Brushless motor rotor and brushless motor

Abstract

The invention relates to the technical field of brushless motors, and discloses a brushless motor rotor and a brushless motor, the brushless motor rotor comprises a rotor module, the rotor module comprises a first rotor chip, a second rotor chip and a rotor shaft, the first rotor chip and the second rotor chip are formed by laminating a plurality of silicon steel sheet punching sheets, the rotor shaft penetrates through the first rotor chip and the second rotor chip, the back face of the first rotor chip and the back face of the second rotor chip are laminated and attached, a dislocation angle is formed between the second rotor chip and the first rotor chip, the first rotor chip is provided with a plurality of first chip grooves, and the second rotor chip is provided with a plurality of second chip grooves. Each first chip groove and each second chip groove are provided with a magnetic shoe, and the arc of the magnetic shoe is smaller than the outer diameter arc of the rotor. According to the invention, the harmonic component of the air-gap magnetic field is reduced through the dislocation angle, and the stability and reliability of the brushless motor are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of brushless motors, and more particularly, to a brushless motor rotor and a brushless motor. Background Art

[0002] Electric power steering is a steering technology that has been gradually applied to automobiles since the late 1990s. With the rapid development of brushless motor technology, the commonly used power assist mechanism in automobiles has been gradually replaced by brushless motors from complex hydraulic mechanisms. The brushless motor on the automobile steering wheel can balance the steering lightness at low vehicle speeds and the handling stability at high speeds. However, the harmonic components of the current brushless motor will generate a periodically changing electromagnetic force between the stator and the rotor. When the frequency of the electromagnetic force approaches the natural frequency of the brushless motor structure, it will cause the vibration of the brushless motor and reduce the control accuracy, ultimately resulting in a jerky feeling when the automobile steering wheel is turned, thus increasing the difficulty of operating the steering wheel.

[0003] Therefore, it is necessary to design a brushless motor rotor and a brushless motor to solve the problems existing in the current technology. Summary of the Invention

[0004] In view of this, the present invention provides a brushless motor rotor and a brushless motor, aiming to solve the problem that the harmonic components of the current brushless motor will generate a periodically changing electromagnetic force between the stator and the rotor, causing the vibration of the brushless motor and reducing the control accuracy, ultimately resulting in a jerky feeling when the automobile steering wheel is turned, thus increasing the difficulty of operating the steering wheel.

[0005] On the one hand, the present invention provides a brushless motor rotor, comprising: a rotor module, the rotor module including a first rotor chip, a second rotor chip and a rotor shaft; the first rotor chip and the second rotor chip are stacked and formed by laminating a plurality of silicon steel sheet stampings; the rotor shaft penetrates through the first rotor chip and the second rotor chip; the back surface of the first rotor chip and the back surface of the second rotor chip are stacked and adhered; a misalignment angle is formed between the second rotor chip and the first rotor chip; the first rotor chip is provided with a plurality of first rivet holes, the second rotor chip is provided with a plurality of second rivet holes, and the plurality of first rivet holes and the plurality of second rivet holes are aligned based on the misalignment angle and rivets are inserted; the first rotor chip is provided with a plurality of first chip grooves, the second rotor chip is provided with a plurality of second chip grooves, and a magnetic tile is arranged in each first chip groove and each second chip groove; the arc of the magnetic tile is smaller than the arc of the rotor outer diameter.

[0006] Further, the brushless motor rotor includes: The slot pitch at the top of each of the first chip slots and each of the second chip slots is smaller than the slot pitch at the bottom. The magnetic tile is fitted into each of the first chip slots and each of the second chip slots, and the magnetic tile is a rare earth permanent magnet tile.

[0007] Further, the brushless motor rotor includes: The magnetic tile is provided with a chamfer, and the chamfer is R0.3; The arc of the magnetic tile is R9.5, the width of the magnetic tile is 12 mm, the length of the magnetic tile is 18.5 mm, and the surface of the magnetic tile is nickel-plated.

[0008] Further, the misalignment angle is determined by the following method, including: Align the first rotor chip and the second rotor chip, and obtain the first output signal of the rotation of the first rotor chip and the second rotor chip. Preprocess the first output signal, and determine the initial waveform diagram according to the result of the preprocessing; Misalign the first rotor chip and the second rotor chip, record the initial misalignment angle, and obtain the second output signal of the rotation after the misalignment of the first rotor chip and the second rotor chip. Preprocess the second output signal, and determine the secondary waveform diagram according to the result of the preprocessing; Compare the initial waveform diagram and the secondary waveform diagram, and judge whether to adjust the initial misalignment angle according to the comparison result. When it is determined to adjust the initial misalignment angle, determine each adjusted waveform diagram according to the adjustment result; Determine the misalignment angle based on the waveform parameters of the initial waveform diagram, the secondary waveform diagram and the adjusted waveform diagram.

