Motor rotor, motor, compressor and household appliance

Abstract

The invention relates to a motor rotor, a motor, a compressor and a household appliance, and relates to the technical field of permanent magnet synchronous motors. The motor rotor comprises a rotor core, a plurality of permanent magnet slot groups are arranged on the rotor core, each permanent magnet slot group comprises a first permanent magnet slot, and each first permanent magnet slot comprises a first slot section, a second slot section and a third slot section communicated with the first slot section and the second slot section, the first permanent magnet is arranged in the first groove section and is provided with a first pole surface facing the second groove section; the second permanent magnet is arranged in the second groove section and is provided with a second pole surface facing the first groove section; the third permanent magnet is installed in the third groove section, the first end of the third permanent magnet abuts against the first pole face, and the second end of the third permanent magnet abuts against the second pole face. Therefore, the anti-demagnetization capability of the motor rotor is improved, magnetic leakage between the first permanent magnets and the second permanent magnets is avoided, and the utilization rate of the permanent magnets is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of permanent magnet synchronous motors, and in particular to a motor rotor, a motor and a compressor. Background Art

[0002] The internal permanent magnet synchronous motor has permanent magnets inserted in the rotor of the motor, and has the advantages of large reluctance torque and strong weak magnetic field speed expansion capability. The permanent magnets of the traditional internal permanent magnet synchronous motor are of a one-type structure, and the torque of the motor is increased by inserting the one-type structure permanent magnets extending in the tangential direction into the magnetic steel slots of the rotor core.

[0003] In the related art, the magnetic steel in the rotor core is arranged into a V-shaped structure symmetrical along the d axis, which can utilize the radial space of the rotor core, increase the amount of magnetic steel used, and improve the magnetic conductivity density of the motor rotor, thereby improving the performance of the rotor.

[0004] However, when the permanent magnet synchronous motor rotor is overloaded, armature reaction will occur, causing demagnetization of the permanent magnet. The V-shaped structure is formed by two separate magnetic steels. After unilateral demagnetization, the rotor's magnetic field will suddenly change, which can easily lead to increased iron and copper losses in the motor and reduced efficiency. Summary of the invention

[0005] The present invention provides a motor rotor, a motor, a compressor and a household appliance, which are used to enhance the anti-demagnetization capability of the motor rotor and improve the performance of the motor.

[0006] In a first aspect, the present invention provides a motor rotor, comprising: a rotor core, a plurality of permanent magnet slot groups are arranged on the rotor core, the permanent magnet slot group comprises a first permanent magnet slot, the first permanent magnet slot comprises a first slot segment and a second slot segment spaced apart from each other, and a third slot segment connecting the first slot segment and the second slot segment;

[0007] A first permanent magnet installed in the first slot segment, the first permanent magnet having a first pole surface facing the second slot segment;

[0008] a second permanent magnet installed in the second slot segment, the second permanent magnet having a second pole face facing the first slot segment; and

[0009] A third permanent magnet is installed in the third slot segment, wherein a first end of the third permanent magnet abuts against the first pole surface, and a second end of the third permanent magnet abuts against the second pole surface.

[0010] In one embodiment, the first permanent magnet and the second permanent magnet are arranged at an angle, and the gap between the first permanent magnet and the second permanent magnet gradually increases in the radial direction, and the distance between the inner end of the first permanent magnet and the inner end of the second permanent magnet is a first length;

[0011] The radial outer side surface of the third permanent magnet is in contact with the inner wall of the third slot segment. The third permanent magnet is located between the first permanent magnet and the second permanent magnet. The length of the third permanent magnet along the tangential direction of the rotor core is greater than the first length.

[0012] In one embodiment, a first wedge surface is disposed at the first end of the third permanent magnet, and a second wedge surface is disposed at the second end of the third permanent magnet. The first wedge surface is in contact with and abuts against the first pole surface, and the second wedge surface is in contact with and abuts against the second pole surface.

[0013] In one embodiment, a fourth permanent magnet spaced apart from the third permanent magnet is further installed in the third slot segment, the fourth permanent magnet is located on a side of the third permanent magnet close to the center of the rotor core, and the inner side surface of the fourth permanent magnet is in contact with the inner wall of the third slot segment;

[0014] A third inclined wedge surface is provided at one end of the fourth permanent magnet, and the third inclined wedge surface abuts against the inner end surface of the first permanent magnet. A fourth inclined wedge surface is provided at the other end of the fourth permanent magnet, and the fourth inclined wedge surface abuts against the inner end surface of the second permanent magnet.

[0015] In one embodiment, the third permanent magnet and the fourth permanent magnet both extend along a straight line, and the third permanent magnet is parallel to the fourth permanent magnet.

[0016] In one embodiment, the angle between the first slot segment and the third slot segment is φ1, wherein 135°≤φ1≤155°.

[0017] In one embodiment, the first permanent magnet and the second permanent magnet are symmetrical along a first straight line, the first straight line passes through the center of the rotor core's rotation axis along the radial direction of the rotor core, and the third permanent magnet is perpendicular to the first straight line and symmetrical along the first straight line.

[0018] In one embodiment, the first permanent magnet and the second permanent magnet are symmetrical along a first straight line, the permanent magnet slot group also includes a second permanent magnet slot and a third permanent magnet slot symmetrical along the first straight line, the second permanent magnet slot and the third permanent magnet slot are both located radially outside the third slot segment, and the rotor core is also provided with a magnetic flux sorting slot between the second permanent magnet slot and the third permanent magnet slot.

