A double-tooth stator core and motor

Abstract

The present application provides a double-tooth stator core and motor, wherein the double-tooth stator core comprises a plurality of stator laminations, the stator laminations comprising a plurality of sequentially connected stator units, the stator units having a second tooth portion, a yoke portion and a first tooth portion, a wall surface shape of the first tooth portion facing away from the second tooth portion matching a wall surface shape of the yoke portion facing away from the second tooth portion. The defect of low material utilization rate of the stator lamination in the prior art can be overcome.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric machines, in particular to a double-tooth stator core and an electric machine. BACKGROUND

[0002] In order to achieve large torque output without increasing the size of the electric machine, a double-rotor electric machine is usually used. The stator core of the double-rotor electric machine is a double-tooth core, which is divided into an outer tooth portion and an inner tooth portion. The outer tooth portion and an outer magnetic ring form an armature, and the inner tooth portion and an inner magnetic ring form an armature.

[0003] The stator forms of the prior art are generally divided into four types: whole-circle type, block type, coiled type, and straight strip type. The material utilization rate of the whole-circle type stator is low, and the winding speed is slow. Each stator unit of the block type stator needs to be wound separately, and the wire ends are numerous after splicing, the process is complex, and the circular precision is low. The structure of the coiled type stator is complex, and the process is difficult. The straight strip type stator has comprehensive advantages in the above aspects, and is therefore most widely used in fan motors.

[0004] Referring to Figure 1 As shown in the figure, the traditional stator core is generally in a staggered plug-in arrangement, that is, two rows of stator punching sheet tooth portions are staggered and plugged into a group, and punching is performed simultaneously. According to the shape of the traditional stator core, two lap joints 01 must be reserved during arrangement, one of which is a lap joint reserved between the two rows of stator punching sheets in a group, and the width thereof is df1, and the other is a lap joint reserved between each group, and the width thereof is df2. The material utilization rate of a row of stator punching sheets = V1*2 / L1 / (b1+hj1+bf1+bf2), wherein V1 is the practical area of the traditional stator punching sheet, so eliminating the lap joint can greatly improve the material utilization rate of the stator punching sheet. SUMMARY

[0005] Therefore, the present application provides a double-tooth stator core and an electric machine, which can overcome the defect of low material utilization rate of the stator punching sheet in the prior art.

[0006] In order to solve the above problems, the present application provides a double-tooth stator core, which comprises a plurality of stator punching sheets, the stator punching sheet comprises a plurality of stator units connected in sequence, the stator unit has a second tooth portion, a yoke portion and a first tooth portion, and the wall surface shape of the first tooth portion away from the second tooth portion matches the wall surface shape of the yoke portion away from the second tooth portion.

[0007] In some embodiments, the second tooth portion is provided with a second tooth top on both sides, a rotating portion is arranged at the connection between the second tooth top and the second tooth portion, and the second tooth top can rotate around the rotating portion. When the stator punching sheet inner pole shoe is circular, a notch is arranged between the second tooth tops of adjacent two stator units.

[0008] In some embodiments, the second tooth top is provided with a circular hole at the connection between the second tooth top and the second tooth portion, a first groove is opened at the connection between the second tooth top and the second tooth portion, the first groove is in communication with the circular hole, and the second tooth top is at least partially connected with the second tooth portion. When the second tooth top is rotated and bent, there is at least partial gap between the second tooth top and the second tooth portion.

[0009] In some embodiments, the second tooth portion has the same number of winding turns as the first tooth portion, and the length L1 of the second tooth portion and the length L2 of the first tooth portion satisfy:

[0010] R 2 -(R-L1) 2 =(r+L2) 2 -r 2 wherein R is the maximum distance between the second tooth portion and the center of the circle when the stator lamination inner pole shoe is in a circle, and r is the maximum distance between the first tooth portion and the center of the circle when the stator lamination inner pole shoe is in a circle.

[0011] In some embodiments, two adjacent stator units are connected by a connecting bridge, and a second groove is provided on the wall surface of the connecting bridge facing the center of the circle when the stator lamination inner pole shoe is in a circle. A through hole is provided on the connecting bridge, the second groove is in communication with the through hole, a second rotation point is provided on the connecting bridge, the second rotation point is a quadrant point of the through hole, the second rotation point (x, y) satisfies: x = (R-L2-h1)*tan(180° / Z1), y = R-L2-h1, wherein h1 is the height of the connecting bridge, Z1 is the number of the stator units, R is the maximum distance between the second tooth portion and the center of the circle when the stator lamination inner pole shoe is in a circle, and L2 is the length of the first tooth portion.