[0009] Further, when preprocessing the first output signal, it includes: The preprocessing includes signal amplification, signal filtering and signal shaping, and the preprocessed first output signal is used as a signal output; Connect the signal output to the channel of an oscilloscope to determine the tooth-slot waveform, and judge whether to adjust the oscilloscope according to the tooth-slot waveform.

[0010] Further, when judging whether to adjust the oscilloscope according to the tooth-slot waveform, it includes: Judge whether to adjust the oscilloscope according to the amplitude and waveform frequency of the tooth-slot waveform; When the amplitude of the tooth-slot waveform is greater than the vertical display range of the oscilloscope, increase the vertical gear of the oscilloscope; When the amplitude of the tooth slot waveform is less than or equal to the vertical display range of the oscilloscope, the vertical gear of the oscilloscope is maintained; When the waveform frequency of the tooth slot waveform is greater than 0.5 times the sampling rate of the oscilloscope, the sampling rate of the oscilloscope is increased or the oscilloscope is replaced; When the waveform frequency of the tooth slot waveform is less than or equal to 0.5 times the sampling rate of the oscilloscope, the sampling rate of the oscilloscope is maintained.

[0011] Further, when comparing the initial waveform diagram and the secondary waveform diagram and determining whether to adjust the initial misalignment angle according to the comparison result, it includes: When the amplitude of the secondary waveform diagram is equal to the amplitude of the initial waveform diagram, it is determined that the initial misalignment angle is not adjusted, and the initial misalignment angle is determined as the misalignment angle; When the amplitude of the secondary waveform diagram is not equal to the amplitude of the initial waveform diagram, it is determined that the initial misalignment angle is adjusted.

[0012] Further, when it is determined to adjust the initial misalignment angle, determining each adjusted waveform diagram according to the adjustment result includes: When it is determined to adjust the initial misalignment angle, based on the initial misalignment angle, the initial misalignment angle is successively increased, and each adjusted waveform diagram and the corresponding adjusted initial misalignment angle are recorded.

[0013] Further, when determining the misalignment angle based on the waveform parameters of the initial waveform diagram, the secondary waveform diagram, and the adjusted waveform diagram, it includes: Compare the amplitudes of the initial waveform diagram, the secondary waveform diagram, and the adjusted waveform diagram, determine the waveform diagram corresponding to the smallest amplitude among them, and determine the initial misalignment angle or the adjusted initial misalignment angle corresponding to this waveform diagram as the misalignment angle.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: By forming a misalignment angle between the first rotor chip and the second rotor chip, the magnetic field distribution is changed, avoiding the coupling condition between the periodic electromagnetic force generated by the harmonic components and the natural frequency of the motor, thereby reducing the vibration amplitude, reducing the jerks when the vehicle steering wheel is turned, improving the comfort of driving control. Moreover, the reduction of vibration improves the running stability and reliability of the brushless motor, reduces the motor parameter fluctuations and mechanical errors caused by vibration, and further improves the control accuracy of the brushless motor. In automotive electric power steering, reliable motor control can accurately achieve the assistance characteristics of light steering at low speed and stable steering at high speed, improving the control performance of the vehicle. The arc of the magnetic tile is smaller than the arc of the rotor outer diameter, making the air gap length between the stator and the rotor module change regularly, further weakening the harmonic components in the air gap magnetic field, reducing the vibration and harmonic torque of the brushless motor during operation, avoiding the reduction of control accuracy caused by vibration, and finally avoiding the risk of jerks when the vehicle steering wheel is turned.

[0015] On the other hand, the present application also provides a brushless motor for applying the above-mentioned brushless motor rotor, including: Slip rings, bearings, end caps, stators, motor casings and rotor modules; The motor casing is used to protect the slip rings, bearings, end caps, stators and rotor modules; The end cap is installed at one end of the motor casing, and the end cap and the motor casing together form a closed space; The bearings are respectively sleeved at both ends of the rotor module, and the rotor module is located at the central position of the closed space; The stator is fixed inside the motor casing and surrounds the rotor module; The slip ring is arranged inside the end cap, and the slip ring is used to transmit current to the rotor module.