[0019] In one embodiment, the second permanent magnet slot includes a fourth slot segment and a fifth slot segment, permanent magnets are respectively installed in the fourth slot segment and the fifth slot segment, and the fifth slot segment is parallel to the second slot segment;

[0020] The fourth slot segment is arranged at an angle to the fifth slot segment, one end of the fourth slot segment is connected to the fifth slot segment, and the other end of the fourth slot segment extends toward the outer edge of the rotor core.

[0021] In one embodiment, a plurality of trimming grooves are provided on the outer edge of the rotor core, the number of the trimming grooves is equal to the number of the permanent magnet slot groups, and each trimming groove is respectively provided between two adjacent permanent magnet slot groups.

[0022] In a second aspect, the present invention further provides a motor, which comprises the motor rotor described above.

[0023] In a third aspect, the present invention further provides a compressor, which comprises the above-mentioned motor.

[0024] In a fourth aspect, the present invention further provides a household appliance comprising the above-mentioned motor.

[0025] Compared with the prior art, the advantage of the present invention is that the first end of the third permanent magnet is fitted with the first pole face of the first permanent magnet, and the magnetic material of the first end of the third permanent magnet is used to improve the magnetic field environment of the first permanent magnet under strong magnetic conditions, which is equivalent to using the third permanent magnet to increase the thickness of the first permanent magnet and improve the anti-demagnetization ability of the first permanent magnet. Similarly, the second end of the third permanent magnet is fitted with the second pole face, thereby improving the anti-demagnetization ability of the second permanent magnet. This improves the anti-demagnetization ability of the motor rotor.

[0026] In addition, the first permanent magnet and the second permanent magnet, which are spaced apart from each other, are connected by a third permanent magnet arranged in the third slot segment, and the magnetic conductivity density of the area between the first permanent magnet and the second permanent magnet is increased by the third permanent magnet, thereby avoiding magnetic leakage between the first permanent magnet and the second permanent magnet and improving the utilization rate of the permanent magnets. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Hereinafter, the present invention will be described in more detail based on embodiments and with reference to the accompanying drawings.

[0028] Figure 1 is an end view of a rotor core in an embodiment of the present invention;

[0029] Figure 2 is a schematic diagram of an end face of a motor rotor in an embodiment of the present invention;

[0030] Figure 3 yes Figure 2 Schematic diagram of the local structure in;

[0031] Figure 4 is an end view of a rotor core in an embodiment of the present invention;

[0032] Figure 5 It is a schematic diagram of the local structure of the rotor core;

[0033] Figure 6 It is a schematic diagram of the local structure of the rotor core;

[0034] Figure 7It is a schematic diagram of the local structure of the rotor core;

[0035] Figure 8 is a back electromotive force waveform diagram of a motor in an embodiment of the present invention;

[0036] Fig. 9 It is the back electromotive force waveform diagram of the motor in the prior art;

[0037] Fig.10 A graph showing the motor efficiency of a motor in an embodiment of the present invention and a motor in the prior art;

[0038] Fig.11 is a graph showing the demagnetization rates of the motor in the embodiment of the present invention and the motor in the prior art;

[0039] Fig.12 It is a structural diagram of a motor after each permanent magnet is hidden in an embodiment of the present invention.

[0040] Reference numerals:

[0041] 100. rotor core;

[0042] 110, first permanent magnet slot; 111, first slot section; 112, second slot section; 113, third slot section;

[0043] 120, second permanent magnet slot; 121, fourth slot segment; 122, fifth slot segment;

[0044] 130, third permanent magnet slot;

[0045] 140. The first magnetic beam sorting slot;

[0046] 150. The second magnetic beam sorting slot;

[0047] 160, trimming groove;

[0048] 170, shaft hole;

[0049] 181, positioning portion; 182, limiting portion;

[0050] 210, first permanent magnet; 211, first pole surface; 220, second permanent magnet; 221, second pole surface; 230, third permanent magnet; 231, first oblique wedge surface; 232, second oblique wedge surface; 240, fourth permanent magnet; 241, third oblique wedge surface; 242, fourth oblique wedge surface;

[0051] 300. Stator. DETAILED DESCRIPTION

[0052] The present invention will be further described below in conjunction with the accompanying drawings.

[0053] See also Figure 1 and Figure 2 As shown, a motor rotor provided by the present invention includes: a rotor core 100, a core assembly is provided with a plurality of permanent magnet slot groups, the permanent magnet slot groups include a first permanent magnet slot 110, and the first permanent magnet slot 110 is installed with a first permanent magnet 210, a second permanent magnet 220, a third permanent magnet 230 and a fourth permanent magnet 240.

[0054] Continue to see Figure 3 and Figure 4 As shown, the first permanent magnet slot 110 includes a first slot section 111 and a second slot section 112 spaced apart from each other, the first permanent magnet 210 is installed in the first slot section 111, and the second permanent magnet 220 is installed in the second slot section 112. The first permanent magnet 210 has a first pole face 211 facing the second slot section 112, and the second permanent magnet 220 has a second pole face 221 facing the first slot section 111.

[0055] See also Figure 2 and Figure 3 As shown, the first permanent magnet 210 and the second permanent magnet 220 are combined to form a V-shaped structure. Compared with installing a single type of permanent magnet in the rotor core 100, arranging them to form a V-shaped structure can increase the amount of permanent magnets used, thereby increasing the magnetic field strength of the motor rotor.

