Monitoring device for permanent magnet synchronous motor

By employing a dual monitoring method combining eddy current sensors and pressure sensors, along with automated cleaning components, the problems of insufficient reliability and inconvenient maintenance associated with single-sensor monitoring are resolved, achieving high-precision and low-cost motor condition monitoring.

CN120831041APending Publication Date: 2025-10-24HUAINAN UNITED UNIVERSITY
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Patent Information

Application Number
CN202511000862.9
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2025-07-21
Publication Date
2025-10-24

AI Technical Summary

Technical Problem

Existing monitoring methods for permanent magnet synchronous motors rely on a single sensor, resulting in insufficient reliability of monitoring data, high and inconvenient maintenance costs, and the sensor is susceptible to contamination, which affects measurement accuracy.

Method used

Employing a dual monitoring approach using both eddy current and pressure sensors, combined with unique cleaning components including a spring-loaded telescopic airbag, elastic sheet, non-woven fabric, and a miniature air pump, the sensor probe is automatically cleaned, ensuring monitoring accuracy and reliability.

Benefits of technology

This improves the accuracy and reliability of monitoring the output shaft runout and offset of permanent magnet synchronous motors, reduces maintenance costs and downtime, and enhances the safety of equipment operation.

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Abstract

The invention discloses a monitoring device for a permanent magnet synchronous motor, and relates to the technical field of motor monitoring, the monitoring device comprises a mounting rack, an eddy current sensor and a monitoring assembly, the mounting rack coaxially sleeves an output shaft of the motor and is fixed at the end part of the motor, the eddy current sensor is mounted on the mounting rack, and the monitoring assembly is arranged on the mounting rack. The cleaning assembly comprises a spring telescopic air bag, an elastic piece, a non-woven fabric, a micro inflation pump and an electromagnetic valve. When the eddy current sensor probe needs to be cleaned, the spring telescopic air bag is inflated through the micro inflation pump, the elastic piece and the non-woven fabric are driven to move to a narrow space between the probe and the output shaft, and dust, oil dirt and other impurities on the surface of the probe are cleaned. And after cleaning is completed, the whole cleaning process is automatically completed through exhaust of the electromagnetic valve, resetting of the spring telescopic air bag and automatic separation of the non-woven fabric from the probe, the sensor does not need to be manually disassembled, the maintenance cost is greatly reduced, the downtime is greatly shortened, and the maintenance convenience is improved.
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Description

Technical Field

[0001] The present invention relates to the technical field of motor monitoring, and in particular to a monitoring device for a permanent magnet synchronous motor. Background Art

[0002] Permanent magnet synchronous motors (PMSMs) are widely used in industrial production, mechanical transmission, and other fields due to their high efficiency and energy-saving advantages. However, to ensure their normal operation and detect potential faults in a timely manner, real-time monitoring of the operating status of their output shafts is crucial.

[0003] Traditional permanent magnet synchronous motor monitoring methods mainly rely on a single sensor, such as an eddy current sensor, to measure the runout of the output shaft. However, this method has certain limitations:

[0004] 1. Insufficient reliability of monitoring data: Relying on only one sensor to monitor the motor output shaft vibration, when the sensor fails or is interfered with, it cannot provide reliable monitoring data, which may lead to misjudgment of the motor's operating status, thereby affecting the safety and stability of the equipment.

[0005] 2. High maintenance cost and inconvenience: During long-term use, the probe of the eddy current sensor is easily contaminated by impurities such as dust and oil, resulting in reduced measurement accuracy and even false alarms or abnormal sensitivity, making it impossible to accurately monitor the actual operating status of the motor output shaft. When the eddy current sensor probe is contaminated and needs to be cleaned, it is often necessary to stop the machine and perform manual cleaning. Due to the small gap between the eddy current sensor and the permanent magnet synchronous motor, this is not only difficult to clean, but may also damage the sensor due to improper operation, further affecting the normal operation of the equipment. Summary of the Invention

[0006] The object of the present invention is to provide a monitoring device for a permanent magnet synchronous motor to overcome the above-mentioned defects in the prior art.

