Motor, compressor and household appliance

Abstract

The present invention provides a motor, compressor, and household appliance, wherein an air gap is formed between the stator and rotor of the motor. The stator is cross-sectioned perpendicular to the stator axis. In the cross-section, the contour line of the end of the stator tooth facing the rotor includes a first arc segment and first and second segments located on either side of the first arc segment. The motor proposed in the present invention modifies the width of the air gap by configuring the contour of the stator tooth facing the rotor to comprise a first segment, a first arc segment, and a second segment connected in sequence. This modifies the width of the air gap, thereby varying the width of the entire air gap and thereby changing the air gap magnetic flux density. The harmonic magnetic flux density that primarily generates radial electromagnetic force in the air gap magnetic field is weakened through self-coupling and mutual coupling, thereby preventing the main harmonic magnetic flux density that generates radial electromagnetic force from superimposing in the same direction. This reduces the radial electromagnetic force acting on the stator and rotor of the motor, thereby reducing the radial electromagnetic noise of the motor.

Description

Technical Field

[0001] The present invention relates to the field of motors, and in particular to a motor, a compressor and a household appliance. Background Art

[0002] In the related art, built-in brushless DC motors are widely used in household appliance motors due to their simple structure, high reliability, and high power density due to their tangential rotor pole structure. However, due to their high rotor power density, the coupling between the stator and rotor magnetic fields is enhanced, resulting in a high harmonic content in the motor's air gap magnetic field. This leads to large radial electromagnetic forces, especially prominent low-order electromagnetic forces in space. Therefore, it is particularly important to find appropriate methods to reduce the 4th harmonic electromagnetic force excited by the harmonic magnetic field without excessively sacrificing motor performance. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the existing or improved technology.

[0004] To this end, a first aspect of the present invention provides a motor.

[0005] A second aspect of the present invention provides a compressor.

[0006] A third aspect of the present invention provides a household appliance.

[0007] In view of this, according to a first aspect of the present invention, the present invention proposes a motor, comprising: a stator, the stator comprising a through hole and a plurality of stator teeth; a rotor, arranged in the through hole, the rotor comprising a plurality of sector-shaped portions, the stator teeth and the sector-shaped portions being arranged opposite to each other, wherein the stator is cross-sectioned in a direction perpendicular to the axis of the stator, and in the cross-section, the contour line of the end of the stator tooth facing the rotor comprises a first arc segment and a first segment and a second segment located on both sides of the first arc segment.

[0008] The motor proposed in this invention comprises a stator and a rotor. The stator has multiple stator teeth on its inner side, and the rotor has multiple sectors on its outer side, with the multiple stator teeth and sectors facing each other. Windings are then provided on the stator, and magnetic components are placed on the sectors. These two components generate a rotating magnetic field, driving the rotor.

[0009] In addition, the stator tooth profile and the profile of the opposite rotor sector will cause the fundamental magnetic flux and other high-order harmonic magnetic flux (collectively referred to as harmonic magnetic flux) in the air gap formed between the stator and the rotor, which will generate radial electromagnetic forces on the stator and rotor through self-coupling and mutual coupling.

[0010] Furthermore, the present invention cross-sections the stator perpendicular to the stator axis. In this cross-section, the profile of the stator teeth facing the rotor is configured as a first segment, a first arc segment, and a second segment connected in sequence. This changes the width of the air gap, and the entire air gap width is varied, thereby changing the air gap magnetic flux density. When the rotor rotates, the harmonic magnetic flux density that primarily generates radial electromagnetic force in the air gap magnetic field is weakened through self-coupling and mutual coupling, thereby preventing the main harmonic magnetic flux density that generates radial electromagnetic force from superimposing in the same direction, reducing the radial electromagnetic force on the motor stator and rotor, and thus reducing the radial electromagnetic noise of the motor.

[0011] In addition, the motor in the above technical solution proposed by the present invention may also have the following additional technical features:

[0012] In the above technical solution, further, one end of the first segment connected to the first arc segment is closer to the rotor than the other end of the first segment, and one end of the second segment connected to the first arc segment is closer to the rotor than the other end of the second segment.

[0013] In this technical solution, when the rotor rotates, the air gap when entering the stator teeth is larger, and the increase in the air gap will increase the magnetic circuit voltage drop on the air gap side, thereby reducing the magnetic saturation at this location, reducing the superposition of harmonic magnetic flux in the same direction, reducing the radial electromagnetic force on the motor stator and rotor, and thereby reducing the radial electromagnetic noise of the motor.

[0014] In any of the above technical solutions, the rotor is further cross-sectioned in a direction perpendicular to the axis of the rotor. In the cross-section, the contour line of the end of the sector portion facing the stator includes: a second arc segment and a first curved segment and a second curved segment located on both sides of the second arc segment.

[0015] In this technical solution, the rotor is sectioned perpendicular to the stator axis. In the section, the profile of the rotor's sector-shaped portion facing the stator is configured as a first curved segment, a second circular arc, and a second curved segment connected in sequence, further changing the width of the air gap. As the rotor rotates, because the stator teeth include a first and second segment, and the sector-shaped portion has three curved segments, the change in the entire air gap is greater, and the harmonic flux density that primarily generates the radial electromagnetic force is more significantly weakened. This prevents the main harmonic flux density that generates the radial electromagnetic force from superimposing in the same direction, reduces the radial electromagnetic force on the stator and rotor, and thus reduces the radial electromagnetic noise of the motor.

[0016] In any of the above technical solutions, further, the first segment and the second segment on the stator tooth are symmetrically arranged with the center line of the first arc segment as the symmetry axis; the first curved segment and the second curved segment on the fan-shaped portion are symmetrically arranged with the center line of the second arc segment as the symmetry axis.