[0056] See also Figure 1 and Figure 4 As shown, the first permanent magnet slot 110 also includes a third slot segment 113 connecting the first slot segment 111 with the second slot segment 112, and a third permanent magnet 230 is installed in the third slot segment 113, and the first end of the third permanent magnet 230 abuts against the first pole surface 211, and the second end of the third permanent magnet 230 abuts against the second pole surface 221.

[0057] Since the first end of the third permanent magnet 230 abuts against the first pole surface 211 of the first permanent magnet 210, it is equivalent to providing a protruding structure made of permanent magnetic material protruding outward from the first pole surface 211, thereby increasing the thickness of the first permanent magnet 210 at the first pole surface 211 and improving the anti-demagnetization ability of the first permanent magnet 210.

[0058] Similarly, since the second end of the third permanent magnet 230 abuts against the second pole surface 221 of the second permanent magnet 220, it is equivalent to providing a protruding structure made of permanent magnetic material protruding outward from the second pole surface 221, thereby increasing the thickness of the second permanent magnet 220 at the second pole surface 221 and improving the anti-demagnetization ability of the second permanent magnet 220.

[0059] In addition, since the opposite ends of the third permanent magnet 230 are respectively in contact with the first permanent magnet 210 and the second permanent magnet 220, the magnetic flux density between the first permanent magnet 210 and the second permanent magnet 220 can be increased. The magnetic flux leakage between the first permanent magnet 210 and the second permanent magnet 220 is reduced, the sinusoidal degree of the magnetic flux density is improved, the higher harmonic content is reduced, and the operation balance is increased.

[0060] See also Figure 1 and Figure 4 As shown, in some implementations, the first permanent magnet 210 and the second permanent magnet 220 are arranged at an angle, and the gap between the first permanent magnet 210 and the second permanent magnet 220 gradually increases in the radial direction (d-axis direction), and the distance between the inner end of the first permanent magnet 210 (the end pointing to the center of the rotor core 100) and the inner end of the second permanent magnet 220 (the end pointing to the center of the rotor core 100) is a first length ( Figure 5 L5), the radial outer side surface of the third permanent magnet 230 is in contact with the inner wall of the third slot segment 113, the third permanent magnet 230 is located between the first permanent magnet 210 and the second permanent magnet 220, and the length of the third permanent magnet 230 along the tangential direction of the rotor core 100 (direction perpendicular to the d-axis) is greater than the first length.

[0061] That is to say, the first permanent magnet 210 and the second permanent magnet 220 are combined to form a V-shaped structure, and the tip of the V-shaped structure points to the center of the rotating shaft of the rotor core 100. Since the length of the third permanent magnet 230 along the tangential direction of the rotor core 100 is greater than the first length, it is possible to avoid the third permanent magnet 230 from radially passing through the gap between the first permanent magnet 210 and the second permanent magnet 220, thereby limiting the third permanent magnet 230 and preventing the third permanent magnet 230 from moving inward. Since the radial outer side surface of the third permanent magnet 230 is in contact with the inner wall of the third slot segment 113, it is possible to avoid the third permanent magnet 230 from moving outward. In other words, the third permanent magnet 230 is limited by the cooperation of the first permanent magnet 210, the second permanent magnet 220 and the inner wall of the third slot segment 113. During the installation process, one of the first permanent magnet 210 and the second permanent magnet 220 can be installed in the corresponding slot body first, and then the third permanent magnet 230 can be inserted into the third slot section 113. Finally, the permanent magnet that is not installed between the first permanent magnet 210 and the second permanent magnet 220 can be inserted into the corresponding slot body to limit the third permanent magnet 230.

[0062] It is understandable that when the permanent magnet installation slot is opened on the rotor core 100, not only the arrangement of the permanent magnets needs to be considered, but also the stress concentration on the side wall of the slot body needs to be avoided as much as possible. As shown in the figure, since the opposite ends of the third permanent magnet 230 in the tangential direction abut against the permanent magnet, the opposite ends of the third permanent magnet 230 in the tangential direction are avoided from abutting against the inner wall of the slot body of the rotor core 100.

[0063] Since the two opposite ends (the first end and the second end) of the third permanent magnet 230 in the tangential direction are not pressed against the inner wall of the third slot section 113, that is, the third permanent magnet 230 does not press the rotor core 100 in the tangential direction, the tangential pressing force of the third permanent magnet 230 can be transmitted to the rotor core 100 through the first permanent magnet 210 or the second permanent magnet 220. As can be seen from the figure, the contact surface of the first permanent magnet 210 and the second permanent magnet 220 with the rotor core 100 in the tangential direction is large, compared with the rotor core 100 directly contacting the first end or the second end of the third permanent magnet 230, stress concentration on the rotor core 100 is avoided, and the life of the rotor core 100 is extended.

[0064] In some implementations, the material of the first permanent magnet 210 and the second permanent magnet 220 may be magnetic steel, specifically AlNiCo magnetic steel, ferrite magnetic steel, NdFeB magnetic steel or sintered NdFeB. NdFeB magnetic steel is preferably selected to make the first permanent magnet 210 and the second permanent magnet 220, as NdFeB magnetic steel has higher magnetic properties, remanence and coercive force.

[0065] See also Figure 3 As shown, the first end of the third permanent magnet 230 is provided with a first inclined wedge surface 231 , and the second end of the third permanent magnet 230 is provided with a second inclined wedge surface 232 . The first inclined wedge surface 231 is in contact with and abuts the first pole surface 211 , and the second inclined wedge surface 232 is in contact with and abuts the second pole surface 221 .

