Motor

Abstract

The invention provides a motor, the motor comprises a rotor pressing plate and a rotor iron core, the rotor iron core comprises a first silicon steel sheet, and the first silicon steel sheet is provided with magnetic steel grooves with the same layout so as to accommodate permanent magnets; a pressing plate body of the rotor pressing plate comprises at least one layer of second silicon steel sheets, and each layer of second silicon steel sheets is provided with magnetic steel grooves which are the same as the first silicon steel sheets in layout. The pressing plate body and the rotor iron core are staggered and overlapped at a target angle in the axial direction, so that an overlapping area exists between a partial area of each permanent magnet and the pressing plate body. In the rotor pressing plate, the pressing plate body is realized through the silicon steel sheet, and a stainless steel pressing plate is manufactured without adopting a special process, so that the manufacturing cost and the material cost can be saved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of motors, and in particular to a motor. Background Art

[0002] Due to its advantages of high efficiency, high torque density, high power factor, etc., permanent magnet synchronous motors are widely used in various fields such as industry and household appliances. For permanent magnet synchronous motors, the permanent magnets are inserted into the magnetic steel slots inside the rotor core, and the rotor pressure plate is fixed to the end of the rotor core by rivets. The rotor pressure plate not only fixes the permanent magnets in the axial direction, but also has a direct impact on the stability, noise control and thermal management of the motor. In the prior art, the rotor pressure plate material of the motor is usually stainless steel. The rotor pressure plate includes a pressure plate body, an axial hole and a rivet hole. A special process is required to manufacture the stainless steel pressure plate, and its manufacturing cost and material cost are both relatively high. Summary of the invention

[0003] The technical problem to be solved by the present disclosure is to provide a motor in order to overcome the above-mentioned defects in the prior art.

[0004] The present invention solves the above technical problems through the following technical solutions:

[0005] A motor comprises a rotor pressure plate and a rotor core, wherein the rotor core comprises a first silicon steel sheet, wherein the first silicon steel sheet is provided with magnetic steel slots with the same layout to accommodate permanent magnets; the pressure plate body of the rotor pressure plate comprises at least one layer of second silicon steel sheets, wherein each layer of the second silicon steel sheets is provided with magnetic steel slots with the same layout as the first silicon steel sheets; the pressure plate body and the rotor core are axially staggered by a target angle so that a partial area of ​​each permanent magnet overlaps with the pressure plate body.

[0006] Optionally, the target angle θ satisfies the following conditions: 0<θ<2π and θ≠k*π / p, k=1, 2, …2p-1, and p is the number of pole pairs of the motor.

[0007] Optionally, the target angle θ satisfies the following conditions: 0<θ<2π and θ=n*π / 2 / p, n=1,3…4p-1, and p is the number of pole pairs of the motor.

[0008] Optionally, the first silicon steel sheet and the second silicon steel sheet are both provided with rivet holes and shaft holes, the rivet holes are located between the magnetic steel slots and the shaft holes, and after the target angle is overlapped, there is at least one rivet hole on the pressure plate body corresponding to the rivet hole on the rotor core.

[0009] Optionally, the number of the rivet holes is an even number, and the rivet holes are evenly distributed along the circumference of the shaft hole.

[0010] Optionally, the centers of at least some of the rivet holes are located on a first target symmetry axis; the first target symmetry axis is the symmetry axis of two magnetic steel slots closest to the rivet holes;

[0011] And / or, the centers of at least some of the rivet holes are located on a second target symmetry axis; the second target symmetry axis is the symmetry axis of the magnetic steel slot closest to the rivet hole.

[0012] Optionally, the rotor pressure plate includes 6 rivet holes, which are evenly distributed along the circumference of the shaft hole, and the centers of 2 rivet holes are located on a first target symmetry axis; the first target symmetry axis is the symmetry axis of the two magnetic steel slots closest to the rivet holes; the centers of 4 rivet holes are located on a second target symmetry axis; the second target symmetry axis is the symmetry axis of the magnetic steel slot closest to the rivet hole.

[0013] Optionally, the minimum distance between the rivet hole and the nearest magnetic steel slot satisfies the minimum distance of the rotor mechanical strength of the motor;

[0014] And / or, the minimum distance between the rivet hole and the shaft hole satisfies the minimum distance required for the mechanical strength of the rotor.

[0015] Optionally, the shape of the permanent magnet includes at least one of the following: crescent-shaped, straight-shaped, V-shaped, double V-shaped, U-shaped, and ▽-shaped.

[0016] Optionally, a magnetic barrier is provided in the magnetic leakage area of ​​the pressure plate body.

[0017] On the basis of being in accordance with the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present disclosure.

