Rotor lamination with unevenly distributed pole shoes and unipolar electric machine

Abstract

The utility model provides a kind of uneven distribution pole shoe's rotor punching sheet and unipolar machine, rotor punching sheet is annular, the inner wall of rotor punching sheet has pole shoe and be used for installing the mounting slot of same polarity magnetic steel, multiple mounting slots are unevenly spaced in the circumferential direction of rotor punching sheet and set in rotor punching sheet, pole shoe and mounting slot are alternately arranged along the circumferential direction of rotor punching sheet, pole shoe is provided with the magnetic separation groove between mounting slot, the width of each magnetic separation groove along the circumferential direction of rotor punching sheet is not equal, rotor punching sheet has vertical symmetry axis along the center of rotor punching sheet, multiple mounting slots and multiple pole shoes are divided into left side portion and right side portion by vertical symmetry axis, left side portion and right side portion are symmetrical relative to vertical symmetry axis. The width of each magnetic separation groove is not equal, by adjusting the width of each magnetic separation groove to achieve the purpose of offsetting pole shoe and magnetic pole, and then introduce a harmonic component with original harmonic amplitude equal, opposite phase, inhibit motor cogging torque.

Description

Technical Field

[0001] This utility model relates to a rotor lamination with unevenly distributed pole shoes and a unipolar motor. Background Technology

[0002] In permanent magnet motors, the interaction between the permanent magnets and the armature core slots generates cogging torque. If no suppression measures are taken, this will cause torque pulsation, leading to vibration, noise, and affecting the system's control accuracy. For internal rotor permanent magnet motors, stator skew or rotor skew methods are often used to reduce cogging torque and improve control performance. However, these methods are complex, increase manufacturing costs, and generate axial magnetic pull, which can affect motor lifespan. Furthermore, they distort the back electromotive force waveform, reducing motor efficiency. Utility Model Content

[0003] The technical problem to be solved by this utility model is to overcome the defects of the prior art and provide a rotor lamination with unevenly distributed pole shoes and a unipolar motor.

[0004] The present invention solves the above-mentioned technical problems through the following technical solution:

[0005] A rotor lamination with unevenly distributed pole shoes for use in a unipolar motor is disclosed. The rotor lamination is annular, and its inner wall has pole shoes and mounting slots for mounting magnets of the same polarity. Multiple mounting slots are unevenly spaced along the circumferential direction of the rotor lamination. The pole shoes and mounting slots are alternately arranged along the circumferential direction of the rotor lamination. A magnetic isolation slot is provided between the pole shoes and the mounting slots. The width of each magnetic isolation slot along the circumferential direction of the rotor lamination is unequal. The rotor lamination has a vertical axis of symmetry passing through its center. The multiple mounting slots and multiple pole shoes are divided into a left side and a right side by the vertical axis of symmetry, and the left side and the right side are symmetrical with respect to the vertical axis of symmetry.

[0006] In this design, the pole shoes and mounting slots of the rotor laminations are unevenly distributed on the inner wall of the rotor laminations. Furthermore, the pole shoes and mounting slots on the left side are symmetrical about the vertical axis of symmetry relative to the pole shoes and mounting slots on the right side. A magnetic isolation slot is provided between each pole shoe and mounting slot, and the width of each magnetic isolation slot is unequal. By adjusting the width of each magnetic isolation slot, the pole shoes and magnetic poles are offset, thereby introducing a harmonic component with the same amplitude but opposite phase as the original harmonic. This cancels out the first-order tooth harmonic, suppresses the motor cogging torque, and achieves better NVH (Noise, Vibration, and Harshness) performance. In addition, by adjusting the width of the magnetic isolation slot, the magnetic field lines at the location of the magnetic isolation slot can be optimized, preventing local magnetic flux saturation and improving motor performance.

