Inner stator core, outer rotor motor, compressor

Abstract

The present invention provides an inner stator core, an outer rotor motor, and a compressor. The inner stator core includes a core outer ring and a core inner ring. The core outer ring includes a tooth boot ring and a plurality of uniformly spaced stator teeth on the inner ring wall of the tooth boot ring. The plurality of stator teeth extend radially inward along the core outer ring, and a stator slot is formed between two adjacent stator teeth. The stator slot has a slot opening. The core inner ring includes an inner yoke portion. The inner yoke portion is concentric with the tooth boot ring and is connected to the free ends of the plurality of stator teeth so that the stator slot forms a closed slot. According to the present invention, the stator-rotor air gap is more uniform, and the torque ripple is minimized; it is possible to use the conventional winding equipment for the outer stator core for winding, without separately supporting relevant winding equipment for the inner stator core, thereby reducing the manufacturing cost of the motor.

Description

Technical Field

[0001] The present invention belongs to the technical field of motor manufacturing, and particularly relates to an inner stator core, an outer rotor motor, and a compressor. Background Art

[0002] The current outer rotor motor has a structure in which the outer rotor is sleeved on the outer peripheral side of the inner stator core. For the convenience of winding, most of the stator slots of the inner stator core are radially outward opening slots. Due to the opening of such an opening slot structure, the inner stator core has torque pulsation, low motor energy efficiency, and a corresponding winding device needs to be designed separately for it, and the traditional outer stator core winding device cannot be used, making the winding operation relatively complex. In view of the above problems, a spliced inner core appears in the related art, which can make the stator slots of the inner stator core be closed slots while meeting the winding requirements, thereby reducing the torque pulsation of the motor and improving the motor energy efficiency. However, there is still a seam on the outer side of the stator of this spliced inner stator core, and there is still relatively large torque pulsation. Summary of the Invention

[0003] Therefore, the present invention provides an inner stator core, an outer rotor motor, and a compressor, which can overcome the deficiencies of the relatively large torque pulsation and inconvenient winding of the inner stator core in the related art.

[0004] To solve the above problems, the present invention provides an inner stator core, including an iron core outer ring and an iron core inner ring. The iron core outer ring includes a tooth yoke ring and a plurality of evenly spaced stator teeth on the inner ring wall of the tooth yoke ring. The plurality of stator teeth extend radially inward along the iron core outer ring, and a stator slot is formed between two adjacent stator teeth. The stator slot has a slot opening. The iron core inner ring includes an inner yoke portion, and the inner yoke portion is concentric with the tooth yoke ring and connected to the free ends of the plurality of stator teeth so that the stator slot forms a closed slot.

[0005] Preferably, there are a plurality of evenly spaced slot plug columns on the outer ring wall of the inner yoke portion, and the slot plug columns are embedded in the slot openings of the stator slots.

[0006] Preferably, the iron core outer ring is an integrally formed structure, and / or the iron core inner ring is an integrally formed structure; and / or, there is an interference fit between the outer peripheral wall of the inner yoke portion and the end face of the free end of the stator tooth.

[0007] Preferably, in the projection on a plane perpendicular to the axis of the inner stator core, the bottom of the stator slot is a V-shaped bottom, the opening of the V-shaped bottom faces the slot opening side, the V-shaped bottom is symmetric about the first diameter line of the inner stator core, and the included angle between one side of the V-shaped bottom and the first diameter line is δ, where δ = 57° - 61°.

[0008] Preferably, the sharp corner position at the bottom of the V-shaped groove is an arc, and the arc is concentric with the outer ring of the iron core.

[0009] Preferably, the outer diameter of the outer ring of the iron core is Rs0, the radial thickness corresponding to the arc at the tooth boot ring is b0, and b0 = 0.03 * 2 * π * Rs0 / Ns, where Ns is the number of stator teeth.

[0010] Preferably, when projected onto a plane perpendicular to the axis of the inner stator iron core, the stator teeth have a first wall and a second wall that are parallel to each other, and the radial lengths of the first wall and the second wall are hs, and 0.09 * 2 * Rs0 < hs < 1.05 * 2 * Rs0.

[0011] Preferably, when projected onto a plane perpendicular to the axis of the inner stator iron core, the distance between the first wall and the second wall is bs1, and bs1 = 0.52 * 360 / (2 * Ns).

