A motor with a rotor assembly having high stability and a control method thereof

Abstract

The application discloses a motor with a high-stability rotor assembly and a control method thereof, and aims to provide a motor with a high-stability rotor assembly and a control method thereof, which are low in noise and long in service life, and the technical scheme is as follows: a casing, a stator assembly and a rotor assembly are included, the rotor assembly comprises a rotating shaft, a rotor core sleeved on the rotating shaft, an insulation structure arranged at both ends of the rotor core, a commutator arranged on the rotating shaft, a wave-shaped gasket sleeved between the commutator and the rotor core and an insulation structure sleeved on the rotating shaft, one side of the wave-shaped gasket is abutted against an end face of the commutator, and the other side is abutted against the insulation structure, so as to provide an axial pre-tightening force to limit axial movement of the rotor assembly along the rotating shaft direction. The application is suitable for the technical field of rotor assemblies.

Description

Technical Field

[0001] This invention relates to the field of rotor assembly technology, and more specifically, to a motor with a highly stable rotor assembly. Background Technology

[0002] In existing technologies, components such as the rotor core and commutator are sequentially mounted on the shaft for assembly. Due to the influence of machining tolerances, assembly gaps, and thermal expansion and contraction and alternating loads during motor operation, the components of the rotor assembly are prone to axial displacement along the shaft. Axial displacement leads to unstable contact between the commutator and brushes, exacerbating commutation sparks and brush wear, and in severe cases, even causing commutation failure. Furthermore, it causes a shift in the axial relative position between the rotor core and stator, disrupting the uniformity of the air gap magnetic field and increasing motor vibration and noise. Current solutions use ordinary flat shims to fill the assembly gaps, but flat shims lack elastic compensation capabilities and cannot provide a continuous and stable axial preload. Under long-term vibration and temperature fluctuations, the gaps will reappear, making it difficult to fundamentally suppress the axial displacement problem.

[0003] Meanwhile, existing rotor cores are mostly formed by axially stacking multiple rotor laminations, with magnet mounting slots cut into the outer edges of the laminations for embedding magnets. Traditional magnet mounting slots are mostly straight slots or simple open slot structures. To ensure smooth assembly of the magnets, a certain assembly gap needs to be reserved between the slot and the magnet. When the motor runs at high speed, the magnets are prone to slight circumferential and radial movement and collisions within the slot, generating significant mechanical and electromagnetic noise. At the same time, it will cause distortion of the air gap magnetic field, reducing the stability of motor operation. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a motor with low noise, long life and high stability rotor assembly.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a motor with a highly stable rotor assembly, comprising a housing, a stator assembly, and a rotor assembly. The rotor assembly includes a shaft, a rotor core sleeved on the shaft, insulating structures disposed at both ends of the rotor core, a commutator disposed on the shaft, a wave-shaped gasket sleeved between the commutator and the rotor core, and an insulating structure sleeved on the shaft. One side of the wave-shaped gasket abuts against the end face of the commutator, and the other side abuts against the insulating structure, for providing axial preload to limit the axial movement of the rotor assembly along the shaft direction.

[0006] The invention is further configured such that: the rotor core is formed by stacking multiple rotor laminations along the axial direction; the outer edge of the rotor laminations is uniformly provided with multiple magnet mounting slots along the circumferential direction; a magnetic pole portion is formed between two adjacent magnet mounting slots; a vibration damping slot extending radially is provided on the magnetic pole portion; the vibration damping slot divides the magnetic pole portion into two symmetrical halves.

[0007] The present invention is further configured such that the distance from the bottom end of the vibration damping groove to the center of the rotor lamination is not greater than the distance from the bottom end of the magnet mounting groove to the center of the rotor lamination.

[0008] The present invention is further configured such that: the insulating structure includes a first insulating paper layer and a second insulating paper layer sleeved on the rotating shaft and located at both ends of the rotor core axially, the first insulating paper layer and the second insulating paper layer respectively covering the end faces of both ends of the rotor core, and the wave-shaped gasket abuts against the outer side of the first insulating paper layer or the second insulating paper layer.

[0009] The present invention is further configured such that: the waveform gasket is a waveform elastic washer, and the narrow peripheral ring of the waveform elastic washer has a plurality of limiting protrusions on the side of the narrow peripheral ring of the waveform elastic washer facing the commutator, and the end face of the commutator has a plurality of limiting grooves corresponding to it, and the limiting protrusions are embedded in the limiting grooves to prevent the waveform elastic washer from rotating circumferentially relative to the commutator.