[0018] The positive progressive effect of the present disclosure is that in the present disclosure, the pressure plate body of the rotor pressure plate is realized by silicon steel sheets, and there is no need to adopt a special process to manufacture the stainless steel pressure plate, which can save manufacturing cost and material cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic structural diagram of a rotor core having a crescent-shaped permanent magnet provided by an exemplary embodiment of the present disclosure;

[0020] Figure 2 A schematic structural diagram of a rotor pressure plate with crescent-shaped magnetic steel slots provided by an exemplary embodiment of the present disclosure;

[0021] Figure 3 A schematic diagram of a structure of a rotor core and a rotor pressure plate after being stacked is provided in accordance with an exemplary embodiment of the present disclosure;

[0022] Figure 4 A schematic diagram of the structure of a motor provided by an exemplary embodiment of the present disclosure;

[0023] Figure 5 A schematic diagram of another structure of a rotor core and a rotor pressure plate after being stacked according to an exemplary embodiment of the present disclosure;

[0024] Figure 6 A schematic structural diagram of a rotor core with a straight-line permanent magnet provided by an exemplary embodiment of the present disclosure;

[0025] Figure 7 A schematic structural diagram of a rotor pressure plate with a straight-line magnetic steel slot provided in an exemplary embodiment of the present disclosure;

[0026] Figure 8 A schematic diagram of another structure of a rotor core and a rotor pressure plate after being stacked according to an exemplary embodiment of the present disclosure;

[0027] Fig. 9 A schematic diagram of the effect of magnetic field distribution of a rotor pressure plate without magnetic barriers provided by an exemplary embodiment of the present disclosure;

[0028] Fig.10 A schematic structural diagram of a magnetic barrier of a rotor pressure plate provided by an exemplary embodiment of the present disclosure;

[0029] Fig.11 A schematic diagram of the size relationship of a magnetic barrier of a rotor pressure plate provided by an exemplary embodiment of the present disclosure;

[0030] Fig.12 An exemplary embodiment of the present disclosure provides a method for 1 Schematic diagram of the effect of magnetic field distribution on the rotor pressure plate with magnetic barriers;

[0031] Fig.13 A schematic structural diagram of another magnetic barrier of a rotor pressure plate provided by an exemplary embodiment of the present disclosure;

[0032] Fig.14 An exemplary embodiment of the present disclosure provides a method for 2 Schematic diagram of the effect of magnetic field distribution on the rotor pressure plate with magnetic barriers;

[0033] Fig.15 An exemplary embodiment of the present disclosure provides a magnetic flux leakage region L 1 and leakage magnetic area L 2 A schematic diagram of the structure of a motor with a rotor pressure plate having magnetic barriers;

[0034] Fig.16 An exemplary embodiment of the present disclosure provides a Fig. 9A comparative schematic diagram of the no-load back electromotive force of the motor shown, the motor including the rotor pressure plate without magnetic barriers, and the motor including the rotor pressure plate of stainless steel;

[0035] Fig.17 A schematic structural diagram of a motor including a rotor pressure plate without a magnetic barrier provided by an exemplary embodiment of the present disclosure;

[0036] Fig.18 A schematic structural diagram of a motor including a rotor pressure plate with a magnetic barrier provided in an exemplary embodiment of the present disclosure;

[0037] Fig.19 A schematic structural diagram of another magnetic barrier of a rotor pressure plate provided by an exemplary embodiment of the present disclosure;

[0038] Fig. 20 A schematic structural diagram of another magnetic barrier of a rotor pressure plate provided as an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0039] The present disclosure is further described below by way of examples, but the present disclosure is not limited to the scope of the examples.

[0040] Prefixes such as "first" and "second" are used in the embodiments of the present disclosure only to distinguish different description objects, and have no limiting effect on the position, order, priority, quantity or content of the described objects. The use of prefixes such as ordinal numbers to distinguish description objects in the embodiments of the present disclosure does not constitute a limitation on the described objects. For the statement of the described objects, please refer to the description in the context of the claims or embodiments, and no unnecessary limitation should be constituted due to the use of such prefixes. In addition, in the description of the present embodiment, unless otherwise specified, the meaning of "plurality" is two or more.

[0041] The present disclosure provides a motor, see Figure 1 and Figure 2 The motor includes a rotor core 11 and a rotor pressure plate 21. The rotor core 11 includes a first silicon steel sheet. The first silicon steel sheet is provided with magnetic steel slots with the same layout to accommodate permanent magnets 12. The polarities of two adjacent permanent magnets are opposite. In the figure, the blue permanent magnet is N polarity, and the red permanent magnet is S polarity. The pressure plate body of the rotor pressure plate 21 includes at least one layer of second silicon steel sheet, and each layer of the second silicon steel sheet is provided with magnetic steel slots 211 with the same layout as the first silicon steel sheet; the pressure plate body and the rotor core are axially staggered at a target angle so that a partial area of ​​each permanent magnet overlaps with the pressure plate body, so that the pressure plate body can fix the permanent magnet.