[0017] In this technical solution, the first section and the second section on the same stator tooth are symmetrically arranged with the center line of the first arc section as the axis of symmetry, and the first curved section and the second curved section on the same sector are symmetrically arranged with the center line of the second arc section as the axis of symmetry, so that the clockwise rotation and counterclockwise rotation of the rotor can achieve the same effect, so that the motor can become a bidirectional rotation motor.

[0018] In any of the above technical solutions, further, the first section includes at least one straight line and / or at least one curved line; and / or the second section includes at least one straight line and / or at least one curved line.

[0019] In this technical solution, the first segment may include any of the following situations: a straight line, a curve, a straight line and a curve, a straight line and multiple curves, multiple straight lines and a curve, or multiple straight lines and multiple curves.

[0020] The second segment can include any of the following: a straight line, a curve, a straight line and a curve, a straight line and multiple curves, multiple straight lines and a curve, or multiple straight lines and multiple curves.

[0021] In any of the above technical solutions, further, based on the situation that the first segment includes a straight line and the second segment includes a straight line, the stator is cross-sectioned in a direction perpendicular to the axis of the stator. In the cross-section, the complementary angle of the acute angle formed between the center line of the first segment and the center line of the first arc segment is greater than or equal to 0° and less than or equal to the quotient of the center angle of the stator and the pole slot matching factor, wherein the pole slot matching factor is one-fourth of the product of the number of stator teeth and the number of sector portions.

[0022] In this technical solution, by limiting the relative angle between the first section and the second section as mentioned above, the back electromotive force distortion of the motor can be kept at a lower level, thereby achieving the purpose of reducing the tangential electromagnetic vibration of the motor, improving electromagnetic noise, and increasing the power density of the motor.

[0023] In any of the above technical solutions, the stator is further cross-sectioned in a direction perpendicular to the axis of the stator. On the cross-section, the center angle of the second arc segment is greater than or equal to the quotient of the center angle of the stator and the pole-slot matching factor, and less than or equal to 2 times the quotient of the center angle of the stator and the pole-slot matching factor.

[0024] In this technical solution, by limiting the center angle of the second arc segment, the setting positions of the first curved segment and the second curved segment are indirectly limited, thereby limiting the degree of change of the air gap, and thus limiting the weakening of the radial electromagnetic force to a better range.

[0025] In any of the above technical solutions, further, a stator slot is formed between two adjacent stator teeth, and the stator is cross-sectioned in a direction perpendicular to the axis of the stator. In the cross-section, the slot width of the stator slot is h, the slot height of the stator slot is b, and the length of the first section is L, where L is greater than or equal to The minimum of and h, less than or equal to The maximum of 2h and 2h.

[0026] In this technical solution, by limiting the lengths of the first and second sections as mentioned above, the tangential torque pulsation and core loss of the motor can be reduced, thereby achieving the purpose of reducing the tangential electromagnetic vibration of the motor, improving electromagnetic noise, and increasing the power density of the motor.

[0027] In any of the above technical solutions, further, an air gap is formed between the stator and the rotor, and the stator is cross-sectioned in a direction perpendicular to the axis of the stator. On the cross-section, the ratio of the maximum value of the air gap to the minimum value of the air gap is greater than or equal to 1.62 and less than or equal to 3.5.

[0028] In this technical solution, the ratio of the minimum air gap to the maximum air gap is limited to rationalize the Castiglione coefficient, increase the power density of the motor, and enhance the performance of the motor.

[0029] In any of the above technical solutions, further, it also includes: a winding provided on the stator; and a magnetic component provided on the rotor.

[0030] In this technical solution, windings are provided on the stator and magnetic components are provided on the rotor. The two can generate a rotating magnetic field to drive the rotor to rotate.

[0031] According to a second aspect of the present invention, the present invention provides a compressor, comprising: a motor as provided in any one of the above technical solutions.

[0032] The compressor proposed in the present invention includes the motor proposed in any one of the above technical solutions, and therefore has all the beneficial effects of the motor proposed in any one of the above technical solutions, which will not be listed one by one here.

[0033] According to a third aspect of the present invention, the present invention provides a household appliance, comprising: a motor as provided in any one of the above technical solutions; or a compressor as provided in any one of the above technical solutions.

[0034] The household appliance proposed in the present invention includes a motor as proposed in any one of the above technical solutions; or a compressor as proposed in any one of the above technical solutions. Therefore, it has all the beneficial effects of the motor as proposed in any one of the above technical solutions; or the compressor as proposed in any one of the above technical solutions, which are not listed one by one here.

[0035] Additional aspects and advantages of the invention will become apparent from the description which follows, or may be learned by practice of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0037] Figure 1 A schematic structural diagram of a motor provided by one embodiment of the present invention is shown;

[0038] Figure 2 A schematic structural diagram of stator teeth in a motor provided by one embodiment of the present invention is shown;

[0039] Figure 3 A schematic structural diagram of a fan-shaped portion and a magnetic component in a motor provided by one embodiment of the present invention is shown;

[0040] Figure 4 A schematic diagram showing the structure of a notch in a motor provided by one embodiment of the present invention is shown;

[0041] Figure 5 A schematic structural diagram of stator teeth in a motor provided by one embodiment of the present invention is shown;

[0042] Figure 6 A diagram showing a corresponding relationship between a complementary angle α1 of an acute angle formed between a first segment and a center line of a first arc segment of a motor provided by one embodiment of the present invention and a peak value of a cogging torque;

[0043] Figure 7 A diagram showing the corresponding relationship between the length of the first section and the peak value of the cogging torque in a motor provided by one embodiment of the present invention;

[0044] Figure 8 A diagram showing the corresponding relationship between the center angle of the second arc segment and the quadruple frequency electromagnetic force in a motor provided by one embodiment of the present invention;

[0045] Figure 9 A diagram showing the corresponding relationship between electromagnetic force and magnetic flux density of a motor provided by an embodiment of the present invention and a motor in related art under the same air gap;

[0046] Figure 10 A graph showing the corresponding relationship between the ratio of the maximum value δmax of the air gap to the minimum value δmin of the air gap and the motor loss in a motor provided by one embodiment of the present invention is shown.

