Rotor assembly, motor, compressor, air conditioner

Abstract

The present invention provides a rotor assembly, a motor, a compressor, and an air conditioner, wherein the rotor assembly includes a rotor core, a first magnetic steel in a straight line shape and a V-shaped magnetic steel group at both ends of the first magnetic steel are mounted on the rotor core, the coercive force of the first magnetic steel is lower than the coercive force of the magnetic steel in the V-shaped magnetic steel group, the d-axis of the magnetic pole coincides with the symmetry axis of the first magnetic steel, and the V-shaped magnetic steel group is symmetrical about the d-axis, and a first magnetic isolation structure is provided between the end of the first magnetic steel and the V-shaped magnetic steel group, the first magnetic isolation structure includes a magnetic isolation hole body, and the magnetic isolation hole body has a first magnetic isolation groove extending away from the d-axis along the circumference of the rotor core. According to the present invention, the low-coercive force magnetic steel can improve the non-sinusoidal condition of the motor back electromotive force in both the charging and demagnetization conditions, thereby improving the current harmonics and the torque pulsation and harmonic loss caused by the current harmonics, and increasing the running stability and efficiency of the motor; at the same time, the difficulty of charging and demagnetizing the low-coercive force magnetic steel can be reduced.

Description

Technical Field

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

[0002] Variable flux permanent magnet motors can adjust magnetic properties online by using low coercive force magnetic steel, and have broad application prospects in electric vehicles, high-speed machine tools, flywheel energy storage and other fields. However, like conventional permanent magnet motors, they also have problems such as non-sinusoidal back electromotive force and large torque pulsation. In particular, in order to increase the output torque, variable flux motors usually adopt a hybrid permanent magnet structure design, including low coercive force and high coercive force magnetic steel. At the same time, because variable flux motors need to magnetize and demagnetize low coercive force magnetic steel when operating under different working conditions, the internal magnetic circuit structure of variable flux motors is far more complex than that of conventional permanent magnet motors, and its problems such as non-sinusoidal back electromotive force and torque pulsation are more serious. Summary of the invention

[0003] Therefore, the present invention provides a rotor assembly, a motor, a compressor, and an air conditioner, which can overcome the serious shortcomings of the variable flux permanent magnet motor in the related art, such as the non-sinusoidal back electromotive force and the torque pulsation problem.

[0004] In order to solve the above problems, the present invention provides a rotor assembly, including a rotor core, the rotor core having multiple magnetic poles, under the same magnetic pole, the rotor core is equipped with a first magnetic steel in a straight line and a V-shaped magnetic steel group at both ends of the first magnetic steel, the coercive force of the first magnetic steel is lower than the coercive force of the magnetic steel in the V-shaped magnetic steel group, the d-axis of the magnetic pole coincides with the symmetry axis of the first magnetic steel, and the V-shaped magnetic steel group is symmetrical about the d-axis, a first magnetic isolation structure is provided between the end of the first magnetic steel and the V-shaped magnetic steel group, the first magnetic isolation structure includes a magnetic isolation hole body, and the magnetic isolation hole body has a first magnetic isolation groove extending away from the d-axis along the circumference of the rotor core.

[0005] In some embodiments, the magnetic isolation hole body further comprises a second magnetic isolation groove extending away from the d-axis along the circumferential direction of the rotor core, and the first magnetic isolation groove is located radially outside the second magnetic isolation groove.

[0006] In some embodiments, the V-shaped magnetic steel group includes a second magnetic steel in a second magnetic steel slot close to the d-axis and a third magnetic steel in a third magnetic steel slot away from the d-axis, and a third magnetic isolation groove is provided corresponding to the third magnetic steel slot. The third magnetic isolation groove is located on a side of the third magnetic steel slot close to the second magnetic steel slot, and the third magnetic isolation groove extends along the axial direction of the rotor core toward the d-axis.

[0007] In some embodiments, the first magnetic isolation groove, the second magnetic isolation groove and the third magnetic isolation groove are all fan-ring shaped and concentrically arranged; and / or, the magnetic isolation hole body is connected to the first magnetic steel groove and the second magnetic steel groove where the first magnetic steel is located, and the third magnetic isolation groove is connected to the third magnetic steel groove.