[0007] Preferably, each of the mounting slots has a radial axis of symmetry passing through the center of the rotor lamination, the radial axis of symmetry being offset by an angle relative to the radial axes of symmetry of the uniformly distributed mounting slots. for:

[0008] ,

[0009] Where n is a natural number, It is the least common multiple of the number of slots and the number of poles of the unipolar motor.

[0010] In this scheme, the offset is adjusted to the value obtained by the above formula. The value is chosen to minimize the cogging torque, thus resulting in better NVH performance. For example, when the permanent magnet position angle changes... At that time, the phase of each harmonic component of the cogging torque will shift by n. Where n is the harmonic order, and the amplitude of the harmonics remains constant. Therefore, the overall waveform of the cogging torque is shifted in the angular domain by an amount of . However, since different harmonics have different phase shifts, the overall waveform is the result of the superposition of phase shifts.

[0011] Preferably, the inner surface of the pole shoe is a plane, and the plane is perpendicular to a straight line passing through the center of the rotor lamination.

[0012] In this scheme, the above-mentioned structural configuration is adopted to smooth the air gap magnetic reluctance at the pole shoe and reduce torque fluctuation.

[0013] Preferably, each of the mounting slots has a radial axis of symmetry passing through the center of the rotor lamination, the unipolar motor has 15 slots and 5 poles, and the central angles of the regions enclosed by adjacent radial axes of symmetry in the rotor laminations are 70.5°, 70.5°, 75°, 75° and 69° respectively.

[0014] In this design, the motor using the above parameters maintains the machinability of the rotor laminations, achieves uniform air gap magnetic flux density, and reduces the fourth-order tooth harmonics. Specifically, the magnetic poles and pole shoes are offset by 1.5º.

[0015] Preferably, the central angle corresponding to the pole shoe in the rotor lamination is... Greater than or equal to 30° and less than or equal to 48°.

[0016] In this scheme, by limiting the above parameters, the air gap magnetic flux density of different harmonic orders of the rotor can be reduced, thereby reducing the harmonic content of the main magnetic flux and suppressing the cogging torque.

[0017] Preferably, the width of each pole shoe along the circumferential direction of the rotor lamination is equal, and the width of each mounting slot along the circumferential direction of the rotor lamination is equal.

[0018] In this solution, there is no need to adjust the width of the pole shoe and the mounting groove. The purpose of offsetting the pole shoe and the magnetic pole can be achieved simply by adjusting the width of the magnetic shielding groove.

[0019] Preferably, the mounting groove includes a first mounting groove, which is symmetrical about the vertical axis of symmetry. The magnetic shielding groove includes a first magnetic shielding groove, and the first magnetic shielding groove is provided on both sides of the first mounting groove. The central angle corresponding to the first magnetic shielding groove in the rotor lamination is [value missing]. , The value range is 0 < ε ≤ 6°.

[0020] In this design, the central angle corresponding to the first magnetic isolation slot in the rotor lamination is... By overcoming parameter limitations, the order air gap magnetic flux density can be actively offset to obtain the optimal first pole shoe 101 pole arc coefficient, thereby suppressing motor cogging torque, reducing torque fluctuations, and improving the motor's NVH performance.

[0021] Preferably, the mounting slot further includes a second mounting slot, and the two second mounting slots are symmetrical about the vertical axis of symmetry.

[0022] The magnetic isolation groove includes a second magnetic isolation groove, which is located at one end of the second mounting groove near the first magnetic isolation groove. The central angle of the second magnetic isolation groove in the rotor lamination is β, and the value of β is in the range of 0<β≤7°.

[0023] In this scheme, by limiting the central angle β corresponding to the second magnetic isolation slot in the rotor lamination, the order air gap magnetic flux can be actively canceled to obtain the optimal second pole shoe arc coefficient, thereby suppressing the motor cogging torque, reducing torque fluctuation and improving the motor's NVH performance.