[0016] It can be understood that the above-mentioned brushless motor rotor and brushless motor have the same beneficial effects, which will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention. Moreover, throughout the drawings, the same reference numerals are used to represent the same components. In the drawings: Figure 1 is a schematic structural diagram of a brushless motor rotor provided by an embodiment of the present invention; Figure 2 is a schematic structural diagram of the flip of a brushless motor rotor provided by an embodiment of the present invention; Figure 3 Schematic structural diagram of removing magnetic tiles from a brushless motor rotor provided by an embodiment of the present invention; Figure 4 Schematic structural diagram of the front side of the first rotor chip provided by an embodiment of the present invention; Figure 5 Schematic structural diagram of the back side of the second rotor chip provided by an embodiment of the present invention; Figure 6 Side view of a brushless motor rotor provided by an embodiment of the present invention; Figure 7 Front view of the magnetic tile provided by an embodiment of the present invention; Figure 8 Flowchart for determining the misalignment angle of a brushless motor rotor provided by an embodiment of the present invention; Figure 9 Cross-sectional schematic diagram of a brushless motor provided by an embodiment of the present invention.

[0018] In the figure, 1 is the first rotor chip; 10 is the first chip groove; 11 is the first rivet hole; 2 is the second rotor chip; 20 is the second chip groove; 21 is the second rivet hole; 3 is the rotor shaft; 4 is the rivet; 5 is the magnetic tile; 50 is the chamfer; 6 is the slip ring; 7 is the bearing; 8 is the end cover; 9 is the stator; 10 is the motor housing; 100 is the rotor module. Detailed implementation manners

[0019] Hereinafter, exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be fully conveyed to those skilled in the art. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. Hereinafter, the present invention will be described in detail with reference to the drawings and in combination with the embodiments.

[0020] Refer to Figures 1-6As shown in the figure, in some embodiments of the present application, a brushless motor rotor includes: a rotor module 100, the rotor module 100 includes a first rotor chip 1, a second rotor chip 2 and a rotor shaft 3. The first rotor chip 1 and the second rotor chip 2 are composed of a plurality of silicon steel sheet punchings stacked together. The rotor shaft 3 penetrates through the first rotor chip 1 and the second rotor chip 2. The back surface of the first rotor chip 1 and the back surface of the second rotor chip 2 are stacked and adhered together. A misalignment angle is formed between the second rotor chip 2 and the first rotor chip 1. The first rotor chip 1 is provided with a plurality of first rivet holes 11, and the second rotor chip 2 is provided with a plurality of second rivet holes 21. The plurality of first rivet holes 11 and the plurality of second rivet holes 21 are aligned based on the misalignment angle and rivets 4 are inserted. The first rotor chip 1 is provided with a plurality of first chip grooves 10, and the second rotor chip 2 is provided with a plurality of second chip grooves 20. Each first chip groove 10 and each second chip groove 20 are provided with magnetic tiles 5. The arc of the magnetic tile 5 is smaller than the arc of the rotor outer diameter.

[0021] Specifically, the first rotor chip 1 and the second rotor chip 2 are composed of a plurality of silicon steel sheet punchings stacked together. The silicon steel sheet has the characteristics of high magnetic permeability and low hysteresis loss, which can effectively conduct magnetism and reduce energy loss. The specific number of silicon steel sheets is determined according to different types of automobile steering wheels. The rotor shaft 3 penetrates through the first rotor chip 1 and the second rotor chip 2 to Figure 1 take the surface of the first rotor chip 1 as the front surface, stack and adhere the back surface of the first rotor chip 1 and the back surface of the second rotor chip 2. The first rivet holes 11 and the second rivet holes 21 are preferably four. Since the positions of the first rivet holes 11 on the front surface of the first rotor chip 1 and the second rivet holes 21 on the back surface of the second rotor chip 2 do not overlap, effective alignment cannot be achieved when inserting the rivets 4. Therefore, the second rotor chip 2 is rotated counterclockwise to form a misalignment angle to align the first rivet holes 11 and the second rivet holes 21, and then the rivets 4 are inserted into the first rivet holes 11 and the second rivet holes 21, ensuring the structural stability of the first rotor chip 1 and the second rotor chip 2 after misalignment.