[0042] from Figure 1 and Figure 2It can be seen that the rotor core and the rotor pressure plate in this embodiment are completely identical, including structural parameters and materials. The rotor pressure plate and the rotor core are both made of silicon steel sheets, and both are stamped by the rotor core mold, which can save the stamping mold of the rotor pressure plate.

[0043] It should be noted that the number of layers of silicon steel sheets included in the rotor pressure plate can be set according to actual needs, and can be set to 1 layer, 2 layers, 3 layers, or even more.

[0044] In this embodiment, the pressure plate body of the rotor pressure plate is realized by silicon steel sheets, and there is no need to adopt a special process to manufacture the stainless steel pressure plate, which can save manufacturing cost and material cost.

[0045] In one embodiment, the rotor pressure plate and the rotor core are both provided with shaft holes 212, magnetic steel slots 211 and rivet holes 213, and the magnetic steel slots 211 are evenly distributed on the circumference of the rotor pressure plate / rotor core.

[0046] The permanent magnets included in the motor of this embodiment can be permanent magnets of different shapes, and the shapes of the permanent magnets include at least one of the following: crescent-shaped / fan-shaped, straight-shaped, V-shaped, double V-shaped, U-shaped, and ▽-shaped.

[0047] In one embodiment, the target axial overlap angle θ between the pressure plate body and the rotor core satisfies the following conditions: 0<θ<2π and θ≠k*π / p, k=1, 2, ... 2p-1, p is the number of pole pairs of the motor.

[0048] Preferably, θ=n*π / 2 / p, n=1,3…4p-1, and p is the number of pole pairs of the motor.

[0049] In one embodiment, the rivet hole is located between the magnetic steel slot and the shaft hole, and after the target angle is overlapped, there is at least one rivet hole on the pressure plate body corresponding to the rivet hole on the rotor core, so that the rotor pressure plate can be fixed to the end of the rotor core through the rivet hole and rivets, thereby playing the role of fixing the permanent magnet in the axial direction.

[0050] For example, after the rotor pressure plate rotates by an angle of θ, at least q rivet holes of the rotor pressure plate and the rotor core completely overlap in the axial direction, and the rotor pressure plate and the rotor core can be fixed with at least q rivets. In particular, when the rotation angle of the rotor pressure plate is 90°, the number of pole pairs p of the motor is an odd number, and q is 2, the four rivet holes of the rotor core overlap with the four rivet holes of the rotor pressure plate, and the rotor core and the rotor pressure plate can be connected with four rivets.

[0051] In one embodiment, the number of the rivet holes is an even number, and the rivet holes are evenly distributed along the circumference of the shaft hole.

[0052] For example, the number of rivet holes is 2q, q≥2. Two rotor cores are used as rotor pressure plates, which are rotated clockwise or counterclockwise by θ (0<θ<2π and θ≠k*π / p, k=1,2,…2p-1) in the axial direction. At this time, at least q rivet holes of the rotor pressure plate and the rotor core completely overlap, and the rotor pressure plate and the rotor core can be fixed by at least q rivets.

[0053] In one embodiment, the number of rivet holes is 2q, wherein the minimum distance between the q rivet holes and the two nearest magnetic steel slots must be no less than d 1 Distance: The minimum distance between the rivet hole and the shaft hole must be no less than d 2 Distance, d 1 d 2 To meet the minimum distance required for the mechanical strength of the rotor, the positions of the remaining q rivet holes are obtained by rotating the aforementioned q rivet holes counterclockwise or clockwise by a mechanical angle of θ along the circumferential direction, where the preferred value of θ is n*π / 2 / p, n=1,3…4p-1. Similarly, the minimum distance between the remaining q rivet holes and the two nearest magnetic steel slots must be no less than d 3 Distance, the minimum distance between the remaining q rivet holes and the shaft hole must be no less than d 4 Distance, d 3 d 4 The minimum distance required to ensure the mechanical strength of the rotor.

[0054] In one embodiment, the centers of at least some of the rivet holes are located on a first target symmetry axis; the first target symmetry axis is the symmetry axis of the two magnetic steel slots closest to the rivet holes.

[0055] In one embodiment, the centers of at least some of the rivet holes are located on the second target symmetry axis; the second target symmetry axis is the symmetry axis of the magnetic steel slot closest to the rivet hole.

[0056] From the perspective of the symmetry of the motor rotor magnetic circuit, the center position of the q rivet holes is preferably between two adjacent magnetic steel slots corresponding to permanent magnets of different polarities (the first target symmetry axis). Furthermore, on this basis, the remaining q rivet holes are obtained by rotating the above q rivet holes counterclockwise or clockwise by a mechanical angle of θ in the circumferential direction, and the center position of the remaining q rivet holes is on the center line of the magnetic steel slot (the second target symmetry axis).