[0024] Preferably, the magnetic isolation groove includes a third magnetic isolation groove, which is located at the end of the second mounting groove away from the second magnetic isolation groove. The central angle of the third magnetic isolation groove in the rotor lamination is γ, and the value of γ is in the range of 0 < γ ≤ 10°.

[0025] In this scheme, by limiting the central angle γ corresponding to the third magnetic isolation slot in the rotor lamination, the order air gap magnetic flux can be actively canceled to obtain the optimal third pole shoe arc coefficient, thereby suppressing the motor cogging torque, reducing torque fluctuation and improving the motor's NVH performance.

[0026] A unipolar motor comprising rotor laminations with unevenly distributed pole shoes as described above.

[0027] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of this utility model.

[0028] The significant advantages of this invention are as follows: the pole shoes and mounting slots of the rotor lamination are unevenly distributed on the inner wall of the rotor lamination, and the pole shoes and mounting slots on the left side are symmetrical with respect to the vertical axis of symmetry relative to the pole shoes and mounting slots on the right side. A magnetic isolation slot is provided between each pole shoe and mounting slot, and the width of each magnetic isolation slot is unequal. By adjusting the width of each magnetic isolation slot, the pole shoes and magnetic poles are offset, thereby introducing a harmonic component with the same amplitude but opposite phase as the original harmonic. This cancels out the first-order tooth harmonic, suppresses the motor cogging torque, and achieves better NVH (Noise, Vibration, and Harshness) performance. Furthermore, by adjusting the width of the magnetic isolation slot, the magnetic field lines at the location of the magnetic isolation slot can be optimized, preventing local magnetic flux saturation and improving motor performance. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the rotor laminations with unevenly distributed pole shoes according to a preferred embodiment of the present invention. Figure 1 .

[0030] Figure 2 This is a schematic diagram of the rotor laminations with unevenly distributed pole shoes according to a preferred embodiment of the present invention. Figure 2 .

[0031] Figure 3 This is a comparison diagram of the order harmonic suppression effects of a unipolar motor (after offset) according to a preferred embodiment of the present invention and a unipolar single-motor (without offset) in the prior art.

[0032] Figure 4 This is a comparison chart of torque fluctuation data between a unipolar motor (optimized pole arc coefficient) of a preferred embodiment of the present invention and a unipolar single-motor (unoptimized pole arc coefficient) of the prior art.

[0033] Explanation of reference numerals in the attached figures:

[0034] Extreme Boots 10

[0035] First Extreme Boot 101

[0036] Second Pole Boot 102

[0037] Third Pole Boots 103

[0038] Mounting slot 20

[0039] First mounting slot 201

[0040] Second mounting slot 202

[0041] Magnetic shielding groove 30

[0042] First magnetic shielding groove 301

[0043] Second magnetic shielding groove 302

[0044] Third magnetic shielding groove 303

[0045] Vertical axis of symmetry 100

[0046] Radial symmetry axis 200 Detailed Implementation

[0047] The present invention will be described more clearly and completely below with reference to the accompanying drawings, using a preferred embodiment.

