane, it is fixed to the pump cover by means of the connecting flange and the pump body fixing screws, a rotor shaft is installed in the pump cover through a front bearing and a rear bearing, a thrust plate is sleeved on the circumferential side of the rotor shaft, and the thrust plate is fixed to the rotor shaft through a limit plate, the thrust plate forms a self-adjusting movable joint with the rotor shaft through a spherical surface, and the thrust plate forms a wedge-shaped water film with the thrust surface of the front bearing when rotating at high speed.

[0007] Furthermore, multiple groups of MEMS accelerometers are installed at the front bearing and the rear bearing in the pump cover, and the MEMS accelerometers are electrically connected to an embedded DSP processor. The embedded DSP processor combines the monitoring data of the MEMS accelerometers with the vibration energy entropy model to calculate the vibration energy entropy, and compares the vibration energy entropy with a preset threshold to analyze the current bearing wear status.

[0008] Furthermore, the vibration energy entropy model formula is:

[0009]

[0010] Where, Hv: vibration energy entropy; Ei: vibration energy of the i-th frequency band; Etotal: total vibration energy; N: total number of frequency bands after wavelet packet decomposition.

[0011] Furthermore, the embedded DSP processor is electrically connected to a host computer analysis system, and the host computer analysis system calculates the wear trend coefficient by combining the vibration energy entropy with the wear trend coefficient calculation formula, and then performs maintenance suggestion analysis according to the wear trend coefficient.

[0012] Furthermore, the wear tendency coefficient calculation formula is:

[0013]

[0014] Where, β: wear trend coefficient; Hv,t: vibration energy entropy in the tth time window; Mean value of vibration energy entropy; The mean of the time window sequence numbers.

[0015] Furthermore, the embedded DSP processor and the host computer analysis system are electrically connected to a cloud analysis platform, and the cloud analysis platform calculates the comprehensive health index by combining the wear trend coefficient and the vibration energy entropy with the comprehensive health index calculation formula, and then performs equipment health status analysis based on the comprehensive health index.

[0016] Furthermore, the comprehensive health index calculation formula is:

[0017]

[0018] Wherein, Γ: comprehensive health index; T: current bearing temperature; T0: bearing temperature reference value; Hv0: initial vibration energy entropy reference value; α, β: dynamic weight coefficients, and α+β=1.

[0019] Furthermore, the MEMS accelerometers are in three groups, and the three groups of MEMS accelerometers are distributed at 120° intervals, with a sampling frequency of 20 kHz.

[0020] Furthermore, the embedded DSP processor updates the vibration energy entropy every five minutes, the host computer analysis system calculates the wear trend coefficient every hour, and the cloud analysis platform generates a comprehensive health index every day.

[0021] Furthermore, when the vibration energy entropy exceeds the preset threshold for three consecutive times, the embedded DSP processor triggers a primary warning; when the wear trend coefficient is greater than 0.15, the embedded DSP processor starts a maintenance recommendation program; when the comprehensive health index is less than 0.7, the cloud analysis platform generates a device health report.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The pump cover of this scheme is provided with radial and thrust integrated sliding bearings, and the thrust plate and the shaft that are worn against the bearings are spherical joint self-adjusting structures, which can follow the rotation of the shaft to form a wedge-shaped water film between the thrust plate and the thrust bearing, which can ensure the safe lubrication and support of the water-lubricated bearing, reduce bearing wear, and effectively improve the operating durability of the pump;

[0024] 2. This solution combines the vibration energy distribution characteristics with the temperature evolution trend to overcome the limitations of single parameter detection; the trend coefficient is used to achieve quantitative prediction of wear development and support preventive maintenance decisions; frequency domain energy entropy analysis is used to effectively suppress the impact of fluid pulsation noise; a multi-parameter correlation model is established to achieve a technological leap from threshold alarm to health status assessment; the modular design can adapt to the monitoring needs of shielded electric pumps of different specifications. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0026] Figure 1 A cross-sectional schematic diagram of a high-durability multi-stage canned motor pump provided by an embodiment of the present invention;

[0027] Figure 2 An enlarged cross-sectional view of a thrust plate spherical joint of a high-durability multi-stage canned motor pump provided in an embodiment of the present invention.

[0028] In the figure: 1. Pump inlet; 2. First-stage impeller; 3. Pump body; 4. Space guide vane; 5. Secondary impeller; 6. Water outlet channel; 7. Pump outlet; 8. Final impeller; 9. Pump body fixing screws; 10. Pump cover; 11. Motor fixing screws; 12. Front bearing; 13. Thrust plate; 14. Rotor shaft; 15. Center hole flow channel; 16. Stator; 17. Stator shielding sleeve; 18. Rotor; 19. Rear bearing. DETAILED DESCRIPTION

[0029] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0030] The following detailed description is an exemplary description, which is intended to provide further detailed description of the present invention. Unless otherwise specified, all technical terms used in the present invention have the same meaning as those generally understood by those skilled in the art to which the present invention belongs. The terms used in the present invention are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present invention.

