Motor rotor, motor, compressor, air conditioner

Abstract

The present invention provides a motor rotor, a motor, a compressor, and an air conditioner, wherein the motor rotor includes a rotor core, the rotor core has a plurality of magnetic poles arranged along its circumference, and under the same magnetic pole, the rotor core is constructed with a plurality of V-shaped magnetic steel grooves arranged in sequence along the circumference of the rotor core, the V-shaped openings of the plurality of V-shaped magnetic steel grooves face the outer circle of the rotor core, the V-shaped magnetic steel groove has a first groove section and a second groove section intersecting to form a V shape, and magnetic steel is respectively arranged in the first groove section and the second groove section. According to the present invention, under the same magnetic pole, there are a plurality of magnetic pole centers arranged along the circumference of the rotor core, which can change the magnetic pole magnetic field from a waveform of air gap magnetic density with large distortion at both ends and a sharp narrowing to a structure with a small distortion rate at both ends and a pit in the middle, thereby reducing the harmonic content at both ends of the air gap magnetic density, and at the same time increasing the effective value of the air gap magnetic density, improving the excitation of the motor, increasing the motor output, while reducing the motor harmonics and improving the motor vibration.

Description

Technical Field

[0001] The invention belongs to the technical field of motor manufacturing, and in particular relates to a motor rotor, a motor, a compressor and an air conditioner. Background Art

[0002] The existing variable frequency air conditioner is a permanent magnet synchronous motor, using a permanent magnet rotor structure. The industry mostly uses a single-layer or multi-layer "I", "V", or "U" shaped magnetic steel structure. If the number of poles is p, then the corresponding number of magnetic pole centers is also p. For example Figure 5 The number of rotor poles with a straight-line magnetic steel structure is 6, and the corresponding number of magnetic pole centers is also 6. Figure 6 The number of rotor poles with a V-shaped magnetic steel structure is 6, and the corresponding number of magnetic pole centers is also 6. This structure will cause large harmonics in the motor's air gap magnetic density, and the motor's electromagnetic force is mainly affected by the motor's air gap magnetic density. The large number of air gap magnetic density harmonics leads to more harmonics of various orders and orders of the motor, generating harmonic electromagnetic forces. The motor, as the vibration source of the compressor, will excite vibrations of various orders of the compressor, causing the compressor to vibrate more. Summary of the invention

[0003] Therefore, the present invention provides a motor rotor, a motor, a compressor, and an air conditioner, which can overcome the shortcomings of the related art that the magnetic field air gap flux density waveform corresponding to the rotor magnetic pole with a single magnetic pole center has large distortion at both ends, high harmonic content, and low effective value of the air gap flux density, which leads to large vibration of the motor and the corresponding motor using the same.

[0004] In order to solve the above problems, the present invention provides a motor rotor, including a rotor core, the rotor core having a plurality of magnetic poles arranged along its circumference, and under the same magnetic pole, the rotor core is constructed with a plurality of V-shaped magnetic steel slots arranged in sequence along the circumference of the rotor core, the V-shaped openings of the plurality of V-shaped magnetic steel slots face one side of the outer circle of the rotor core, the V-shaped magnetic steel slot has a first slot segment and a second slot segment intersecting to form the V-shape, and magnetic steels are respectively provided in the first slot segment and the second slot segment.

[0005] In some embodiments, the plurality of V-shaped magnetic steel grooves include a first V-shaped magnetic steel groove and a second V-shaped magnetic steel groove, the first V-shaped magnetic steel groove is provided with a first magnetic steel and a second magnetic steel arranged in a V shape, the second V-shaped magnetic steel groove is provided with a third magnetic steel and a fourth magnetic steel arranged in a V shape, the magnetic pole has a D axis, the first V-shaped magnetic steel groove and the second V-shaped magnetic steel groove are symmetrical about the D axis, the first magnetic steel and the fourth magnetic steel are symmetrical about the D axis, and the second magnetic steel and the third magnetic steel are symmetrical about the D axis; or, the magnetic pole has a D axis, and the plurality of V-shaped magnetic steel grooves are symmetrical about the D axis.