[0022] It can be understood that, due to the misalignment angle formed between the first rotor chip 1 and the second rotor chip 2, according to the principle of magnetic circuit superposition, the synthesized air-gap magnetic density after misalignment is: ; wherein, B(θ) represents the synthesized air-gap magnetic density, B1(θ) represents the air-gap magnetic density generated by the first rotor chip 1, B2(θ-α) represents the air-gap magnetic density of the second rotor chip at the misalignment angle, θ represents the spatial angle, α represents the misalignment angle, and the formula is expanded by Fourier transform to determine that the synthesized air-gap magnetic density is the superposition of multiple cosine waves: ; Among them, Bn(θ) represents the synthesized harmonic, An represents the magnetic flux density amplitude of the nth harmonic, represents the phase angle of the nth harmonic. It can be known from the Fourier transform expansion that the existing misalignment angle will cause the harmonic components to cancel each other out. For example, for the nth harmonic: ; When this formula is satisfied (k is an integer), the harmonic components will be cancelled out. By the misalignment angle, the distribution of the air-gap magnetic field is changed. Through the misalignment of the first rotor chip 1 and the second rotor chip 2, the harmonic characteristics of the air-gap magnetic field are adjusted, the distribution and frequency characteristics of the electromagnetic force are changed, and the electromagnetic force frequency is avoided from approaching the natural frequency of the brushless motor, thereby reducing the vibration of the motor and the harmonic torque. The first chip slots 10 and the second chip slots 20 are preferably eight. A magnetic tile 5 is arranged in each of the first chip slots 10 and the second chip slots 20. The arc of the magnetic tile 5 is smaller than the arc of the rotor outer diameter. The magnetic tile 5, as a permanent magnet, provides a corresponding magnetic field, so that the air-gap length between the stator 9 and the rotor module 100 changes regularly, further weakening the harmonic components in the air-gap magnetic field, reducing the vibration and harmonic torque of the brushless motor during operation, improving the stability and reliability of the brushless motor, and avoiding the risk of reduced control accuracy due to vibration, which ultimately causes a jerky feeling when the vehicle steering wheel is turned.

[0023] In some embodiments of the present application, the brushless motor rotor includes: the slot pitch at the top of each first chip slot 10 and each second chip slot 20 is smaller than the slot pitch at the bottom. The magnetic tile 5 is fitted with each first chip slot 10 and each second chip slot 20. The magnetic tile 5 is a rare earth permanent magnet tile 5.

[0024] Referring to Figure 7 shown, in some embodiments of the present application, the brushless motor rotor includes: the magnetic tile 5 is provided with a chamfer 50, the chamfer 50 is R0.3, the arc of the magnetic tile 5 is R9.5, the width of the magnetic tile 5 is 12 mm, the length of the magnetic tile 5 is 18.5 mm, and the surface of the magnetic tile 5 is nickel-plated.

[0025] Specifically, the slot pitch at the top of each first chip slot 10 and each second chip slot 20 is smaller than that at the bottom, forming a "converging angle" in the slot shape. This enables the magnetic tile 5 to achieve a wedging effect after being inserted into the first chip slot 10 and the second chip slot 20, enhancing the stability between the magnetic tile 5 and each chip slot, preventing the risk of loosening or displacement of the magnetic tile 5 during high-speed rotation, and improving the reliability of the magnetic tile 5. Moreover, the magnetic tile 5 is made of a rare-earth permanent magnet magnetic tile 5, which has the characteristics of high magnetic energy product and high coercivity. The magnetic energy is three times that of ordinary ferrite magnets, capable of forming a stable magnetic field in the air gap, effectively enhancing the assistance adaptability of the electric power steering under low-speed and high-speed conditions. The chamfer 50 of the magnetic tile 5 avoids damage to the edges and corners of the magnetic tile 5. Meanwhile, it prevents the magnetic tile 5 from being damaged due to edge stress concentration during high-speed rotation, improving the mechanical strength of the magnetic tile 5. Since the arc of the magnetic tile 5 is R9.5, which is smaller than the arc of the rotor outer diameter, it helps to form a continuous and smooth air-gap magnetic field during operation, reducing the cogging effect and magnetic field distortion, and further enhancing the smoothness of operation. The surface of the magnetic tile 5 is nickel-plated, which can effectively prevent the corrosion and rust of the magnetic tile 5 in humid or high-temperature environments, enhancing its antioxidant performance and improving the overall wear resistance and impact resistance of the magnetic tile 5.

[0026] Refer to Figure 8 As shown, in some embodiments of the present application, the misalignment angle is determined by the following method, including: S100: Align the first rotor chip with the second rotor chip, obtain the first output signal of the rotation of the first rotor chip and the second rotor chip, preprocess the first output signal, and determine the initial waveform diagram according to the result of the preprocessing; S200: Misalign the first rotor chip and the second rotor chip, record the initial misalignment angle, obtain the second output signal of the rotation after the misalignment of the first rotor chip and the second rotor chip, preprocess the second output signal, and determine the secondary waveform diagram according to the result of the preprocessing; S300: Compare the initial waveform diagram with the secondary waveform diagram, judge whether to adjust the initial misalignment angle according to the comparison result. When it is determined to adjust the initial misalignment angle, determine each adjusted waveform diagram according to the adjustment result; S400: Determine the misalignment angle based on the waveform parameters of the initial waveform diagram, the secondary waveform diagram, and the adjusted waveform diagram.