[0031] Example:

[0032] like Figure 1-2 The high-durability multi-stage canned electric pump shown in the figure is composed of a pump inlet 1, a first-stage impeller 2, a pump body 3, a space guide vane 4, a secondary impeller 5, a water outlet channel 6, a pump outlet 7, a final impeller 8, a pump body fixing screw 9, a pump cover 10, a motor fixing screw 11, a front bearing 12, a thrust plate 13, a rotor shaft 14, a center hole flow channel 15, a stator 16, a stator shielding sleeve 17, a rotor 18, and a rear bearing 19. Among them, the pump inlet 1 is installed at the front end of the pump body 3, the first-stage impeller 2, the space guide vane 4, the secondary impeller 5, the water outlet channel 6, and the final impeller 8 are installed on the inner side of the pump body 3, the pump outlet 7 is installed on one side of the pump body 3, the pump cover 10 is located at the rear side of the pump body 3, and the pump body 3 is provided with an inlet pipe, an outlet pipe and a connecting flange. After the space guide vane 4 is pressed, it is fixed to the pump cover 10 by the pump body fixing screw 9 through the connecting flange. Not only will the deformation of the inlet and outlet pipes not cause leakage at the pump body seal, but also the maintenance is more convenient. The motor fixing screw 11 is installed on the side opposite to the pump body fixing screw 9, and the front bearing 12, thrust plate 13, rotor shaft 14, center hole flow channel 15, stator 16, stator shielding sleeve 17, rotor 18 and rear bearing 19 are all installed inside the pump cover 10, wherein the front end of the rotor shaft 14 is rotatably connected through the front bearing 12, the thrust plate 13 is sleeved on the peripheral side of the rotor shaft 14, the center hole flow channel 15 is located on the inner side of the rotor shaft 14, the rotor 18 is sleeved on the peripheral side of the rotor shaft 14, the stator 16 is sleeved on the peripheral side of the rotor 18, the stator shielding sleeve 17 is sleeved on the peripheral side of the stator 16, and the rear end of the rotor shaft 14 is rotatably connected to the pump cover 10 through the rear bearing 19. It should be noted that the thrust plate 13 forms a self-adjusting movable joint with the rotor shaft 14 through a spherical surface. The thrust plate 13 is fixed to the rotor shaft 14 through a limit plate. When the thrust plate 13 rotates at high speed, it forms a wedge-shaped water film with the thrust surface of the front bearing, thereby reducing the wear of the bearing and extending the service life of the bearing.

[0033] In this solution, the water pump is installed on one side of the pump cover, and the motor is installed on the other side of the pump cover. The pump cover is equipped with thrust and radial bearings, and the motor and the water pump are coaxially connected, which is not only simple and compact in structure, but also more stable and reliable. In addition, the pump body has its own mounting flange, and the deformation of the inlet and outlet pipelines at the user's site will not cause the pump body stop seal to fail and leak. The pump cover is equipped with radial and thrust integrated sliding bearings, and the thrust plate and the shaft that are rubbed against the bearing are spherical joint self-adjusting structures, which can follow the rotation of the shaft to form a wedge-shaped water film between the thrust plate and the thrust bearing, which can ensure the safe lubrication and support of the water-lubricated bearing, reduce bearing wear, and effectively improve the operating durability of the pump.

[0034] It should be noted that in order to monitor the bearing wear in the canned motor pump in real time, this solution further provides a three-level architecture detection solution through vibration energy entropy analysis, wear trend coefficient calculation and comprehensive health index evaluation, including:

[0035] 1. The embedded DSP processor detects the current bearing wear status based on the vibration energy entropy model:

[0036]

[0037] Wherein, Hv: vibration energy entropy, characterizing the current bearing wear state (the larger the value, the more dispersed the energy distribution); Ei: vibration energy of the i-th frequency band (obtained through wavelet packet decomposition); Etotal: total vibration energy (the sum of the energy of each frequency band), data source: acceleration sensor sampling signal (10-20kHz); N: the total number of frequency bands after wavelet packet decomposition.

[0038] 2. The upper computer analysis system calculates the wear development rate based on the wear trend coefficient:

[0039]

[0040] Where, β: wear trend coefficient, characterizing the wear development rate (positive value indicates accelerated deterioration); Hv,t: vibration energy entropy in the tth time window; Mean value of vibration energy entropy; Mean of time window sequence number (rolling calculation window k=15), data source: historical vibration energy entropy sequence.

[0041] 3. The cloud analysis platform calculates and evaluates the remaining life of the equipment based on the comprehensive health index:

[0042]

[0043] Wherein, Γ: comprehensive health index, representing the remaining life of the equipment (the lower the index, the higher the risk); T: current bearing temperature (infrared temperature measurement module); T0: bearing temperature reference value; Hv0: initial vibration energy entropy reference value; α, β: dynamic weight coefficient (α+β=1); data source: vibration entropy database and temperature monitoring data.