[0057] by Figure 1 Taking the rotor core shown as an example, M 1 、M 2 、M 3 are rivet holes, which are on the center line (the first target symmetry axis) of the magnetic steel slots where the adjacent permanent magnets with different polarities are located, and their minimum distance from the adjacent magnetic steel slots is d 1 , the minimum distance from the shaft hole is d 2 ;m1 、m 2 、m 3 The rotor core and the rotor pressure plate are rotated 30° counterclockwise (n=1). They are on the center line of the magnetic steel slot (the second target symmetry axis), and their minimum distance from the magnetic steel slot is d 3 , the minimum distance from the shaft hole is d 4 .

[0058] and Figure 1 Correspondingly, see Figure 2 , rivet hole M of rotor pressure plate 1 、M 2 、M 3 Just match the rivet holes m of the rotor core 1 、m 2 、m 3 One-to-one correspondence, at this time, the rotor pressure plate has an overlapping area with the permanent magnet in the axial direction, that is, the rotor pressure plate can block part of the permanent magnet area to achieve the fixation of the permanent magnet. Figure 3 The rotor pressure plate and the rotor core can be fixed axially by three rivets 31, thereby fixing the permanent magnet in the axial direction. It can be understood that q and its target angle can also take other values.

[0059] Figure 4 A schematic diagram of the structure of a motor with q=2, 4 rivet holes and 2 rivets is shown.

[0060] Figure 5 FIG. 1 shows a partial structural schematic diagram of a motor with a target angle of 90° and a crescent-shaped permanent magnet. The target angle is 90°, that is, the pressure plate body and the rotor core are axially staggered by 90°. At this time, the rivet hole M of the pressure plate body 1 、M 2 Just match the rivet holes m of the rotor core 1 、m 2 In one-to-one correspondence, the pressure plate body can block part of the permanent magnet in the axial direction. In the figure, the rotor pressure plate and the rotor core can be fixed in the axial direction by two rivets, thereby fixing the permanent magnet in the axial direction.

[0061] In other implementations, in order to enhance the fixing effect of the rotor pressure plate, two or more rivets may be added to fix the rotor pressure plate and the rotor core.

[0062] In one embodiment, the rotor pressure plate includes 6 rivet holes, the 6 rivet holes are evenly distributed along the circumference of the shaft hole, and the centers of 2 rivet holes are located on the first target symmetry axis; the first target symmetry axis is the symmetry axis of the two magnetic steel slots closest to the rivet holes; the centers of 4 rivet holes are located on the second target symmetry axis; the second target symmetry axis is the symmetry axis of the magnetic steel slot closest to the rivet holes.

[0063] In one embodiment, if p is an odd number, the rotor pressure plate includes 4 rivet holes, the 4 rivet holes are evenly distributed along the circumference, and the center positions of 2 rivet holes are located between two adjacent magnetic steel slots corresponding to permanent magnets of different polarities (first target symmetry axis), and the center positions of the 2 rivet holes are optimally on the center line of the magnetic steel slot (second target symmetry axis).

[0064] Figure 6-8 The partial structural schematic diagrams of the motor respectively show a rotor core with a straight permanent magnet, a rotor pressure plate with a straight magnetic steel slot, and a pressure plate body and the rotor core axially staggered by 90°. The motor in the figure has 4 poles and 6 slots, that is, p=2, the number of rivet holes is 4, that is, q is 2, and the number of rivets is 2. Figure 6 Medium 1 、M 2 are rivet holes, which are located on the center lines of the adjacent magnetic steel slots where the permanent magnets with different polarities are located, and their minimum distance from the adjacent magnetic steel slots is d 1 , the minimum distance from the shaft hole is d 2 , m 1 、m 2 M 1 、M 2 Rotate 45° (n=1) counterclockwise to get the mechanical angle. They are on the center line of the magnetic steel slot, and their minimum distance from the magnetic steel slot is d 3 , the minimum distance from the shaft hole is d 4 . Figure 7 Middle rotor pressure plate and Figure 6 The rotor core shown is 45° apart in the axial direction, and the rivet holes M 1 、M 2 Just match the rivet holes m of the rotor core 1 、m 2 One-to-one correspondence, at this time, the rotor pressure plate can block the permanent magnet in the axial direction. The rotor pressure plate and the rotor core can be fixed in the axial direction by two rivets, thereby fixing the permanent magnet in the axial direction.

[0065] In one embodiment, a magnetic barrier is provided in the magnetic leakage region of the pressure plate body, and the magnetic barrier can block the magnetic leakage flux path of the permanent magnet through the rotor pressure plate, thereby suppressing the magnetic leakage of the rotor pressure plate.

[0066] In this embodiment, a magnetic barrier is provided in the magnetic leakage area of ​​the pressure plate body, thereby effectively reducing the magnetic leakage at the rotor end, avoiding a significant drop in back electromotive force, and ensuring the torque output of the motor under the same current excitation.