[0027] Specifically, when determining the misalignment angle, first align the first rotor chip with the second rotor chip. At this time, drive the rotor shaft to obtain the first output signal generated during their rotation. After preprocessing the first output signal, a waveform diagram regarding the spatial angle can be obtained, that is, the initial waveform diagram, which is used as a reference benchmark diagram for subsequent operations. Misalign the first rotor chip and the second rotor chip. When misaligning, first increase the angle by 1°, that is, the second rotor chip rotates counterclockwise by 1°, and record this initial misalignment angle. Obtain the second output signal when they rotate again after misalignment, and perform the same preprocessing operation on it to obtain a secondary waveform diagram. By misaligning the first rotor chip and the second rotor chip, the internal magnetic field distribution is changed, which may cause a difference between the secondary waveform diagram and the initial waveform diagram. Compare the initial waveform diagram and the secondary waveform diagram. If it is found that there is a difference in the waveform diagram at the current initial misalignment angle, it indicates that by changing the misalignment angle between the first rotor chip and the second rotor chip, the harmonic components in the air-gap magnetic field can be adjusted. At this time, it is determined that the initial misalignment angle needs to be adjusted, and the same rotation and preprocessing are performed after each adjustment to ensure consistency during adjustment. According to the waveform parameters between the adjusted waveform diagram, the initial waveform diagram, and the secondary waveform diagram generated after each adjustment, the optimal misalignment angle can be comprehensively analyzed and determined, thereby effectively changing the distribution and variation law of the electromagnetic force between the stator and the rotor module, and thus effectively reducing the vibration of the motor.

[0028] In some embodiments of the present application, when preprocessing the first output signal, it includes: the preprocessing includes signal amplification, signal filtering, and signal shaping. The preprocessed first output signal is used as a signal output, and the signal output is connected to the channel of an oscilloscope to determine the cogging waveform, and whether to adjust the oscilloscope is judged according to the cogging waveform.

[0029] In some embodiments of the present application, when judging whether to adjust the oscilloscope according to the cogging waveform, it includes: judging whether to adjust the oscilloscope according to the amplitude and waveform frequency of the cogging waveform. When the amplitude of the cogging waveform is greater than the vertical display range of the oscilloscope, the vertical gear of the oscilloscope is increased. When the amplitude of the cogging waveform is less than or equal to the vertical display range of the oscilloscope, the vertical gear of the oscilloscope is maintained. When the waveform frequency of the cogging waveform is greater than 0.5 times the sampling rate of the oscilloscope, the sampling rate of the oscilloscope is increased or the oscilloscope is replaced. When the waveform frequency of the cogging waveform is less than or equal to 0.5 times the sampling rate of the oscilloscope, the sampling rate of the oscilloscope is maintained.

[0030] Specifically, the first output signal contains the electrical signals of the rotor module and the stator during operation. There may be certain noise and interference, and the signal intensity may be weak. Through signal amplification, the signal intensity can be enhanced to ensure that the signal is effectively captured in subsequent processing and analysis. Signal filtering removes high-frequency noise and clutter in the signal to avoid these interference factors affecting the judgment of the operating state. Signal shaping processes the signal into a regular and stable waveform for subsequent analysis. After preprocessing, the preprocessed first output signal is used as the signal output and connected to the channel of the oscilloscope to determine the cogging waveform. The cogging waveform intuitively reflects the characteristics of the interaction between the internal magnetic field and the rotor module. Due to the influence of the product parameters and product type of the oscilloscope, the oscilloscope may not be able to display the entire cogging waveform, and the oscilloscope needs to be adjusted accordingly based on the cogging waveform.

[0031] It can be understood that whether to adjust the oscilloscope is judged according to the amplitude and waveform frequency of the cogging waveform. When the amplitude of the cogging waveform is greater than the vertical display range of the oscilloscope, if the vertical range is not increased, the cogging waveform will not be fully displayed, resulting in deviation during reading. Increasing the vertical range can make the cogging waveform fully presented. When the amplitude is less than or equal to the vertical display range, the vertical range can be maintained. In this embodiment, the sampling rate of the oscilloscope is set between 500 MSa / s and 1 GSa / s, which is specifically determined according to the actual signal output. For the waveform frequency, when the waveform frequency is greater than 0.5 times the sampling rate of the oscilloscope, if the sampling rate is not increased or the oscilloscope is not replaced, problems such as waveform distortion and data loss will occur in the cogging waveform. If the oscilloscope is selected to be replaced, the preprocessed first output signal is used as the signal output and reconnected to the channel of the replaced oscilloscope to re-determine the cogging waveform, and the replaced oscilloscope is still selected in subsequent processing. If the waveform frequency is less than or equal to 0.5 times the sampling rate of the oscilloscope, the sampling rate can be maintained. The corresponding adjustment of the oscilloscope improves the accuracy and reliability of determining the misalignment angle.