[0008] In some embodiments, the radius of the outer circumferential wall of the rotor core is R, the radial distance between the radial outer wall of the first magnetic isolation groove and the outer circumferential wall of the rotor core is R2, and the radial distance between the radial outer wall and the radial inner wall of the first magnetic isolation groove is r2, 0<R2<R / 40, and / or, R / 30≤r2<R / 20; and / or, the radial distance between the radial outer wall of the second magnetic isolation groove and the outer circumferential wall of the rotor core is R3, and the radial distance between the radial outer wall and the radial inner wall of the second magnetic isolation groove is r3, R / 10<R3<R / 12, and / or, R / 30<r3≤R / 20; and / or, the radial distance between the radial outer wall of the third magnetic isolation groove and the outer circumferential wall of the rotor core is R1, and the radial distance between the radial outer wall and the radial inner wall of the third magnetic isolation groove is r1, R / 10<R1<R / 12, and / or, R / 30<r1≤R / 20.

[0009] In some embodiments, the q-axis located in the circumferential extension direction of the first magnetic isolation groove and adjacent to the d-axis is a reference q-axis, the number of magnetic pole pairs on the rotor core is P, the central angle between the slot wall of the first magnetic isolation groove facing the reference q-axis and the reference q-axis is α2, the central angle between the slot wall of the second magnetic isolation groove facing the reference q-axis and the reference q-axis is α3, and the central angle between the slot wall of the third magnetic isolation groove facing the reference q-axis and the reference q-axis is α1, 360° / 18 / P<α1<360° / 10 / P<α2<α3<360° / 6 / P.

[0010] In some embodiments, 360 / 15 / P<α3-α1<360° / 9 / P, 0≤α3-α2<360° / 60 / P.

[0011] In some embodiments, R / 30≤r2<r3≤r1≤R / 20.

[0012] The present invention also provides a motor, comprising the above-mentioned rotor assembly.

[0013] The present invention also provides a compressor, comprising the above-mentioned rotor assembly.

[0014] The present invention also provides an air conditioner, comprising the above-mentioned motor or the above-mentioned compressor.

[0015] The present invention provides a rotor assembly, a motor, a compressor, and an air conditioner, wherein the first magnetic isolation structure is arranged in the area between the end of the first magnetic steel and the V-shaped magnetic steel group, and the first magnetic isolation groove is designed to extend toward the V-shaped interior of the V-shaped magnetic steel group, which can change the corresponding internal magnetic circuit and air gap magnetic field of the motor, so that the low coercive force magnetic steel can improve the non-sinusoidal condition of the motor back electromotive force in both the charging and demagnetization conditions, thereby improving the current harmonics and the torque pulsation and harmonic losses caused by the current harmonics, and increasing the running stability and efficiency of the motor; at the same time, the structure can further reduce the influence of the high coercive force magnetic steel on the low coercive force magnetic steel, and reduce the difficulty of charging and demagnetizing the low coercive force magnetic steel, that is, a smaller current can be used for charging and demagnetization, thereby ensuring that the motor can operate stably and reliably. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of a rotor assembly according to an embodiment of the present invention (axial partial view, under the same magnetic pole);

[0017] Figure 2 This is a comparison diagram of the no-load line back electromotive force of the low coercive force magnetic steel (first magnetic steel) under demagnetization of the technology of the present invention and the prior art;

[0018] Figure 3 It is a comparison diagram of the no-load line back electromotive force of the technology of the present invention and the prior art under the magnetization condition of the low coercive force magnetic steel (first magnetic steel).