[0010] The invention is further configured such that: the magnet mounting groove is a dovetail groove structure, a magnet is installed in the dovetail groove, and when the vibration damping groove is expanded under the action of external force, the two halves can undergo elastic deformation to both sides respectively, thereby eliminating the gap between the magnet and the side wall of the dovetail groove and fastening the half to the magnet.

[0011] This application also provides a motor control method with a highly stable rotor assembly, the operation steps of which are as follows: S1. Assembly pre-tightening calibration: During the rotor assembly process, axial pressing force is applied to the wave shims to form a set axial pre-tightening force, which restricts the axial movement of the rotor assembly. Pre-tightening assembly is performed on the magnet body in the magnet mounting slot, and the elastic deformation of the damping groove is used to eliminate the assembly gap between the magnet body and the magnet mounting slot. S2. Pre-start self-check: Before the motor is powered on and started, the initial axial movement of the rotor, the circumferential assembly position of the commutator and the no-load reference parameters are checked to verify the assembly effectiveness of the rotor assembly. S3. Closed-loop control during operation: When the motor is running, the rotor axial displacement signal and radial vibration signal are collected in real time. The axial movement is suppressed by combining the elastic pre-tightening characteristics of the waveform shims and the radial vibration of the magnetic poles is suppressed by combining the energy absorption characteristics of the vibration damping grooves and current regulation. S4. Status monitoring and fault protection: Real-time monitoring of magnet preload status and commutator circumferential limit status; when abnormal status is detected, early warning, power reduction or shutdown protection is implemented.

[0012] The present invention is further configured such that: the axial movement suppression in step S3 specifically involves: real-time acquisition of rotor axial displacement, electric drive current fluctuation and speed signals, and analysis of the amplitude, frequency and trend of axial movement; Three threshold ranges are set for axial movement: normal range ≤ 0.08 mm, warning range 0.08 mm to 0.15 mm, and fault range > 0.15 mm. When the axial displacement is within the normal range, the inherent elastic preload of the wave shim adaptively offsets small axial load fluctuations. When the axial displacement is within the warning range, the axial component of the armature current is adjusted to change the axial electromagnetic attraction between the stator and rotor, which, together with the elastic force of the wave shim, forms a compound pre-tightening effect. When the axial displacement is within the fault range, it is determined that the waveform gasket has failed due to fatigue or that the assembly is loose, and power reduction operation is executed and a first-level warning is triggered.

[0013] The present invention is further configured such that: the radial vibration suppression of the magnetic pole in step S3 specifically involves: real-time acquisition of the radial vibration acceleration signal of the motor housing and the stator current harmonics, and identification of the vibration frequency and amplitude of the magnetic pole part; The three threshold ranges for radial vibration acceleration are set as follows: Normal range ≤20m / s² 2 The warning range is 20m / s 2 ~40m / s 2 Fault range > 40m / s 2 ; When the vibration acceleration is within the normal range, the magnetic pole vibration energy is passively consumed by the deformation energy absorption effect of the damping groove. When the vibration acceleration is in the warning range, a counteracting current harmonic is injected into the stator winding to counteract the main excitation frequency of the magnetic pole vibration and work with the damping slot to suppress the vibration amplitude. When vibration is detected to be approaching the resonance range and the amplitude continues to rise, the motor operating speed is actively fine-tuned by ±5% to ±10% to avoid the resonance speed point.

[0014] The present invention is further configured such that: the monitoring of the pre-tightening state of the magnet in step S4 specifically involves: real-time acquisition of the internal temperature and back electromotive force waveform of the motor, and determining whether there is a gap between the magnet body and the side wall of the magnet mounting slot by the harmonic distortion rate of the back electromotive force; The motor's internal operating temperature is set to three levels: normal operating temperature range is -20℃ to 120℃, high temperature warning range is 120℃ to 150℃, and over-temperature protection range is >150℃. Two thresholds are set for the back EMF harmonic distortion rate: ≤5% in good pre-tightening condition, 5% to 10% in gap warning condition, and >10% in pre-tightening failure condition. When the temperature is within the normal operating range, the elastic deformation margin of the damping groove is used to automatically compensate for the thermal deformation and maintain the clamping force between the two halves and the magnet. When the temperature is in the high temperature warning range or the harmonic distortion rate is in the gap warning state, adjust the armature current parameters to compensate for the temperature drift of the magnet operating point. When the temperature is in the over-temperature protection range or the harmonic distortion rate is in the pre-tightening failure state, the pre-tightening failure warning is triggered, and the maximum output torque of the motor is limited to 60% to 80% of the rated value.