[0032] In some embodiments of the present application, when comparing the initial waveform diagram and the secondary waveform diagram and judging whether to adjust the initial misalignment angle according to the comparison result, it includes: when the amplitude of the secondary waveform diagram is equal to the amplitude of the initial waveform diagram, it is determined that the initial misalignment angle is not adjusted, and the initial misalignment angle is determined as the misalignment angle; when the amplitude of the secondary waveform diagram is not equal to the amplitude of the initial waveform diagram, it is determined that the initial misalignment angle is adjusted.

[0033] Specifically, when the amplitude of the secondary waveform diagram is equal to that of the initial waveform diagram, it indicates that the harmonic components in the air-gap magnetic field cannot be adjusted by changing the angle of the second rotor chip, and it is determined that the initial misalignment angle is not adjusted. If there are differences in the waveform diagrams at the current initial misalignment angle, it indicates that the harmonic components in the air-gap magnetic field can be adjusted by changing the misalignment angle between the first rotor chip and the second rotor chip. At this time, it is determined that the initial misalignment angle needs to be adjusted. Through experimental tests, it is found that by changing the misalignment angle between the first rotor chip and the second rotor chip, a phase difference appears in the induction signals of the two rotor chips, and a phase interference phenomenon is caused after misalignment. The phase interference has a certain impact on the spatial distribution of the magnetic density. Some harmonic components (such as slot harmonics and harmonics related to torque ripple) will be partially cancelled due to opposite phases, thereby reducing the content of high-order harmonics in the overall magnetic density, suppressing electromagnetic vibration and noise interference, and improving the stability and reliability of the rotor module.

[0034] In some embodiments of the present application, when it is determined to adjust the initial misalignment angle, the adjusted waveform diagrams after each adjustment are determined according to the adjustment results, including: when it is determined to adjust the initial misalignment angle, taking the initial misalignment angle as a reference, sequentially increasing the initial misalignment angle, and recording the adjusted waveform diagrams after each adjustment and the corresponding adjusted initial misalignment angles.

[0035] In some embodiments of the present application, when determining the misalignment angle based on the waveform parameters of the initial waveform diagram, the secondary waveform diagram, and the adjusted waveform diagram, it includes: comparing the amplitudes of the initial waveform diagram, the secondary waveform diagram, and the adjusted waveform diagram, determining the waveform diagram corresponding to the smallest amplitude among them, and determining the initial misalignment angle or the adjusted initial misalignment angle corresponding to this waveform diagram as the misalignment angle.

[0036] Specifically, with the initial misalignment angle (1°) as the reference, each adjustment increases the angle by 1° based on the periodic characteristics of the harmonic distribution (the harmonic components of the electromagnetic force between the stator and rotor modules show periodic fluctuations with the change of relative position). By gradually adjusting the angle, the phase of the harmonic components can be shifted. Record the corresponding adjusted waveform diagram after each adjustment, which is beneficial to exploring the "cancellation interference" region of harmonic superposition, that is, finding the optimal angle position where the harmonic components can cancel each other out. The amplitude of the waveform diagram directly reflects the magnitude of the harmonic energy. In electric power steering, the smaller the amplitude, the smoother the electromagnetic force fluctuation and the weaker the motor vibration. By comparing the amplitudes of the initial waveform diagram, secondary waveform diagram, and all adjusted waveform diagrams, the angle with the lowest harmonic energy can be located. Based on the principle of Fourier analysis, the motor vibration is mainly driven by harmonic components of specific frequencies, and a certain misalignment angle can minimize the combined amplitude of these harmonic components. By gradually approaching the misalignment angle, the minimum value of the reduction of harmonic components can be determined, thereby improving the effect of vibration suppression. In this embodiment, the determined misalignment angle is 5°.