[0019] The reference numerals are:

[0020] 1. rotor core; 21. first magnetic steel; 22. second magnetic steel; 23. third magnetic steel; 31. first magnetic isolation groove; 32. second magnetic isolation groove; 33. third magnetic isolation groove. DETAILED DESCRIPTION

[0021] See also Figures 1 to 3As shown, according to an embodiment of the present invention, a rotor assembly is provided, including a rotor core 1, wherein the rotor core 1 has a plurality of magnetic poles, and under the same magnetic pole, a first magnetic steel 21 in the shape of a straight line and a V-shaped magnetic steel group at both ends of the first magnetic steel 21 are installed on the rotor core 1, the coercive force of the first magnetic steel 21 is lower than the coercive force of the magnetic steel in the V-shaped magnetic steel group, the d-axis of the magnetic pole coincides with the symmetry axis of the first magnetic steel 21, and the V-shaped magnetic steel group is symmetrical about the d-axis, and a first magnetic isolation structure is provided between the end of the first magnetic steel 21 and the V-shaped magnetic steel group, and the first magnetic isolation structure includes a magnetic isolation hole body, and the magnetic isolation hole body has a first magnetic isolation groove 31 extending away from the d-axis along the circumferential direction of the rotor core 1, that is, the first magnetic isolation groove 31 extending toward the V-shaped inner part of the V-shaped magnetic steel group. In this technical solution, the first magnetic isolation structure is arranged in the area between the end of the first magnetic steel 21 and the V-shaped magnetic steel group, and the first magnetic isolation groove 21 is designed to extend toward the inside of the V-shaped magnetic steel group, which can change the corresponding internal magnetic circuit and air gap magnetic field of the motor, so that the low coercive force magnetic steel can improve the non-sinusoidal condition of the motor back electromotive force in both the charging and demagnetization conditions, thereby improving the current harmonics and the torque pulsation and harmonic losses caused by the current harmonics, and increasing the running stability and efficiency of the motor; at the same time, the structure can further reduce the influence of the high coercive force magnetic steel on the low coercive force magnetic steel, and reduce the difficulty of charging and demagnetizing the low coercive force magnetic steel, that is, a smaller current can be used for charging and demagnetization, thereby ensuring that the motor can operate stably and reliably.

[0022] In some embodiments, the magnetic isolation hole body also has a second magnetic isolation groove 32 extending away from the d-axis along the circumferential direction of the rotor core 1, and the first magnetic isolation groove 31 is located radially outside the second magnetic isolation groove 32. By arranging the second magnetic isolation groove 32 at the radial inner position of the first magnetic isolation groove 31, the magnetic circuit of the corresponding V-shaped magnetic steel group can be further concentrated in the V-shaped area, thereby further reducing the influence of high coercive force magnetic steel (that is, the magnetic steel in the V-shaped magnetic steel group) on low coercive force magnetic steel (that is, the first magnetic steel 31), thereby reducing the difficulty of charging and demagnetizing the low coercive force magnetic steel.

[0023] In some embodiments, the V-shaped magnetic steel group includes a second magnetic steel 22 located in a second magnetic steel slot close to the d-axis and a third magnetic steel 23 located in a third magnetic steel slot away from the d-axis, and a third magnetic isolation groove 33 is provided corresponding to the third magnetic steel slot. The third magnetic isolation groove 33 is located on a side of the third magnetic steel slot close to the second magnetic steel slot, and the third magnetic isolation groove 33 extends along the axial direction of the rotor core 1 toward the d-axis. The third magnetic isolation groove 33 can further gather the magnetic circuit of the V-shaped magnetic steel group within the V-shaped area, so that the low coercive force magnetic steel can further improve the non-sinusoidal back electromotive force of the motor when it is in the state of charging and demagnetization.

[0024] The first magnetic isolation groove 31, the second magnetic isolation groove 32 and the third magnetic isolation groove 33 can be rectangular grooves. In some embodiments, the first magnetic isolation groove 31, the second magnetic isolation groove 32 and the third magnetic isolation groove 33 are all fan-shaped and concentrically arranged. The fan-shaped and concentric arrangements facilitate the unified setting of the size and relative position of each magnetic isolation groove and simplify the parameter relationship; and / or, the magnetic isolation hole body is connected to the first magnetic steel groove and the second magnetic steel groove where the first magnetic steel 21 is located, and the third magnetic isolation groove 33 is connected to the third magnetic steel groove, which can make the structure of the magnetic isolation hole body and the third magnetic isolation groove 33 simpler.