[0067] The shape of the magnetic barrier can be circular, rectangular, trapezoidal, etc. In order to achieve the best effect of suppressing the leakage of the rotor pressure plate, the optimal magnetic barrier shape is determined according to the axial overlapping area of ​​the permanent magnet and the rotor pressure plate and / or the shape of the permanent magnet.

[0068] When no magnetic barrier is set, the magnetic field of the rotor pressure plate is as follows: Fig.15 As shown in the figure, due to the high magnetic permeability of the rotor pressure plate, the motor has obvious leakage flux, that is, the leakage flux area L 1 and leakage magnetic area L 2 For the leakage magnetic area L 1 , the leakage flux path is the permanent magnet N pole-rotor core-rotor pressure plate-rotor core-permanent magnet S pole-permanent magnet N pole. For the leakage flux area L 2 , and its leakage flux path is N-pole permanent magnet-rotor core-rotor pressure plate-rotor core-S-pole permanent magnet-rotor core-N-pole permanent magnet and N-pole permanent magnet-rotor pressure plate-S-pole permanent magnet-rotor core-N-pole permanent magnet.

[0069] In one embodiment, the magnetic leakage area includes: a first sub-area located between two adjacent through holes and facing the permanent magnet, that is, Fig.15 The leakage magnetic field L 1 ; The first sub-area L 1 The shape of the first magnetic barrier in the first sub-region is determined according to the shape of the permanent magnet facing the first sub-region.

[0070] The first magnetic barrier can suppress the leakage flux of a single permanent magnet through the rotor pressure plate, and the leakage flux path is the N pole of the single permanent magnet-rotor core-rotor pressure plate-rotor core-S pole of the single permanent magnet-N pole of the single permanent magnet.

[0071] In one embodiment, see Fig.16 and Fig.17 The shape of the first magnetic barrier is based on the first magnetic barrier arcs l connected end to end. 1 , the second magnetic barrier arc l 2 、The third magnetic barrier arc l 3 and the fourth magnetic barrier arc l 4 It is determined that the first magnetic barrier arc, the second magnetic barrier arc, the third magnetic barrier arc and the fourth magnetic barrier arc have the following constraint relationship:

[0072] ; ; ;

[0073] Among them, R 1 , R 2 , R 3 and R 4 They are respectively the first inner arc, the first outer arc, and the first magnetic barrier arc l of the first permanent magnet facing the first magnetic barrier 1 and the second magnetic barrier arc l 2 The radius of the first inner arc, the first outer arc, the first magnetic barrier arc l 1 and the second magnetic barrier arc l2 The center of the circle is the first center O 1 ; a 1 From the first inner arc to the first magnetic barrier arc l 1 The minimum distance, a 2 is the first magnetic barrier arc l 1 To the second magnetic barrier arc l 2 The minimum distance, a 3 From the first outer arc to the second magnetic barrier arc l 2 The minimum distance; h m is the thickness of the permanent magnet; R 5 , R 6 They are respectively the second outer arc of the through hole close to the third magnetic barrier arc, the third magnetic barrier arc l 3 The radius of the second outer arc and the third magnetic barrier arc are both the second center O 2 ; b 1 From the second outer arc to the third magnetic barrier arc l 3 The minimum distance; R 7 , R 8 They are arc l close to the fourth magnetic barrier 4 The radius of the third outer arc of the through hole and the radius of the fourth magnetic barrier arc l 4 The radius of the fourth magnetic barrier arc l 4 The center of the third outer arc is the third center O 3 ; b 2 From the third outer arc to the fourth magnetic barrier arc l 4 The minimum distance.

[0074] Since the leakage flux mainly occurs in the magnetic steel width h m So set the constraint relationship In other implementations, you can also set Setting the constraint relations b1>0 and b2>0 can ensure that the entire rotor pressure plate is connected and has a certain structural strength, thereby preventing deformation caused by centrifugal force after the rotor rotates.

[0075] Fig.16 , Fig.17 The structure of the rotor pressure plate is explained by taking the example of the rotor pressure plate rotating 90° (target angle) counterclockwise relative to the rotor core axis. In actual applications, the target angle can be set according to actual needs.

[0076] In one embodiment, the first center O 1 , the second center O 2 and the third center O 3 The distances to the center O of the shaft hole are equal.

[0077] If the distances from the center of each arc to the center of the shaft hole are different, there exists b 1、b 2 The problem of asymmetric stress is likely to cause deformation of the rotor pressure plate. In this embodiment, the distance from the center of each arc to the center of the shaft hole is set to be the same, then b 1 、b 2 The width is the same, which is beneficial to b 1 、b 2 Evenly distribute the stress after the rotor rotates, thereby reducing or even avoiding the deformation of the rotor pressure plate.

