DESC:APPARATUS FOR DETECTING MAGNET ABNORMALITY
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority from Indian Provisional Patent Application No. 202221062150 filed on 01/11/2022, the entirety of which is incorporated herein by a reference.
TECHNICAL FIELD
The present disclosure generally relates to magnetic abnormality detection. Particularly, the present disclosure relates to apparatus for detecting magnet abnormality.
BACKGROUND
Permanent magnet motor adopts permanent magnet excitation in the rotor for the efficient operation. A continuous and stable source of magnetic field strength is provided by permanent magnets within the motor. The permanent magnets keep the motor in sync with the magnetic field created by the stator windings. Thus, the characteristics of magnets are crucial during the service life of motor and play a major role in maintaining motor’s speed and performance.
The permanent magnet motor in comparison to an electrically excited motor, has no rotor copper loss and higher efficiency, therefore the permanent magnet motors are widely used in the fields of automobiles, aerospace, medical appliances and the like. However, most of the permanent magnet motors are susceptible to occurrence of various abnormalities like magnet demagnetization and magnetic shift, after a certain period of life cycle or under harsh operating conditions.
When the permanent magnet synchronous motor is operated in an excessively severe environment such as high temperature, overload, overcurrent or overvoltage, a demagnetization phenomenon occurs. The existence of repeated mechanical stresses, such as shocks or vibrations also reduces the magnetism of the permanent magnets. The reduced magnetism causes an increase in motor current to produce the same torque and burns out the motor in extreme cases, thereby endangering the safety of users.
The permanent magnet is fragile, usually fixed on the motor’s rotor in a sticking or embedding way and has a huge attraction force with the iron core after being magnetized. The magnets may shift from their ideal position, when the motor is continuously running under harsh operating. During high-speed applications of the motor, the centrifugal forces cause permanent magnets to move towards or away from the axis of rotation. The aforesaid shift influences the performance of the motor, and brings about problems of vibration, noise, torque fluctuation and the like. Therefore, it is required to critically examine any abnormal condition in characteristics and positioning of the magnets of the permanent magnet rotor.
Typically, it is required to disassemble the rotor, like removing the rotor sleeve for examining the permanent magnets. Such examination procedure is tedious and labour intensive. Moreover, the repeated assembling and disassembling of the rotor increases the chances of improper assembly leading to damage to permanent magnets or other components of the rotor.
Therefore, there exists a need for an apparatus for detecting abnormality in the permanent magnet that overcomes the one or more problems associated as set forth above.
SUMMARY
An object of the present disclosure is to provide an apparatus for accurately detecting abnormality in a permanent magnet rotor without removing any rotor sleeve.
In accordance with the first aspect of the present disclosure, there is provided an arrangement for detecting an abnormality in at least one permanent magnet of a test rotor. The arrangement comprises a reference rotor, a plurality of sensors and a frame. The reference rotor comprises of a plurality of reference permanent magnets. The test rotor comprises of a plurality of test permanent magnets. The plurality of sensors is configured to measure a magnitude of magnetic flux. The frame is configured to accommodate the reference rotor, the plurality of sensors and the test rotor. The test rotor rotates freely on the frame and locks position when the plurality of test permanent magnets aligns with the plurality of reference permanent magnets.
The present disclosure provides an arrangement for detecting an abnormality in at least one permanent magnet of a test rotor. The arrangement as disclosed in the present disclosure is advantageous in terms of eliminating the need for disassembling of the rotor for detecting abnormality in the at least one permanent magnet. The disclosed arrangement is advantageous in terms of maintaining the integrity of the rotor for a larger period of service life. Advantageously, the disclosed arrangement prevents the risks of damage, misalignment, or contamination in rotor. The disclosed arrangement is advantageous in terms of allowing for a faster examination of the rotor for detecting magnetic abnormality. Furthermore, the disclosed arrangement eliminates the risk of reassembly errors such as mispositioning of permanent magnets in the rotor.
Additional aspects, advantages, features, and objects of the present disclosure would be made apparent from the drawings and the detailed description of the illustrative embodiments constructed in conjunction with the appended claims that follow.
It will be appreciated that features of the present disclosure are susceptible to being combined in various combinations without departing from the scope of the present disclosure as defined by the appended claims.
BRIEF DESCRIPTION OF DRAWINGS
The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the present disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale. Wherever possible, like elements have been indicated by identical numbers.