[0048] like Figure 1 and Figure 2 As shown, this embodiment discloses a rotor lamination with unevenly distributed pole shoes, which is used in a unipolar motor. The rotor lamination is annular, and its inner wall has pole shoes 10 and mounting grooves 20 for mounting magnets of the same polarity. Multiple mounting grooves 20 are unevenly spaced along the circumferential direction of the rotor lamination. The pole shoes 10 and mounting grooves 20 are alternately arranged along the circumferential direction of the rotor lamination. A magnetic isolation groove 30 is provided between the pole shoes 10 and the mounting grooves 20. The width of each magnetic isolation groove 30 is not equal along the circumferential direction of the rotor lamination. The rotor lamination has a vertical axis of symmetry 100 passing through the center of the rotor lamination in the vertical direction. The multiple mounting grooves 20 and multiple pole shoes 10 are divided into a left portion and a right portion by the vertical axis of symmetry 100. The left portion and the right portion are symmetrical with respect to the vertical axis of symmetry 100. The pole shoes 10 and mounting slots 20 of the rotor lamination are unevenly distributed on the inner wall of the rotor lamination. The pole shoes 10 and mounting slots 20 on the left side are symmetrical with respect to the vertical axis of symmetry 100, respectively, compared to the pole shoes 10 and mounting slots 20 on the right side. A magnetic isolation slot 30 is provided between each pole shoe 10 and mounting slot 20. The width of each magnetic isolation slot 30 is unequal. By adjusting the width of each magnetic isolation slot 30, the pole shoes 10 and magnetic poles are offset, thereby introducing a harmonic component with the same amplitude but opposite phase to the original harmonic. This cancels out the tooth harmonics of different orders (different offsets can cancel out different orders of harmonics), suppresses the motor cogging torque, and achieves better NVH (Noise, Vibration, Harshness) performance. Furthermore, by adjusting the width of the magnetic isolation slot 30, the magnetic field lines at the location of the magnetic isolation slot 30 can be optimized, preventing local magnetic flux saturation and improving motor performance.

[0049] like Figure 1 As shown, each mounting slot 20 has a radial symmetry axis 200 passing through the center of the rotor lamination, and the offset angle of the radial symmetry axis 200 relative to the radial symmetry axis 200 of the uniformly distributed mounting slots 20 is... for:

[0050] ,

[0051] Where n is a natural number, This is the least common multiple of the number of slots and poles of a unipolar motor. The offset is obtained by adjusting the offset to the value obtained from the above formula. The value is chosen to minimize the cogging torque, thus resulting in better NVH performance. For example, when the permanent magnet position angle changes... At that time, the phase of each harmonic component of the cogging torque will shift by n. Where n is the harmonic order, and the amplitude of the harmonics remains constant. Therefore, the overall waveform of the cogging torque is shifted in the angular domain by an amount of . However, since different harmonics have different phase shifts, the overall waveform is the result of the superposition of phase shifts.

[0052] Preferably, the inner surface of the pole shoe 10 is a plane, and the plane is perpendicular to the straight line passing through the center of the rotor lamination, so that the air gap magnetic resistance at the pole shoe 10 is smooth and the torque fluctuation is reduced.

[0053] like Figure 1 As shown, in this embodiment, each mounting slot 20 has a radial symmetry axis 200 passing through the center of the rotor lamination. The unipolar motor has 15 slots and 5 poles. The central angles of the regions enclosed by adjacent radial symmetry axes 200 in the rotor lamination are 70.5°, 70.5°, 75°, 75°, and 69°, respectively. This maintains the machinability of the rotor lamination, ensures uniform air gap magnetic flux density, and reduces the fourth-order tooth harmonics. The magnetic poles and pole shoes 10 are offset by 1.5°.

[0054] like Figure 2 As shown, preferably, the central angle corresponding to the pole shoe 10 in the rotor lamination is... A value greater than or equal to 30° and less than or equal to 48° can reduce the air gap magnetic flux density of different harmonic orders of the rotor, thereby reducing the harmonic content of the main magnetic flux and suppressing the cogging torque.

[0055] In this embodiment, the width of each pole shoe 10 along the circumferential direction of the rotor lamination is equal, and the width of each mounting slot 20 along the circumferential direction of the rotor lamination is equal. Therefore, there is no need to adjust the width of the pole shoe 10 and the mounting slot 20; the purpose of offsetting the pole shoe 10 and the magnetic pole can be achieved simply by adjusting the width of the magnetic isolation slot 30.

[0056] In an optional embodiment, the pole shoes can be set to be unequal or the width of the mounting groove can be set to be unequal, and in conjunction with magnetic shielding grooves of different widths, the purpose of offsetting the pole shoes and magnetic poles can also be achieved.