[0037] In summary, the beneficial effects of the present invention are as follows: By forming a misalignment angle between the first rotor chip and the second rotor chip, the distribution of the magnetic field is changed, avoiding the coupling condition between the periodic electromagnetic force generated by harmonic components and the natural frequency of the motor, thereby reducing the vibration amplitude, reducing the jerks when the car steering wheel is turned, and improving the comfort of driving control. Moreover, the reduction of vibration improves the running stability and reliability of the brushless motor, reduces the motor parameter fluctuations and mechanical errors caused by vibration, and further improves the control accuracy of the brushless motor. In automotive electric power steering, reliable motor control can accurately achieve the assist characteristics of light steering at low speeds and stable steering at high speeds, improving the vehicle handling performance. The arc of the magnetic tile is smaller than the arc of the rotor outer diameter, resulting in a regular change in the air gap length between the stator and rotor modules, further weakening the harmonic components in the air gap magnetic field, reducing the vibration and harmonic torque of the brushless motor during operation, avoiding the risk of reduced control accuracy due to vibration, and ultimately resulting in jerks when the car steering wheel is turned.

[0038] In another preferred manner based on the above embodiment, refer to Figure 9As shown, this embodiment provides a brushless motor for applying the above-mentioned brushless motor rotor, including: a collector ring 6, a bearing 7, an end cover 8, a stator 9, a casing 10 and a rotor module 100, the casing 10 is used to protect the collector ring 6, the bearing 7, the end cover 8, the stator 9 and the rotor module 100, the end cover 8 is installed at one end of the casing 10, the end cover 8 and the casing 10 together constitute a closed space, the bearing 7 is respectively mounted on both ends of the rotor module 100, the rotor module 100 is located at the center of the closed space, the stator 9 is fixed inside the casing 10 and surrounds the rotor module 100, the collector ring 6 is arranged inside the end cover 8, and the collector ring 6 is used to transmit current to the rotor module 100.

[0039] Specifically, the housing 10, as an external protective component, provides physical protection for the internal collector ring 6, bearing 7, end cover 8, stator 9 and rotor module 100 to resist external mechanical impact, dust, water vapor and other damage. The end cover 8 is installed at one end of the housing 10, and together with the housing 10, it forms a closed space, which can further isolate the external environment, ensure that the internal components of the brushless motor work in a relatively stable and clean environment, and reduce the probability of failure caused by external factors. The bearing 7 is sleeved on both ends of the rotor module 100 to support the rotor module 100, so that the rotor module 100 can rotate flexibly and stably in the center of the closed space, reducing the energy loss and mechanical wear caused by radial and axial shaking during rotation. The stator 9 is fixed inside the casing 10 and surrounds the rotor module 100. The winding of the stator 9 will generate a rotating magnetic field when the power is connected. The collector ring 6 is arranged inside the end cover 8 and transmits current to the rotor module 100, so that the rotor module 100 generates a magnetic field. The magnetic field of the rotor module 100 interacts with the rotating magnetic field generated by the stator 9. According to the law of electromagnetic induction and the left-hand rule, the rotor module 100 starts to rotate under the action of electromagnetic force, thereby realizing the conversion of electrical energy into mechanical energy. The spatial layout of the stator 9 and the rotor module 100 and the current transmission function of the collector ring 6 can realize the conversion of electromagnetic energy, so that the brushless motor outputs a stable torque, thereby meeting the power requirements of the electric power steering.

[0040] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems or computer program products. Therefore, the present application may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0041] This application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram can be implemented by computer program instructions, as well as the combination of flows and / or blocks in the flowchart and / or block diagram. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or means for implementing the functions specified in multiple blocks.

[0042] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including instruction means, and the instruction means implement the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or means for implementing the functions specified in multiple blocks.

[0043] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process. Therefore, the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or means for implementing the functions specified in multiple blocks.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications or equivalent replacements can still be made to the specific implementation manners of the present invention. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention shall be covered by the protection scope of the claims of the present invention.

Claims

1. A brushless motor rotor, characterized in that, Comprising: A rotor module, the rotor module includes a first rotor chip, a second rotor chip and a rotor shaft; The first rotor chip and the second rotor chip are composed of a plurality of silicon steel sheet stampings stacked; The rotor shaft penetrates through the first rotor chip and the second rotor chip; The back surface of the first rotor chip and the back surface of the second rotor chip are stacked and adhered; A misalignment angle is formed between the second rotor chip and the first rotor chip; The first rotor chip is provided with a plurality of first rivet holes, the second rotor chip is provided with a plurality of second rivet holes, and the plurality of first rivet holes and the plurality of second rivet holes are aligned based on the misalignment angle and rivets are inserted; The first rotor chip is provided with a plurality of first chip grooves, the second rotor chip is provided with a plurality of second chip grooves, and a magnetic tile is arranged in each first chip groove and each second chip groove; The arc of the magnetic tile is smaller than the arc of the rotor outer diameter.

2. The brushless motor rotor according to claim 1, wherein, Comprising: The groove spacing at the top of each first chip groove and each second chip groove is smaller than the groove spacing at the bottom. The magnetic tile is fitted with each first chip groove and each second chip groove, and the magnetic tile is a rare earth permanent magnet tile.