[0066] That is, the inclination angle of the inclined surface at the first end corresponds to the inclination angle of the first permanent magnet 210, so that the first wedge surface 231 can have a larger contact area with the first permanent magnet 210, thereby avoiding concentrated stress between the first permanent magnet 210 and the second permanent magnet 220.

[0067] See also Figure 3 As shown, since the first end of the third permanent magnet 230 is attached to the side of the first permanent magnet 210 facing the second slot section 112, and the second end of the third permanent magnet 230 is attached to the side of the second permanent magnet 220 facing the first slot section 111, and the first permanent magnet 210 and the second permanent magnet 220 are arranged obliquely, the cross section of the third permanent magnet 230 extending tangentially is trapezoidal. Among them, since the first permanent magnet 210 and the second permanent magnet 220 are symmetrical along the d axis extending tangentially, and the third permanent magnet 230 extending tangentially is perpendicular to the d axis, the trapezoidal cross section of the third permanent magnet 230 is an isosceles trapezoidal structure. Further, since the spacing between the first permanent magnet 210 and the second permanent magnet 220 gradually increases along the radial direction, it is necessary to set the trapezoidal cross section of the third permanent magnet 230 so that the side length of the radial outer side is greater than the side length of the radial inner side.

[0068] See also Figure 3As shown, in some implementations, a fourth permanent magnet 240 spaced apart from the third permanent magnet 230 is further installed in the third slot segment 113, and the fourth permanent magnet 240 is located on a side of the third permanent magnet 230 close to the center of the rotor core 100, and the inner side surface of the fourth permanent magnet 240 is in contact with the inner wall of the second slot segment 112;

[0069] A third bevel surface 241 is disposed at one end of the fourth permanent magnet 240 , and the third bevel surface 241 abuts against the inner end surface of the first permanent magnet 210 . A fourth bevel surface 242 is disposed at the other end of the fourth permanent magnet 240 , and the fourth bevel surface 242 abuts against the inner end surface of the second permanent magnet 220 .

[0070] That is to say, at least two permanent magnets (the third permanent magnet 230 and the fourth permanent magnet 240) are not only installed in the third slot section 113. And the opposite ends of the fourth permanent magnet 240 are also respectively abutted on the first permanent magnet 210 and the second permanent magnet 220. In other words, the anti-demagnetization ability of the first permanent magnet 210 and the second permanent magnet 220 can also be improved by the fourth permanent magnet 240. In the event of extreme working conditions, even if one of the third permanent magnet 230 or the fourth permanent magnet 240 is demagnetized, the other can be used to reduce the demagnetization risk of the first permanent magnet 210 and the second permanent magnet 220, thereby avoiding significant changes in the magnetic field environment of the rotor and affecting the performance of the rotor.

[0071] In addition, since the opposite ends of the fourth permanent magnet 240 are in contact with the inner end surface of the first permanent magnet 210 or the inner end surface of the second permanent magnet 220, the first permanent magnet 210 can be used to radially position the end of the fourth permanent magnet 240 provided with the third bevel surface 241, and the fourth permanent magnet 240 can be pressed radially inward to prevent the end of the fourth permanent magnet 240 provided with the third bevel surface 241 from moving toward the side away from the center of the rotor core 100. Similarly, the second permanent magnet 220 can be used to radially position the end of the fourth permanent magnet 240 provided with the fourth bevel surface 242, and the fourth permanent magnet 240 can be pressed radially inward to prevent the end of the fourth permanent magnet 240 provided with the fourth bevel surface 242 from moving toward the side away from the center of the rotor core 100. The inner side surface of the fourth permanent magnet 240 is in contact with the inner wall of the third slot segment 113 , and the inner wall of the rotor core 100 at the third slot segment 113 can prevent the fourth permanent magnet 240 from moving radially inward.

[0072] That is, through the cooperation of the first permanent magnet 210 , the second permanent magnet 220 and the third slot segment 113 , the fourth permanent magnet 240 can be limited on both the inner and outer sides in the radial direction, so that the fourth permanent magnet 240 is kept in a specific position.

[0073] according to Figure 2 and Figure 3It can be known that the first permanent magnet 210 and the second permanent magnet 220 can press the third permanent magnet 230 radially outwardly against the inner wall of the third slot segment 113, and the first permanent magnet 210 and the second permanent magnet 220 can also press the fourth permanent magnet 240 radially inwardly against the inner wall of the third slot segment 113. Thus, the third permanent magnet 230 and the fourth permanent magnet 240 are pressed in the third slot segment 113 in two opposite directions, so that the third permanent magnet 230 and the fourth permanent magnet 240 form a hole structure in the second slot segment 112. Compared with manufacturing the third permanent magnet 230 and the fourth permanent magnet 240 as one, the thickness of the permanent magnet in the third slot segment 113 is increased without increasing the amount of permanent magnet material, and the thickness of the third permanent magnet 230 in the third slot segment 113 is increased, and the anti-demagnetization ability of the permanent magnet in the third slot segment 113 is improved.

[0074] Before inserting the third permanent magnet 230 and the fourth permanent magnet 240 into the third slot segment 113, first insert the first permanent magnet 210 into the first slot segment 111, and insert the second permanent magnet 220 into the second slot segment 112, then fit the outer side surface of the third permanent magnet 230 with the inner wall of the third slot segment 113, and fit the inner side surface of the fourth permanent magnet 240 with the inner wall of the third slot segment 113, and use the first pole surface 211 of the first permanent magnet 210 and the second pole surface 221 of the second permanent magnet 220 to prevent the third permanent magnet 230 from moving radially inward, and use the inner end surface of the first permanent magnet 210 and the inner end surface of the second permanent magnet 220 to prevent the fourth permanent magnet 240 from moving radially outward, thereby achieving radial positioning of the third permanent magnet 230 and the fourth permanent magnet 240.