[0057] like Figure 1and Figure 2 As shown, the mounting groove 20 includes a first mounting groove 201, which is symmetrical about the vertical axis of symmetry 100. The magnetic isolation groove 30 includes a first magnetic isolation groove 301. The first magnetic isolation groove 301 is provided on both sides of the first mounting groove 201. The central angle corresponding to the first magnetic isolation groove 301 in the rotor lamination is... , The value range is 0 < ε ≤ 6°. The central angle corresponding to the first magnetic isolation slot 301 in the rotor lamination is... By overcoming parameter limitations, the order air gap magnetic flux density can be actively offset to obtain the optimal first pole shoe 101 pole arc coefficient, thereby suppressing motor cogging torque, reducing torque fluctuations, and improving the motor's NVH performance.

[0058] like Figure 1 and Figure 2 As shown, the mounting slot 20 also includes a second mounting slot 202. The two second mounting slots 202 are symmetrical with respect to the vertical axis of symmetry 100. The magnetic isolation slot 30 includes a second magnetic isolation slot 302, which is located at the end of the second mounting slot 202 near the first magnetic isolation slot 301. The central angle corresponding to the second magnetic isolation slot 302 in the rotor lamination is β, and the value of β ranges from 0 to 7°. By limiting the parameter of the central angle β corresponding to the second magnetic isolation slot 302 in the rotor lamination, the order air gap magnetic flux can be actively canceled to obtain the optimal pole arc coefficient of the second pole shoe 102, thereby suppressing the motor cogging torque, reducing torque fluctuation, and improving the NVH performance of the motor.

[0059] The magnetic isolation slot 30 includes a third magnetic isolation slot 303, which is located at the end of the second mounting slot 202 away from the second magnetic isolation slot 302. The central angle corresponding to the third magnetic isolation slot 303 in the rotor lamination is γ, and the value of γ ranges from 0 to 10°. By limiting the parameter of the central angle γ corresponding to the third magnetic isolation slot 303 in the rotor lamination, the order air gap magnetic flux can be actively canceled, and the optimal pole arc coefficient of the third pole shoe 103 can be obtained to suppress the motor cogging torque, reduce torque fluctuation, and improve the NVH performance of the motor.

[0060] The expression for the first pole shoe 101 is:

[0061]

[0062] The expression for the second pole shoe 102 is:

[0063]

[0064] The expression for the third pole shoe 103 is:

[0065]

[0066] in, The polar arc width, For polar distance, For correction factor, The central angle corresponding to pole shoe 10 in the rotor lamination. β is the central angle corresponding to the first magnetic isolation slot 301 in the rotor lamination, β is the central angle corresponding to the second magnetic isolation slot 302 in the rotor lamination, and γ is the central angle corresponding to the third magnetic isolation slot 303 in the rotor lamination.

[0067] This embodiment also discloses a unipolar motor, which includes rotor laminations with unevenly distributed pole shoes as described above. Figure 1 and Figure 2 As shown, the stator is embedded inside the rotor laminations.

[0068] Through software simulation, the order harmonic suppression effect of the unipolar motor (after offset) in this embodiment is compared with that of the existing unipolar single-motor (without offset), and the results are as follows: Figure 3 The diagram shows a comparison of the order harmonic suppression effects of the unipolar motor (after offset) of this embodiment and the unipolar single machine (without offset) of the prior art. It can be seen from the figure that the harmonics of each order of the motor in this embodiment are significantly reduced, especially the reduction effect of the cogging torque of the 4th and 5th orders is particularly obvious.

[0069] Through software simulation, the torque data of the unipolar motor (optimized pole arc coefficient) in this embodiment are compared with those of the existing unipolar single-motor (unoptimized pole arc coefficient), and the results are as follows: Figure 4 The figure shows a comparison of torque fluctuation data between the unipolar motor (optimized pole arc coefficient) of this embodiment and the unipolar single machine (unoptimized pole arc coefficient) of the prior art. It can be seen from the figure that the torque fluctuation of this embodiment is greatly reduced.