[0047] in, Figures 1 to 5 The corresponding relationship between the reference numerals and component names is as follows:

[0048] 100 motor, 110 stator, 112 stator teeth, 114 first segment, 116 first arc segment, 118 second segment, 120 rotor, 122 sector, 124 second arc segment, 126 first curved segment, 128 second curved segment, 140 winding, 150 magnetic member, 160 slot. DETAILED DESCRIPTION

[0049] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present invention and the features therein can be combined with each other without conflict.

[0050] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0051] Refer to the following Figures 1 to 10 The motor 100 and the compressor provided according to some embodiments of the present invention are described.

[0052] Example 1

[0053] like Figure 1 、 Figure 2 and Figure 5 As shown, the present invention provides a motor 100 including a stator 110 and a rotor 120 .

[0054] The stator 110 is provided with a through hole, the rotor 120 is disposed in the through hole, the stator 110 is provided with a plurality of stator teeth 112 facing the rotor 120 , and the rotor 120 is provided with a plurality of sector portions 122 facing the stator 110 .

[0055] The stator 110 is cross-sectioned in a direction perpendicular to the axis of the stator 110 . In the cross-section, the multiple stator teeth 112 have the same profile. The side of the stator tooth 112 facing the rotor 120 includes a first segment 114 , a first circular arc segment 116 , and a second segment 118 connected in sequence.

[0056] The motor 100 provided by the present invention has an air gap formed between the stator 110 and the rotor 120. A winding 140 can be disposed between two adjacent stator teeth 112 of the stator 110, and a magnetic element 150 can be disposed between two adjacent sectors 122 of the rotor 120. The magnetic element 150 generates magnetic flux in the air gap, which interacts with the magnetic flux generated by the winding 140 when power is applied to drive the rotor 120 to rotate. A gap, i.e., an air gap, must exist between the rotor 120 and the stator 110 to ensure normal rotation of the rotor 120.

[0057] In addition, the outline of the stator teeth 112 and the outline of the sector portion 122 of the rotor 120 facing it will cause the fundamental magnetic flux and other high-order harmonic magnetic flux (collectively referred to as harmonic magnetic flux) in the air gap, which will generate radial electromagnetic forces on the stator 110 and the rotor 120 through self-coupling and mutual coupling.

[0058] Furthermore, the present invention cross-sections the stator 110 in a direction perpendicular to the axis of the stator 110. In the cross-section, the profile of the stator teeth 112 of the stator 110 facing the rotor 120 is configured as a first segment 114, a first arc segment, and a second segment 118 connected in sequence. This changes the width of the air gap, and the width of the entire air gap varies, thereby changing the air gap flux density. When the rotor 120 rotates, the air gap flux density at each position is dynamic. When the rotor 120 rotates, the harmonic flux density that primarily generates the radial electromagnetic force is weakened through self-coupling and mutual coupling, thereby preventing the main harmonic flux density that generates the radial electromagnetic force from superimposing in the same direction, reducing the radial electromagnetic force on the stator 110 and rotor 120, and thus reducing the noise of the motor 100.

[0059] Specifically, the first segment may include any of the following situations: a straight line segment, a curved line segment, a straight line segment and a curved line segment, a straight line segment and multiple curved lines segment, multiple straight lines segment and a curved line segment, or multiple straight lines segment and multiple curved lines segment.

[0060] The second segment can include any of the following: a straight line, a curve, a straight line and a curve, a straight line and multiple curves, multiple straight lines and a curve, or multiple straight lines and multiple curves.

[0061] Among them, the first section and the second section are both straight lines, which can make the change of the air gap a gradual change, make the change of the air gap magnetic density more reasonable, avoid jumping changes, and further ensure the reduction of radial force.

[0062] More specifically, the curve is an arc line.

[0063] Example 2:

[0064] like Figure 2 As shown, based on Example 1, further, the end of the first segment 114 away from the first arc segment 116 is farther away from the rotor 120 than the end connected to the first arc segment 116, and the end of the second segment 118 away from the first arc segment 116 is farther away from the rotor 120 than the end connected to the first arc segment 116.

[0065] In this embodiment, the stator teeth 112 form a cut-edge structure on the side facing the rotor 120, so that when the rotor 120 rotates, the air gap entering the stator teeth 112 is larger. The increase in the air gap will increase the magnetic circuit voltage drop on the air gap side, thereby reducing the magnetic saturation at this location, further reducing the superposition of harmonic magnetic flux in the same direction, reducing the radial electromagnetic force on the stator 110 and rotor 120 of the motor 100, and thereby reducing the radial electromagnetic noise of the motor 100.

[0066] Example 3:

[0067] like Figure 3 As shown, on the basis of Example 1 or Example 2, the rotor 120 is further cross-sectioned in a direction perpendicular to the axis of the rotor 120. In the cross-section, the contour of the fan-shaped portion 122 facing the stator 110 includes a first curved segment 126, a second arc segment 124 and a second curved segment 128 in sequence.

[0068] Furthermore, the center O of the second arc segment 124 is located on the axis of the rotor 120 .

[0069] In this embodiment, the rotor 120 is cross-sectioned perpendicular to the axis of the stator 110. In the cross-section, the contour of the sector 122 of the rotor 120 facing the stator 110 is configured as a first curved segment 126, a second circular arc, and a second curved segment 128, which are connected in sequence. This further changes the width of the air gap. Consequently, when the rotor 120 rotates, because the stator teeth 112 include a first segment 114 and a second segment 118, and the sector 122 has three curved segments, the change in the entire air gap is greater, which more significantly weakens the harmonic flux density that primarily generates the radial electromagnetic force. This prevents the primary harmonic flux density that generates the radial electromagnetic force from superimposing in the same direction, reduces the radial electromagnetic force acting on the stator 110 and rotor 120, and thus reduces the radial electromagnetic noise of the motor 100.