[0075] See also Figure 2 and Figure 3 As shown, the third permanent magnet 230 and the fourth permanent magnet 240 both extend in a straight line, and the third permanent magnet 230 and the fourth permanent magnet 240 are parallel. Since the third permanent magnet 230 and the fourth permanent magnet 240 extend in a straight line and are arranged in parallel, the third slot segment 113 can be set as a strip structure with uniform width when designing the third slot segment 113, which reduces the processing difficulty of the third slot segment 113. Specifically, by opening the third slot segment 113 perpendicular to the d-axis direction of the permanent magnet slot group, the third permanent magnet 230 and the fourth permanent magnet 240 that are attached to the inner wall of the third slot segment 113 can both extend in a straight line in a direction perpendicular to the d-axis of the permanent magnet slot group. In other implementations, the extension direction of the third slot segment 113 and the d-axis of the permanent magnet slot group can also be set at an angle, so that the extension direction of the third permanent magnet 230 and the fourth permanent magnet 240 that are attached to the inner wall of the third slot segment 113 is an acute angle relative to the d-axis direction of the permanent magnet slot group.

[0076] See also Figure 7 As shown, the width of the third slot segment 113 along the d-axis direction is h3, the width of the third permanent magnet 230 in the d-axis direction is d3, and the width of the fourth permanent magnet 240 in the d-axis direction is d4, wherein, h3 >d3+d4. After the third permanent magnet 230 and the fourth permanent magnet 240 are simultaneously inserted into the third slot section 113, a gap is left in the third slot section 113, thereby improving the anti-demagnetization capability of the combination formed by the third permanent magnet 230 and the fourth permanent magnet 240.

[0077] In some implementations, the widths of the third permanent magnet 230 and the fourth permanent magnet 240 in the d-axis direction are equal, that is, d3 = d4.

[0078] As shown in the figure, in some implementations, the angle between the first slot segment 111 and the third slot segment 113 is φ1, where 135°≤φ1≤155°. Specifically, φ1 refers to the angle between the inner wall of the first slot segment 111 facing the second slot segment 112 and the third slot segment 113.

[0079] In some implementations, the first slot segment 111 and the second slot segment 112 are symmetrical along the d-axis of the permanent magnet slot group, and the extension direction of the third slot segment 113 is perpendicular to the d-axis of the permanent magnet slot group. It can be understood that since the first slot segment 111 and the second slot segment 112 are symmetrical along the d-axis, the angle between the second slot segment 112 and the third slot segment 113 is equal to the angle between the first slot segment 111 and the third slot segment 113, that is, the angle between the second slot segment 112 and the third slot segment 113 is also φ1.

[0080] Among them, the angle between the inner wall of the inner end of the first slot segment 111 and the third slot segment 113 is φ2. In some implementations, the cross-sectional shape of the first slot segment 111 is a rectangle, that is, the inner wall of the inner end of the first slot segment 111 and the inner wall of the first slot segment 111 facing the second slot segment 112 are perpendicular to each other, that is, φ1+φ2=270°. In some implementations, in order to reduce the processing difficulty of the first permanent magnet slot 110 and ensure the main magnetic flux of the permanent magnet of the motor, φ1 and φ2 satisfy the formula: 0.8≤φ2 / φ1≤1, that is, 135°≤φ1≤150°.

[0081] See also Figure 6As shown, the rotor core 100 is formed with protruding positioning portions 181 at opposite ends of the inner side wall of the third slot segment 113, and the inner end portion of the first permanent magnet 210 abuts against the side of one of the positioning portions 181, and the end surface portion of the inner end of the second permanent magnet 220 abuts against the side of the other positioning portion 181. In other words, a portion of the inner end surface of the first permanent magnet 210 abuts against the side of the positioning portion 181, and another portion abuts against the third inclined wedge surface 241 of the fourth permanent magnet. Similarly, a portion of the end surface of the inner end of the second permanent magnet 220 abuts against the side of the positioning portion 181, and another portion abuts against the fourth inclined wedge surface 242 of the fourth permanent magnet. In other words, by forming two protruding positioning portions 181 in the first permanent magnet slot, the first permanent magnet 210 and the second permanent magnet 220 can be positioned.

[0082] See also Figure 6 As shown, the rotor core is further provided with protruding limiting portions 182 at the opposite ends of the outer side wall of the third slot segment 113, and the outer side tips of the third permanent magnet 230 at both tangential ends abut against the limiting portions 182, that is, the third permanent magnet 230 is limited not only by the first permanent magnet 210 and the second permanent magnet 220, but also by the protruding limiting portions 182.

[0083] See also Figure 2 as well as Figure 3 As shown, in some implementations, the first permanent magnet 210 and the second permanent magnet 220 are symmetrical along a first straight line (coincident with the d-axis), the first straight line passes through the center of the rotation axis of the rotor core 100 along the radial direction of the rotor core 100, and the third permanent magnet 230 is perpendicular to the first straight line, and the third permanent magnet 230 is symmetrical along the first straight line.

[0084] Since the first permanent magnet 210 and the second permanent magnet 220 are symmetrical along the first straight line extending radially, the magnetic fields of the first permanent magnet 210 and the second permanent magnet 220 can be combined along the first straight line. The third permanent magnet 230 is perpendicular to the first straight line, and the direction of the magnetic field generated by the third permanent magnet 230 is also along the first straight line. In other words, through the above arrangement, the direction of the combined magnetic field of the first permanent magnet 210, the second permanent magnet 220 and the third permanent magnet 230 can be along the radial direction (first straight line), ensuring the main magnetic flux of the motor permanent magnet.