[0015] The beneficial effects of this invention are: 1. The rotor assembly is the core rotating working structure, specifically including a shaft, rotor core, insulation structure, commutator, and wave-shaped gasket. The rotor core is fixedly sleeved on the outside of the shaft, forming an integrated rotating structure with the shaft. It is the core component for electromagnetic coupling and torque generation in the motor. The commutator is synchronously sleeved on the shaft, working with brushes to achieve current commutation and ensure continuous and stable forward rotation of the rotor. Insulation structures are provided at both ends of the rotor core, sleeved on the outside of the shaft, to achieve electrical isolation between the rotor core and adjacent components, effectively preventing electrical faults such as leakage, short circuits, and creepage, and ensuring the electrical safety of the motor operation. A wave-shaped gasket is assembled between the commutator and the rotor core, with the entire gasket sleeved on the outside of the shaft for precise positioning and assembly. Abutment and limiting structures are formed on both axial sides of the wave-shaped gasket, with one end face tightly abutting against the end face of the commutator and the other end face tightly abutting against the surface of the insulation structure at the end of the rotor core. After the motor is assembled, the wave shim is in a slightly compressed state, which can continuously provide a stable axial elastic preload, effectively eliminating the axial assembly gap between the various assembly parts of the rotor assembly, and strictly limiting the overall movement and offset of the rotor assembly along the shaft axis.

[0016] 2. The rotor core is formed by tightly stacking multiple rotor laminations axially. This stacked structure ensures a compact overall structure and high coaxiality of the rotor core, effectively reducing magnetic gap loss and ensuring electromagnetic stability. Multiple magnet mounting slots are evenly distributed circumferentially along the outer edge of each rotor lamination for precise installation and fixation of the magnet structure. A magnetic pole portion is formed between two adjacent magnet mounting slots, constituting the core magnetic pole region for rotor electromagnetic operation. A radially extending vibration damping groove is formed on the magnetic pole portion, penetrating the pole portion and dividing the corresponding magnetic pole portion into two symmetrical halves. This symmetrical slotted structure effectively releases the electromagnetic vibration and mechanical stress generated during high-speed rotation of the rotor core, weakens the high-frequency vibration amplitude of the magnetic pole portion, improves vibration resonance during rotor operation, further reduces motor operating noise and vibration amplitude, and, combined with the axial preload structure, forms an all-around vibration stabilization and noise reduction effect, significantly improving the stability of high-speed rotor operation. The distance from the bottom end of the vibration damping groove to the center of the rotor lamination is no greater than the distance from the bottom end of the magnet mounting groove to the center of the rotor lamination. This dimensional limit design ensures that the radial opening depth of the vibration damping groove is controlled. While realizing the release of magnetic pole vibration and stress relief, it effectively avoids the problems of reduced magnetic pole structural strength and reduced effective electromagnetic conduction area caused by excessively deep vibration damping grooves, thus balancing the vibration reduction and noise reduction effect with rotor structural strength and electromagnetic performance.

[0017] 3. The insulation structure includes a first insulating paper layer and a second insulating paper layer sleeved on the rotating shaft and located at both axial ends of the rotor core. The first and second insulating paper layers completely cover and adhere to the end faces of both ends of the rotor core, forming complete electrical isolation between the axial ends of the rotor core. This effectively prevents electrical faults such as leakage, short circuits, and creepage, ensuring the electrical safety of the motor operation. It also prevents direct contact and wear between the rotor core end faces and adjacent metal components. The corrugated gasket axially abuts against the outer surface of the first or second insulating paper layer, forming a flexible isolation abutment structure. This ensures axial pre-tightening and limiting effects while preventing direct hard contact between the corrugated gasket and the rotor core, thus preventing pressure damage, abnormal noise, and wear problems on the core end faces. Specifically, the corrugated gasket adopts a corrugated elastic washer structure, which is sleeved on the outside of the rotating shaft for precise positioning and assembly. The waveform elastic washer has a narrow peripheral ring. Several limiting protrusions extend outward from the side of the narrow peripheral ring facing the commutator. Correspondingly, the end face of the commutator has a limiting groove that matches each limiting protrusion. During assembly, the limiting protrusions are embedded into the limiting grooves to form a circumferential anti-rotation limiting structure. This can effectively prevent the waveform elastic washer from rotating circumferentially or slipping relative to the commutator under high-speed motor operation and high-frequency vibration conditions, avoid the problems of washer friction and wear, preload attenuation and failure, and ensure the long-term stability and reliability of the preload structure.