[0070] Example 4:

[0071] like Figures 1 to 5 As shown, based on any one of Examples 1 to 3, further, the first segment 114 and the second segment 118 on the stator tooth 112 are symmetrically arranged with the center line of the first arc segment 116 as the symmetry axis.

[0072] In this embodiment, the first segment 114 and the second segment 118 on the same stator tooth 112 are symmetrically arranged with the center line of the first arc segment 116 as the symmetry axis, so that the clockwise rotation and counterclockwise rotation of the rotor 120 can achieve the same effect, making the motor 100 a bidirectional rotation motor 100.

[0073] Example 5:

[0074] like Figures 1 to 5 As shown, based on any one of Examples 1 to 4, further, the first curved segment 126 and the second curved segment 128 on the sector portion 122 are symmetrically arranged with the center line of the second arc segment 124 as the symmetry axis.

[0075] In this embodiment, the first curved segment 126 and the second curved segment 128 on the same sector 122 are symmetrically arranged with the center line of the second arc segment 124 as the symmetry axis, so that the clockwise rotation and counterclockwise rotation of the rotor 120 can achieve the same effect, making the motor 100 suitable for bidirectional rotation.

[0076] Example 6:

[0077] like Figure 2 As shown, based on any one of Examples 1 to 6, the stator 110 is further cross-sectioned in a direction perpendicular to the axis of the stator 110. In the cross-section, the complementary angle α1 of the acute angle formed between the center line of the first segment 114 and the center line of the first arc segment 116 is greater than or equal to 0° and less than or equal to the quotient of the center angle of the stator 110 (360°) and the pole-slot matching factor, wherein the pole-slot matching factor is one-fourth of the product of the number Z of the stator teeth 112 and the number 2p of the sector portions 122.

[0078] That is, 0°≤α1≤360°÷(p×Z÷2).

[0079] In this embodiment, Figure 6 As shown, taking the number of stator teeth 112 as 12 and the number of sector portions 122 as 8, that is, Z=12, 2p=8, as an example, the value range of α1 is 0°≤α1≤15°, and as the complementary angle α1 of the angle between the center line of the first segment 114 and the first arc segment 116 gradually increases, the back-electromotive force distortion first decreases and then increases, and when α1 satisfies 0≤α1≤360°÷(p×Z÷2), the back-electromotive force distortion rate is at a relatively low level, thereby achieving the purpose of reducing the tangential electromagnetic vibration of the motor 100, improving the electromagnetic noise, and increasing the power density of the motor 100.

[0080] Specifically, since the first segment 114 and the second segment 118 are symmetrically arranged with respect to the center line of the first arc segment 116, the complementary angle of the acute angle formed between the second segment 118 and the center line of the first arc segment 116 is also α1, which also conforms to 0°≤α1≤360°÷(p×Z÷2), and will not be elaborated here.

[0081] Moreover, according to the basic electromagnetic relationship within the motor 100, the interaction between the harmonics in the back electromotive force and the fundamental wave and harmonics of the current is the source of the ripple torque of the motor 100. Combined with the cogging torque calculation formula, the change in the magnetic field energy in the air gap is the reason for the cogging torque of the motor 100. The combined action of the cogging torque and the ripple torque forms the tangential torque pulsation of the motor 100. Therefore, by limiting the angle formed by the center line of the first segment 114 and the first circular arc segment 116 (the center line of the second segment 118 and the first circular arc segment 116), the magnetic field energy can be greatly changed at the slot position by changing the slot magnetic permeability, while avoiding more serious distortion of the air gap magnetic field, thereby avoiding a large distortion of the back electromotive force.

[0082] Example 7:

[0083] like Figure 3 As shown, on the basis of any one of Examples 1 to 6, the stator 110 is further cross-sectioned in a direction perpendicular to the axis of the stator 110. In the cross-section, the center angle α2 of the second arc segment 124 is greater than or equal to the quotient of the center angle of the stator 110 (360°) and the pole slot matching factor, and is less than or equal to 2 times the quotient of the center angle of the stator 110 and the pole slot matching factor, wherein the pole slot matching factor is one-fourth of the product of the number Z of the stator teeth 112 and the number 2p of the sector portions 122.

[0084] That is, 360°÷(p×Z÷2)≤α2≤2×360°÷(p×Z÷2).

[0085] In this embodiment, Figure 8 As shown, taking the example that the number of stator teeth 112 is 12 and the number of sector portions 122 is 8, the value range of α2 is 15°≤α2≤30°, and, as α2 gradually increases, the 4th-harmonic frequency electromagnetic force tends to first increase and then decrease, and, at 360°÷(p×Z÷2)≤α2≤2×360°÷(p×Z÷2), the 4th-harmonic frequency electromagnetic force is at a lower level, thereby further reducing the superposition of harmonic magnetic flux in the same direction, reducing the radial electromagnetic force on the stator 110 and the rotor 120 of the motor 100, and thereby reducing the radial electromagnetic noise of the motor 100.

[0086] Specifically, based on the fundamental principles of electromagnetic fields within motor 100, the self-coupling and mutual coupling of the harmonics within the air gap flux density are the fundamental causes of the radial electromagnetic force. Electromagnetic analysis results show that the generation of the quadruple-frequency electromagnetic force is closely related to harmonic flux density with a temporal order difference of 4. To reduce the amplitude of harmonic flux density with a temporal order difference of 4 (a frequency of 4), the authors propose a method for reducing the amplitude of harmonic flux density with a temporal order difference of 4.

[0087] In this embodiment, the center angle corresponding to the second arc segment 124 is limited to be greater than or equal to the quotient of the center angle of the inner diameter of the stator 110 and the pole slot matching factor, and less than or equal to twice the quotient of the center angle of the inner diameter of the stator 110 and the pole slot matching factor, that is, 360°÷(p×Z÷2)≤α2≤2×360°÷(p×Z÷2), thereby keeping the 4th-harmonic frequency electromagnetic force at a relatively low level.