[0012] Preferably, when projected onto a plane perpendicular to the axis of the inner stator iron core, the circumferential width of the slot plug is w0, and w0 = 0.48 * 360 / (2 * Ns); and / or, when projected onto a plane perpendicular to the axis of the inner stator iron core, the radial height of the slot plug is hj, and hj = 0.1hs.

[0013] Preferably, the inner yoke portion has a central through hole, and the diameter of the central through hole is Rsi, and 0.6 * Rs0 < Rsi < 0.75 * Rs0.

[0014] Preferably, an oil return flow channel is formed on the inner iron core ring, the oil return flow channel penetrates through the two axial end faces of the inner iron core ring and is spiral, and the spiral oil return flow channel takes the central axis of the central through hole as the spiral winding center line.

[0015] Preferably, the oil return flow channel is formed on the inner wall of the central through hole and is an open slot opening towards the central through hole.

[0016] Preferably, in the radial cross-section of the inner iron core ring, the shape of the open slot is an obtuse triangle, and the obtuse angle of the obtuse triangle is the angle opposite to the opening side of the open slot.

[0017] Preferably, the open slot spirally rotates 180° around the central axis of the central through hole.

[0018] The present invention also provides an outer rotor motor, including an inner stator assembly and an outer rotor assembly sleeved on the outer peripheral side of the inner stator assembly, the inner stator assembly includes an inner stator iron core, and the inner stator iron core is the above-mentioned inner stator iron core.

[0019] Preferably, the outer rotor assembly includes a rotor yoke and a plurality of permanent magnets evenly spaced on the inner circumferential wall of the rotor yoke. The magnetic polarities of two adjacent permanent magnets are opposite to each other. The permanent magnets are symmetric about the second diameter line of the inner stator core, and the circumferential ends of the permanent magnets have trimming edges.

[0020] Preferably, when projected onto a plane perpendicular to the axis of the inner stator core, the permanent magnets are tile-shaped. The central angle of the permanent magnet relative to the center of the inner stator core is θ. On the inner circumferential wall of the permanent magnet, there are a first point and a second point that are symmetric about the second diameter line. The central angles of the first point and the second point relative to the center of the inner stator core are β. The radius of the inner circumferential wall of the permanent magnet is Ri, the radius of the outer circumferential wall of the permanent magnet is Ro, and the length of the trimming edge is e1, where e1 = 0.5*(θ*Ri - β*Ro)*0.83. The starting points of the trimming edges are the first point and the second point.

[0021] Preferably, the number of pole pairs of the outer rotor assembly is Nr, and θ satisfies: 0.87 < θ*2*Nr / 360 < 0.95.

[0022] Preferably, the outer radius of the rotor yoke is Rro, the inner radius of the rotor yoke is Rri, and Rro = 1.14*Rri; and / or, the axial height of the rotor yoke is H1, the total axial height of the permanent magnets is H2, and H1 ≥ H2 ≥ 0.95H1.

[0023] The present invention further provides a compressor, including the above-mentioned outer rotor motor.

[0024] For the inner stator core, outer rotor motor, and compressor provided by the present invention, on the one hand, the inner stator core adopts closed slots without seams at the tooth tip rings, making the stator-rotor air gap between the inner stator core and the matching outer rotor core more uniform, and minimizing torque ripple to the greatest extent; on the other hand, the stator slots have openings facing the radially inner side of the inner stator core, and it is possible to wind the coils using traditional outer stator core winding equipment without the need to separately match relevant winding equipment for the inner stator core, reducing the manufacturing cost of the motor. Description of the Drawings

[0025] Figure 1 is a schematic structural diagram of the inner stator core according to an embodiment of the present invention (projected along the axial direction, that is, a radial plane view);

[0026] Figure 2 is Figure 1 a three-dimensional disassembled structural diagram of the inner stator core in

[0027] Figure 3 is Figure 1Schematic structural diagram of the iron core outer ring in

[0028] Figure 4 is Figure 1 Schematic structural diagram of the iron core inner ring in

[0029] Figure 5 is Figure 1 Schematic diagram of the position arrangement of the opening slots after the circumferential expansion of the central through hole of the iron core inner ring in

[0030] Figure 6 Schematic structural diagram of the outer rotor motor according to an embodiment of the present invention (axial projection, that is, radial plane view, some components are omitted);

[0031] Figure 7 is Figure 6 Schematic structural diagram of the outer rotor assembly in

[0032] Figure 8 is Figure 7 Partial enlarged view at position A in

[0033] Figure 9 Torque ripple curves of the motor under different rotational frequency conditions using closed slots (the present invention) and open slots (the prior art).