[0007] A monitoring device for a permanent magnet synchronous motor comprises a mounting frame, an eddy current sensor and a monitoring assembly. The mounting frame is coaxially sleeved on the output shaft of the motor and fixed to the end of the motor. The eddy current sensor is mounted on the mounting frame and its probe surface is cleaned by a cleaning assembly. Several monitoring assemblies are provided and evenly distributed on the circumference of the mounting frame and are used to monitor the output shaft runout of the motor.

[0008] Preferably, the mounting frame includes a fixing ring, an outer ring body and an inner ring body, the outer ring body is arranged on the outside of the fixing ring and is detachably connected to the end of the motor, and the inner ring body is arranged on the inside of the fixing ring.

[0009] Preferably, the cleaning assembly comprises a spring telescopic air bag, elastic sheets, non-woven fabric, a micro air pump and a solenoid valve, the eddy current sensor is fixed by two threaded sleeves and a fixing ring, a barrel connected with one of the threaded sleeves is sleeved on the eddy current sensor, the spring telescopic air bag is sleeved on the eddy current sensor and one end of the spring telescopic air bag is connected with the threaded sleeve, the other end of the spring telescopic air bag is provided with a moving ring, a plurality of elastic sheets are uniformly distributed along the circumference of the moving ring, the non-woven fabric is in a circular ring structure and one end of the non-woven fabric is adhered to the elastic sheets, a plurality of openings are uniformly distributed along the circumference of the non-woven fabric, the micro air pump is arranged outside the fixing ring and the air outlet of the micro air pump is connected with the spring telescopic air bag through a pipeline, and the solenoid valve is installed on the exhaust pipe of the spring telescopic air bag.

[0010] Preferably, the monitoring assembly comprises a top rod, a pressure sensor and a compression spring, the top rod is slidingly connected in a mounting groove on the inner ring body, the outer end of the top rod abuts against the output shaft of the motor and the top rod is provided with a baffle disc in the mounting groove, the pressure sensor is coaxially arranged on the inner wall of the mounting groove and the top rod, the compression spring is sleeved on the top rod and the pressure sensor, and the inner end of the top rod abuts against the surface of the pressure sensor.

[0011] Preferably, the outer end of the top rod is in a conical structure.

[0012] Preferably, the inner ring body is provided with a cover plate at the top of the mounting groove.

[0013] Preferably, the four corners of the cover plate are connected with the inner ring body by bolts.

[0014] Preferably, the outer ring body is connected with the end of the motor by bolts.

[0015] Preferably, the eddy current sensor is provided with two and is symmetrically arranged on the two sides of the fixing ring.

[0016] The present application has the following beneficial effects:

[0017] 1、The application adopts the mode of simultaneously monitoring by using an eddy current sensor and a pressure sensor. The eddy current sensor can accurately measure the distance change between the output shaft and the sensor probe in a non-contact manner, and can sensitively detect the macroscopic jumping of the output shaft and surface defects; the pressure sensor can detect the pressure change of the ejector rod when the output shaft jumps and deviates, and through the direct contact between the ejector rod and the output shaft, the small jumping of the output shaft can be more accurately perceived, especially for the small axial and radial deviation caused by factors such as manufacturing precision, installation error or load change, which can effectively supplement the possible deficiencies of the eddy current sensor in monitoring small displacement, thereby greatly improving the precision and accuracy of monitoring the jumping deviation of the output shaft of the permanent magnet synchronous motor. The double monitoring mechanism of the eddy current sensor and the ejector rod can verify and supplement each other, avoid the monitoring distortion caused by factors such as signal interference and mechanical failure of a single monitoring method, and enhance the reliability of monitoring the jumping deviation of the output shaft of the permanent magnet synchronous motor, thereby providing more reliable monitoring guarantee for the safe operation of the motor.