[0006] In some embodiments, the V-shaped angle of the first V-shaped magnetic steel groove is c, 90°≤c≤125°.

[0007] In some embodiments, the second magnetic steel and the third magnetic steel form an angle d, 80°≤d≤100°.

[0008] In some embodiments, a first magnetic steel slot is provided on the side of the first V-shaped magnetic steel slot and the second V-shaped magnetic steel slot facing the axis of the rotor core, a first auxiliary magnetic steel is installed in the first magnetic steel slot, and the radial outer magnetic properties of the first auxiliary magnetic steel are the same as the radial outer magnetic properties of the first magnetic steel, the second magnetic steel, the third magnetic steel, and the fourth magnetic steel, respectively.

[0009] In some embodiments, the first magnetic steel slot is a straight-line slot, the first auxiliary magnetic steel is a straight-line magnetic steel, and the first magnetic steel slot and the first auxiliary magnetic steel are symmetrical about the D axis.

[0010] In some embodiments, a radial distance between the radial inner side of the first auxiliary magnetic steel and the axial center of the rotor core is f, 0.35g≤f≤0.4g, where g is the outer diameter of the rotor core.

[0011] In some embodiments, a second magnetic steel slot is further constructed on the rotor core corresponding to the area between two adjacent magnetic poles, and a second auxiliary magnetic steel is installed in the second magnetic steel slot. The magnetic properties of the circumferential first side of the second auxiliary magnetic steel are the same as the magnetic properties of the radial outer side of the first auxiliary magnetic steel in the magnetic pole adjacent to the first side.

[0012] In some embodiments, the rotor core has a Q-axis, and the second auxiliary magnetic steel is symmetrical about the Q-axis.

[0013] In some embodiments, a radial distance between a side of the second auxiliary magnetic steel close to the axis of the rotor core and the axis of the rotor core is e, 0.25g≤e≤0.35g, where g is an outer diameter of the rotor core.

[0014] In some embodiments, the number of magnetic poles of the rotor core is 2p, the number of the V-shaped magnetic steel slots is a, a≤6p; and / or the sum of the number of the first magnetic steel slots and the second magnetic steel slots is b, b≤4p.

[0015] The present invention also provides a motor, comprising the motor rotor mentioned above.

[0016] The present invention also provides a compressor, comprising the above-mentioned motor.

[0017] The present invention also provides an air conditioner, comprising the above-mentioned compressor.

[0018] The present invention provides a motor rotor, a motor, a compressor, and an air conditioner. The multiple V-shaped magnetic steel grooves enable the same magnetic pole to have multiple magnetic pole centers arranged along the circumference of the rotor core. Compared with the motor rotor with a single magnetic pole center in the related art, the magnetic pole magnetic field can be changed from a waveform of air gap flux density with large distortion at both ends and a sharp narrowing to a structure with a small distortion rate at both ends and a pit in the middle, thereby reducing the harmonic content at both ends of the air gap flux density and increasing the effective value of the air gap flux density, thereby improving the excitation of the motor, increasing the motor output, reducing the motor harmonics, and improving the motor vibration. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the structure of the motor rotor of an embodiment of the present invention (axial projection), which shows the situation that there are two magnetic pole centers under each magnetic pole;

[0020] Figure 2 Schematic diagram of the structure of the motor rotor of an embodiment of the present invention (axial projection);

[0021] Figure 3 Schematic diagram of the structure of the motor rotor of an embodiment of the present invention (axial projection), showing the position parameters of related components;

[0022] Figure 4 It is a schematic diagram of a straight-line magnetic steel structure in the related art having a single magnetic pole center under each magnetic pole;

[0023] Figure 5 It is a schematic diagram of a V-shaped magnetic steel structure in the related art having a single magnetic pole center under each magnetic pole;

[0024] Figure 6 for Figure 5 A comparison diagram of the air gap flux density of a motor rotor with a single magnetic pole center, a motor rotor with multiple magnetic pole centers having the main pole magnetic steel structure of the present application, and a motor rotor with the main pole magnetic steel structure and the auxiliary pole magnetic steel structure of the present application.