[0034] The reference signs are represented as:

[0035] 1. Iron core outer ring; 11. Tooth boot ring; 12. Stator tooth; 121. First wall; 122. Second wall; 13. Stator slot; 2. Iron core inner ring; 21. Inner ring yoke; 211. Central through hole; 212. Oil return flow channel; 22. Slot plug column; 100. Inner stator iron core; 200. Outer rotor assembly; 201. Rotor yoke; 202. Permanent magnet; 203. Trim; 2031. First point; 2032. Second point. Detailed implementation manners

[0036] With reference to Figures 1 to 9As shown, according to an embodiment of the present invention, there is provided an inner stator core including an outer core ring 1 and an inner core ring 2. The outer core ring 1 includes a tooth yoke ring 11 and a plurality of uniformly spaced stator teeth 12 on the inner circumferential wall of the tooth yoke ring 11. The plurality of stator teeth 12 extend radially inward along the outer core ring 1, and a stator slot 13 is formed between two adjacent stator teeth 12. The stator slot 13 has a slot opening. The inner core ring 2 includes an inner yoke portion 21. The inner yoke portion 21 is concentric with the tooth yoke ring 11 and is connected to the free ends of the plurality of stator teeth 12 so that the stator slot 13 forms a closed slot. In this technical solution, on the one hand, the inner stator core uses a closed slot, and there is no seam at the tooth yoke ring 11 of the closed slot, making the stator-rotor air gap between the inner stator core and the matching outer rotor core more uniform, and minimizing torque ripple. On the other hand, the stator slot 13 has an opening facing the radially inner side of the inner stator core, and it is possible to wind the coil around the corresponding stator teeth 12 using a conventional outer stator core winding device without separately supporting relevant winding equipment for the inner stator core, reducing the manufacturing cost of the motor. It should be noted that in combination with Figure 9 As shown, the torque ripple of the closed slot of the present invention is less than that of the open slot at the same frequency under different motor rotation frequencies.

[0037] In some embodiments, there are a plurality of uniformly spaced slot plugs 22 on the outer circumferential wall of the inner yoke portion 21. The slot plugs 22 are fitted into the slot openings of the stator slots 13, which can ensure the reliable fixation of the relative position between the inner yoke portion 21 and the outer core ring 1.

[0038] It can be understood that the outer core ring 1 and the inner core ring 2 are a detachable assembly structure. Before assembling the two, the coil can be wound around the corresponding stator teeth 12 using a conventional outer stator core winding device and then the inner core ring 2 can be assembled.

[0039] In some embodiments, both the outer core ring 1 and the inner core ring 2 are integrally formed structures; there is an interference fit between the outer circumferential wall of the inner yoke portion 21 and the end face of the free end of the stator teeth 12, simplifying the structure of the inner stator core.

[0040] Projected onto a plane perpendicular to the axis of the inner stator core, the bottom of the stator slot 13 is a V-shaped bottom. The opening of the V-shaped bottom faces the slot opening side. The V-shaped bottom is symmetric about the first diameter line of the inner stator core. The included angle between one side of the V-shaped bottom and the first diameter line is δ, and δ = 57° - 61°, preferably 60°, which can ensure the improvement of the magnetic field saturation at the tooth yoke ring 11 corresponding to the stator slot 13.

[0041] In some embodiments, the sharp corner position at the bottom of the V-shaped groove is an arc, and the arc is concentric with the outer ring 1 of the iron core, which can improve the magnetic density saturation and mechanical strength of the corresponding part. To further ensure the magnetic density saturation and mechanical strength, the outer diameter of the outer ring 1 of the iron core is Rs0, and the radial thickness of the arc corresponding to the tooth boot ring 11 is b0, b0 = 0.03 * 2 * π * Rs0 / Ns, where Ns is the number of stator teeth 12.

[0042] Preferably, when projected onto a plane perpendicular to the axis of the inner stator iron core, the stator teeth 12 have a first wall 121 and a second wall 122 that are parallel to each other, which can reduce the assembly difficulty and processing difficulty. The radial lengths of the first wall 121 and the second wall 122 are hs.