[0088] like Figure 8 As shown, taking the example that the number of stator teeth 112 is 12 and the number of sector portions 122 is 8, that is, Z=12, 2p=10, 360°÷(p×Z÷2)≤α2≤2×360°÷(p×Z÷2), that is, 12°≤α2≤24°.

[0089] In one of the embodiments calculated in this embodiment, the 4th harmonic frequency radial force gradually increases as the center angle α2 corresponding to the second arc segment 124 increases, and the 4th order electromagnetic force shows a trend of first increasing and then decreasing.

[0090] The effects of different outer contour shapes of the sector portion 122 of the rotor 120 on the 4th harmonic frequency electromagnetic force are calculated through experimental and simulation analysis, and the calculation shows that.

[0091] When 12°≤α2≤24°, the quadruple frequency electromagnetic force of the motor 100 is relatively low, thereby ensuring a low vibration level of the motor 100 and reducing the noise of the motor 100.

[0092] Example 8:

[0093] like Figure 4 As shown, based on any one of Examples 1 to 7, further, a stator slot is formed between two adjacent stator teeth 112, and the stator 110 is cross-sectioned in a direction perpendicular to the axis of the stator 110. In the cross-section, the width h of the slot opening 160 of the stator slot, the height b of the slot opening 160 of the stator slot, and the length L of the first section 114 satisfy that L is greater than or equal to The minimum of and h, less than or equal to The maximum of 2h and 2h.

[0094] Right now Specifically, for The minimum of the two, for The maximum of 2h and 2h.

[0095] For example: b = 1mm, h = 1mm, then The value of L is between 0.25mm and 2mm.

[0096] b=2mm,h=0.5mm,then The value of L is between 0.5mm and 2mm.

[0097] In this embodiment, Figure 7 As shown, the cogging torque in the motor 100 decreases first and then increases as the length L of the first section 114 and the second section 118 gradually increases, and when L is within a range, the cogging torque is at a relatively low level.

[0098] Specifically, the value range of L can be 1.5 mm to 2.5 mm, and further, 2.2 mm.

[0099] In addition, the change in the length L of the first section 114 and the second section 118 changes the air gap permeability and the magnetic field energy in the stator slot area, thereby improving the back EMF distortion rate and cogging torque of the motor.

[0100] Example 9:

[0101] like Figure 5 As shown, on the basis of any one of Examples 1 to 7, an air gap is further formed between the stator 110 and the rotor 120, and the stator 110 is cross-sectioned in a direction perpendicular to the axis of the stator 110. On the cross-section, the ratio of the maximum value δmax of the air gap to the minimum value δmin of the air gap is greater than or equal to 1.62 and less than or equal to 3.5.

[0102] That is, since the side of the stator tooth 112 facing the sector portion 122 has the first segment 114, the first arc segment 116, and the second segment 118, and the side of the sector portion 122 facing the stator tooth 112 has the first curved segment 126, the second arc segment 124, and the second curved segment 128, the air gap between the stator 110 and the rotor 120 varies.

[0103] Among them, 1.62≤δmax÷δmin≤3.5.

[0104] In this embodiment, the ratio of the minimum air gap to the maximum air gap is limited to rationalize the Castor coefficient, thereby increasing the power density of the motor 100 and improving the performance of the motor 100 .

[0105] Specifically, motor efficiency is closely related to loss. For the motor 100 provided by the present invention, the main body loss of the motor 100 mainly includes the copper loss and iron core loss of the motor 100. The present invention can change the proportional distribution of copper loss and iron loss in different operating conditions of the motor 100 by changing the ratio of the maximum value δmax and the minimum value δmin of the air gap, thereby resulting in the optimal ratio of copper loss to iron loss when the motor 100 operates in different working conditions, thereby achieving the purpose of improving the operating efficiency of the motor 100.

[0106] Specifically, if Figure 10As shown in FIG. 1 , in the present invention, the core loss changes with the ratio of the maximum air gap value δmax to the minimum air gap value δmin. As the ratio of the maximum air gap value δmax to the minimum air gap value δmin gradually increases, the core loss gradually decreases. As the ratio of the maximum air gap value δmax to the minimum air gap value δmin gradually increases, the back electromotive force gradually decreases. However, the loss of the winding 140 gradually increases, resulting in the total loss of the motor 100 first decreasing and then increasing. The efficiency of the motor 100 increases as the loss decreases.

[0107] In this embodiment, the motor 100 rotates at a relatively high speed, and the core loss of the stator 110 accounts for the main component of the loss of the motor 100. Reducing the core loss of the motor 100 is a more effective means to improve the efficiency of the motor 100. Therefore, the ratio of the maximum value of the air gap δmax to the minimum value of the air gap δmin is limited to between 1.62 and 3.5, thereby controlling the core loss and the loss of the winding 140 to a relatively low range, thereby controlling the total loss of the motor 100 to a low level, and improving the efficiency of the motor 100 to a relatively high level.

[0108] Further, if Figure 9 As shown, the air gap parameter in this application is the maximum value of the air gap δmax.

[0109] Specifically, when the 4-fold frequency electromagnetic force is maintained at 1700 N / m 2 The fundamental magnetic flux density of the conventional method is 0.45T, while the fundamental magnetic flux density of the method of reducing the electromagnetic force by 4 times the frequency of the present invention is 0.50T, which is an increase of 11.1% in fundamental magnetic flux density. Correspondingly, the no-load back electromotive force is increased by 11.1%, thereby improving the efficiency of the motor 100.

[0110] Example 10:

[0111] like Figure 1 and Figure 5 As shown, based on any one of Examples 1 to 9, further comprising: a winding 140 provided on the stator 110 ; and a magnetic component 150 provided on the rotor 120 .

[0112] In this embodiment, a winding 140 is provided on the stator 110, and a magnetic member 150 is provided on the rotor 120. The two can generate a rotating magnetic field to drive the rotor 120 to rotate.