[0025] The reference numerals are:

[0026] 1. rotor core; 11. first V-shaped magnetic steel slot; 111. first magnetic steel; 112. second magnetic steel; 12. second V-shaped magnetic steel slot; 121. third magnetic steel; 122. fourth magnetic steel; 2. first magnetic steel slot; 21. first auxiliary magnetic steel; 3. second magnetic steel slot; 31. second auxiliary magnetic steel. DETAILED DESCRIPTION

[0027] See also Figures 1 to 6As shown, according to an embodiment of the present invention, a motor rotor is provided, including a rotor core 1, wherein the rotor core 1 has a plurality of magnetic poles arranged along its circumferential direction, and it can be understood that the magnetic properties of two adjacent magnetic poles are opposite (N pole or S pole), and under the same magnetic pole (which can be N pole or S pole), the rotor core 1 is constructed with a plurality of V-shaped magnetic steel slots arranged in sequence along the circumferential direction of the rotor core 1, and the V-shaped openings of the plurality of V-shaped magnetic steel slots face one side of the outer circle of the rotor core 1, and the V-shaped magnetic steel slot has a first slot segment and a second slot segment intersecting to form the V-shape, and magnetic steels are respectively arranged in the first slot segment and the second slot segment, and the intersection of the perpendicular midlines of the opposite sides of the magnetic steels respectively arranged in the first slot segment and the second slot segment forms the magnetic pole center of the corresponding V-shaped magnetic steel slot (as shown in FIG. Figure 1 As shown in FIG. 1 , the plurality of V-shaped magnetic steel slots enable the same magnetic pole to have a plurality of magnetic pole centers arranged along the circumference of the rotor core 1 , compared with the motor rotor with a single magnetic pole center in the related art (e.g. Figure 5 The motor rotor of the structure shown in the figure can change the magnetic pole magnetic field from a sharply narrowed air gap flux waveform with large distortion at both ends to a structure with small distortion rate at both ends and a pit in the middle, thereby reducing the harmonic content at both ends of the air gap flux and increasing the effective value of the air gap flux (Bavg), thereby improving the excitation of the motor, increasing the motor output, reducing the motor harmonics and improving the motor vibration.

[0028] Specifically, the plurality of V-shaped magnetic steel slots and the magnetic steels arranged therein together constitute a main pole magnetic steel structure under a magnetic pole of the rotor core 1, and the main pole magnetic steel structure has a plurality of magnetic pole centers, which can correct the air gap magnetic flux edge magnetic field, so that the air gap magnetic flux edge magnetic field distortion rate is reduced, and at the same time, the effective air gap magnetic flux can be greatly provided, which is B avg Provide the greatest contribution, understandable, B avg ∝Magnetic flux ψ PM , and through the motor torque formula (1), the first half is the torque generated by the motor permanent magnet, which increases with the flux linkage ψ PM The increase in can effectively increase the permanent magnet torque generated by the permanent magnet, thereby increasing the output torque T of the motor. em :

[0029]

[0030] In the above formula, p is the number of pole pairs, pieces; β is the angle between is and d axis, °; Ld is the direct axis inductance, H; Lq is the quadrature axis inductance, H; is is the stator current, A.

[0031] As a specific implementation, preferably, the plurality of V-shaped magnetic steel grooves include a first V-shaped magnetic steel groove 11 and a second V-shaped magnetic steel groove 12, wherein the first V-shaped magnetic steel groove 11 is provided with a first magnetic steel 111 and a second magnetic steel 112 arranged in a V shape, and the second V-shaped magnetic steel groove 12 is provided with a third magnetic steel 121 and a fourth magnetic steel 122 arranged in a V shape, and the magnetic pole has a D axis, and the first V-shaped magnetic steel groove 11 and the second V-shaped magnetic steel groove 12 are symmetrical about the D axis, the first magnetic steel 111 and the fourth magnetic steel 122 are symmetrical about the D axis, and the second magnetic steel 112 and the third magnetic steel 121 are symmetrical about the D axis; or, the magnetic pole has a D axis, and the plurality of V-shaped magnetic steel grooves are symmetrical about the D axis, and the magnetic steel structure symmetrical about the D axis makes the magnetic pole magnetic field corresponding to the magnetic pole symmetrical, and can make the two ends of the air gap magnetic density waveform symmetrical, and the periodic operation is more stable. The V-shaped structure of the first V-shaped magnetic steel groove 11 itself can be symmetrical or asymmetrical.