[0043] 0.09 * 2 * Rs0 < hs < 1.05 * 2 * Rs0 can provide sufficient space for the motor winding to be inserted and will not cause the problem of too low slot fill factor; when projected onto a plane perpendicular to the axis of the inner stator iron core, the distance between the first wall 121 and the second wall 122 is bs1, bs1 = 0.52 * 360 / (2 * Ns), which can ensure a good magnetic density saturation effect and will not reach oversaturation, keeping the losses of the motor at a low level.

[0044] In some embodiments, when projected onto a plane perpendicular to the axis of the inner stator iron core, the circumferential width of the slot plug 22 is w0, w0 = 0.48 * 360 / (2 * Ns), which makes the slot plug 22 fit more smoothly into the slot opening of the stator slot 13 without displacement deviation; the radial height of the slot plug 22 is hj, hj = 0.1hs. The height of the slot plug 22 satisfying this relationship can improve the reliability of the cooperation between the outer ring 1 of the iron core and the inner ring 2 of the iron core, make full use of the area of the stator slot 13, be convenient for processing and will not overly affect the insertion of the motor winding into the stator slot 13.

[0045] In some embodiments, the inner yoke portion 21 has a central through hole 211, and the diameter of the central through hole is Rsi, 0.6 * Rs0 < Rsi < 0.75 * Rs0, which can ensure the overall structural strength of the inner ring 2 of the iron core.

[0046] In some embodiments, an oil return flow channel 212 is formed on the inner iron core ring 2. The oil return flow channel 212 penetrates through the two axial end faces of the inner iron core ring 2 and is spiral. The spiral oil return flow channel 212 takes the central axis of the central through hole 211 as the spiral surrounding center line, and can collect and guide the oil droplets at one axial end of the inner stator iron core to the other axial end, thereby improving the oil return efficiency. There are multiple oil return flow channels 212, and the multiple oil return flow channels 212 are evenly spaced along the circumferential direction of the central through hole 211. The oil return flow channel 212 can be arranged in the inner yoke portion 21 or formed on the inner wall of the central through hole 211, and is an open slot opening towards the central through hole 211. Correspondingly, in the radial cross-section of the inner iron core ring 2, the shape of the open slot is an obtuse triangle, and the obtuse angle of the obtuse triangle is the angle opposite to the opening side of the open slot. Adopting this structure can reduce the retention of oil in the open slot due to the too small included angle at the bottom of the open slot, increase the smoothness of oil return, and improve the oil return efficiency. In a specific embodiment, the obtuse angle of the obtuse triangle is 105°, and the remaining two acute angles are 45° and 30°.

[0047] In some embodiments, the open slot spirally rotates 180° around the central axis of the central through hole 211. For details, see Figure 5 As shown, when the central through hole 211 is unfolded along its circumferential direction, taking a single oil return flow channel 212 as an example, it starts from one axial end of the inner yoke portion 21 and ends at the midpoint of the unfolded circumference at the other axial end of the inner yoke portion 21. The setting of this path length fully takes into account the design purposes of increasing the opportunity for oil droplet convergence and reducing the oil droplet travel distance, so that the oil droplets can converge sufficiently and fall as soon as possible.

[0048] According to an embodiment of the present invention, an outer rotor motor is further provided, which includes an inner stator assembly and an outer rotor assembly 200 sleeved on the outer peripheral side of the inner stator assembly. The inner stator assembly includes an inner stator iron core 100, and the inner stator iron core 100 is the above-mentioned inner stator iron core. In some embodiments, the outer rotor assembly 200 includes a rotor yoke portion 201 and a plurality of magnetic steels 202 (specifically, permanent magnets for example) evenly spaced on the inner wall of the rotor yoke portion 201. The magnetic polarities of two adjacent magnetic steels 202 are opposite. The magnetic steels 202 are symmetric about the second diameter line of the inner stator iron core 100. The circumferential two ends of the magnetic steels 202 have trimming edges 203. By providing the trimming edges 203 at the circumferential two ends of the magnetic steels 202, the air-gap magnetic density waveform can be optimized, thereby reducing the back electromotive force harmonics and at the same time reducing the amount of magnetic steel used.