[0078] In one embodiment, ∠O 1 OO 2 =30°; and / or, ∠O 1 OO 3 =30°; the above angles can be determined according to 360° / number of poles / 2. The two angles are set equal to make the left and right magnetic barriers symmetrical.

[0079] It should be noted that b 1 、b 2 、a 1 、a 3 、a 2 The value of cannot be too small and needs to meet the mechanical strength requirements of the rotor. In one embodiment, b 1 、b 2 、a 1 、a 3 、a 2 Both meet the minimum distance required for the motor's rotor mechanical strength.

[0080] See also Fig.18 , the figure shows that the number of stator slots of the motor is 9, the number of poles of the permanent magnet is 6, the shape of the permanent magnet is crescent-shaped, the number of rivets is 4, the rotor pressure plate is rotated 90° (target angle) counterclockwise relative to the rotor core axis, and b 1 =b 2 =0.5mm, a 1 =a 3 =0.5mm, a 2 =4mm, the magnetic field distribution of the rotor pressure plate using the first magnetic barrier, it can be seen that the leakage magnetic area L 1 The magnetic leakage has been significantly suppressed.

[0081] In one embodiment, the magnetic flux leakage area includes: a second sub-area located on one side of the inner arc of the through hole and facing the permanent magnet, that is, Fig.19 Middle leakage magnetic area L 2 The area L facing the permanent magnet 21 The shape of the second magnetic barrier in the second sub-region is determined according to the shape of the permanent magnet facing the second sub-region.

[0082] The second magnetic barrier can suppress the leakage flux of a single permanent magnet through the rotor pressure plate, and the leakage flux path is the N pole of the single permanent magnet-rotor core-rotor pressure plate-rotor core-S pole of the single permanent magnet-N pole of the single permanent magnet.

[0083] In one embodiment, see Fig.19 The shape of the second magnetic barrier located in the second sub-area is based on the fifth magnetic barrier arc l connected end to end in sequence. 5 、The sixth magnetic barrier arc l 6 , the seventh magnetic barrier arc l 7 and the eighth magnetic barrier arc l 8 Determine; the fifth magnetic barrier arc l 5 、The sixth magnetic barrier arc l 6 、The seventh magnetic barrier arc l 7 and the eighth magnetic barrier arc l 8 It has the following constraints:

[0084] ; ; ;

[0085] Among them, R 9 , R 10 , R 11 and R 12 They are the second inner arc, the fourth outer arc, and the fifth magnetic barrier arc l of the permanent magnet facing the second magnetic barrier respectively. 5 and the sixth magnetic barrier arc l 6 The radius of the second inner arc, the fourth outer arc, and the fifth magnetic barrier arc l 5 and the sixth magnetic barrier arc l 6 The center of the circle is the fourth circle center O 4 ;d 1 is the minimum distance from the second inner arc to the fifth magnetic barrier arc, d 2 is the fifth magnetic barrier arc l 5 To the sixth magnetic barrier arc l 6 The minimum distance, d 3 From the fourth outer arc to the sixth magnetic barrier arc l 6 The minimum distance; h m is the thickness of the permanent magnet; R 14 , R ro The seventh magnetic barrier arc l 7 The radius, the outer diameter of the rotor core, the rotor core and the seventh magnetic barrier arc l 7 O is the same center as the hole axis; c 1 From the outer edge of the rotor core to the seventh magnetic barrier arc l 7 The minimum distance; R 16 R is the radius of the third inner arc of the through hole close to the eighth magnetic barrier arc, 17 is the eighth magnetic barrier arc l8 The radius of the eighth magnetic barrier arc l 8 The center of the third inner arc is the fifth center O. 5 ;c 3 From the third inner arc to the eighth magnetic barrier arc l 8 The minimum distance.

[0086] Since the leakage flux mainly occurs in the magnetic steel width h m So set the constraint relationship In other implementations, you can also set . Set constraint relationship c 1 >0, c 3 >0 can ensure that the entire rotor pressure plate is connected and has a certain structural strength to prevent deformation caused by centrifugal force after the rotor rotates.

[0087] In one embodiment, the second sub-region includes two second magnetic barriers, and the two second magnetic barriers are symmetrically distributed about the target symmetry axis; the target symmetry axis is the symmetry axis of the permanent magnets that the two second magnetic barriers are facing respectively. Fig.19 The fifth magnetic barrier arc l 9 、The sixth magnetic barrier arc l 10 、The seventh magnetic barrier arc l 11 and the eighth magnetic barrier arc l 12 The magnetic barrier formed is another symmetrical magnetic barrier. The parameters and constraint relationships of the two second magnetic barriers in the second sub-area are the same, except that the centers of the circles are different. The arc l of the fifth magnetic barrier 9 and the sixth magnetic barrier arc l 10 The center of the circle is O 6 .