3. The brushless motor rotor according to claim 2, wherein, Comprising: The magnetic tile is provided with a chamfer, and the chamfer is R0.3; The arc of the magnetic tile is R9.5, the width of the magnetic tile is 12 mm, the length of the magnetic tile is 18.5 mm, and the surface of the magnetic tile is nickel-plated.

4. The brushless motor rotor according to claim 3, characterized in that, The misalignment angle is determined by the following method, including: Align the first rotor chip with the second rotor chip, and obtain the first output signal of the rotation of the first rotor chip and the second rotor chip. Preprocess the first output signal, and determine the initial waveform diagram according to the result of the preprocessing; Misalign the first rotor chip and the second rotor chip, record the initial misalignment angle, and obtain the second output signal of the rotation after the first rotor chip and the second rotor chip are misaligned. Preprocess the second output signal, and determine the secondary waveform diagram according to the result of the preprocessing; Compare the initial waveform diagram and the secondary waveform diagram, and judge whether to adjust the initial misalignment angle according to the comparison result. When it is determined to adjust the initial misalignment angle, determine each adjusted waveform diagram according to the adjustment result; Determine the misalignment angle based on the waveform parameters of the initial waveform diagram, the secondary waveform diagram and the adjusted waveform diagram.

5. The brushless motor rotor according to claim 4, characterized in that When preprocessing the first output signal, including: The preprocessing includes signal amplification, signal filtering and signal shaping, and the preprocessed first output signal is used as a signal output; Connect the signal output to the channel of an oscilloscope to determine the tooth-slot waveform, and judge whether to adjust the oscilloscope according to the tooth-slot waveform.

6. The brushless motor rotor according to claim 5, characterized in that, When judging whether to adjust the oscilloscope according to the tooth-slot waveform, including: Judge whether to adjust the oscilloscope according to the amplitude and waveform frequency of the tooth-slot waveform; When the amplitude of the tooth-slot waveform is greater than the vertical display range of the oscilloscope, increase the vertical gear of the oscilloscope; When the amplitude of the tooth-slot waveform is less than or equal to the vertical display range of the oscilloscope, maintain the vertical gear of the oscilloscope; When the waveform frequency of the tooth groove waveform is greater than 0.5 times the sampling rate of the oscilloscope, increase the sampling rate of the oscilloscope or replace the oscilloscope; When the waveform frequency of the tooth groove waveform is less than or equal to 0.5 times the sampling rate of the oscilloscope, maintain the sampling rate of the oscilloscope.

7. The brushless motor rotor according to claim 6, wherein When comparing the initial waveform diagram and the secondary waveform diagram and determining whether to adjust the initial misalignment angle according to the comparison result, it includes: When the amplitude of the secondary waveform diagram is equal to the amplitude of the initial waveform diagram, it is determined that the initial misalignment angle is not adjusted, and the initial misalignment angle is determined as the misalignment angle; When the amplitude of the secondary waveform diagram is not equal to the amplitude of the initial waveform diagram, it is determined that the initial misalignment angle is adjusted.

8. The brushless motor rotor according to claim 7, characterized in that, When it is determined to adjust the initial misalignment angle, determine the adjusted waveform diagram after each adjustment according to the adjustment result, including: When it is determined to adjust the initial misalignment angle, based on the initial misalignment angle, sequentially increase the initial misalignment angle, and record the adjusted waveform diagram after each adjustment and the corresponding adjusted initial misalignment angle.

9. The brushless motor rotor according to claim 8, characterized in that, When determining the misalignment angle based on the waveform parameters of the initial waveform diagram, secondary waveform diagram and adjusted waveform diagram, it includes: Compare the amplitudes of the initial waveform diagram, secondary waveform diagram and adjusted waveform diagram, determine the waveform diagram corresponding to the smallest amplitude among them, and determine the initial misalignment angle or the adjusted initial misalignment angle corresponding to this waveform diagram as the misalignment angle.

10. A brushless motor for use with a brushless motor rotor as described in any one of claims 1-9, characterized in that, It includes: Slip ring, bearing, end cover, stator, housing and rotor module; The housing is used to protect the slip ring, bearing, end cover, stator and rotor module; The end cover is installed at one end of the housing, and the end cover and the housing together form a closed space; The bearings are respectively sleeved at both ends of the rotor module, and the rotor module is located at the central position of the closed space; The stator is fixed inside the housing and surrounds the rotor module; The slip ring is arranged inside the end cover, and the slip ring is used to transmit current to the rotor module.

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