[0085] It can be understood that the fourth permanent magnet 240 is also perpendicular to the first straight line and symmetrical along the first straight line, that is, the direction of the magnetic fields of the four permanent magnets in the first permanent magnet slot 110 after synthesis is along the first straight line.

[0086] See also Figure 2 and Figure 3As shown, in some implementations, the first permanent magnet 210 and the second permanent magnet 220 are symmetrical along the first straight line, the permanent magnet slot group further includes a second permanent magnet slot 120 and a third permanent magnet slot 130 symmetrical along the first straight line, the second permanent magnet slot 120 and the third permanent magnet slot 130 are both located radially outside the third slot segment 113, and the rotor core 100 is further provided with a magnetic flux sorting slot between the second permanent magnet slot 120 and the third permanent magnet slot 130. Since the second permanent magnet slot 120 and the third permanent magnet slot 130 are provided radially outside the third slot segment 113, the permanent magnets in the second permanent magnet slot 120 and the third permanent magnet slot 130 can be used to increase the magnetic flux density of the rotor, thereby guiding the stator magnetic field and reducing magnetic flux leakage.

[0087] By setting a magnetic flux sorting groove between the second permanent magnet groove 120 and the third permanent magnet groove 130, the air in the magnetic flux sorting groove is used to increase the magnetic resistance at the magnetic flux sorting groove, thereby reducing the magnetic flux lines passing through the magnetic flux sorting groove, and guiding the magnetic flux lines to the first permanent magnet groove 110, thereby ensuring the main magnetic flux of the permanent magnet of the motor.

[0088] See also Figure 5 As shown, the second permanent magnet slot 120 includes a fourth slot section 121 and a fifth slot section 122, wherein permanent magnets are respectively installed in the fourth slot section 121 and the fifth slot section 122, and the fifth slot section 122 is parallel to the second slot section 112; the fourth slot section 121 and the fifth slot section 122 are arranged at an angle, one end of the fourth slot section 121 is connected to the fifth slot section 122, and the other end of the fourth slot section 121 extends toward the outer edge of the rotor core 100. By arranging the fifth slot section 122 in parallel with the second slot section 112 and installing a permanent magnet in the fifth slot section 122, the magnetic field strength at the second slot section 112 can be improved, and by extending the end of the fourth slot section 121 away from the fifth slot section 122 toward the outer edge of the rotor core 100, the magnetic field strength at the outer edge of the rotor core 100 at the fifth slot section 122 can be improved, thereby avoiding magnetic leakage in the fifth slot section 122 area and improving the utilization rate of the permanent magnet.

[0089] See also Figure 5 As shown, the length of the permanent magnet in the fifth slot segment 122 is greater than the length of the permanent magnet in the fourth slot segment 121. The air gap flux density at the fifth slot segment 122 can be increased, so that the permanent magnet magnetic field can be effectively utilized and the output torque capacity of the motor can be increased to the maximum extent.

[0090] In some implementations, the fifth slot segment 122 is perpendicular to the fourth slot segment 121 , and an extending direction of the fifth slot segment 122 is parallel to the first straight line.

[0091] See also Figure 4As shown, in some implementations, a plurality of slicing grooves are provided on the outer edge of the rotor core 100, the number of the trimming grooves 160 is equal to the number of the permanent magnet slot groups, and one trimming groove 160 is provided between each two adjacent permanent magnet slot groups. In other words, the trimming grooves 160 are provided at the q-axis of the permanent magnet slot group, which can improve the back electromotive force peak effect of the motor.

[0092] It is understandable that the rotor core 100 is provided with a plurality of permanent magnet slot groups evenly distributed along the circumferential direction, wherein the number of the permanent magnet slot groups can be selected according to the actual working condition of the motor rotor. Figure 4 As shown, six permanent magnet slot groups evenly distributed along the circumferential direction are arranged on the rotor core 100 .

[0093] In order to more clearly illustrate the technical solution of the present application, a specific implementation scheme using the motor rotor of the present application is described in detail below.

[0094] See also Figure 4 As shown, six permanent magnet slot groups are arranged on the rotor core 100, and the permanent magnet slot groups include a first permanent magnet slot 110, a second permanent magnet slot 120 and a third permanent magnet slot 130. Among them, the first permanent magnet slot 110 is generally in a U-shaped structure. The first permanent magnet slot 110 includes a first slot section 111, a third slot section 113 and a second slot section 112 that are connected in sequence. A first permanent magnet 210 is installed in the first slot section 111, a second permanent magnet 220 is installed in the second slot section 112, and a third permanent magnet 230 and a fourth permanent magnet 240 are installed in the third slot section 113.

[0095] Wherein, the length of the first permanent magnet 210 and the length of the second permanent magnet 220 are both L3, and in this embodiment, 8mm≤L3≤10mm. The thickness of the first permanent magnet 210 and the second permanent magnet 220 is d2, and in this embodiment, 1.4mm≤d2≤1.7mm. The first permanent magnet 210 and the second permanent magnet 220 are arranged at an angle and are symmetrical along the d axis of the permanent magnet slot group. And the distance (first length) between the inner end of the first permanent magnet 210 and the inner end of the second permanent magnet 220 is L4, and in this embodiment, 8mm≤L4≤10mm.

