CN112838729A - Motor assembly and motor - Google Patents

Motor assembly and motor Download PDF

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Publication number
CN112838729A
CN112838729A CN202011603672.3A CN202011603672A CN112838729A CN 112838729 A CN112838729 A CN 112838729A CN 202011603672 A CN202011603672 A CN 202011603672A CN 112838729 A CN112838729 A CN 112838729A
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China
Prior art keywords
stator
rotor
motor
cogging torque
rotors
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CN202011603672.3A
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Chinese (zh)
Inventor
白冰
魏正平
杨静帆
陈家兴
黄积光
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Gree Electric Appliances Inc of Zhuhai
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Gree Electric Appliances Inc of Zhuhai
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Priority to CN202011603672.3A priority Critical patent/CN112838729A/en
Publication of CN112838729A publication Critical patent/CN112838729A/en
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K16/00—Machines with more than one rotor or stator
    • H02K16/02—Machines with one stator and two or more rotors
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K16/00—Machines with more than one rotor or stator
    • H02K16/04—Machines with one rotor and two stators
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K29/00—Motors or generators having non-mechanical commutating devices, e.g. discharge tubes or semiconductor devices
    • H02K29/03—Motors or generators having non-mechanical commutating devices, e.g. discharge tubes or semiconductor devices with a magnetic circuit specially adapted for avoiding torque ripples or self-starting problems
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K2213/00—Specific aspects, not otherwise provided for and not covered by codes H02K2201/00 - H02K2211/00
    • H02K2213/03—Machines characterised by numerical values, ranges, mathematical expressions or similar information

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Permanent Magnet Type Synchronous Machine (AREA)
  • Iron Core Of Rotating Electric Machines (AREA)

Abstract

The application provides a motor element and a motor. The motor assembly comprises a stator and a rotor, wherein the rotor and the stator are arranged in a matching way; the number of the magnetic poles of the two rotors is the same, and the magnetic pole center line of one rotor and the magnetic pole center line of the other rotor at the corresponding position are arranged in a staggered manner; or two stators cooperating with a rotor. Through the generated staggered cogging torque waveforms, the two cogging torque waveforms are mutually offset under a proper dislocation angle, so that the cogging torque can be effectively reduced, even the cogging torque is eliminated, and the vibration absorption and noise reduction of the motor are effectively reduced.