[0032] In some embodiments, the V-shaped angle of the first V-shaped magnetic steel slot 11 is c, 90°≤c≤125°, and the V-shaped angle of the first V-shaped magnetic steel slot 11 is limited within this angle range, which can control the air gap magnetic flux distortion rate of the motor to be less than 30%, and the effective value of the air gap magnetic flux Bavg>0.65T. The second magnetic steel 112 and the third magnetic steel 121 form an angle d, 80°≤d≤100°, and the angle of the second magnetic steel 112 and the third magnetic steel 121 is limited within this angle range, which can control the air gap magnetic flux distortion rate of the motor to be less than 30%, and the effective value of the air gap magnetic flux Bavg>0.65T.

[0033] In some embodiments, the first V-shaped magnetic steel slot 11 and the second V-shaped magnetic steel slot 12 are provided with a first magnetic steel slot 2 on the side facing the axis of the rotor core 1, and the first auxiliary magnetic steel 21 is installed in the first magnetic steel slot 2. The magnetic properties of the radial outer side of the first auxiliary magnetic steel 21 are the same as the magnetic properties of the radial outer sides of the first magnetic steel 111, the second magnetic steel 112, the third magnetic steel 121, and the fourth magnetic steel 122. The setting of the first auxiliary magnetic steel 21 can correct the harmonics of the magnetic steel at the edge of the magnetic density and improve the magnetic density amplitude. The best is that the first magnetic steel slot 2 is a straight slot, the first auxiliary magnetic steel 21 is a straight magnetic steel, and the first magnetic steel slot 2 and the first auxiliary magnetic steel 21 are symmetrical about the D axis, which can make the two ends of the air gap magnetic density waveform symmetrical and the periodic operation more stable.

[0034] In some embodiments, the radial distance between the radial inner side of the first auxiliary magnetic steel 21 and the axis center of the rotor core 1 is f, 0.35g≤f≤0.4g, wherein g is the outer diameter of the rotor core 1. By limiting the radial distance between the radial inner side of the first auxiliary magnetic steel 21 and the axis center of the rotor core 1 within this range, the air gap magnetic flux distortion rate of the motor can be controlled to be less than 30%, and the effective value of the air gap magnetic flux Bavg>0.65T.

[0035] In some embodiments, a second magnetic steel slot 3 is further constructed on the rotor core 1 corresponding to the area between two adjacent magnetic poles, and a second auxiliary magnetic steel 31 is installed in the second magnetic steel slot 3. The magnetic properties of the circumferential first side of the second auxiliary magnetic steel 31 are the same as the magnetic properties of the radial outer side of the first auxiliary magnetic steel 21 in the magnetic pole adjacent to the first side. By setting the second auxiliary magnetic steel 31, the middle pit of the air gap magnetic field generated by the first magnetic steel 111, the second magnetic steel 112, the third magnetic steel 121, and the fourth magnetic steel 122 can be filled to improve the sinusoidality of the magnetic field curve. Preferably, the rotor core 1 has a Q axis, and the second auxiliary magnetic steel 31 is symmetrical about the Q axis, which can make the middle section of the air gap magnetic density waveform symmetrical and the periodic operation more stable. It should be noted that the first auxiliary magnetic steel 21 and the second auxiliary magnetic steel 31 together constitute the auxiliary pole magnetic steel structure of the motor rotor of the present invention.