Embodiments of the present disclosure will now be described, by way of example only, with reference to the following diagrams wherein:
Figure 1 illustrates a perspective view of an arrangement for detecting an abnormality in at least one permanent magnet of a test rotor, in accordance with an embodiment of the present disclosure.
Figure 2 illustrates a perspective view of a test rotor without a rotor sleeve, in accordance with an embodiment of the present disclosure.
In the accompanying drawings, an underlined number is employed to represent an item over which the underlined number is positioned or an item to which the underlined number is adjacent. A non-underlined number relates to an item identified by a line linking the non-underlined number to the item. When a number is non-underlined and accompanied by an associated arrow, the non-underlined number is used to identify a general item at which the arrow is pointing.
DETAILED DESCRIPTION
The following detailed description illustrates embodiments of the present disclosure and ways in which they can be implemented. Although some modes of carrying out the present disclosure have been disclosed, those skilled in the art would recognize that other embodiments for carrying out or practicing the present disclosure are also possible.
The description set forth below in connection with the appended drawings is intended as a description of certain embodiments of apparatus for detecting magnet abnormality and is not intended to represent the only forms that may be developed or utilized. The description sets forth the various structures and/or functions in connection with the illustrated embodiments; however, it is to be understood that the disclosed embodiments are merely exemplary of the disclosure that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.
While the disclosure is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the drawings and will be described in detail below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.
The terms “comprise”, “comprises”, “comprising”, “include(s)”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, or system that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or system. In other words, one or more elements in a system or apparatus preceded by “comprises... a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or apparatus.
In the following detailed description of the embodiments of the disclosure, reference is made to the accompanying drawings which are shown by way of illustration-specific embodiments in which the disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.
The present disclosure will be described herein below with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the description with unnecessary detail.
As used herein, the terms “motor”, “electric motor” and “permanent magnet motor” are used interchangeably and refer to an electromagnetic machine having magnets placed on a rotor, designed to convert electrical energy into mechanical motion or rotation. The motor typically comprises a housing or frame, stator element and a rotor element. The stator contains coils, and the rotor is positioned within the stator. When electrical energy is supplied to the stator, a magnetic field generates in stator that interacts with the rotor rotating the shaft and thus, converting the electrical energy into mechanical energy.
As used herein, the term “arrangement” refers to the specific configuration of mechanical elements, positioned in a specific order or pattern to make them suitable for the purpose of detecting abnormality in magnets of the rotor. It is to be understood that the arrangement may further comprises electronic components, required for achieving the aforementioned objective.
As used herein, the terms “abnormality”, and “anomaly” are used interchangeably and refer to deviation in the behaviour of the permanent magnet from its normal behaviour. The abnormal condition may include however is not limited to magnet shift and magnet demagnetisation.
As used herein, the term “test rotor” refers to a rotor of a permanent magnet motor to be examined for detecting abnormality in the at least one magnet of the rotor.
As used herein, the terms “test permanent magnets” or “plurality of test permanent magnets” are used interchangeably and refer to permanent magnets of the rotor that are required to be examined for detecting any magnetic abnormality.
As used herein, the term “reference rotor” refers to a healthy state permanent magnet rotor. The reference rotor is an open sleeve rotor with its sleeve removed to physically expose the permanent magnets present in the rotor. The reference rotor is utilised to refer the position of the plurality of test permanent magnets when the test rotor aligns with the reference rotor.
As used herein, the term “frame’” refers to a structural component or element that provides support and movement to various other components such as the reference rotor, the plurality of sensors and the test rotor, particularly in the disclosed arrangement.
As used herein, the terms “plurality of sensors” and “sensors” are used interchangeably and refer to a sensing device configured to determine the values of magnetic flux generated by test permanent magnets and reference permanent magnets. The sensor may include any sensor suitable for the purpose of sensing the value of magnetic flux.
As used herein, the terms “plurality of reference permanent magnets” and “reference permanent magnets” and reference magnets are used interchangeably and refer to the set of plurality of permanent magnets located in the reference rotor to establish the locking/alignment of the poles of test permanent magnets.
As used herein, the terms “open sleeve rotor”, “un-sleeved rotor” and “open rotor” are used interchangeably and refer to a rotor without the circumferential sleeve leading to exposed circumferential surface comprising permanent magnets.