[0044] In actual operation, three sets of MEMS accelerometers (120° intervals) are first installed on the pump bearing seat, with a sampling frequency of 20kHz. Then, wavelet noise reduction is performed through the embedded system and the energy distribution of each frequency band is calculated. The vibration energy entropy Hv is updated every five minutes, the wear trend coefficient β is calculated every hour, and the comprehensive health index Γ is generated every day. When Hv exceeds the preset threshold three times in a row, a primary warning is triggered. When β>0.15, the maintenance recommendation program is started, and when Γ<0.7, an equipment health report is generated.

[0045] This solution combines the vibration energy distribution characteristics with the temperature evolution trend to overcome the limitations of single parameter detection; realizes quantitative prediction of wear development through trend coefficient to support preventive maintenance decisions; uses frequency domain energy entropy analysis to effectively suppress the influence of fluid pulsation noise; establishes a multi-parameter correlation model to achieve a technological leap from threshold alarm to health status assessment; and the modular design can adapt to the monitoring needs of shielded motor pumps of different specifications.

[0046] It is known from common technical knowledge that the present invention can be implemented by other embodiments that do not deviate from its spirit or essential features. Therefore, the above disclosed embodiments are only illustrative in all respects and are not exclusive. All changes within the scope of the present invention or within the scope equivalent to the present invention are included in the present invention.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A high-durability multi-stage canned motor pump, characterized in that: The invention comprises a pump body (3) and a pump cover (10), wherein the pump body (3) is provided with an inlet pipe, an outlet pipe and a connecting flange, and after the pump body (3) is pressed against a space guide vane (4), it is fixed to the pump cover (10) by means of a pump body fixing screw (9) through the connecting flange, a rotor shaft (14) is installed in the pump cover (10) through a front bearing (12) and a rear bearing (19), a thrust plate (13) is sleeved on the circumferential side of the rotor shaft (14), and the thrust plate (13) is fixed to the rotor shaft (14) through a limit plate, the thrust plate (13) forms a self-adjusting movable joint with the rotor shaft (14) through a spherical surface, and the thrust plate (13) forms a wedge-shaped water film with the thrust surface of the front bearing (12) when rotating at a high speed.

2. The high-durability multi-stage canned motor pump according to claim 1 is characterized in that: A plurality of groups of MEMS accelerometers are installed at the front bearing (12) and the rear bearing (19) in the pump cover (10), and the MEMS accelerometers are electrically connected to an embedded DSP processor. The embedded DSP processor combines monitoring data of the MEMS accelerometers with a vibration energy entropy model to calculate vibration energy entropy, and compares the vibration energy entropy with a preset threshold value to analyze the current bearing wear state.

3. The high-durability multi-stage canned motor pump according to claim 2 is characterized in that: The vibration energy entropy model formula is: Where, Hv: vibration energy entropy; Ei: vibration energy of the i-th frequency band; Etotal: total vibration energy; N: the total number of frequency bands after wavelet packet decomposition.

4. The high-durability multi-stage canned motor pump according to claim 2 is characterized in that: The embedded DSP processor is electrically connected to a host computer analysis system, and the host computer analysis system calculates the wear trend coefficient by combining the vibration energy entropy with the wear trend coefficient calculation formula, and then performs maintenance suggestion analysis according to the wear trend coefficient.

5. The high-durability multi-stage canned motor pump according to claim 4 is characterized in that: The wear tendency coefficient calculation formula is: Where, β: wear trend coefficient; Hv,t: vibration energy entropy in the tth time window; Mean value of vibration energy entropy; Mean of the time window sequence number.

6. The high-durability multi-stage canned motor pump according to claim 4 is characterized in that: The embedded DSP processor and the host computer analysis system are electrically connected to a cloud analysis platform, and the cloud analysis platform calculates the comprehensive health index by combining the wear trend coefficient and the vibration energy entropy with the comprehensive health index calculation formula, and then performs equipment health status analysis based on the comprehensive health index.

7. The high-durability multi-stage canned motor pump according to claim 6 is characterized in that: The comprehensive health index calculation formula is: Where, Γ: comprehensive health index; T: current bearing temperature; T0: bearing temperature reference value; Hv0: initial vibration energy entropy reference value; α, β: dynamic weight coefficients, and α+β=1.

8. The high-durability multi-stage canned motor pump according to claim 2 is characterized in that: The MEMS accelerometers are divided into three groups, and the three groups of MEMS accelerometers are distributed at intervals of 120°, with a sampling frequency of 20 kHz.

9. The high-durability multi-stage canned motor pump according to claim 6 is characterized in that: The embedded DSP processor updates the vibration energy entropy every five minutes, the host computer analysis system calculates the wear trend coefficient every hour, and the cloud analysis platform generates a comprehensive health index every day.

10. The high-durability multi-stage canned motor pump according to claim 6, characterized in that: When the vibration energy entropy exceeds the preset threshold three times in a row, the embedded DSP processor triggers a primary warning; When the wear trend coefficient is greater than 0.15, the embedded DSP processor starts a maintenance suggestion program; When the comprehensive health index is less than 0.7, the cloud analysis platform generates a device health report.

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