[0018] 4. The magnet mounting groove adopts a dovetail groove structure design. The groove has a tapering and limiting characteristic, and a magnet is embedded and fixed in the groove. The dovetail groove's inverted structure can form a basic limit on the magnet, preventing it from radially detaching. When the rotor rotates at high speed and generates centrifugal force or is subjected to vibration, the damping groove can be slightly expanded, causing the two halves of the magnetic pole to elastically deform to both sides. After deformation, the two halves can tightly fit and squeeze the magnet in the dovetail groove, automatically eliminating the assembly gap between the magnet and the side wall of the dovetail groove. This ensures that the two halves are firmly fastened and fixed to the outside of the magnet, completely solving the problems of magnet loosening, displacement, abnormal noise, and even detachment caused by assembly gaps and long-term vibration relaxation in traditional dovetail groove installations. Attached Figure Description

[0019] Figure 1 This is a partial cross-sectional view of the present invention; Figure 2 This is a flowchart illustrating an embodiment of a motor control method with a highly stable rotor assembly according to the present invention; Figure 1-2 Reference numerals in the attached drawings: 1. Housing; 2. Shaft; 3. Rotor lamination; 4. Waveform gasket; 5. Insulation structure; 6. Magnet mounting groove; 7. Vibration damping groove; 8. Magnetic pole section; 9. First insulation layer; 10. Second insulation layer. Detailed Implementation

[0020] Reference Figure 1-2 The embodiments of the present invention will be further described below.

[0021] For ease of explanation, spatial relative terms such as “up,” “down,” “left,” and “right” are used in the embodiments to describe the relationship of one element or feature shown in the figures relative to another element or feature. It should be understood that, in addition to the orientations shown in the figures, spatial terms are intended to include different orientations of the device in use or operation. For example, if the device in the figures is inverted, an element described as being “down” of other elements or features would be positioned “up” of those other elements or features. Therefore, the exemplary term “down” can encompass both up and down orientations. The device may be positioned in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0022] Moreover, relational terms such as “first” and “second” are used merely to distinguish one component from another that has the same name, without necessarily requiring or implying any such actual relationship or order between the components.

[0023] Figures 1 to 2The motor shown includes a highly stable rotor assembly, comprising a housing 1, a stator assembly, and a rotor assembly. The rotor assembly includes a shaft 2, a rotor core sleeved on the shaft 2, insulating structures 5 at both ends of the rotor core, a commutator on the shaft 2, a wave-shaped gasket 4 sleeved between the commutator and the rotor core, and the insulating structure 5 sleeved on the shaft 2. The rotor core is fixedly sleeved on the outside of the shaft 2, forming an integral rotating structure with the shaft 2. It is the core component for electromagnetic coupling and torque generation in the motor. The commutator is synchronously sleeved on the shaft 2 and works with brushes to achieve current commutation, ensuring continuous and stable forward rotation of the rotor. Insulating structures 5 are provided at both ends of the rotor core, sleeved on the outside of the shaft 2, which can achieve electrical isolation between the rotor core and adjacent components, effectively preventing electrical faults such as leakage, short circuit, and creepage, and ensuring the electrical safety of motor operation. A wave-shaped gasket 4 is assembled between the commutator and the rotor core, and the wave-shaped gasket 4 is entirely sleeved on the outside of the shaft 2 to achieve precise positioning and assembly. The wave-shaped shim 4 has abutment and limiting structures on both sides of its axial direction. One end face of the wave-shaped shim is in close contact with the end face of the commutator, and the other end face is in close contact with the surface of the insulation structure 5 at the end of the rotor core. After the motor is assembled, the wave-shaped shim 4 is in a slightly compressed state, which can continuously provide a stable axial elastic preload, effectively eliminating the axial assembly gap between the various assembly parts of the rotor assembly, and strictly limiting the overall movement and displacement of the rotor assembly along the axial direction of the shaft 2.