[0036] In some embodiments, the radial distance between the side of the second auxiliary magnetic steel 31 close to the axis of the rotor core 1 and the axis of the rotor core 1 is e, 0.25g≤e≤0.35g, and the radial distance between the side of the second auxiliary magnetic steel 31 close to the axis of the rotor core 1 and the axis of the rotor core 1 is limited to this range, which can control the air gap magnetic flux distortion rate of the motor to be less than 30%, and the effective value of the air gap magnetic flux Bavg>0.65T.

[0037] In order to simplify the magnetic pole structure design of the motor rotor, in some embodiments, the number of magnetic poles of the rotor core 1 is 2p, the number of the V-shaped magnetic steel slots is a, a≤6p; and / or the sum of the number of the first magnetic steel slots 2 and the second magnetic steel slots 3 is b, b≤4p. Figures 1 to 3 In the motor rotor shown in FIG. , p=3, a=12, and b=12. Each magnetic steel can be, for example, a permanent magnet commonly used.

[0038] In the present invention, based on the main pole structure of the plurality of V-shaped magnetic steel slots and the plurality of magnetic steels arranged therein, and through the auxiliary arrangement of the first auxiliary magnetic steel 21 and the second auxiliary magnetic steel 31, the air gap magnetic density of the motor can be adjusted together. According to formulas (2) and (3), the electromagnetic force of the motor is affected by the air gap magnetic density B of the motor, and the electromagnetic force is the main excitation source of the motor vibration. Through this invention, the vibration of the motor can be effectively reduced.

[0039]

[0040]

[0041] In formulas (2) and (3), pr is the radial electromagnetic force, N / m 2 ; pt is the tangential electromagnetic force, N / m 2 ; Br is the radial air gap magnetic flux, T; Bt is the tangential air gap magnetic flux, T; μ0 is the vacuum magnetic permeability, H / m.

[0042] See also Figure 6 As shown, the 0° position in the figure corresponds to Figure 2 The stator-rotor air gap at the D-axis position in the figure is shown in the figure. From the D-axis under one magnetic pole, the motor rotor rotates 60° clockwise (or counterclockwise) to the D-axis under the next adjacent magnetic pole. Figure 5 The air gap flux density curves of the motor rotor with a single magnetic pole center, the motor rotor with multiple magnetic pole centers having the main pole magnetic steel structure of the present application, and the motor rotor with the main pole magnetic steel structure and the auxiliary pole magnetic steel structure of the present application. Figure 6 The following table data can be obtained:

[0043]

[0044] Compared with the original conventional "V"-shaped scheme (conventional scheme), after it becomes two-section main pole (only main pole structure), although there is an obvious pit in the middle section of the air gap magnetic flux, the edge magnetic flux is significantly increased, as shown in the above table, the effective value of the air gap magnetic flux increases by 3.2% and the harmonics decrease by 1.2%; adding two sections of auxiliary pole structure (main pole + auxiliary pole structure) further optimizes the edge and center of the air gap magnetic flux. As shown in the above table, the effective value of the air gap magnetic flux increases by 10% and the harmonics decrease by 16.1%, which greatly increases the air gap magnetic flux and significantly reduces the harmonic content, thereby improving the motor output and reducing the motor electromagnetic force harmonics.

[0045] According to an embodiment of the present invention, there is further provided a motor, comprising the motor rotor described above.

[0046] According to an embodiment of the present invention, a compressor is also provided, comprising the above-mentioned motor.

[0047] According to an embodiment of the present invention, there is also provided an air conditioner, comprising the above-mentioned compressor.

[0048] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0049] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention. The above are only preferred embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present invention, and these improvements and variations should also be regarded as the protection scope of the present invention.