[0096] The third slot section 113 is set to a trapezoidal structure to connect the first slot section 111 and the second slot section 112 on both sides, and the length of the inner wall of the third slot section 113 arranged radially outward is L5. In this embodiment, 12mm≤L5≤14mm.

[0097] By setting the length of the third permanent magnet 230 to L5 and setting the inclination angles of the inclined surfaces on both sides of the third permanent magnet 230 according to the angle between the first permanent magnet 210 and the second permanent magnet 220, when the third permanent magnet 230 is installed in the third slot section 113, the first inclined wedge surface 231 at the first end of the third permanent magnet 230 is in contact with the first permanent magnet 210, and the second inclined wedge surface 232 at the second end of the third permanent magnet 230 is in contact with the second permanent magnet 220. The radial outer side surface of the third permanent magnet 230 is in contact with the inner wall of the third slot section 113.

[0098] The fourth permanent magnet 240 in the third slot section 113 is also configured to have a trapezoidal cross section, and the inner side (the side close to the rotor center) of the trapezoidal cross section of the fourth permanent magnet 240 is longer than the outer side (the side far from the rotor center), so that both ends of the fourth permanent magnet 240 are held in the third slot section 113 by the abutment of the inner ends of the first permanent magnet 210 and the second permanent magnet 220, and the inner side edge of the fourth permanent magnet 240 is pressed against the inner wall of the third slot section 113.

[0099] The thickness d3 of the third permanent magnet 230 in the radial direction is equal to the thickness d4 of the fourth permanent magnet 240 in the radial direction. In this embodiment, 1 mm ≤ d3 = d4 ≤ 1.2 mm. The gap between the third permanent magnet 230 and the fourth permanent magnet 240 in the radial direction is h3-d3-d4. In this embodiment, 0.8 mm ≤ h3-d3-d4 ≤ 1 mm.

[0100] The angle between the first pole face 211 (the side of the first permanent magnet 210 facing the second slot segment 112) and the third slot segment 113 is φ1, and in this embodiment, 135°≤φ1≤155°. The angle between the end face of the inner end of the first permanent magnet 210 and the third slot segment 113 is φ2, and in this embodiment, 120°≤φ2≤130°.

[0101] The third permanent magnet slot 130 and the fourth permanent magnet slot are located radially outside the third slot segment 113, and the third permanent magnet slot 130 and the fourth permanent magnet slot are symmetrical along the d-axis of the permanent magnet slot group. The third permanent magnet slot 130 includes a fourth slot segment 121 and a fifth slot segment 122 which are perpendicular to each other, wherein the fifth slot segment 122 is parallel to the third slot segment 113 and both extend in a direction perpendicular to the d-axis. The fourth slot segment 121 is perpendicular to the fifth slot segment 122, and the fourth slot segment 121 extends in the direction of the d-axis. The thickness of the fourth slot segment 121 and the fifth slot segment 122 are both d1, and in this embodiment, 0.8mm≤d1≤1mm.

[0102] The length L2 of the fourth slot segment 121 is greater than the length L1 of the fifth slot segment 122 . In this embodiment, 3 mm ≤ L1 ≤ 4.2 mm, and 5 mm ≤ L2 ≤ 6 mm.

[0103] See also Figure 4-Figure 6 As shown, two magnetic flux sorting grooves are arranged between the second permanent magnet groove 120 and the third permanent magnet groove 130, and both magnetic flux sorting grooves are located radially outside the third permanent magnet groove 130. The two magnetic flux sorting grooves are symmetrical along the d axis of the permanent magnet groove group. For the convenience of explanation, the magnetic flux sorting groove close to the second permanent magnet groove 120 of the two magnetic flux sorting grooves is called the first magnetic flux sorting groove 140, and the magnetic flux sorting groove close to the third permanent magnet groove 130 is called the second magnetic flux sorting groove 150. Among them, the distance between the inner end of the first magnetic flux sorting groove 140 and the fourth groove segment 121 is h1, and the distance between the inner end of the first magnetic flux sorting groove 140 and the fifth groove segment 122 is h2. In this embodiment, h1=h2≥2mm.

[0104] See also Figure 7 As shown, a trimming groove 160 is provided on the outer edge of the rotor core 100 , and the depth of the trimming groove 160 is q1 . In this embodiment, 1.2 mm≤q1≤1.3 mm.

[0105] See also Figure 8 As shown in the figure, the induced electromotive force of the motor rotor designed according to the above dimensions is optimized to 61.98. Fig. 9 In the figure, the back electromotive force waveform of the motor rotor before the improvement is shown, and it can be seen that the induced electromotive force of the motor rotor before the improvement is 57.81. In other words, by adopting the motor rotor structure of the present application, the induced electromotive force of the motor rotor is improved. And by comparing the back electromotive force waveforms before and after the improvement, it can be seen that the back electromotive force waveform of the motor rotor after the improvement is closer to the sine curve, which improves the performance of the motor rotor.

[0106] See also Fig.10 As shown in FIG. 1 , the motor efficiency of the improved motor rotor is higher than that of the motor of the prior art. Fig.11 As shown, it can be known that the demagnetization rate of the motor rotor of the present invention under various working currents is lower than the demagnetization rate of the motor in the prior art. In addition, the demagnetization rate of the motor of the present invention is still maintained at less than 5% when the working current is 31A. Compared with the motor in the prior art, the motor of the present invention can be applied to higher working currents and can withstand heavier loads. This shows that the anti-demagnetization ability of the improved motor rotor has been improved.