[0024] The rotor core is formed by stacking multiple rotor laminations 3 axially. This stacked structure ensures a compact overall structure and high coaxiality of the rotor core, effectively reducing magnetic gap loss and ensuring electromagnetic stability. Multiple magnet mounting slots 6 are evenly distributed circumferentially along the outer edge of each rotor lamination 3 for precisely embedding and fixing the magnet structure. A magnetic pole portion 8 is formed between two adjacent magnet mounting slots 6, constituting the core magnetic pole region for rotor electromagnetic operation. A radially extending vibration damping groove is formed on the magnetic pole portion 8, penetrating it and dividing the corresponding magnetic pole portion 8 into two symmetrical halves. This symmetrical slotted structure effectively releases the electromagnetic vibration and mechanical stress generated during high-speed rotation of the rotor core, weakens the high-frequency vibration amplitude of the magnetic pole portion 8, improves vibration resonance during rotor operation, further reduces motor noise and vibration amplitude, and, combined with the axial preload structure, achieves an all-around vibration stabilization and noise reduction effect, significantly improving the stability of high-speed rotor operation.

[0025] The distance from the bottom end of the vibration damping groove to the center of the rotor lamination 3 is not greater than the distance from the bottom end of the magnet mounting groove 6 to the center of the rotor lamination 3. This dimensional limit design ensures that the radial opening depth of the vibration damping groove is controlled. While realizing the release of magnetic pole vibration and stress relief, it effectively avoids the problems of reduced magnetic pole structural strength and reduced effective electromagnetic conduction area caused by excessively deep vibration damping grooves, thus balancing the vibration reduction and noise reduction effect with rotor structural strength and electromagnetic performance.

[0026] The insulation structure 5 includes a first insulating paper layer and a second insulating paper layer sleeved on the rotating shaft 2 and located at both axial ends of the rotor core. The first and second insulating paper layers cover the end faces of both ends of the rotor core, forming complete electrical isolation between the axial ends of the rotor core. This effectively prevents electrical faults such as leakage, short circuits, and creepage, ensuring the electrical safety of the motor operation. It also prevents direct contact and wear between the rotor core end faces and adjacent metal components. The wave-shaped gasket 4 axially abuts against the outer surface of the first or second insulating paper layer, forming a flexible isolation abutment structure. This ensures axial pre-tightening and limiting effects while preventing direct hard contact between the wave-shaped gasket 4 and the rotor core, thus preventing pressure damage, abnormal noise, and wear on the core end faces. The wave-shaped gasket 4 specifically adopts a wave-shaped elastic washer structure, which is sleeved on the outside of the rotating shaft 2 for precise positioning and assembly.

[0027] The waveform gasket 4 is a waveform elastic washer. The narrow peripheral ring of the waveform elastic washer has multiple limiting protrusions on the side facing the commutator. Correspondingly, the end face of the commutator has limiting grooves that match each limiting protrusion. During assembly, the limiting protrusions are embedded into the limiting grooves to form a circumferential anti-rotation limiting structure. This can effectively prevent the waveform elastic washer from rotating circumferentially or slipping relative to the commutator under high-speed motor operation and high-frequency vibration conditions, avoid the problems of gasket friction wear and preload attenuation failure, and ensure the long-term stability and reliability of the preload structure.

[0028] The magnet mounting groove 6 has a dovetail groove structure with a tapering and limiting feature. A magnet is embedded and fixed within the groove. The dovetail groove's inverted structure provides basic restraint for the magnet, preventing it from radially dislodging. When the rotor operates at high speed, generating centrifugal force or subjected to vibration, the damping groove can expand slightly, causing the two halves of the magnetic pole section 8 to elastically deform to both sides. The deformed halves tightly press against the magnet within the dovetail groove, automatically eliminating the assembly gap between the magnet and the dovetail groove sidewall. This ensures the two halves are firmly fastened and fixed to the outside of the magnet, completely solving the problems of magnet loosening, displacement, abnormal noise, and even detachment caused by assembly gaps and long-term vibration relaxation in traditional dovetail groove magnet installations.