[0018] 2、The application adopts a unique cleaning assembly, which includes a spring telescopic air bag, an elastic sheet, a non-woven fabric, a micro inflator and a solenoid valve. When the eddy current sensor probe needs to be cleaned, the spring telescopic air bag is inflated by the micro inflator, the elastic sheet and the non-woven fabric are driven to move to the narrow space between the probe and the output shaft, and the dust, oil stains and other impurities on the surface of the probe are cleaned. After cleaning, the spring telescopic air bag is reset by the solenoid valve, the non-woven fabric automatically separates from the probe, and the whole cleaning process is automatically completed without the need of manual disassembly of the sensor, which greatly reduces the maintenance cost and downtime and improves the convenience of maintenance. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of the application.

[0020] Figure 2 It is a schematic diagram of the structure of the mounting frame, the eddy current sensor, the cleaning assembly and the monitoring assembly of the application.

[0021] Figure 3 It is a schematic diagram of the structure of the spring telescopic air bag, the moving ring, the elastic sheet and the non-woven fabric of the application. Figure 2 It is a partial enlarged view of A in FIG. 4.

[0022] Figure 4 It is a schematic diagram of the structure of the eddy current sensor and part of the cleaning assembly of the application.

[0023] Figure 5 It is a schematic diagram of the structure of the spring telescopic air bag, the moving ring, the elastic sheet and the non-woven fabric of the application.

[0024] Figure 6 It is a schematic diagram of the structure of the spring telescopic air bag, the moving ring, the elastic sheet and the non-woven fabric of the application. Figure 2 It is a schematic diagram of the structure when the cover plate is not installed.

[0025] Figure 7 For Figure 6 A local enlarged view at B.

[0026] In the figure, 1, mounting frame; 11, fixed ring; 12, outer ring body; 13, inner ring body; 131, mounting groove; 2, eddy current sensor; 21, threaded sleeve; 3, monitoring assembly; 31, top rod; 32, baffle disc; 33, pressure sensor; 34, compression spring; 35, cover plate; 4, cleaning assembly; 41, cylinder; 42, spring telescopic air bag; 43, moving ring; 44, elastic sheet; 45, non-woven fabric; 451, opening; 46, micro inflator pump; 461, pipeline; 47, electromagnetic valve; 48, exhaust pipe; 5, motor; 51, output shaft. DETAILED DESCRIPTION

[0027] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description herein is for describing the specific embodiments only and is not intended to be limiting of the application; the use of the terms "including", "comprising" and "having" and any variations thereof in this description and in the claims are intended to cover both the inclusive and exclusive cases.

[0029] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase "in an embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another. Those skilled in the art will appreciate that embodiments described herein can be combined with other embodiments.

[0030] As Figures 1-7 shown, the application provides a monitoring device for permanent magnet synchronous motor, comprising mounting frame 1, eddy current sensor 2 and monitoring assembly 3;

[0031] It should be noted that the mounting frame 1 is coaxially sleeved on the output shaft 51 of the motor 5 and fixed to the end of the motor 5. The mounting frame 1 includes a fixing ring 11, an outer ring body 12 and an inner ring body 13. The outer ring body 12 is arranged on the outside of the fixing ring 11 and is connected to the end of the motor 5 by bolts. The inner ring body 13 is arranged on the inside of the fixing ring 11.

[0032] In addition, the eddy current sensor 2 is mounted on the mounting frame 1 and its probe surface is cleaned by the cleaning assembly 4. The eddy current sensor 2 is provided with two symmetrically arranged on both sides of the fixing ring 11, and the distance between the output shaft 5141 and the probe thereon is measured at all times by the eddy current sensor 22;

[0033] In addition, the cleaning assembly 4 includes a spring telescopic airbag 42, an elastic sheet 44, a non-woven fabric 45, a micro air pump 46 and a solenoid valve 47. The eddy current sensor 2 is fixed to the fixed ring 11 by two threaded sleeves 21 threaded thereon. The eddy current sensor 2 is provided with a cylinder 41 connected to one of the threaded sleeves 21. The spring telescopic airbag 42 is sleeved on the eddy current sensor 2 and one end of which is connected to the threaded sleeve 21. The other end of the spring telescopic airbag 42 is provided with a movable ring 43. Several elastic sheets 44 are evenly distributed along the circumference of the movable ring 43. The non-woven fabric 45 is a circular structure and its inner end is adhered to the elastic sheet 44. Several openings 451 are evenly distributed along the circumference of the non-woven fabric 45. The micro air pump 46 is provided on the outside of the fixed ring 11 and its air outlet is connected to the spring telescopic airbag 42 through a pipe 461. The solenoid valve 47 is installed on the exhaust pipe 48 of the spring telescopic airbag 42;