[0088] In one embodiment, the magnetic flux leakage area includes: a third sub-area located on one side of the inner arc of the through hole and facing the area between the two permanent magnets, that is, Fig.19 Middle leakage magnetic area L 2 The area L facing the permanent magnet 22 .

[0089] The third magnetic barrier in the third sub-region can suppress the leakage flux of adjacent permanent magnets through the rotor pressure plate, and the leakage flux path is N-pole permanent magnet-rotor core-rotor pressure plate-rotor core-S-pole permanent magnet-rotor core-N-pole permanent magnet and N-pole permanent magnet-rotor pressure plate-S-pole permanent magnet-rotor core-N-pole permanent magnet.

[0090] In one embodiment, the shape of the third magnetic barrier is based on the ninth magnetic barrier arc l connected end to end. 13 、The tenth magnetic barrier arc l 14 、The eleventh magnetic barrier arc l 15 and the twelfth magnetic barrier arc l 16Confirm; the ninth magnetic barrier arc l 13 、The tenth magnetic barrier arc l 14 、The eleventh magnetic barrier arc l 15 and the twelfth magnetic barrier arc l 16 It has the following constraints:

[0091] ;

[0092] Among them, R 13 is the ninth magnetic barrier arc l 13 The radius of the ninth magnetic barrier arc l 13 The center of the circle is the fourth center; g 1 is the ninth magnetic barrier arc l 13 Minimum distance to the fourth outer arc; is the eleventh magnetic barrier arc l 15 To the twelfth magnetic barrier arc l 16 The minimum distance of the eleventh magnetic barrier arc l 15 The same center as the shaft hole; the twelfth magnetic barrier arc l 16 The center of the circle is the fifth circle center O 5 . It is the radial distance from the midpoint of the inner arc of the through hole to the edge of the rotor pressure plate.

[0093] The ninth magnetic barrier arc l 13 The tenth magnetic barrier arc l 14 The target symmetry axis is symmetrically distributed; the target symmetry axis is the symmetry axis of the permanent magnets that the two second magnetic barriers are facing.

[0094] In one embodiment, the fourth circle center O 4 and the fifth O 5 The distances from the center of each arc to the center of the shaft hole are equal. In this embodiment, the distances from the center of each arc to the center of the shaft hole are set to be the same, which is conducive to evenly distributing the stress after the rotor rotates, thereby reducing or even avoiding deformation of the rotor pressure plate.

[0095] In one embodiment, ∠O 4 OO 5 =30°; and / or, ∠O 5 OO 6 =30°. The above angles can be determined according to 360° / number of poles / 2. The two angles are set equal to make the left and right magnetic barriers symmetrical.

[0096] It should be noted that c 1 、c 3 The value of cannot be too small and needs to meet the mechanical strength requirements of the rotor. In one embodiment, c 1 、c 3 Both meet the minimum distance required for the motor's rotor mechanical strength.

[0097] See also Fig. 20 , the figure shows that the number of stator slots of the motor is 9, the number of poles of the permanent magnet is 6, the shape of the permanent magnet is crescent-shaped, the number of rivets is 4, the rotor pressure plate is rotated 90° (target angle) counterclockwise relative to the rotor core axis, and d 1 =d 3 =0.5mm, d 2 =4mm, c 1 =c 3 =0.6mm, c 2 =7.5mm, g 1 =0.2mm, the magnetic field distribution of the rotor pressure plate using the second and third magnetic barriers, it can be seen that the leakage magnetic area L 2 The magnetic leakage has been significantly suppressed.

[0098] In one embodiment, the magnetic flux leakage region includes at least two of the first sub-region, the second sub-region, and the third sub-region.

[0099] Fig.15 A schematic diagram of a motor structure is shown, in which the rotor pressure plate included in the motor is in the leakage magnetic area L 1 , L 2 Open the magnetic barrier and suppress the leakage magnetic field area L 1 , L 2 The magnetic flux leakage and the magnetic barrier parameter is b 1 =b 2 =0.6mm, a 1 =a 3 =0.5mm, a 2 =4mm, d 1 =d 3 =0.5mm, d 2 =4mm, c 1 =c 3 =0.6mm, c 2 =7.5mm, g 1 =0.2mm. Fig.16 The comparison of the no-load back EMF of the motor under different schemes is shown in the figure. When the rotor pressure plate with magnetic barrier is adopted in this embodiment, the effective value of the no-load back EMF of the motor is 54 V when the motor speed is 1500 rpm. Compared with the rotor pressure plate without magnetic barrier, the effective value of the no-load back EMF of the motor is increased by 9.53%; compared with the stainless steel rotor pressure plate, the effective value of the no-load back EMF of the motor is reduced by 3.57%.