[0029] This application also provides a motor control method with a highly stable rotor assembly, the operation steps of which are as follows: S1. Assembly pre-tightening calibration: During the rotor assembly process, axial pressing force is applied to the wave shim 4 to form a set axial pre-tightening force, which restricts the axial movement of the rotor assembly, and pre-tightening assembly is performed on the magnet body in the magnet mounting groove 6. The elastic deformation of the damping groove is used to eliminate the assembly gap between the magnet body and the magnet mounting groove 6. S2. Pre-start self-check: Before the motor is powered on and started, the initial axial movement of the rotor, the circumferential assembly position of the commutator and the no-load reference parameters are checked to verify the assembly effectiveness of the rotor assembly. S3. Closed-loop control during operation: When the motor is running, the rotor axial displacement signal and radial vibration signal are collected in real time. Combined with the elastic pre-tightening characteristics of the waveform shim 4, axial movement is suppressed. Combined with the energy absorption characteristics of the vibration damping groove and current regulation, the radial vibration of the magnetic pole is suppressed. S4. Status monitoring and fault protection: Real-time monitoring of magnet preload status and commutator circumferential limit status; when abnormal status is detected, early warning, power reduction or shutdown protection is implemented.

[0030] The present invention is further configured such that: the axial movement suppression in step S3 specifically involves: real-time acquisition of rotor axial displacement, electric drive current fluctuation and speed signals, and analysis of the amplitude, frequency and trend of axial movement; Three threshold ranges are set for axial movement: normal range ≤ 0.08 mm, warning range 0.08 mm to 0.15 mm, and fault range > 0.15 mm. When the axial displacement is within the normal range, the small axial load fluctuations are adaptively offset by the inherent elastic preload of the waveform shim 4. When the axial displacement is in the warning range, the axial component of the armature current is adjusted to change the axial electromagnetic attraction between the stator and rotor, which, together with the elastic force of the wave shim 4, forms a compound pre-tightening effect. When the axial displacement is within the fault range, it is determined that the waveform gasket 4 has failed due to fatigue or is loosely assembled, and power reduction operation is executed and a first-level warning is triggered.

[0031] The present invention is further configured such that: the radial vibration suppression of the magnetic pole in step S3 specifically involves: real-time acquisition of the radial vibration acceleration signal of the motor housing and the stator current harmonics, and identification of the vibration frequency and amplitude of the magnetic pole part 8; The three threshold ranges for radial vibration acceleration are set as follows: Normal range ≤20m / s² 2 The warning range is 20m / s 2 ~40m / s 2 Fault range > 40m / s 2 ; When the vibration acceleration is within the normal range, the magnetic pole vibration energy is passively consumed by the deformation energy absorption effect of the damping groove. When the vibration acceleration is in the warning range, a counteracting current harmonic is injected into the stator winding to counteract the main excitation frequency of the magnetic pole vibration and work with the damping slot to suppress the vibration amplitude. When vibration is detected to be approaching the resonance range and the amplitude continues to rise, the motor operating speed is actively fine-tuned by ±5% to ±10% to avoid the resonance speed point.

[0032] The present invention is further configured such that: the monitoring of the pre-tightening state of the magnet in step S4 specifically involves: real-time acquisition of the internal temperature and back electromotive force waveform of the motor, and determining whether there is a gap between the magnet body and the side wall of the magnet mounting groove 6 by the harmonic distortion rate of the back electromotive force; The motor's internal operating temperature is set to three levels: normal operating temperature range is -20℃ to 120℃, high temperature warning range is 120℃ to 150℃, and over-temperature protection range is >150℃. Two thresholds are set for the back EMF harmonic distortion rate: ≤5% in good pre-tightening condition, 5% to 10% in gap warning condition, and >10% in pre-tightening failure condition. When the temperature is within the normal operating range, the elastic deformation margin of the damping groove is used to automatically compensate for the thermal deformation and maintain the clamping force between the two halves and the magnet. When the temperature is in the high temperature warning range or the harmonic distortion rate is in the gap warning state, adjust the armature current parameters to compensate for the temperature drift of the magnet operating point. When the temperature is in the over-temperature protection range or the harmonic distortion rate is in the pre-tightening failure state, the pre-tightening failure warning is triggered, and the maximum output torque of the motor is limited to 60% to 80% of the rated value.