[0113] Specifically, the winding 140 includes a conductive wire, which is wound around the stator teeth 112 to form the winding 140. The magnetic member 150 is a permanent magnet.

[0114] Example 11:

[0115] The embodiment provided by the present invention solves the problem of quadruple frequency radial vibration noise caused by the main magnetic field of the interior permanent magnet motor 100.

[0116] Specifically, if Figures 1 to 5 As shown, the present invention provides a motor 100, including a stator 110 and a rotor 120. The stator 110 includes a stator yoke, Z stator teeth 112 distributed along the circumferential direction, and stator slots formed between two consecutive stator teeth 112. The rotor 120 includes 2p sector-shaped portions 122 distributed along the circumferential direction, permanent magnet mounting slots formed between two consecutive sector-shaped portions 122, 2p connecting bridges connected to the sector-shaped portions 122, and an annular portion connected to the connecting bridges.

[0117] The side of the stator tooth 112 facing the rotor 120 includes a first arc segment 116 concentric with the annular portion, that is, the first arc segment 116 with its center located at the rotation axis of the rotor 120 , and a first segment and a second segment 118 connected to the first arc segment 116 .

[0118] The rotor 120 includes a sector-shaped portion 122. The side of the sector-shaped portion 122 facing the stator 110 includes a second arc segment 124 and a first curved segment 126 and a second curved segment 128 connected to the second arc segment 124 on either side. The first arc segment 116 is concentric with the second arc segment 124, and the first arc segment 116 and the second arc segment 124 are axisymmetric about the centerline of the second arc segment 124. This reduces the large quadruple frequency radial vibration noise and core loss caused by the harmonic magnetic field while maintaining the fundamental magnetic field in the air gap of the motor 100 substantially unchanged.

[0119] The stator 110 includes a stator tooth 112, which includes a first arc segment 116 concentric with the annular portion, and a first segment 114 and a second segment 118 connected to the first arc segment 116. The complementary angle of the acute angle formed by the centerline of the first segment 114 and the first arc segment 116 is greater than or equal to 0° and less than or equal to the quotient of the center angle of the inner diameter of the stator 110 and the pole slot matching factor. The complementary angle of the acute angle formed by the second segment 118 and the centerline of the first arc segment 116 is greater than or equal to 0° and less than or equal to the quotient of the center angle of the inner diameter of the stator 110 and the pole slot matching factor, that is, 0°≤α1≤360°÷(p×Z÷2). In addition, the length L of the first segment 114 or the second segment 118, the height h of the stator slot 160, and the width b of the stator slot 160 satisfy the following conditions: By limiting the angle and length of the first section 114 or the second section 118 , the tangential torque pulsation and core loss of the motor 100 can be reduced, thereby achieving the purpose of reducing the tangential electromagnetic vibration of the motor 100 , improving electromagnetic noise, and increasing the power density of the motor 100 .

[0120] The rotor 120 includes a sector 122. The outer contour of the sector 122 on the side facing the stator 110 includes a second arc segment 124 and a first curved segment 126 and a second curved segment 128 connected to both sides of the second arc segment 124. The second arc segment 124 is concentric with the first arc segment 116. The first curved segment 126 and the second curved segment 128 are axially symmetrical about the center line of the second arc segment 124. The center angle of the second arc segment 124 is greater than or equal to the center angle of the stator 110. The quotient of the inner diameter center angle and the pole-slot matching factor is less than or equal to twice the quotient of the inner diameter center angle of the stator 110 and the pole-slot matching factor, that is, 360°÷(p×Z÷2)≤α2≤2×360°÷(p×Z÷2). By limiting the angle of the second arc segment 124, the air gap magnetic field harmonics of the motor 100 can be reduced, the 4th harmonic frequency radial electromagnetic force of the motor 100 can be reduced, and the 4th harmonic frequency electromagnetic vibration of the motor 100 can be reduced, thereby achieving the purpose of reducing the 4th harmonic frequency electromagnetic noise of the motor 100.

[0121] The distance between the midpoint of the first arc segment 116 and the midpoint of the second arc segment 124 forms the minimum value δmin of the air gap. The maximum distance between the first segment 114 or the second segment 118 and the first curved segment 126 or the second curved segment 128 along the radial direction of the stator 110 forms the maximum value δmax of the air gap. The quotient of the maximum value δmax of the air gap and the minimum value δmin of the air gap should satisfy 1.62≤δmax÷δmin≤3.5. By limiting the quotient of the maximum value δmax of the air gap and the minimum value δmin of the air gap, the Castiglione coefficient can be rationalized and the power density of the motor 100 can be improved.

[0122] In this embodiment, Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 and Figure 5 shown. Figure 1 The figure is a schematic structural diagram of an embodiment of the motor 100 provided by the present invention. Specifically, it is a schematic cross-sectional diagram showing a rotor 120 nested within a stator 110. The stator 110 comprises a stator yoke, Z circumferentially distributed stator teeth 112, and stator slots adjacent to the stator teeth 112. The stator slots house windings 140. The rotor 120 comprises circumferentially distributed sector portions 122. The sector portions 122 form mounting slots for permanent magnets, which are embedded therein. The sector portions 122 are connected to the annular shaft sleeve by a connecting bridge.

[0123] Figure 2Schematic diagram of parameters of stator tooth 112 in motor 100 provided by the present invention. Stator tooth 112 includes a first arc segment 116 concentric with the annular sleeve, a first segment 114, and a second segment 118. First segment 114 and second segment 118 are symmetrical about the centerline of first arc segment 116. The complementary angle α1 formed between the acute angle formed by first segment 114 and second segment 118 and the centerline of first arc segment 116 is respectively. The length of first segment 114 and second segment 118 is both L.