[0012] In some embodiments, the height h1 of the connecting bridge satisfies: h1 = (12%~16%)*hj2, wherein hj2 is the minimum width of the yoke portion.

[0013] In some embodiments, the wall surface of the yoke portion facing away from the second tooth portion is provided with a boss, the boss is provided with a chamfer, and the height h2 of the boss is greater than the radius of the chamfer.

[0014] In some embodiments, a wall surface of the first tooth portion facing away from the second tooth portion is provided with a process groove, a width b3 of the process groove satisfies: b3=2*(b2+h2-L2-L1-h1)*tan(180° / Z1), wherein Z1 is the number of the stator units, b2 is the height of the stator unit, L2 is the length of the first tooth portion, L1 is the length of the second tooth portion, and h1 is the height of the connecting bridge.

[0015] In some embodiments, when the stator punching sheet is in a straight strip form, one end of the stator punching sheet is provided with a third groove, and the other end is provided with a first protrusion, the third groove is matched with the first protrusion, and a width b4 of the first protrusion satisfies: b4=(20%-40%)*(hj2+h2) / tan(180° / Z1), wherein Z1 is the number of the stator units, and hj2 is the minimum width of the yoke portion.

[0016] In some embodiments, both ends of the stator punching sheet are provided with a second protrusion, the two second protrusions are oppositely arranged, and the second protrusion is located on the end of the stator punching sheet away from the first protrusion.

[0017] In some embodiments, one end of the first tooth portion facing away from the second tooth portion has two first tooth tips, and an end surface of the first tooth tip facing away from the second tooth portion is a straight surface.

[0018] The application also provides an electric machine comprising the double-tooth portion stator core.

[0019] The double-tooth portion stator core and the electric machine provided by the application have the following advantages: the inner diameter surface shape of the first tooth portion is matched with the inner surface shape of the yoke portion, when the stator units are arranged in a straight strip form, two rows of stator punching sheets can be arranged by being inserted into each other in a close manner, no allowance is needed between the two rows of stator punching sheets, the allowance is eliminated, the material length of the arrangement can be greatly shortened, the material utilization rate of the stator punching sheet is improved, and the cost of the stator core is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a schematic diagram of the arrangement of the prior art;

[0021] Figure 2 It is a structural schematic diagram of the double-tooth portion stator core of the embodiment of the application;

[0022] Figure 3 It is a structural schematic diagram of the stator unit in the double-tooth portion stator core of the embodiment of the application;

[0023] Figure 4 It is a structural schematic diagram of the inner pole shoe of the double-tooth portion stator core of the embodiment of the application;

[0024] Figure 5A partial enlarged view of the double-tooth portion stator core of the embodiment of the present application Figure 5

[0025] Figure 6 A structure schematic view of the outer pole shoe of the double-tooth portion stator core of the embodiment of the present application

[0026] Figure 7 A layout schematic view of the double-tooth portion stator core of the embodiment of the present application

[0027] Figure 8 A structure schematic view of the double-tooth portion stator core of another embodiment of the present application

[0028] Figure 9 A layout schematic view of the double-tooth portion stator core of another embodiment of the present application

[0029] Figure 10 An undesirable punching stator sheet schematic view when there is no process slot and boss in the double-tooth portion stator core of the embodiment of the present application

[0030] The reference signs are as follows:

[0031] 01, the lap; 1, the second tooth portion; 2, the third groove; 3, the yoke portion; 4, the first tooth portion; 5, the buckle point; 6, the second tooth top; 7, the first tooth top; 8, the rotating portion; 9, the first protrusion; 10, the lap; 11, the second protrusion; 12, the slot; 13, the straight face; 14, the excess material; 15, the connecting bridge. DETAILED DESCRIPTION

[0032] Referring to Figures 2 to 10 , according to the embodiment of the present application, a motor rotor assembly is provided, comprising a plurality of stator sheets, the stator sheets comprising a plurality of sequentially connected stator units, the stator units having a second tooth portion 1, a yoke portion 3 and a first tooth portion 4, the wall surface shape of the first tooth portion 4 facing away from the second tooth portion 1 matching the wall surface shape of the yoke portion 3 facing away from the second tooth portion 1. In this technical solution, the first tooth portion 4 has two first tooth tops 7, preferably, a plurality of buckle points 5 are provided on the second tooth portion 1 and the first tooth portion 4, the double-tooth portion stator core is formed by laminating a plurality of stator sheets, after lamination, the plurality of stator sheets can be fixed by the buckle points 5, referring to Figure 6 and Figure 8 ​As shown, the inner diameter surface shape of the first tooth portion 4 matches the inner surface shape of the yoke portion 3. When the stator unit is arranged in a straight strip manner, the two rows of stator punching sheets can be fitted together for insertion and arrangement. No overlap is required between the two rows of stator punching sheets. Eliminating the overlap can greatly shorten the length of the arrangement material, improve the material utilization rate of the stator punching sheets, and reduce the cost of the stator core. The forming process only requires welding after forming into a circle, and does not require the traditional block-type separate splicing process and multiple welding processes, thereby reducing the input of production personnel and improving production efficiency.