[0033] This invention, through a deep integration of a highly stable rotor mechanical structure and a dedicated closed-loop control method, combines the advantages of both passive mechanical stabilization and active electrical compensation. It effectively solves the technical defects of traditional motors, such as rotor axial movement, large radial vibration of magnetic poles, loosening of magnets over long-term operation, poor adaptability to operating conditions, and delayed fault response. By eliminating assembly gaps at the source through assembly pre-tightening calibration, and relying on the elastic pre-tightening characteristics of the waveform shims 4 in conjunction with a graded axial movement control strategy, it can adaptively suppress rotor axial movement under different operating conditions, significantly reducing rotor axial vibration and abnormal operating noise. Simultaneously, by utilizing the elastic energy absorption deformation characteristics of the magnetic pole damping grooves, and combining them with vibration graded control, harmonic cancellation, and resonance avoidance control logic, it effectively weakens high-frequency vibration and resonance problems of the magnetic poles, significantly improving rotor operational stability. By monitoring the motor's operating temperature and back EMF harmonic distortion rate in real time, the pre-tightening state of the magnets is accurately determined. Combined with temperature drift compensation, torque limiting, graded early warning, and shutdown protection mechanisms, the deformation error of the magnet structure under high-temperature conditions can be dynamically compensated, effectively avoiding faults such as magnet loosening and failure, and electromagnetic performance degradation, ensuring the long-term stability of the magnet's clamping. Overall, this achieves comprehensive optimization in all dimensions: controllable motor assembly precision, real-time adjustable operating status, and proactive fault risk prevention. It significantly improves the motor's operational stability, control precision, and safety reliability under complex operating conditions across the entire temperature range, high and low loads, and high-frequency start-stop cycles, effectively extending the overall service life of the motor and reducing equipment maintenance costs.

[0034] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any ordinary changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included within the protection scope of the present invention.

Claims

1. A motor with a highly stable rotor assembly, comprising a housing (1), a stator assembly, and a rotor assembly, characterized in that, The rotor assembly includes a shaft (2), a rotor core sleeved on the shaft (2), an insulating structure (5) at both ends of the rotor core, a commutator on the shaft (2), a wave-shaped gasket (4) sleeved between the commutator and the rotor core, and an insulating structure (5) sleeved on the shaft (2). One side of the wave-shaped gasket (4) abuts against the end face of the commutator, and the other side abuts against the insulating structure (5), which is used to provide axial preload to limit the axial movement of the rotor assembly along the direction of the shaft (2).

2. The motor with a highly stable rotor assembly according to claim 1, characterized in that, The rotor core is formed by stacking multiple rotor laminations (3) axially. Multiple magnet mounting slots (6) are uniformly provided on the outer edge of the rotor laminations (3) along the circumferential direction. A magnetic pole part (8) is formed between two adjacent magnet mounting slots (6). A vibration damping groove extending radially is provided on the magnetic pole part (8). The vibration damping groove divides the magnetic pole part (8) into two symmetrical halves.

3. The motor with a highly stable rotor assembly according to claim 2, characterized in that, The distance from the bottom end of the vibration damping groove to the center of the rotor lamination (3) is not greater than the distance from the bottom end of the magnet mounting groove (6) to the center of the rotor lamination (3).

4. The motor with a highly stable rotor assembly according to claim 1, characterized in that, The insulation structure (5) includes a first insulating paper layer and a second insulating paper layer sleeved on the rotating shaft (2) and located at both ends of the rotor core axially. The first insulating paper layer and the second insulating paper layer respectively cover the end faces of both ends of the rotor core. The wave-shaped gasket (4) abuts against the outer side of the first insulating paper layer or the second insulating paper layer.

5. A motor with a highly stable rotor assembly according to claim 1, characterized in that, The waveform gasket (4) is a waveform elastic washer. The narrow peripheral ring of the waveform elastic washer has multiple limiting protrusions on the side facing the commutator. The end face of the commutator has multiple limiting grooves. The limiting protrusions are embedded in the limiting grooves to prevent the waveform elastic washer from rotating circumferentially relative to the commutator.

6. A motor with a highly stable rotor assembly according to claim 2, characterized in that, The magnet mounting groove (6) is a dovetail groove structure. A magnet is installed in the dovetail groove. When the vibration damping groove is expanded under the action of external force, the two halves can undergo elastic deformation to both sides, thereby eliminating the gap between the magnet and the side wall of the dovetail groove and fastening the half to the magnet.