[0034] In addition, the monitoring assembly 3 is provided with several and evenly distributed on the circumference of the mounting frame 1 and is used to monitor the vibration of the output shaft 51 of the motor 5. The monitoring assembly 3 includes a push rod 31, a pressure sensor 33 and a compression spring 34. The push rod 31 is slidably connected to the mounting groove 131 on the inner ring body 13. The inner ring body 13 is provided with a cover plate 35 at the top of the mounting groove 131. The four corners of the cover plate 35 are respectively connected to the inner ring body 13 by bolts, which facilitates the disassembly and assembly of the cover plate 3535 and the inner ring body 1313;

[0035] In addition, the outer end of the push rod 31 abuts against the output shaft 51 of the motor 5 and a baffle 32 is provided in the mounting groove 131. The outer end of the push rod 31 is a conical structure. A pressure sensor 33 is provided on the inner wall of the mounting groove 131 coaxially with the push rod 31. The compression spring 34 is sleeved on the push rod 31 and the pressure sensor 33. The inner end of the push rod 31 abuts against the surface of the pressure sensor 33. The output shaft 5141 of the permanent magnet synchronous motor 54 is monitored for runout deviation through the pressure sensor 3333.

[0036] DETAILED DESCRIPTION AND PRINCIPLES

[0037] When monitoring the output shaft 51 of the permanent magnet synchronous motor 5, the top rod 31 of the monitoring assembly 3 is abutted on the surface of the output shaft 51 of the permanent magnet synchronous motor 5 under the action of the compressed spring 34 on the top rod 31, and the eddy current sensor 2 on both sides of the fixed ring 11 measures the distance between the output shaft 51 and the probe thereon at any time and transmits the data to the controller;

[0038] Meanwhile, the top rod 31 is abutted on the output shaft 51 of the permanent magnet synchronous motor 5 at any time, and when the output shaft 51 of the permanent magnet synchronous motor 5 jumps and deviates, it will drive the top rod 31 to move in the mounting groove 131 on the inner ring body 13, and the pressure sensor 33 will be extruded in the process of the movement of the top rod 31, and the pressure sensor 33 will transmit the data to the controller, so that the eddy current sensor 2 and the pressure sensor 33 are monitored at the same time to avoid the distortion of the monitoring of the jumping and deviation of the output shaft 51 of the permanent magnet synchronous motor 5;

[0039] When the sensitivity of the eddy current sensor 2 is abnormal or false, the operation of the motor 5 is stopped, and then the micro air pump 46 inflates the spring telescopic air bag 42 through the pipeline 461 to make the spring telescopic air bag 42 elongate and drive the elastic sheet 44 to move along the cylinder 41, when the elastic sheet 44 moves to the end of the eddy current sensor 2, the non-woven fabric 45 is bent towards the eddy current sensor 2 under the action of the elastic sheet 44, and when the elastic sheet 44 continues to move and contacts the output shaft 51 of the motor 5, the elastic sheet 44 is extruded and deformed, so that the elastic sheet 44 and the non-woven fabric 45 are located in the narrow space between the output shaft 51 of the motor 5 and the probe of the eddy current sensor 2, and the probe of the eddy current sensor 2 is cleaned through the non-woven fabric 45, when the cleaning of the probe of the eddy current sensor 2 is completed, the micro air pump 46 stops working, the electromagnetic valve 47 on the exhaust pipe 48 is opened, the gas in the spring telescopic air bag 42 is discharged, and the spring telescopic air bag 42 is reset to the cylinder 41 under the action of the spring force of the spring telescopic air bag 42, so that the non-woven fabric 45 is separated from the probe of the eddy current sensor 2;

[0040] When the non-woven fabric 45 is used for many times, the mounting frame 1 is disassembled from the motor 5, and the non-woven fabric 45 is replaced.