[0124] Furthermore, based on the fundamental electromagnetic relationships within motor 100, the interaction between the harmonics in the back EMF and the fundamental and harmonics of the current is the root cause of the ripple torque of motor 100. Combined with the cogging torque calculation formula, the change in magnetic field energy within the air gap is the cause of the cogging torque of motor 100. The combined action of cogging torque and ripple torque creates the tangential torque pulsation of motor 100. Therefore, by limiting the angle formed by first segment 114 and the centerline of first arc segment 116 (second segment 118 and the centerline of first arc segment 116), the slot permeance is changed to achieve a significant change in magnetic field energy at the slot location, while simultaneously avoiding significant distortion of the air gap magnetic field and, consequently, significant distortion of the back EMF. Furthermore, the change in length L between first segment 114 and second segment 118 alters the air gap permeance and the magnetic field energy in the stator slot region, thereby improving the motor's back EMF distortion rate and cogging torque.

[0125] like Figure 6 As shown, Figure 6 In the motor 100 provided by the present invention, a corresponding relationship diagram of the complementary angle α1 of the acute angle formed between the center line of the first segment 114 and the center line of the first arc segment 116 and the peak value of the cogging torque reflects that the back-EMF distortion rate changes with the angle α1 between the first segment 114 and the second segment 118. As the angle α1 between the first segment 114 and the second segment 118 gradually increases, the back-EMF distortion first decreases and then increases, and when α1 is within a certain range, the back-EMF distortion rate is at a relatively low level.

[0126] That is, 0°≤α1≤360°÷(p×Z÷2).

[0127] Furthermore, if Figure 7 As shown, Figure 7 The corresponding relationship diagram of the length of the first section 114 and the peak value of the cogging torque in the motor 100 provided by the present invention reflects that the cogging torque changes with the length L of the first section 114 and the second section 118. As the length L of the first section 114 and the second section 118 gradually increases, the cogging torque first decreases and then increases, and when L is within a certain range, the cogging torque is at a relatively low level.

[0128] Right now

[0129] Specifically, the number of stator slots Z is 12, the number of poles of the rotor 120 is 8, the angle α1 between the first section 114 and the second section 118 is 12°, and the length L is 2.2 mm.

[0130] Figure 3 FIG2 is a schematic diagram of the sector portion 122 of the motor 100 provided by the present invention. The rotor 120 includes the sector portion 122. The profile of the sector portion 122 facing the stator 110 includes a second arc segment 124 and first and second curved segments 126 and 128 adjacent to the second arc segment 124. The second arc segment 124 is concentric with the first arc segment 116. The first and second curved segments 126 and 128 are symmetrical about the centerline of the second arc segment 124. The center angle of the second arc segment 124 is α2.

[0131] According to the fundamental principles of the electromagnetic field within motor 100, the self-coupling and mutual coupling of harmonics within the air gap flux density are the fundamental causes of the radial electromagnetic force. Electromagnetic analysis results show that the generation of the 4th harmonic electromagnetic force is closely related to the harmonic flux density with a temporal order difference of 4. To reduce the amplitude of the harmonic flux density with a temporal order difference of 4, the present invention uses extensive optimization analysis to calculate the effect of the outer contour of the sector portion 122 of the rotor 120 on the 4th harmonic electromagnetic force. The center angle corresponding to the second arc segment 124 is greater than or equal to the quotient of the center angle of the inner diameter of the stator 110 and the pole-slot matching factor, and less than or equal to twice the quotient of the center angle of the inner diameter of the stator 110 and the pole-slot matching factor, that is, 360° ÷ (p × Z ÷ 2) ≤ α 2 ≤ 2 × 360° ÷ (p × Z ÷ 2). This results in a relatively low 4th harmonic electromagnetic force.

[0132] like Figure 8 As shown, Figure 8 This is a schematic diagram of the change of the 4th harmonic frequency radial force with the center angle of the second arc segment 124 in one embodiment of the optimized calculation of this application. Figure 8 As shown, as the center angle α2 of the second arc segment 124 gradually increases, the fourth-order electromagnetic force tends to first increase and then decrease.

[0133] like Figure 9 As shown, Figure 9 The motor 100 in the related art reduces the 4th frequency electromagnetic force by increasing the air gap. Specifically, the method of increasing the air gap reduces the coupling degree between the permanent magnet magnetic field and the armature magnetic field, further reducing the amplitude of each harmonic of the 4th frequency electromagnetic force. Figure 8 It can be seen that when the 4-fold frequency electromagnetic force is maintained at 1700 N / m 2 When the fundamental magnetic flux density of the motor 100 in the related art is 0.45T, the fundamental magnetic flux density of the 4-fold frequency electromagnetic force method of the present invention is 0.50T, and the fundamental magnetic flux density is increased by 11.1%. Accordingly, the no-load back electromotive force is increased by 11.1%.

[0134] Figure 4 1 is a schematic diagram of the slot 160 in the motor 100 provided by the present invention. The length of the slot 160 is h and the height of the slot 160 is b.

[0135] Figure 5 1 is a schematic diagram of the structure of the motor 100 provided by the present invention, specifically illustrating the minimum air gap value δmin and the maximum air gap value δmax. The diameter of the first arc segment 116 constitutes the inner diameter of the stator 110, and the diameter of the second arc segment 124 constitutes the outer diameter of the rotor 120. The radial distance between the first arc segment 116 and the second arc segment 124 constitutes the minimum air gap value δmin. The radial distance between the first curved segment 126 or the second curved segment 128 and the first segment 114 and the second segment 118 constitutes the maximum air gap value δmax.

[0136] According to the basic electromagnetic relationship within the motor 100, the interaction between the harmonics in the back electromotive force and the fundamental wave and harmonics of the current is the root cause of the ripple torque of the motor 100. Combined with the cogging torque calculation formula, the change in the magnetic field energy in the air gap is the cause of the cogging torque of the motor 100. The combined action of the cogging torque and the ripple torque forms the tangential torque pulsation of the motor 100.