Description

Motor assembly and motor
Technical Field
The application belongs to the technical field of motors, and particularly relates to a motor assembly and a motor.
Background
High performance permanent magnet motors are required to have good smooth performance and high torque performance in low speed operation, however, there is cogging torque generated by interaction between permanent magnets and stator cogging in permanent magnet motors, which causes vibration and noise, and especially at low speed, the system control accuracy is seriously affected. Therefore, the cogging torque, which is one of important issues to be considered in the high-performance permanent magnet motor, has been the focus of research in the permanent magnet motor. The most common method for improving the cogging torque at present is a stator skewed slot or rotor skewed pole, a fractional slot, a method for optimizing the pole arc coefficient of a magnetic pole, an unequal air gap and the like. The methods only can reduce the peak value of the cogging torque and cannot radically eliminate the cogging torque.
Disclosure of Invention
Therefore, an object of the present invention is to provide a motor assembly and a motor capable of eliminating cogging torque.
In order to solve the above problem, the present application provides a motor assembly including:
the rotor and the stator are arranged in a matched mode;
the number of the magnetic poles of the two rotors is the same, and the magnetic pole center line of one rotor and the magnetic pole center line of the other rotor at the corresponding position are arranged in a staggered mode.
Optionally, one of the rotors is arranged at the periphery of the stator, and the other rotor is arranged inside the stator; and winding structures are arranged on the inner surface and the outer surface of the stator.
Optionally, both of the rotors are disposed inside the stator; and a winding structure is arranged on the inner surface of the stator.
Optionally, the winding structures on the inner and outer surfaces of the stator adopt the same winding mode.
Optionally, two of said rotors share an output shaft.
Optionally, the two magnetic pole center lines are staggered by a preset angle, and the preset angle β is:
Figure RE-GDA0002997360170000021
Figure RE-GDA0002997360170000022
wherein N is a polar logarithm, and K is a nonnegative integer.
According to another aspect of the present application, there is provided a motor assembly including:
the rotor and the stator are arranged in a matched mode;
the stator is provided with two, the rotor is provided with one, the tooth's socket of one stator and the tooth's socket of another stator on the corresponding position are dislocation set.
Optionally, the rotor is disposed inside both of the stators.
Optionally, the tooth grooves of the two stators are staggered by a preset angle, and the preset angle β is:
Figure RE-GDA0002997360170000023
wherein N is the number of tooth grooves, and K is a non-negative integer.
According to another aspect of the present application, there is provided an electric machine comprising an electric machine assembly as described above.
The application provides a motor element includes: the rotor and the stator are arranged in a matched mode; the number of the magnetic poles of the two rotors is the same, and the magnetic pole center line of one rotor and the magnetic pole center line of the other rotor at the corresponding position are arranged in a staggered manner; or two stators cooperating with a rotor. Through the generated staggered cogging torque waveforms, the two cogging torque waveforms are mutually offset under a proper dislocation angle, so that the cogging torque can be effectively reduced, even the cogging torque is eliminated, and the vibration absorption and noise reduction of the motor are effectively reduced.
Drawings
Fig. 1 is a schematic structural diagram of a motor assembly according to an embodiment of the present application;
FIG. 2 is a schematic view of another configuration of a motor assembly according to an embodiment of the present application;
FIG. 3 is a third structural schematic diagram of a motor assembly according to an embodiment of the present disclosure;
fig. 4 is a graph comparing cogging torque of a motor assembly of an embodiment of the present application with a conventional structure.
The reference numerals are represented as:
1. an outer rotor; 11. an outer rotor core; 12. an outer rotor magnetic pole; 121. the magnetic pole center line of the outer rotor; 2. An inner rotor; 21. an inner rotor core; 22. an inner rotor magnetic pole; 221. the central line of the magnetic pole of the inner rotor; 3. a stator; 31. a stator core; 32. a stator winding; 4. an inner stator; 41. an inner stator core; 42. and winding of the inner stator.
Detailed Description
Referring collectively to fig. 1-4, according to an embodiment of the present application, an electric machine assembly includes:
the stator 3 and the rotor are arranged in a matching way, and the rotor and the stator 3 are arranged in a matching way;
the number of the rotor is two, the number of the stator 3 is one, the number of the magnetic poles of the two rotors is the same, and the magnetic pole center line of one rotor and the magnetic pole center line of the other rotor at the corresponding position are arranged in a staggered mode.
This application motor element adopts two rotors and a stator 3 to match the use, there is the phase difference through the magnetic pole central line of two rotors, because the magnetic pole number of two rotors is the same, make the tooth's socket torque wave form that a rotor and stator 3 produced like this, it has the phase difference to produce tooth's socket torque wave form with another rotor and stator 3, under suitable phase difference, the crest and the trough of two tooth's socket torques are relative, offset each other, play the effect that reduces tooth's socket torque peak value.
The following two configurations are included for the position arrangement of the two rotors and the stator 3.
Example 1
As shown in fig. 1, one rotor is disposed on the outer periphery of the stator 3, and the other rotor is disposed inside the stator 3; and winding structures are arranged on the inner surface and the outer surface of the stator 3.
The inner surface of the outer rotor iron core 11 is provided with an outer rotor magnetic pole 12 which is matched with a winding structure on the periphery of the stator 3; the outer surface of the inner rotor iron core 21 is provided with an inner rotor magnetic pole 22 which is matched with a winding structure on the inner surface of the stator 3 for use; in order to produce the effect of reducing the cogging torque better, the winding structure on the inner surface and the outer surface of the stator 3 adopts the same winding mode, and the outer rotor 1 and the inner rotor 2 can share the output shaft, and the generated cogging torques are mutually synthesized.
The stator 3 includes stator windings 32 wound in slots of a stator core 31.
Example 2
As shown in fig. 2, both rotors are provided inside the stator 3; and a winding structure is arranged on the inner surface of the stator 3.