[0107] A shaft hole 170 extending in the axial direction is provided at the center of the rotor core 100 , and a shaft can be installed in the shaft hole 170 to be connected to the rotor core 100 .

[0108] In summary, the motor rotor structure designed in the present application can not only improve the anti-demagnetization ability of the rotor, but also improve the working efficiency of the motor, and also improve the back EMF waveform of the motor rotor, thereby greatly improving the performance of the motor rotor.

[0109] See also Fig.12As shown, in a second aspect, the present invention further provides a motor, which includes the motor rotor described above, and a stator 300 is further provided on the outside of the motor rotor. As can be seen from the above, due to the installation of the motor rotor described above, the working efficiency of the motor can be improved, and it can have a better back electromotive force waveform, and has a stronger anti-demagnetization ability so that it can work under a larger load.

[0110] In a third aspect, the present invention further provides a compressor, which includes the above motor and has all the advantages of the above motor.

[0111] In a fourth aspect, the present invention further provides a household appliance, which includes the above motor and has the advantages of the above motor. The household appliance here can be a refrigeration device with a compressor, or a household appliance driven by a motor, such as a fan and a washing machine.

[0112] Although the present invention has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A motor rotor, characterized in that: It includes: A rotor core, wherein a plurality of permanent magnet slot groups are arranged on the rotor core, wherein the permanent magnet slot group includes a first permanent magnet slot, wherein the first permanent magnet slot includes a first slot segment and a second slot segment spaced apart from each other, and a third slot segment connecting the first slot segment and the second slot segment; A first permanent magnet installed in the first slot segment, the first permanent magnet having a first pole surface facing the second slot segment; a second permanent magnet installed in the second slot segment, the second permanent magnet having a second pole surface facing the first slot segment; as well as A third permanent magnet is installed in the third slot segment, wherein a first end of the third permanent magnet abuts against the first pole surface, and a second end of the third permanent magnet abuts against the second pole surface.

2. The motor rotor according to claim 1, characterized in that: The first permanent magnet and the second permanent magnet are arranged at an angle, and the gap between the first permanent magnet and the second permanent magnet gradually increases in the radial direction, and the distance between the inner end of the first permanent magnet and the inner end of the second permanent magnet is a first length; The radial outer side surface of the third permanent magnet is in contact with the inner wall of the third slot segment. The third permanent magnet is located between the first permanent magnet and the second permanent magnet. The length of the third permanent magnet along the tangential direction of the rotor core is greater than the first length.

3. The motor rotor according to claim 2, characterized in that: The first end of the third permanent magnet is provided with a first inclined wedge surface, and the second end of the third permanent magnet is provided with a second inclined wedge surface. The first inclined wedge surface is in contact with and abuts against the first pole surface, and the second inclined wedge surface is in contact with and abuts against the second pole surface.

4. The motor rotor according to claim 2, characterized in that: A fourth permanent magnet spaced apart from the third permanent magnet is also installed in the third slot segment, the fourth permanent magnet is located on a side of the third permanent magnet close to the center of the rotor core, and the inner side surface of the fourth permanent magnet is in contact with the inner wall of the third slot segment; One end of the fourth permanent magnet is provided with a third inclined wedge surface, which abuts against the inner end surface of the first permanent magnet, and the other end of the fourth permanent magnet is provided with a fourth inclined wedge surface, which abuts against the inner end surface of the second permanent magnet.

5. The motor rotor according to claim 4, characterized in that: The third permanent magnet and the fourth permanent magnet both extend along a straight line, and the third permanent magnet is parallel to the fourth permanent magnet.

6. The motor rotor according to any one of claims 1 to 5, characterized in that: The included angle between the first slot segment and the third slot segment is φ1, wherein 135°≤φ1≤155°.

7. The motor rotor according to any one of claims 1 to 5, characterized in that: The first permanent magnet and the second permanent magnet are symmetrical along a first straight line, the first straight line passes through the center of the rotating shaft of the rotor core along the radial direction of the rotor core, and the third permanent magnet is perpendicular to the first straight line and symmetrical along the first straight line.

8. The motor rotor according to any one of claims 1 to 5, characterized in that: The first permanent magnet and the second permanent magnet are symmetrical along a first straight line, and the permanent magnet slot group also includes a second permanent magnet slot and a third permanent magnet slot symmetrical along the first straight line, the second permanent magnet slot and the third permanent magnet slot are both located radially outside the third slot segment, and the rotor core is also provided with a magnetic flux sorting slot between the second permanent magnet slot and the third permanent magnet slot.

9. The motor rotor according to claim 8, characterized in that: The second permanent magnet slot includes a fourth slot segment and a fifth slot segment, wherein permanent magnets are respectively installed in the fourth slot segment and the fifth slot segment, and the fifth slot segment is parallel to the second slot segment; The fourth slot segment is arranged at an angle to the fifth slot segment, one end of the fourth slot segment is connected to the fifth slot segment, and the other end of the fourth slot segment extends toward the outer edge of the rotor core.

10. The motor rotor according to any one of claims 1 to 5, characterized in that: The outer edge of the rotor core is provided with a plurality of trimming grooves, the number of the trimming grooves is equal to the number of the permanent magnet slot groups, and each of the trimming grooves is respectively arranged between two adjacent permanent magnet slot groups.

11. A motor, characterized in that: It comprises the motor rotor according to any one of claims 1-10.

12. A compressor, characterized in that: It comprises the motor as claimed in claim 11.

13. A household appliance, characterized in that: It comprises the motor as claimed in claim 11.

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