7. A motor control method with a highly stable rotor assembly according to any one of claims 1-6, characterized in that, The operation steps are as follows: S1. Assembly pre-tightening calibration: During the assembly of the rotor assembly, an axial pressing force is applied to the wave shim (4) to form a set axial pre-tightening force, which restricts the axial movement of the rotor assembly. The magnet body in the magnet mounting groove (6) is pre-tightened and assembled. The elastic deformation of the damping groove is used to eliminate the assembly gap between the magnet body and the magnet mounting groove (6). S2. Pre-start self-check: Before the motor is powered on and started, the initial axial movement of the rotor, the circumferential assembly position of the commutator and the no-load reference parameters are checked to verify the assembly effectiveness of the rotor assembly. S3. Closed-loop control during operation: When the motor is running, the rotor axial displacement signal and radial vibration signal are collected in real time. The axial movement is suppressed by combining the elastic pre-tightening characteristics of the waveform pad (4) and the magnetic pole radial vibration is suppressed by combining the energy absorption characteristics of the damping groove and the current regulation. S4. Status monitoring and fault protection: Real-time monitoring of magnet preload status and commutator circumferential limit status; when abnormal status is detected, early warning, power reduction or shutdown protection is implemented.

8. A motor control method with a highly stable rotor assembly according to claim 7, characterized in that, The axial movement suppression in step S3 specifically involves: real-time acquisition of rotor axial displacement, electric drive current fluctuation and speed signals, and analysis of the amplitude, frequency and trend of axial movement. Three threshold ranges are set for axial movement: normal range ≤ 0.08 mm, warning range 0.08 mm to 0.15 mm, and fault range > 0.15 mm. When the axial displacement is within the normal range, the small axial load fluctuation is adaptively offset by the inherent elastic preload of the wave shim (4). When the axial displacement is in the warning range, the axial component of the armature current is adjusted to change the axial electromagnetic attraction between the stator and rotor, forming a compound pre-tightening effect with the elastic force of the waveform shim (4). When the axial displacement is within the fault range, it is determined that the waveform gasket (4) has failed due to fatigue or is loosely assembled, and power reduction operation is performed and a first-level warning is triggered.

9. A motor control method with a highly stable rotor assembly according to claim 7, characterized in that, The specific steps of the magnetic pole radial vibration suppression in step S3 are as follows: real-time acquisition of the radial vibration acceleration signal of the motor housing and the stator current harmonics, and identification of the vibration frequency and amplitude of the magnetic pole part (8); The three threshold ranges for radial vibration acceleration are set as follows: Normal range ≤20m / s² 2 The warning range is 20m / s 2 ~40m / s 2 Fault range > 40m / s 2 ; When the vibration acceleration is within the normal range, the magnetic pole vibration energy is passively consumed by the deformation energy absorption effect of the damping groove. When the vibration acceleration is in the warning range, a counteracting current harmonic is injected into the stator winding to counteract the main excitation frequency of the magnetic pole vibration and work with the damping slot to suppress the vibration amplitude. When vibration is detected to be approaching the resonance range and the amplitude continues to rise, the motor operating speed is actively fine-tuned by ±5% to ±10% to avoid the resonance speed point.

10. A motor control method with a highly stable rotor assembly according to claim 7, characterized in that, The monitoring of the pre-tightening state of the magnet in step S4 specifically involves: real-time acquisition of the internal temperature and back electromotive force waveform of the motor, and determining whether there is a gap between the magnet body and the side wall of the magnet mounting groove (6) by the harmonic distortion rate of the back electromotive force. The motor's internal operating temperature is set to three levels: normal operating temperature range is -20℃ to 120℃, high temperature warning range is 120℃ to 150℃, and over-temperature protection range is >150℃. Two thresholds are set for the back EMF harmonic distortion rate: ≤5% in good pre-tightening condition, 5% to 10% in gap warning condition, and >10% in pre-tightening failure condition. When the temperature is within the normal operating range, the elastic deformation margin of the damping groove is used to automatically compensate for the thermal deformation and maintain the clamping force between the two halves and the magnet. When the temperature is in the high temperature warning range or the harmonic distortion rate is in the gap warning state, adjust the armature current parameters to compensate for the temperature drift of the magnet operating point. When the temperature is in the over-temperature protection range or the harmonic distortion rate is in the pre-tightening failure state, the pre-tightening failure warning is triggered, and the maximum output torque of the motor is limited to 60% to 80% of the rated value.

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