Claims

1. A motor rotor, characterized in that: The invention comprises a rotor core (1), the rotor core (1) having a plurality of magnetic poles arranged along its circumferential direction, the rotor core (1) having a plurality of V-shaped magnetic steel slots arranged in sequence along the circumferential direction of the rotor core (1) under the same magnetic pole, the V-shaped openings of the plurality of V-shaped magnetic steel slots facing one side of the outer circle of the rotor core (1), the V-shaped magnetic steel slot having a first slot segment and a second slot segment intersecting to form the V-shape, the first slot segment and the second slot segment respectively having magnetic steel; the V-shaped magnetic steel slot comprises a first V-shaped magnetic steel slot ( 11), a second V-shaped magnetic steel groove (12), the first V-shaped magnetic steel groove (11) is provided with a first magnetic steel (111) and a second magnetic steel (112) arranged in a V shape, the second V-shaped magnetic steel groove (12) is provided with a third magnetic steel (121) and a fourth magnetic steel (122) arranged in a V shape, the magnetic pole has a D axis, the first V-shaped magnetic steel groove (11) and the second V-shaped magnetic steel groove (12) are symmetrical about the D axis, and the first magnetic steel (111) and the fourth magnetic steel (122) are symmetrical about the D axis. The second magnetic steel (112) and the third magnetic steel (121) are symmetrical about the D axis; the magnetic pole has a D axis, and the plurality of V-shaped magnetic steel slots are symmetrical about the D axis; a first magnetic steel slot (2) is provided between the first V-shaped magnetic steel slot (11) and the second V-shaped magnetic steel slot (12) on the side facing the axis of the rotor core (1), and a first auxiliary magnetic steel (21) is installed in the first magnetic steel slot (2), and the magnetic properties of the radial outer side of the first auxiliary magnetic steel (21) are similar to those of the first magnetic steel (111) and the second magnetic steel (121). The radial outer magnetic properties of the first magnetic steel (112), the third magnetic steel (121), and the fourth magnetic steel (122) are all the same; a second magnetic steel slot (3) is also constructed on the rotor core (1) corresponding to the area between two adjacent magnetic poles, and a second auxiliary magnetic steel (31) is installed in the second magnetic steel slot (3); the magnetic properties of the circumferential first side of the second auxiliary magnetic steel (31) are the same as the magnetic properties of the radial outer side of the first auxiliary magnetic steel (21) in the magnetic pole adjacent to the first side; and the first magnetic steel slot (2) is a straight slot.

2. The motor rotor according to claim 1, characterized in that: The V-shaped angle of the first V-shaped magnetic steel groove (11) is c, 90°≤c≤125°.

3. The motor rotor according to claim 1, characterized in that: The second magnetic steel (112) and the third magnetic steel (121) form an angle d, 80°≤d≤100°.

4. The motor rotor according to claim 1, characterized in that: The first auxiliary magnetic steel (21) is a straight-line magnetic steel, and the first magnetic steel slot (2) and the first auxiliary magnetic steel (21) are symmetrical about the D axis.

5. The motor rotor according to claim 4, characterized in that: The radial distance between the radial inner side of the first auxiliary magnetic steel (21) and the axis of the rotor core (1) is f, 0.35g≤f≤0.4g, where g is the outer diameter of the rotor core (1).

6. The motor rotor according to claim 1, characterized in that: The rotor core (1) has a Q axis, and the second auxiliary magnetic steel (31) is symmetrical about the Q axis.

7. The motor rotor according to claim 6, characterized in that: The radial distance between the side of the second auxiliary magnetic steel (31) close to the axis of the rotor core (1) and the axis of the rotor core (1) is e, 0.25g≤e≤0.35g, where g is the outer diameter of the rotor core (1).

8. The motor rotor according to claim 1, characterized in that: The number of magnetic poles of the rotor core (1) is 2p, the number of the V-shaped magnetic steel slots is a, a≤6p; and / or the sum of the number of the first magnetic steel slots (2) and the second magnetic steel slots (3) is b, b≤4p.

9. A motor, comprising a motor rotor, characterized in that: The motor rotor is the motor rotor according to any one of claims 1 to 8.

10. A compressor, comprising a motor, characterized in that: The motor is the motor described in claim 9.

11. An air conditioner, comprising a compressor, characterized in that: The compressor is the compressor described in claim 10.

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