As used herein, the terms “closed sleeve rotor”, “sleeved rotor” and “closed rotor” are used interchangeably and refer to a rotor with the circumferential sleeve leading to closed circumferential surface comprising permanent magnets. It is to be understood that the permanent magnets of the rotor are not visible in the closed sleeve rotor.
As used herein, the term “sliding mechanism” refers to a mechanical system that provides linear or translatory motion to an attached component i.e., sensor along the length of the arrangement. The aforesaid motion is achieved through various means, such as rolling contact, frictional contact, or the use of sliding elements, like rollers, bearings, or sliding rails. The sliding mechanism incorporates specific stopping mechanisms to temporarily fix the position of the sensor at required positions.
As used herein, the term “first sensor” refers to a sensor to measure the magnitude of magnetic flux generated by the plurality of test permanent magnets along the length of the test rotor.
As used herein, the term “second sensor” refers to a sensor to measure the magnitude of magnetic flux generated by the plurality of reference permanent magnets along a circumference of the reference rotor.
As used herein, the term “position locking mechanism” refers to a mechanical system to arrest the free movement of the test rotor on the arrangement. The mechanism is designed to prevent unintended or undesired movement, shifting, or displacement of the test rotor once the plurality of test permanent magnets aligns with the plurality of reference permanent magnets. The position locking mechanism may comprise components like pins, bolts, levers, or other components suitable for clamping.
As used herein, the terms “rotatory mechanism” refers to a mechanical system configured to provide rotational motion to the test rotor and the reference rotor simultaneously once the position of the test rotor is locked with respect to the reference rotor.
As used herein, the terms “data processing unit” and “processing unit” are used interchangeably and refer to a computational element that is operable to respond to and processes instructions. Optionally, the processing unit includes, but is not limited to, a microprocessor, a micro-controller, a complex instruction set computing (CISC) microprocessor, a reduced instruction set (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, or any other type of processing circuit. Furthermore, the term “processor” may refer to one or more individual processors, processing devices and various elements associated with a processing device that may be shared by other processing devices. Furthermore, the processing unit may comprise ARM Cortex-M series processors, such as the Cortex-M4 or Cortex-M7, or any similar processor designed to handle real-time tasks with high performance and low power consumption. Furthermore, the processing unit may comprise custom and/or proprietary processors.
As used herein, the term “memory unit” refers to components or storage devices that are communicably coupled with the processing unit and stores ideal value of magnetic flux of specific rotors.
As used herein, the term ‘communicably coupled’ refers to a bi-directional connection between the various components of the battery management system. The bi-directional connection between the various components of the battery management system enables exchange of data between two or more components of the battery management system.
Figure 1, in accordance with an embodiment, describes an arrangement 100 for detecting an abnormality in at least one permanent magnet 102 of a test rotor 104. The arrangement 100 comprises a reference rotor 106, a plurality of sensors 110 and a frame 112. The reference rotor 106 comprises of a plurality of reference permanent magnets 108. The plurality of sensors 110a, 110b are configured to measure a magnitude of magnetic flux. The frame 112 is configured to accommodate the reference rotor 106, the plurality of sensors 110a, 110b and the test rotor 104. The test rotor 104 rotates freely on the frame 112 and locks position when a plurality of test permanent magnets 102 of the test rotor 104 align with the plurality of reference permanent magnets 108.
The present disclosure provides an arrangement 100 for detecting an abnormality in at least one permanent magnet 102 of a test rotor 104. The arrangement 100 is advantageous in terms of eliminating the need for disassembling of the test rotor 104 for detecting abnormality in the at least one permanent magnet 102. The disclosed arrangement 100 is advantageous in terms of maintaining the integrity of the test rotor 104 for a larger period of service life. Advantageously, the disclosed arrangement 100 prevents the risks of damage, misalignment, or contamination in the test rotor 104. The disclosed arrangement 100 is advantageous in terms of allowing for a faster examination of the test rotor 104 for detecting magnetic abnormality in the at least one test permanent magnet 102. Furthermore, the disclosed arrangement 100 eliminates the risk of reassembly errors such as mispositioning of permanent magnets 102 in the test rotor 104.
It is to be understood that the reference rotor 106 is exposed to vicinity of test rotor 104 resulting in flow of magnetic field lines between the test permanent magnets 102 and the complementary poles of plurality of reference permanent magnets 108. Beneficially, the flow of magnetic field lines establishes alignment between test permanent magnets 102 and the complementary poles of plurality of reference permanent magnets 108.