[0070] In the description herein, it should be understood that the terms “upper,” “lower,” “front,” “back,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0071] While specific embodiments of this utility model have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of this utility model is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of this utility model, but all such changes and modifications fall within the scope of protection of this utility model.

Claims

1. A rotor lamination with unevenly distributed pole shoes, used in a unipolar motor, characterized in that, The rotor lamination is annular, and its inner wall has pole shoes and mounting slots for mounting magnets of the same polarity. Multiple mounting slots are unevenly spaced along the circumferential direction of the rotor lamination. The pole shoes and mounting slots are alternately arranged along the circumferential direction of the rotor lamination. A magnetic isolation slot is provided between the pole shoes and the mounting slots. The width of each magnetic isolation slot along the circumferential direction of the rotor lamination is unequal. The rotor lamination has a vertical axis of symmetry passing through its center. The multiple mounting slots and multiple pole shoes are divided into a left side and a right side by the vertical axis of symmetry, and the left side and the right side are symmetrical with respect to the vertical axis of symmetry.

2. The rotor lamination with unevenly distributed pole shoes as described in claim 1, characterized in that, Each of the mounting slots has a radial axis of symmetry passing through the center of the rotor lamination, the offset angle of the radial axis of symmetry relative to the radial axes of symmetry of the uniformly distributed mounting slots. for: ， Where n is a natural number, It is the least common multiple of the number of slots and the number of poles of the unipolar motor.

3. The rotor lamination with unevenly distributed pole shoes as described in claim 1, characterized in that, The inner surface of the pole shoe is a plane, and the plane is perpendicular to a straight line passing through the center of the rotor lamination.

4. The rotor lamination with unevenly distributed pole shoes as described in claim 1, characterized in that, Each of the mounting slots has a radial axis of symmetry passing through the center of the rotor lamination. The unipolar motor has 15 slots and 5 poles. The central angles of the regions enclosed by adjacent radial axes of symmetry in the rotor laminations are 70.5°, 70.5°, 75°, 75° and 69°, respectively.

5. The rotor lamination with unevenly distributed pole shoes as described in claim 4, characterized in that, The pole shoe corresponds to the central angle in the rotor lamination. Greater than or equal to 30° and less than or equal to 48°.

6. The rotor lamination with unevenly distributed pole shoes as described in claim 4, characterized in that, Each of the pole shoes has a width equal to the circumferential width of the rotor lamination, and each of the mounting slots has a width equal to the circumferential width of the rotor lamination.

7. The rotor lamination with unevenly distributed pole shoes as described in claim 6, characterized in that, The mounting groove includes a first mounting groove, which is symmetrical with respect to the vertical axis of symmetry. The magnetic shielding groove includes a first magnetic shielding groove, and the first magnetic shielding groove is provided on both sides of the first mounting groove. The central angle corresponding to the first magnetic shielding groove in the rotor lamination is [missing information]. , The value range is 0 < ε ≤ 6°.

8. The rotor lamination with unevenly distributed pole shoes as described in claim 7, characterized in that, The mounting slot further includes a second mounting slot, and the two second mounting slots are symmetrical about the vertical axis of symmetry. The magnetic isolation groove includes a second magnetic isolation groove, which is located at one end of the second mounting groove near the first magnetic isolation groove. The central angle of the second magnetic isolation groove in the rotor lamination is β, and the value of β is in the range of 0<β≤7°.

9. The rotor lamination with unevenly distributed pole shoes as described in claim 8, characterized in that, The magnetic isolation groove includes a third magnetic isolation groove, which is located at the end of the second mounting groove away from the second magnetic isolation groove. The central angle of the third magnetic isolation groove in the rotor lamination is γ, and the value of γ is 0 < γ ≤ 10°.

10. A unipolar motor, characterized in that, The unipolar motor includes rotor laminations with non-uniformly distributed pole shoes as described in any one of claims 1-9.

Images