[0033] In some embodiments, second tooth tops 6 are provided on both sides of the second tooth portion 1, and a rotating portion 8 is provided at the connection between the second tooth top 6 and the second tooth portion 1. The second tooth top 6 can rotate around the rotating portion 8. When the inner pole shoe of the stator punching sheet is rounded, a slot 12 is provided between the second tooth tops 6 of two adjacent stator units. In this technical solution, the inner pole shoe of the stator punching sheet is the first tooth top 7 of the stator unit, and the inner pole shoe of the stator punching sheet is rounded to form a circle with multiple first tooth tops 7, so as to avoid the length of the second tooth top 6 being limited, increase the length of the second tooth top 6, thereby reducing the slot width of the outer tooth portion after the iron core is rounded, thereby achieving the effect of improving the performance of the motor, ensuring that there is no interference between adjacent second tooth tops 6, increase the length of the second tooth top 6, and reduce the width of the slot 12 after the straight stator iron core is rounded, thereby improving the performance of the motor.

[0034] In some embodiments, a circular hole is provided at the connection between the second tooth top 6 and the second tooth portion 1, and a first groove is provided at the connection between the second tooth top 6 and the second tooth portion 1, the first groove is connected to the circular hole, and the second tooth top 6 is at least partially connected to the second tooth portion 1. When the second tooth top 6 is rotated and bent, there is at least a partial gap between the second tooth top 6 and the second tooth portion 1. In this technical solution, the bending angle of the second tooth top 6 is determined by the second tooth top 6, ensuring that there is no interference between adjacent second tooth tops 6 and between the second tooth top 6 and the yoke 3. It is ensured that when the second tooth top 6 rotates, the second tooth top 6 and the second tooth portion 1 do not overlap with each other, thereby preventing the oil from penetrating into the punching sheet material, causing damage to the punching sheet, and affecting the performance of the motor.

[0035] In some embodiments, the number of winding turns wound on the second tooth portion 1 is the same as that on the first tooth portion 4, and the length L1 of the second tooth portion 1 and the length L2 of the first tooth portion 4 satisfy: R 2 -(R-L1) 2 =(r+L2) 2 -r 2, where R is the maximum distance between the second tooth portion 1 and the center of the circle when the pole shoe inside the stator punching sheet forms a circle, and r is the maximum distance between the first tooth portion 4 and the center of the circle when the pole shoe inside the stator punching sheet forms a circle. In this technical solution, the maximum distance between the first tooth portion 4 and the center of the circle is smaller, and the maximum distance between the second tooth portion 1 and the center of the circle is larger, resulting in a wider slot shape of the second tooth portion 1 and a narrower slot shape of the first tooth portion 4. In order to avoid the phenomenon of too high a slot fill rate on one side and too low a slot fill rate on the other side, the length L1 of the second tooth portion 1 and the length L2 of the first tooth portion 4 satisfy the above formula, ensuring that the slot areas of the second tooth portion 1 and the first tooth portion 4 are basically the same, so that the magnetic field on the stator core is evenly distributed, thereby improving the performance of the motor.

[0036] In some embodiments, see Figure 2 As shown, two adjacent stator units are connected by a connecting bridge 15. When the inner pole shoe of the stator punching sheet forms a circle, a second groove is provided on the wall of the connecting bridge 15 facing the center of the circle. A through hole is provided on the connecting bridge 15. The second groove is connected to the through hole. A second rotation point is provided on the connecting bridge 15. The second rotation point is the quadrant point of the through hole. The center of the circle when the inner pole shoe of the stator punching sheet forms a circle is (0, 0). The second rotation point (x, y) satisfies: x = (R-L2-h1)*tan(180° / Z1), y = R-L2-h1, wherein h1 is the height of the connecting bridge 15, Z1 is the number of the stator units, R is the maximum distance between the second tooth portion 1 and the center of the circle when the inner pole shoe of the stator punching sheet forms a circle, and L2 is the length of the first tooth portion 4. In this technical solution, stress is concentrated on the connecting bridge 15 of the yoke 3 during rounding, which effectively avoids the straight stator core from cracking after rounding.