In an embodiment, the reference rotor 106 is an open sleeve rotor comprising the plurality of reference permanent magnets 108 on cylindrical surface. Beneficially, the plurality of reference permanent magnets 108 of the reference rotor 106 are visible, thus, may be used as reference to identify the position of the test permanent magnets 102 of the of test rotor 104.
In an embodiment, the test rotor 104 is a closed sleeve rotor comprising the plurality of test permanent magnets 102 inside a rotor sleeve 114. Beneficially, the test rotor 104 is not disassembled for the detecting the abnormality in the at least one permanent magnet 102 of the test rotor 104. In other words, the rotor sleeve 114 is not removed for examining the test rotor 104 for the detecting the abnormality in the at least one permanent magnet 102 of the test rotor 104.
In an embodiment, the arrangement 100 comprises a sliding mechanism 116, configured to move horizontally along a length of the arrangement 100. It is to be understood that the sliding mechanism 116 provides the relative movement to the attached component along the length of the test rotor 104. Beneficially, the sliding mechanism 116, enables examination of the plurality of test permanent magnets 102 along the length of the test rotor 104.
In an embodiment, a first sensor 110a of the plurality of sensors 110a, 110b is mounted on the sliding mechanism 116 such that the first sensor 110a is configured to slide along a length of the test rotor 104 to measure the magnitude of magnetic flux generated by the plurality of test permanent magnets 102 along the length of the test rotor 104. Beneficially, the first sensor 110a determines the values of the magnetic flux along the test rotor 104 for detection of the abnormality in the at least one permanent magnet 102 of the test rotor 104. In other words, the sliding movement of the first sensor 110a is carried out for measuring the magnitude of magnetic flux at various longitudinal points on the plurality of test permanent magnets 102.
In an embodiment, a second sensor 110b of the plurality of sensors 110a, 110b is mounted on the arrangement 100 such that the second sensor 110b is configured to measure the magnitude of magnetic flux generated by the plurality of reference permanent magnets 108 along a circumference of the reference rotor 106. It is to be understood that the position of the plurality of reference permanent magnets 108 as detected by the second sensor 110b enables determination of the position of the plurality of test permanent magnets 102 in the test rotor 104.
In an embodiment, the arrangement 100 comprises a position locking mechanism configured to lock the position of the test rotor 104 with respect to the reference rotor 106 after the plurality of test permanent magnets 102 align with the plurality of reference permanent magnets 108. Beneficially, the position locking mechanism enables locking of the position of the test rotor 104 to prevent the relative movement with respect to the reference rotor 106.
In an alternative embodiment, the position of the test rotor 104 with respect to the reference rotor 106 locks due to the magnetic interaction between the plurality of test permanent magnets 102 and the plurality of reference permanent magnets 108. It is to be understood that the attractive forces between the opposite poles of the test permanent magnet 102 and the plurality of reference permanent magnets 108 aligns the plurality of test permanent magnet 102 and the plurality of reference permanent magnets 108.
In an embodiment, the position locking mechanism comprises a rotatory mechanism configured to rotate the test rotor 104 along with rotation of the reference rotor 106 after position of the test rotor 104 is locked. It is to be understood that rotatory mechanism provides the simultaneous rotation of the test rotor 104 and the reference rotor 106. Beneficially, the alignment of the subsequent poles of the plurality of test permanent magnets 102 with the complementary poles of the plurality of reference permanent magnets 108 enables determination of the position plurality of test permanent magnets 102 of the test rotor 104.
In an embodiment, an axis of mounting of the test rotor 104 is parallel to an axis of mounting of the reference rotor 106. It is to be understood that the parallel mounting of the circumferential regions of the test rotor 104 and the reference rotor 106 enables determination of the position plurality of test permanent magnets 102 of the test rotor 104.
In an embodiment, magnitude of the magnetic flux measured by the plurality of sensors 110a, 110b is analyzed to detect the abnormality in the at least one permanent magnet 102 of the test rotor 104. It is to be understood that the magnitude of the magnetic flux measured by the second sensor 110b is used as reference to determine position of the plurality of test permanent magnets 102. The magnitude of the magnetic flux measured by the first sensor 110a is used to detect the abnormality in the at least one permanent magnet 102 of the test rotor 104.
In an embodiment, the arrangement 100 comprises a memory unit configured to store ideal values of the magnitude of the magnetic flux generated by the plurality of test permanent magnets 102 of the test rotor 104.