[0100] In one embodiment, when the rotor pressure plate and the rotor core are axially overlapped by an angle, if the magnetic isolation bridge of the rotor pressure plate coincides with the magnetic isolation bridge of the rotor core in the axial direction, then the magnetic isolation bridge of the rotor pressure plate can act as a third magnetic barrier. At this time, the rotor pressure plate can open the first magnetic barrier and / or the second magnetic barrier to suppress the leakage flux path of a single permanent magnet.

[0101] In one embodiment, the material of the pressure plate body is silicon steel sheet. Preferably, the silicon steel sheet of the rotor core is used as the pressure plate body, and the rotor core and the pressure plate body have exactly the same shape and size. This solution can save the mold cost of the rotor pressure plate, thereby further reducing the cost of the motor.

[0102] It should be noted that the number of layers of silicon steel sheets contained in the pressure plate body can be set according to actual needs. When multiple layers of silicon steel sheets are used, the magnetic barrier has a corresponding multi-layer structure, which can control the distribution of magnetic flux without affecting the direction of magnetic lines of force of other axes, thereby improving the performance of the motor.

[0103] In one embodiment, the target angle θ satisfies the following conditions: 0<θ<2π and θ≠k*π / p, k=1, 2, ... 2p-1, p is the number of pole pairs of the motor. Preferably, θ=n*π / 2 / p, n=1, 3 ... 4p-1.

[0104] It should be noted that when the target angle is different, the overlapping area between the rotor pressure plate and the permanent magnet in the axial direction is also different, and the shape and size of the magnetic barrier also change, but the shape and size of the magnetic barrier can still be designed according to the magnetic barrier constraint conditions provided in the above embodiment.

[0105] Although the specific embodiments of the present disclosure are described above, those skilled in the art should understand that this is only an example, and the protection scope of the present disclosure is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present disclosure, but these changes and modifications all fall within the protection scope of the present disclosure.

Claims

1. A motor, characterized in that: The motor includes a rotor pressure plate and a rotor core, the rotor core includes a first silicon steel sheet, the first silicon steel sheet is provided with magnetic steel slots with the same layout to accommodate permanent magnets; the pressure plate body of the rotor pressure plate includes at least one layer of second silicon steel sheets, each layer of the second silicon steel sheets is provided with magnetic steel slots with the same layout as the first silicon steel sheets; the pressure plate body and the rotor core are axially staggered by a target angle so that a partial area of ​​each permanent magnet has an overlapping area with the pressure plate body.

2. The motor according to claim 1, characterized in that The target angle θ satisfies the following conditions: 0<θ<2π and θ≠k*π / p, k=1, 2, ... 2p-1, and p is the number of pole pairs of the motor.

3. The motor according to claim 1, characterized in that The target angle θ satisfies the following conditions: 0<θ<2π and θ=n*π / 2 / p, n=1,3…4p-1, and p is the number of pole pairs of the motor.

4. The motor according to any one of claims 1 to 3, characterized in that: The first silicon steel sheet and the second silicon steel sheet are both provided with rivet holes and shaft holes, the rivet holes are located between the magnetic steel slots and the shaft holes, and after the target angle is overlapped, there is at least one rivet hole on the pressure plate body corresponding to the rivet hole on the rotor core.

5. The motor according to claim 4, characterized in that The number of the rivet holes is an even number, and the rivet holes are evenly distributed along the circumference of the shaft hole.

6. The motor according to claim 4, characterized in that The centers of at least some of the rivet holes are located on a first target symmetry axis; the first target symmetry axis is the symmetry axis of the two magnetic steel slots closest to the rivet holes; And / or, the centers of at least some of the rivet holes are located on a second target symmetry axis; the second target symmetry axis is the symmetry axis of the magnetic steel slot closest to the rivet hole.

7. The motor according to claim 4, characterized in that The rotor pressure plate includes 6 rivet holes, which are evenly distributed along the circumference of the shaft hole, and the centers of 2 rivet holes are located on the first target symmetry axis; the first target symmetry axis is the symmetry axis of the two magnetic steel slots closest to the rivet holes; the centers of 4 rivet holes are located on the second target symmetry axis; the second target symmetry axis is the symmetry axis of the magnetic steel slot closest to the rivet hole.

8. The motor according to claim 4, characterized in that The minimum distance between the rivet hole and the nearest magnetic steel slot satisfies the minimum distance of the rotor mechanical strength of the motor; And / or, the minimum distance between the rivet hole and the shaft hole satisfies the minimum distance required for the mechanical strength of the rotor.

9. The motor according to any one of claims 1-3 and 5-8, characterized in that: The shape of the permanent magnet includes at least one of the following: crescent shape, straight shape, V shape, double V shape, U shape, and ▽ shape.

10. The motor according to claim 1, characterized in that A magnetic barrier is provided in the magnetic leakage area of ​​the pressing plate body.

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