[0049] Specifically, when projected onto a plane perpendicular to the axis of the inner stator core, the magnet 202 is a tile-shaped magnet. The central angle of the magnet 202 relative to the center of the inner stator core 100 is θ. On the inner circular wall of the magnet 202, there are a first point 2031 and a second point 2032 that are symmetric about the second diameter line. The central angles of the first point 2031 and the second point 2032 relative to the center of the inner stator core 100 are β. The radius of the inner circular wall of the magnet 202 is Ri, the radius of the outer circular wall of the magnet 202 is Ro, and the length of the cut edge 203 is e1, where e1 = 0.5*(θ*Ri - β*Ro)*0.83. The starting points of the cut edge 203 are the first point 2031 and the second point 2032. The design dimensions of this cut edge fully consider the structural characteristics of the oil return channel 212 in the present invention and the load characteristics at the high-speed stage after optimizing the oil return performance of the motor. Due to the improvement of the oil return rate of the compressor system (when applied to a compressor) by the oil return channel 212, the load condition at the high-speed stage of the motor is alleviated. Therefore, the design of the cut edge is for a relatively light load condition.

[0050] Preferably, the number of pole pairs of the outer rotor assembly 200 is Nr, and θ satisfies: 0.87 < θ*2*Nr / 360 < 0.95. When the magnet is less than this range, the torque ripple of the motor increases significantly, and the energy efficiency drops greatly; when the magnet is greater than this range, the saturation of the motor rotor is too high, resulting in waste of permanent magnet materials.

[0051] Preferably, the radius of the outer ring wall of the rotor yoke 201 is Rro, the radius of the inner ring wall of the rotor yoke 201 is Rri, and Rro = 1.14*Rri; and / or, the axial height of the rotor yoke 201 is H1, and the total axial height of the magnet 202 is H2, where H1 ≥ H2 ≥ 0.95H1. The magnet 202 can be a continuous section in the axial direction or multiple discontinuous sections in the axial direction, but the overall assembled height is H2. The rotor height within this range can meet the requirements of the scheme for the back electromotive force.

[0052] According to an embodiment of the present invention, there is also provided a compressor including the above-mentioned outer rotor motor.

[0053] It is easy for those skilled in the art to understand that, on the premise of no conflict, the above-mentioned advantageous ways can be freely combined and superimposed.

[0054] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention. The above is only the preferred implementation manner of the present invention. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the technical principle of the present invention, several improvements and variations can still be made, and these improvements and variations should also be regarded as within the protection scope of the present invention.

Claims

1. An inner stator core, characterized in that, it includes a core outer ring (1) and a core inner ring (2), wherein the core outer ring (1) includes a tooth boot ring (11) and a plurality of evenly spaced stator teeth (12) on the inner ring wall of the tooth boot ring (11), and the plurality of stator teeth (12) extend radially inward along the core outer ring (1), and a stator slot (13) is formed between two adjacent stator teeth (12), the stator slot (13) has a slot opening, the core inner ring (2) includes an inner yoke portion (21), and the inner yoke portion (21) is concentric with the tooth boot ring (11) and is connected to the free ends of the plurality of stator teeth (12) so that the stator slot (13) forms a closed slot; there are a plurality of evenly spaced slot plug posts (22) on the outer ring wall of the inner yoke portion (21); in the projection on a plane perpendicular to the axis of the inner stator core, the bottom of the stator slot (13) is a V-shaped bottom, the opening of the V-shaped bottom faces the slot opening side, and the V-shaped bottom is symmetric about the first diameter line of the inner stator core; the sharp corner position of the V-shaped bottom is an arc, and the arc is concentric with the core outer ring (1); the outer diameter of the core outer ring (1) is Rs0, and the radial thickness of the tooth boot ring (11) corresponding to the arc is b0, b0 = 0.03 * 2 * π * Rs0 / Ns, where Ns is the number of the stator teeth (12).

2. The inner stator core according to claim 1, characterized in that, the slot plug post (22) is embedded in the slot opening of the stator slot (13).

3. The inner stator core according to claim 2, characterized in that, the core outer ring (1) is an integrally formed structure, and / or the core inner ring (2) is an integrally formed structure; and / or, there is an interference fit between the outer peripheral wall of the inner yoke portion (21) and the end face of the free end of the stator tooth (12).

4. The inner stator core according to claim 1, characterized in that, the included angle between one side of the V-shaped bottom and the first diameter line is δ, and δ = 57° - 61°.