[0137] like Figure 10 As shown, Figure 10 In the motor 100 provided by the present invention, the core loss changes with the quotient of the maximum value δmax of the air gap and the minimum value δmin of the air gap. Figure 10 It can be seen that as the quotient of the maximum value of the air gap δmax and the minimum value of the air gap δmin gradually increases, the core loss gradually decreases, but as the quotient of the maximum value of the air gap δmax and the minimum value of the air gap δmin gradually increases, the back electromotive force gradually decreases and the loss of the winding 140 gradually increases, which further causes the total loss of the motor 100 to first decrease and then increase, and the efficiency also to first decrease and then increase.

[0138] In this embodiment, the motor 100 rotates at a relatively high speed, and the core loss of the stator 110 accounts for the main component of the loss of the motor 100. Reducing the core loss of the motor 100 is a more effective means to improve the efficiency of the motor 100. Therefore, in this embodiment, the quotient of the maximum value of the air gap δmax and the minimum value of the air gap δmin is limited to between 1.62 and 3.5, so that the total loss is at a relatively low level, and accordingly, the efficiency is at a relatively high level.

[0139] Example 12:

[0140] According to a second aspect of the present invention, the present invention provides a compressor, comprising: a motor 100 provided in any one of the above embodiments.

[0141] The compressor embodiment provided by the present invention includes the motor 100 provided by any of the above embodiments, and therefore has all the beneficial effects of the motor 100 provided by any of the above embodiments, which will not be described one by one here.

[0142] Example 13:

[0143] According to a third aspect of the present invention, the present invention provides a household appliance, comprising: the motor 100 provided in any one of the above embodiments; or the compressor provided in any one of the above embodiments.

[0144] The household appliance provided by the present invention includes the motor 100 provided in any of the above embodiments; or the compressor provided in any of the above embodiments. Therefore, it has all the beneficial effects of the motor 100 provided in any of the above embodiments; or the compressor provided in any of the above embodiments, which are not listed one by one here.

[0145] Specifically, the household appliance is an air conditioner, a refrigerator, a washing machine or a fan.

[0146] In the present invention, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "plurality" refers to two or more, unless expressly limited otherwise. Terms such as "installed," "connected," "connected," and "fixed" should be interpreted broadly. For example, "connected" can mean a fixed connection, a detachable connection, or an integral connection; "connected" can mean a direct connection or an indirect connection through an intermediary. Those skilled in the art will understand the specific meanings of these terms in the present invention based on specific circumstances.

[0147] In the description of the present invention, it should be understood that the directions or positional relationships indicated by terms such as "up", "down", "left", "right", "front" and "back" are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the present invention.

[0148] Throughout this specification, terms such as "one embodiment," "some embodiments," and "specific embodiments" mean that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0149] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A motor, characterized in that: include: a stator comprising a through hole and a plurality of stator teeth; The rotor is arranged in the through hole, the rotor includes a plurality of sector-shaped parts, and the stator teeth are arranged opposite to the sector-shaped parts. The stator is cross-sectioned in a direction perpendicular to the axis of the stator. In the cross-section, the contour line of the end of the stator tooth facing the rotor includes a first arc segment and a first segment and a second segment located on both sides of the first arc segment. The rotor is cross-sectioned in a direction perpendicular to the axis of the rotor. In the cross-section, the contour line of the end of the sector portion facing the stator includes: a second arc segment and a first curved segment and a second curved segment located on both sides of the second arc segment. An air gap is formed between the stator and the rotor, and the width of the air gap is gradually changed; A stator slot is formed between two adjacent stator teeth. The stator is cross-sectioned in a direction perpendicular to the axis of the stator. In the cross-section, the slot width of the stator slot is h, the slot height of the stator slot is b, and the length of the first segment is L. Among them, L is greater than or equal to The minimum of and h, less than or equal to and 2h, whichever is greater.

2. The motor according to claim 1, characterized in that One end of the first segment connected to the first arc segment is closer to the rotor than the other end of the first segment, and one end of the second segment connected to the first arc segment is closer to the rotor than the other end of the second segment.

3. The motor according to claim 1, characterized in that The first segment and the second segment on the stator tooth are symmetrically arranged with the center line of the first arc segment as the symmetry axis; The first curved segment and the second curved segment on the sector portion are symmetrically arranged with the center line of the second arc segment as the axis of symmetry.

4. The motor according to claim 2, characterized in that The first segment includes at least one straight line segment and / or at least one curved line segment; and / or The second section includes at least one straight line section and / or at least one curved line section.

5. The motor according to claim 4, characterized in that Based on the situation that the first segment includes a straight line, and the second segment includes a straight line, The stator is cross-sectioned in a direction perpendicular to the axis of the stator. In the cross-section, the complementary angle of the acute angle formed between the center line of the first segment and the center line of the first arc segment is greater than or equal to 0° and less than or equal to the quotient of the center angle of the stator and the pole slot matching factor. The pole-slot matching factor is one fourth of the product of the number of the stator teeth and the number of the sector portions.

6. The motor according to claim 2, characterized in that The stator is cross-sectioned in a direction perpendicular to the axis of the stator. In the cross-section, the center angle of the second arc segment is greater than or equal to the quotient of the center angle of the stator and the pole-slot matching factor, and less than or equal to 2 times the quotient of the center angle of the stator and the pole-slot matching factor.

7. The electric motor according to any one of claims 1 to 6, characterized in that An air gap is formed between the stator and the rotor. When the stator is cross-sectioned in a direction perpendicular to the axis of the stator, a ratio of a maximum value of the air gap to a minimum value of the air gap on the cross section is greater than or equal to 1.62 and less than or equal to 3.

5.

8. The motor according to any one of claims 1 to 6, characterized in that Also includes: A winding is provided on the stator; The magnetic component is arranged on the rotor.

9. A compressor, characterized in that: include: A motor as claimed in any one of claims 1 to 8.

10. A household appliance, characterized in that: include: The motor according to any one of claims 1 to 8; or The compressor according to claim 9.

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