[0037] In some embodiments, the height h1 of the connecting bridge 15 satisfies the following: h1 = (12% to 16%) * hj2, where hj2 is the minimum width of the yoke 3 .

[0038] In this technical solution, the strength of the connecting bridge is guaranteed after the straight stator core is rounded, and the rounding operation is easy.

[0039] In some embodiments, the wall surface of the yoke 3 facing away from the second tooth portion 1 is provided with a boss, the boss is provided with a chamfer, and the height h2 of the boss is greater than the radius of the chamfer. Figure 10 As shown, it is prevented that there are thin and long residual materials on both sides of the first tooth portion 4 after the stator punching, thereby avoiding secondary processing.

[0040] In some embodiments, a process groove is provided on the wall of the first tooth portion 4 facing away from the second tooth portion 1, and the width b3 of the process groove satisfies: b3 = 2*(b2+h2–L2–L1-h1)*tan(180° / Z1), wherein Z1 is the number of the stator units, b2 is the height of the stator unit, L2 is the length of the first tooth portion 4, L1 is the length of the second tooth portion 1, and h1 is the height of the connecting bridge 15. In this technical solution, the depth of the process groove is preferably 0.2 to 0.3 mm to ensure that the process chamfer remains in the process groove. The process groove can effectively weaken the tooth torque and torque pulsation of the motor; during the punching process, the engine oil can better penetrate into the punching sheet material, increase lubrication and buffering effects, and prevent damage to the tool and punching sheet; see Figure 10 As shown, the process groove prevents the slender excess material 14 from being left on the connecting bridge 15 of the yoke 3. The process groove can prevent the slender excess material 14 from being left at the corners of the stator punching after punching, thereby avoiding secondary processing; the process groove also weakens the cogging torque and torque pulsation of the motor.

[0041] In some embodiments, see Figure 2 As shown, when the stator punching is a straight bar type, a third groove 2 is provided at one end of the stator punching, and a first protrusion 9 is provided at the other end. The third groove 2 matches the first protrusion 9, and the width b4 of the first protrusion 9 satisfies: b4 = (20% to 40%) * (hj2 + h2) / tan (180° / Z1), where Z1 is the number of stator units and hj2 is the minimum width of the yoke 3. In this technical solution, after the straight bar stator core is rounded, the first protrusion 9 and the third groove 2 are tightly combined, increasing the bonding strength, effectively preventing cracking of the straight bar stator core after rounding, and improving the rounding accuracy of the stator core.

[0042] In some embodiments, see Figure 5 As shown, the two ends of the stator punching are provided with a second protrusion 11, and the two second protrusions 11 are arranged opposite each other. Moreover, the second protrusion 11 is located on the end of the stator punching relatively far away from the first protrusion 9. In this technical solution, the second protrusion 11 is preferably 0.2 to 0.5 mm. The provision of the second protrusion 11 facilitates the welding process between the two ends of the stator punching. It can effectively avoid the phenomenon of cracking at the overlap after the straight stator core is rounded, and ensure the rounding accuracy of the stator core. After the stator core is rounded, the structure of the second protrusion 11 outside the overlap is conducive to the welding process, and the welding process is only one step, which improves production efficiency.

[0043] In some embodiments, see Figure 8 and Figure 9As shown, the end of the first tooth portion 4 facing away from the second tooth portion 1 has two first tooth tops 7, and the end surface of the first tooth top 7 facing away from the second tooth portion 1 is a straight surface. In this technical solution, the first tooth top 7 can also be an arcuate surface, and the end surface of the first tooth top 7 facing away from the second tooth portion 1 is a straight surface. After rounding, the inner diameter surface of the stator core is a regular polygon, which can form an uneven air gap and achieve the effect of reducing motor torque pulsation.

[0044] The present invention provides a double-tooth stator core forming step, according to Figure 7 、 Figure 9 ① Punch out the sheets according to the sample drawing; ② Stack the sheets to the corresponding stack height; ③ Rotate and bend each group of teeth along the rotation point of the yoke to make the inner pole shoe into a circle; ④ Weld the overlap of the yoke; ⑤ Rotate and bend each second tooth top 6 along the rotation point to make the outer pole shoe into a circle.

[0045] The present invention further provides a motor, characterized in that it comprises the double-tooth stator core described in any one of the preceding items.