5. The inner stator core according to claim 1, characterized in that, in the projection on a plane perpendicular to the axis of the inner stator core, the stator tooth (12) has a first wall (121) and a second wall (122) that are parallel to each other, and the radial lengths of the first wall (121) and the second wall (122) are hs, and 0.09 * 2 * Rs0 < hs < 1.05 * 2 * Rs0.

6. The inner stator core according to claim 5, characterized in that, in the projection on a plane perpendicular to the axis of the inner stator core, the distance between the first wall (121) and the second wall (122) is bs1, and bs1 = 0.52 * 360 / (2 * Ns).

7. The inner stator core according to claim 5 or 6, characterized in that, in the projection on a plane perpendicular to the axis of the inner stator core, the circumferential width of the slot plug post (22) is w0, w0 = 0.48 * 360 / (2 * Ns); and / or, when projected onto a plane perpendicular to the axis of the inner stator core, the radial height of the slot plug (22) is hj, and hj = 0.1hs.

8. The inner stator core according to claim 1, wherein, the inner yoke portion (21) has a central through-hole (211), and the diameter of the central through-hole is Rsi, 0.6 * Rs0 < Rsi < 0.75 * Rs0.

9. The inner stator core according to claim 8, wherein, an oil return flow channel (212) is formed on the inner iron core ring (2), the oil return flow channel (212) penetrates through the two axial end faces of the inner iron core ring (2) and is spiral, and the spiral oil return flow channel (212) takes the central axis of the central through-hole (211) as the spiral winding center line.

10. The inner stator core according to claim 9, wherein, the oil return flow channel (212) is formed on the inner wall of the central through-hole (211) and is an open slot opening towards the central through-hole (211).

11. The inner stator core according to claim 10, wherein, when projected onto a plane perpendicular to the axis of the inner stator core, the shape of the open slot is an obtuse triangle, and the obtuse angle of the obtuse triangle is the angle opposite to the opening side of the open slot.

12. The inner stator core according to claim 10, wherein, the open slot spirally rotates 180° around the central axis of the central through-hole (211).

13. An outer rotor motor, comprising an inner stator assembly and an outer rotor assembly (200) sleeved on the outer peripheral side of the inner stator assembly, wherein, the inner stator assembly includes an inner stator core (100), and the inner stator core (100) is the inner stator core according to any one of claims 1 to 12.

14. The outer rotor motor according to claim 13, wherein, the outer rotor assembly (200) includes a rotor yoke portion (201) and a plurality of permanent magnets (202) evenly spaced on the inner ring wall of the rotor yoke portion (201), the magnetic properties of two adjacent permanent magnets (202) are opposite, the permanent magnets (202) are symmetric about the second diameter line of the inner stator core (100), and the circumferential two ends of the permanent magnets (202) have trimming edges (203).

15. The outer rotor motor according to claim 14, wherein, Projected onto a plane perpendicular to the axis of the inner stator core, the permanent magnet (202) is a tile-shaped permanent magnet. The central angle of the permanent magnet (202) relative to the center of the inner stator core (100) is θ. On the inner circular wall of the permanent magnet (202), there are a first point (2031) and a second point (2032) that are symmetric about the second diameter line. The central angles of the first point (2031) and the second point (2032) relative to the center of the inner stator core (100) are β. The radius of the inner circular wall of the permanent magnet (202) is Ri, the radius of the outer circular wall of the permanent magnet (202) is Ro, and the length of the cut edge (203) is e1, where e1 = 0.5 * (θ * Ri - β * Ro) * 0.

83. The starting points of the cut edge (203) are the first point (2031) and the second point (2032).

16. The outer rotor motor according to claim 15, characterized in that the number of pole pairs of the outer rotor assembly (200) is Nr, and θ satisfies: 0.87 < θ * 2 * Nr / 360 < 0.

95.

17. The outer rotor motor according to claim 14, characterized in that the outer ring wall radius of the rotor yoke (201) is Rro, the inner ring wall radius of the rotor yoke (201) is Rri, and Rro = 1.14 * Rri; and / or, the axial height of the rotor yoke (201) is H1, and the total axial height of the permanent magnet (202) is H2, where H1 ≥ H2 ≥ 0.95H1.

18. A compressor, characterized in that it includes the outer rotor motor according to any one of claims 13 to 17.

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