The outer surface of the outer rotor iron core 11 is provided with an outer rotor magnetic pole 12, the outer surface of the inner rotor iron core 21 is provided with an inner rotor magnetic pole 22, and the outer rotor magnetic pole and the inner rotor magnetic pole are all matched with a winding structure on the inner surface of the stator 3 for use; the number of the magnetic poles of the two rotors is the same, the two rotors deviate from a fixed angle, and only the inner surface of the stator 3 is provided with a winding structure to provide a three-phase rotating magnetic field. The stator 3 provides the same magnetic field for the two rotors, different cogging torque waveforms are generated due to different corresponding angles between the magnetic poles on the two rotors and the stator winding 32, and the peak value of the resultant cogging torque is obviously reduced at a proper angle.
Wherein the two rotors share an output shaft.
Based on the two examples above, the analysis was performed in combination with the energy method as follows:
the cogging torque is the derivative of the magnetic common energy inside the permanent magnet motor relative to the position angle of the rotor, and the magnetic energy of the motor is equal to the magnetic common energy when the nonlinearity is not considered. The magnetic energy of the air gap between the stator and the rotor can be approximately expressed as the following formula (1):
Figure RE-GDA0002997360170000041
wherein alpha is the rotor position angle, theta is the rotor rotation angle, W (alpha) is the air gap magnetic energy, mu0For vacuum permeability, B (theta, alpha) is the distribution function of air gap flux density along the armature surface, and L is the coreAxial length, R1And R2Rotor outer diameter and stator inner diameter, G (theta) is the modulation function of air gap flux density affected by stator slotting, BrAnd (theta, alpha) is a distribution function of the remanence of the permanent magnet along the surface of the armature. G2(theta) and
Figure RE-GDA0002997360170000042
the fourier expansion of (a) is the following equation (2) and equation (3), respectively:
Figure RE-GDA0002997360170000043
Figure RE-GDA0002997360170000044
wherein G isanAnd GbnIs G2Fourier coefficient of (theta), BanAnd BbnIs composed of
Figure RE-GDA0002997360170000045
Coefficient of Fourier decomposition, NsIs the number of slots of the stator of the motor, NpThe number of pole pairs of the motor is shown. Substituting the formula (2) and the formula (3) into the formula (1) and obtaining the derivation of the rotor position angle alpha to obtain a general formula (4) of the cogging torque:
Figure RE-GDA0002997360170000051
when the deflection angle of the magnetic pole center lines of the inner rotor and the outer rotor is beta, the cogging torque of the outer rotor and the stator is expressed by a formula (5):
Figure RE-GDA0002997360170000052
the cogging torque of the inner rotor and the stator is formula (6):
Figure RE-GDA0002997360170000053
the resultant cogging torque is formula (7):
Figure RE-GDA0002997360170000054
when in use
Figure RE-GDA0002997360170000055
The cogging torque is given by equation (8):
Figure RE-GDA0002997360170000056
from the above equation (8), when
Figure RE-GDA0002997360170000057
T (α) is 0, i.e.
Figure RE-GDA0002997360170000058
When k is a non-negative integer, cogging torque is minimal. Considering that the harmonic has less influence on the cogging torque amplitude, only considering the cogging torque under the action of the fundamental wave, and taking n as 1, the method is obtained
Figure RE-GDA0002997360170000059
That is, when
Figure RE-GDA00029973601700000510
When (e.g. as
Figure RE-GDA00029973601700000511
Etc.), the cogging torque is theoretically analyzed to be equal to 0.
According to another aspect of the present application, there is provided a motor assembly including:
the stator and the rotor are arranged in a matching way, and the rotor and the stator 3 are arranged in a matching way;
the number of the stators is two, one of the stators is an inner stator 4, and the other stator 3 is an outer stator; the tooth grooves of the stator 3 and the tooth grooves of the inner stator 4 at the corresponding positions are arranged in a staggered mode.
This application motor element adopts two stators and a rotor to match the use, and there is the phase difference in the tooth's socket through two stators, makes the tooth's socket torque wave form that stator 3 and rotor produced like this, and it has the phase difference to produce tooth's socket torque wave form with inner stator 4 and rotor, and under suitable phase difference, the crest and the trough of two tooth's socket torques are relative, offset each other, play the effect that reduces tooth's socket torque peak value.
The number of tooth slots of the two stators can be the same or different. The inner stator 4 is formed by winding an inner stator winding 42 in a tooth slot of an inner stator core 41.
Example 3
The cogging torque generated by the interaction of the rotor and the two stators is mutually synthesized, and the effect of weakening the cogging torque is achieved, as shown in fig. 3. Under the structure, the tooth grooves of the two stators are staggered, and the number of the tooth grooves is increased for the stator combined by the inner stator and the outer stator. Formula (9) is analyzed from the cogging torque:
Figure RE-GDA0002997360170000061
wherein z is the number of grooves, 2p is the number of poles, and n is an integer such that nz/2p is an integer. In the range of changing the relative position of the stator and the rotor by one tooth pitch, the cogging torque is periodically changed, and the period number is changed by the ratio of the number of poles, the number of slots and the greatest common divisor of the number of poles, namely
Figure RE-GDA0002997360170000062
Wherein N ispGCD (z,2p) represents the greatest common divisor of the slot number z and the pole number 2p for the number of cogging torque cycles. Cogging torque amplitude is mainly dependent on B'an，B′anAnd the number of cycles NPInversely proportional, the greater the number of cycles, the corresponding B'anThe smaller and thus the smaller the cogging torque magnitude. Under the condition of no change of the pole number of the motor, the motor can be used for driving the motor to rotate when the motor rotates inside and outsideThe number of stator slots combined in the stator is increased so that the GCD (z,2p) is smaller than that of a single stator (for example, when the greatest common divisor of the number of stator slots and the number of rotor poles is 1), NpRelatively increased, B'anThe peak value of the cogging torque can be effectively reduced by relatively reducing the cogging torque.
According to a further aspect of the present application, there is provided an electric machine comprising an electric machine assembly as described above.
The motor structure adopting the motor components of the three embodiments is compared with the original scheme structure of the traditional motor by testing, and the cogging torque distribution diagram of the motor is simulated, as shown in fig. 4. As can be seen, there is a significant reduction in cogging torque for all three configurations of the present application.
It is easily understood by those skilled in the art that the above embodiments can be freely combined and superimposed without conflict.
The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application. The foregoing is only a preferred embodiment of the present application, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present application, and these modifications and variations should also be considered as the protection scope of the present application.