[0025] In some embodiments, the radius of the outer circumferential wall of the rotor core 1 is R, the radial distance between the radial outer wall of the first magnetic isolation groove 31 and the outer circumferential wall of the rotor core 1 is R2, the radial distance between the radial outer wall and the radial inner wall of the first magnetic isolation groove 31 is r2, 0<R2<R / 40, and / or, R / 30≤r2<R / 20; and / or, the radial distance between the radial outer wall of the second magnetic isolation groove 32 and the outer circumferential wall of the rotor core 1 is R3, The radial distance between the radial outer wall and the radial inner wall of the second magnetic isolation groove 32 is r3, R / 10<R3<R / 12, and / or, R / 30<r3≤R / 20; and / or, the radial distance between the radial outer wall of the third magnetic isolation groove 33 and the outer circumferential wall of the rotor core 1 is R1, and the radial distance between the radial outer wall and the radial inner wall of the third magnetic isolation groove 33 is r1, R / 10<R1<R / 12, and / or, R / 30<r1≤R / 20. In some embodiments, R / 30≤r2<r3≤r1≤R / 20.

[0026] In some embodiments, the q-axis located in the circumferential extension direction of the first magnetic isolation groove 31 and adjacent to the d-axis is a reference q-axis, the number of magnetic pole pairs on the rotor core 1 is P, the center angle between the groove wall of the first magnetic isolation groove 31 facing the reference q-axis and the reference q-axis is α2, the center angle between the groove wall of the second magnetic isolation groove 32 facing the reference q-axis and the reference q-axis is α3, the center angle between the groove wall of the third magnetic isolation groove 33 facing the reference q-axis and the reference q-axis is α4, and the center angle between the groove wall of the third magnetic isolation groove 33 facing the reference q-axis and the reference q-axis is α5. The central angle between the q axes is α1, 360° / 18 / P<α1<360° / 10 / P<α2<α3<360° / 6 / P. For the first magnetic isolation hole 31, by reasonably setting the size of the corresponding central angle α2, the influence of the second magnetic steel 22 and the third magnetic steel 23 of the high coercive force magnetic steel on the first magnetic steel 21 of the low coercive force magnetic steel can be reduced, and the difficulty of charging and demagnetizing the low coercive force magnetic steel can be reduced, that is, a smaller current can be used for charging and demagnetizing, ensuring that the motor can run stably and reliably. Further, 360 / 15 / P<α3-α1<360° / 9 / P, 0≤α3-α2<360° / 60 / P.

[0027] The technical solution of the present invention changes the corresponding internal magnetic circuit and air gap magnetic field of the motor by reasonably setting the spatial relative positions of the first magnetic isolation slot 31, the second magnetic isolation slot 32, and the third magnetic isolation slot 33 and the size of the fan ring, so that the low coercive force magnetic steel can improve the non-sinusoidal back electromotive force of the motor under the condition of charging and demagnetization. At the same time, the sine back electromotive force can improve the torque pulsation and harmonic loss caused by current harmonics and current harmonics, and increase the stability and efficiency of motor operation.

[0028] like Figure 2 and Figure 3 As shown, the non-sinusoidal condition of the no-load back electromotive force of the motor when the low coercive force magnetic steel of the present invention is in the state of magnetization and demagnetization is significantly improved.

[0029] According to an embodiment of the present invention, there is further provided a motor, in particular a variable flux permanent magnet synchronous motor, comprising the above-mentioned rotor assembly.

[0030] According to an embodiment of the present invention, a compressor is further provided, comprising the above-mentioned rotor assembly.

[0031] According to an embodiment of the present invention, there is also provided an air conditioner, comprising the above-mentioned motor or the above-mentioned compressor.

[0032] 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.

[0033] 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 rotor assembly, comprising a rotor core (1), the rotor core (1) having a plurality of magnetic poles, wherein a first magnetic steel (21) in the shape of a straight line and a V-shaped magnetic steel group located at both ends of the first magnetic steel (21) are mounted on the rotor core (1) under the same magnetic pole, the coercive force of the first magnetic steel (21) is lower than the coercive force of the magnetic steel in the V-shaped magnetic steel group, the d-axis of the magnetic pole coincides with the symmetry axis of the first magnetic steel (21), and the V-shaped magnetic steel group is symmetrical about the d-axis, characterized in that: A first magnetic isolation structure is provided between the end of the first magnetic steel (21) and the V-shaped magnetic steel group, the first magnetic isolation structure comprising a magnetic isolation hole body, the magnetic isolation hole body comprising a first magnetic isolation groove (31) extending away from the d-axis along the circumferential direction of the rotor core (1); the magnetic isolation hole body further comprising a second magnetic isolation groove (32) extending away from the d-axis along the circumferential direction of the rotor core (1), the first magnetic isolation groove (31) being located radially outside the second magnetic isolation groove (32).