In an embodiment, the arrangement 100 comprises a data processing arrangement configured to compare the magnitude of the magnetic flux measured by the first sensor 110a and the ideal values of the magnitude of the magnetic flux stored in the memory unit to detect the abnormality in the at least one permanent magnet 102 of the test rotor 104. It is to be understood that if the difference between the magnitude of the magnetic flux measured by the first sensor 110a and the ideal values of the magnitude of the magnetic flux stored in the memory unit is greater than a threshold, the data processing arrangement identifies it as abnormality in the at least one permanent magnet 102 of the test rotor 104.
Figure 2, in accordance with an embodiment, describes the test rotor 104. The test rotor 104 is opened to remove the sleeve 114 and expose the plurality of test magnets 102. It is to be understood that the test rotor 104 is opened to remove the sleeve 114 only for illustrating position of the plurality of test magnets 102 in the test rotor 104. For the purpose of detecting any abnormality in the at least one magnet 102, the test rotor 104 is tested without removing the rotor sleeve 114.
In the description of the present invention, it is also to be noted that, unless otherwise explicitly specified or limited, the terms “disposed,” “mounted,” and “connected” are to be construed broadly, and may for example be fixedly connected, detachably connected, or integrally connected, either mechanically or electrically. They may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.
Modifications to embodiments and combinations of different embodiments of the present disclosure described in the foregoing are possible without departing from the scope of the present disclosure as defined by the accompanying claims. Expressions such as “including”, “comprising”, “incorporating”, “have”, and “is” used to describe and claim the present disclosure are intended to be construed in a non-exclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural where appropriate.
Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the present disclosure, the drawings, and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.

,CLAIMS:We Claim:
1. An arrangement (100) for detecting an abnormality in at least one permanent magnet (102) of a test rotor (104), the arrangement (100) comprises:
- a reference rotor (106), comprising a plurality of reference permanent magnets (108);
- a plurality of sensors (110a, 110b), configured to measure a magnitude of magnetic flux; and
- a frame (112), configured to accommodate the reference rotor (106), the test rotor (104), and the plurality of sensors (110a, 110b),
wherein the test rotor (104) rotates freely on the frame (112) and locks position when a plurality of test permanent magnets (102) of the test rotor (104) align with the plurality of reference permanent magnets (108).
2. The arrangement (100) as claimed in claim 1, wherein the reference rotor (106) is an open sleeve rotor comprising the plurality of reference permanent magnets (108) on cylindrical surface.
3. The arrangement (100) as claimed in claim 1, wherein the test rotor (104) is a closed sleeve rotor comprising the plurality of test permanent magnets (102) inside a rotor sleeve (114).
4. The arrangement (100) as claimed in claim 1, wherein the arrangement (100) comprises a sliding mechanism (116), configured to move horizontally along a length of the arrangement (100).
5. The arrangement (100) as claimed in claim 5, wherein a first sensor (110a) of the plurality of sensors (110a, 110b) is mounted on the sliding mechanism (116) such that the first sensor (110a) is configured to slide along a length of the test rotor (104) to measure the magnitude of magnetic flux generated by the plurality of test permanent magnets (102) along the length of the test rotor (104).
6. The arrangement (100) as claimed in claim 1, wherein a second sensor (110b) of the plurality of sensors (110a, 110b) is mounted on the arrangement (100) such that the second sensor (110b) is configured to measure the magnitude of magnetic flux generated by the plurality of reference permanent magnets (108) along a circumference of the reference rotor (106).
7. The arrangement (100) as claimed in claim 1, wherein the arrangement (100) comprises a position locking mechanism configured to lock the position of the test rotor (104) with respect to the reference rotor (106) after the plurality of test permanent magnets (102) align with the plurality of reference permanent magnets (108).
8. The arrangement (100) as claimed in claim 7, wherein the position locking mechanism comprises a rotatory mechanism configured to rotate the test rotor (104) along with rotation of the reference rotor (106) after position of the test rotor (104) is locked.
9. The arrangement (100) as claimed in claim 1, wherein an axis of mounting of the test rotor (104) is parallel to an axis of mounting of the reference rotor (106).
10. The arrangement (100) as claimed in claim 1, wherein magnitude of the magnetic flux measured by the plurality of sensors (110a, 110b) is analyzed to detect the abnormality in the at least one permanent magnet (102) of the test rotor (104).