Claims (10)

1. An electric machine assembly, comprising:
the stator (3) and the rotor are arranged in a matching way;
the number of the magnetic poles of the two rotors is the same, and the magnetic pole center line of one rotor and the magnetic pole center line of the other rotor at the corresponding position are arranged in a staggered mode.
2. A motor assembly according to claim 1, characterized in that one of said rotors is arranged at the periphery of said stator (3) and the other rotor is arranged inside said stator (3); and winding structures are arranged on the inner surface and the outer surface of the stator (3).
3. A motor assembly according to claim 1, characterized in that both of said rotors are arranged inside said stator (3); and a winding structure is arranged on the inner surface of the stator (3).
4. A motor assembly according to claim 2 or 3, characterised in that the winding structures on the inner and outer surfaces of the stator (3) are wound in the same manner.
5. A motor assembly according to any one of claims 1 to 4, in which two of the rotors share an output shaft.
6. The electric machine assembly according to claim 1, wherein the two pole centerlines are offset by a predetermined angle, the predetermined angle β being:
Figure FDA0002871436780000011
wherein N is a polar logarithm, and K is a nonnegative integer.
7. An electric machine assembly, comprising:
the stator (3) and the rotor are arranged in a matching way;
the stator (3) is provided with two, the rotor is provided with one, one tooth slot of the stator (3) is arranged in a staggered mode with the other tooth slot of the stator (3) in the corresponding position.
8. An electric machine assembly according to claim 7, characterized in that the rotor is arranged inside both stators (3).
9. An electric machine assembly according to claim 7 or 8, characterized in that the slots of the two stators (3) are staggered by a preset angle β:
Figure FDA0002871436780000012
wherein N is the number of tooth grooves, and K is a non-negative integer.
10. An electrical machine comprising an electrical machine assembly according to any one of claims 1 to 9.
CN202011603672.3A 2020-12-30 2020-12-30 Motor assembly and motor Pending CN112838729A (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108448849A (en) * 2018-02-27 2018-08-24 江苏大学 A kind of stator permanent magnetic type birotor magnetic field modulation motor and its design method
CN209375272U (en) * 2018-10-31 2019-09-10 浙江大学 A kind of Double-stator motor of ectonexine permanent magnet dislocation
CN110798037A (en) * 2019-12-05 2020-02-14 歌尔股份有限公司 Permanent magnet synchronous motor
CN111064332A (en) * 2020-01-08 2020-04-24 武汉理工大学 Bilateral Halbach alternate pole type permanent magnet vernier motor

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108448849A (en) * 2018-02-27 2018-08-24 江苏大学 A kind of stator permanent magnetic type birotor magnetic field modulation motor and its design method
CN209375272U (en) * 2018-10-31 2019-09-10 浙江大学 A kind of Double-stator motor of ectonexine permanent magnet dislocation
CN110798037A (en) * 2019-12-05 2020-02-14 歌尔股份有限公司 Permanent magnet synchronous motor
CN111064332A (en) * 2020-01-08 2020-04-24 武汉理工大学 Bilateral Halbach alternate pole type permanent magnet vernier motor

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