2. The rotor assembly according to claim 1, characterized in that The V-shaped magnetic steel group comprises a second magnetic steel (22) located in a second magnetic steel slot close to the d-axis and a third magnetic steel (23) located in a third magnetic steel slot away from the d-axis, a third magnetic isolation slot (33) being provided corresponding to the third magnetic steel slot, the third magnetic isolation slot (33) being located on a side of the third magnetic steel slot close to the second magnetic steel slot, and the third magnetic isolation slot (33) extending along the axial direction of the rotor core (1) towards the d-axis.

3. The rotor assembly according to claim 2, characterized in that: The first magnetic isolation groove (31), the second magnetic isolation groove (32) and the third magnetic isolation groove (33) are all in a fan-shaped ring shape and are arranged concentrically; and / or the magnetic isolation hole body is connected to the first magnetic steel groove and the second magnetic steel groove where the first magnetic steel (21) is located, and the third magnetic isolation groove (33) is connected to the third magnetic steel groove.

4. The rotor assembly according to claim 2, characterized in that: The radius of the outer circumferential wall of the rotor core (1) is R, the radial distance between the radial outer wall of the first magnetic isolation groove (31) and the outer circumferential wall of the rotor core (1) is R2, the radial distance between the radial outer wall and the radial inner wall of the first magnetic isolation groove (31) is r2, 0<R2<R / 40, and / or, R / 30≤r2<R / 20; and / or, the radial distance between the radial outer wall of the second magnetic isolation groove (32) and the outer circumferential wall of the rotor core (1) is R3, the radial distance between the radial outer wall of the first magnetic isolation groove (31) and the radial inner wall is r2, 0<R2<R / 40, and / or, R / 30≤r2<R / 20; and / or, the radial distance between the radial outer wall of the second magnetic isolation groove (32) and the outer circumferential wall of the rotor core (1) is R3, The radial distance between the radial outer wall and the radial inner wall of the second magnetic isolation groove (32) is r3, R / 10<R3<R / 12, and / or, R / 30<r3≤R / 20; and / or, the radial distance between the radial outer wall of the third magnetic isolation groove (33) and the outer circumferential wall of the rotor core (1) is R1, and the radial distance between the radial outer wall and the radial inner wall of the third magnetic isolation groove (33) is r1, R / 10<R1<R / 12, and / or, R / 30<r1≤R / 20.

5. The rotor assembly according to claim 4, characterized in that: The q-axis located in the circumferential extension direction of the first magnetic isolation groove (31) and adjacent to the d-axis is a reference q-axis, the number of magnetic pole pairs on the rotor core (1) is P, the center angle between the groove wall of the first magnetic isolation groove (31) facing the reference q-axis and the reference q-axis is α2, the center angle between the groove wall of the second magnetic isolation groove (32) facing the reference q-axis and the reference q-axis is α3, and the center angle between the groove wall of the third magnetic isolation groove (33) facing the reference q-axis and the reference q-axis is α1, 360° / 18 / P<α1<360° / 10 / P<α2<α3<360° / 6 / P.

6. The rotor assembly according to claim 5, characterized in that 360 / 15 / P<α3-α1<360° / 9 / P, 0≤α3-α2<360° / 60 / P.

7. The rotor assembly according to claim 4 or 5, characterized in that: R / 30≤r2<r3≤r1≤R / 20.

8. A motor, characterized in that: A rotor assembly comprising any one of claims 1 to 7.

9. A compressor, characterized in that: A rotor assembly comprising any one of claims 1 to 7.

10. An air conditioner, characterized in that: Includes the motor as claimed in claim 8, or the compressor as claimed in claim 9.

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