[0041] The above-mentioned embodiments of the application do not constitute a limitation on the protection scope of the application. Any modification, equivalent replacement and improvement made within the spirit and principles of the application shall be included in the protection scope of the claims of the application.

Claims

1. A monitoring device for a permanent magnet synchronous motor, characterized by: The utility model provides an electric motor output shaft jump monitoring device, including mounting frame (1), eddy current sensor (2) and monitoring component (3), mounting frame (1) coaxial sleeve is set on the output shaft (51) of motor (5) and is fixed in the end of motor (5), eddy current sensor (2) is installed on mounting frame (1) and carries out cleaning to its probe surface through cleaning component (4), monitoring component (3) is equipped with several and is evenly distributed on the circumference of mounting frame (1) and is used for monitoring the output shaft (51) jump of motor (5).

2. A monitoring device for a permanent magnet synchronous motor according to claim 1, characterized in that: The mounting frame (1) comprises a fixing ring (11), an outer ring body (12) and an inner ring body (13), the outer ring body (12) is arranged on the outer side of the fixing ring (11) and detachably connected with the end of the motor (5), and the inner ring body (13) is arranged on the inner side of the fixing ring (11).

3. The monitoring device for a permanent magnet synchronous motor according to claim 1, characterized in that: The cleaning component (4) comprises a spring telescopic air bag (42), an elastic sheet (44), a non-woven fabric (45), a micro inflator pump (46) and a solenoid valve (47), the eddy current sensor (2) is fixed with the fixing ring (11) through two threaded sleeves (21) connected thereto, a barrel (41) connected with one of the threaded sleeves (21) is sleeved on the eddy current sensor (2), the spring telescopic air bag (42) is sleeved on the eddy current sensor (2) and one end thereof is connected with the threaded sleeve (21), the other end of the spring telescopic air bag (42) is provided with a moving ring (43), a plurality of elastic sheets (44) are evenly distributed along the circumference of the moving ring (43), the non-woven fabric (45) has a circular ring structure and an inner end thereof is adhered to the elastic sheets (44), a plurality of openings (451) are evenly distributed along the circumference of the non-woven fabric (45), the micro inflator pump (46) is arranged on the outer side of the fixing ring (11) and the air outlet thereof is connected with the spring telescopic air bag (42) through a pipeline (461), and the solenoid valve (47) is mounted on an exhaust pipe (48) of the spring telescopic air bag (42).

4. The monitoring device for a permanent magnet synchronous motor according to claim 1, characterized by: The monitoring component (3) comprises a top rod (31), a pressure sensor (33) and a compression spring (34), the top rod (31) is slidingly connected in a mounting groove (131) on the inner ring body (13), an outer end of the top rod (31) abuts against the output shaft (51) of the motor (5) and a flapper (32) is arranged in the mounting groove (131), a pressure sensor (33) is coaxially arranged on the inner wall of the mounting groove (131) and abuts against the top rod (31), the compression spring (34) is sleeved on the top rod (31) and the pressure sensor (33), and an inner end of the top rod (31) abuts against the surface of the pressure sensor (33).

5. A monitoring device for a permanent magnet synchronous motor according to claim 4, characterized in that: The outer end of the top rod (31) is in a conical structure.

6. The monitoring device for a permanent magnet synchronous motor according to claim 1, characterized by: The inner ring body (13) is provided with a cover plate (35) at the top of the mounting groove (131).

7. The monitoring device for a permanent magnet synchronous motor according to claim 1, characterized by: The four corners of the cover plate (35) are connected with the inner ring body (13) through bolts.

8. The monitoring device for a permanent magnet synchronous motor according to claim 1, characterized by: The outer ring body (12) is connected with the end of the motor (5) through bolts.

9. The monitoring device for a permanent magnet synchronous motor according to claim 1, characterized by: The eddy current sensor (2) is provided with two and symmetrically arranged on both sides of the fixing ring (11).