[0046] The above description is merely a preferred embodiment of the present invention and is 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 within the scope of protection of the present invention. The above description is merely a preferred embodiment of the present invention. It should be noted that those skilled in the art can make various improvements and variations without departing from the technical principles of the present invention, and such improvements and variations shall also be considered within the scope of protection of the present invention.

Claims

1. A double-tooth stator core, characterized in that: The invention comprises a plurality of stator punching sheets, wherein the stator punching sheets comprise a plurality of stator units connected in sequence, wherein the stator unit comprises a second tooth portion (1), a yoke portion (3) and a first tooth portion (4), wherein the shape of the wall of the first tooth portion (4) facing away from the second tooth portion (1) matches the shape of the wall of the yoke portion (3) facing away from the second tooth portion (1); One end of the first tooth portion (4) facing away from the second tooth portion (1) has two first tooth tops (7), and the end surface of the first tooth top (7) facing away from the second tooth portion (1) is a straight surface.

2. The double-tooth stator core according to claim 1, characterized in that: A second tooth top (6) is provided on both sides of the second tooth portion (1); a rotating portion (8) is provided at the connection between the second tooth top (6) and the second tooth portion (1); the second tooth top (6) can rotate around the rotating portion (8); and when the pole shoe inside the stator punching sheet forms a circle, a notch (12) is provided between the second tooth tops (6) of two adjacent stator units.

3. The double-tooth stator core according to claim 2, wherein: A circular hole is provided at the connection between the second tooth top (6) and the second tooth portion (1); a first groove is provided at the connection between the second tooth top (6) and the second tooth portion (1); the first groove is communicated with the circular hole; and the second tooth top (6) and the second tooth portion (1) are at least partially connected. When the second tooth top (6) is rotated and bent, a gap exists at least partially between the second tooth top (6) and the second tooth portion (1).

4. The double-tooth stator core according to claim 2, wherein: The number of turns of the winding wound on the second tooth portion (1) is the same as that on the first tooth portion (4), and the length L1 of the second tooth portion (1) and the length L2 of the first tooth portion (4) satisfy: R 2 -(R-L1) 2 =(r+L2) 2 -r 2 , wherein R is the maximum distance between the second tooth portion (1) and the center of the circle when the inner pole shoe of the stator punching sheet forms a circle, and r is the maximum distance between the first tooth portion (4) and the center of the circle when the inner pole shoe of the stator punching sheet forms a circle.

5. The double-tooth stator core according to claim 1, characterized in that: Two adjacent stator units are connected via a connecting bridge (15); when the inner pole shoe of the stator punching sheet forms a circle, a second groove is provided on the wall of the connecting bridge (15) facing the center of the circle; a through hole is provided on the connecting bridge (15); the second groove is connected to the through hole; a second rotation point is provided on the connecting bridge (15); the second rotation point is a quadrant point of the through hole; the center of the circle when the inner pole shoe of the stator punching sheet forms a circle is taken as point (0, 0); the second rotation point (x, y) satisfies: x = (R-L2-h1)*tan(180° / Z1), y = R-L2-h1, wherein h1 is the height of the connecting bridge (15), Z1 is the number of the stator units, R is the maximum distance between the second tooth portion (1) and the center of the circle when the inner pole shoe of the stator punching sheet forms a circle, and L2 is the length of the first tooth portion (4).

6. The double-tooth stator core according to claim 5, characterized in that: The height h1 of the connecting bridge (15) satisfies the following: h1 = (12% to 16%) * hj2, wherein hj2 is the minimum width of the yoke (3).

7. The double-tooth stator core according to claim 5, characterized in that: A boss is provided on the wall surface of the yoke portion (3) facing away from the second tooth portion (1), the boss is provided with a chamfer, and the height h2 of the boss is greater than the radius of the chamfer.

8. The double-tooth stator core according to claim 7, characterized in that: A process groove is provided on the wall surface of the first tooth portion (4) facing away from the second tooth portion (1), and a width b3 of the process groove satisfies: b3=2*(b2+h2–L2–L1-h1)*tan(180° / Z1), wherein Z1 is the number of the stator units, b2 is the height of the stator units, L2 is the length of the first tooth portion (4), L1 is the length of the second tooth portion (1), and h1 is the height of the connecting bridge (15).

9. The double-tooth stator core according to claim 7, characterized in that: When the stator punching sheet is a straight bar type, a third groove (2) is provided at one end of the stator punching sheet, and a first protrusion (9) is provided at the other end. The third groove (2) matches the first protrusion (9), and the width b4 of the first protrusion (9) satisfies: b4=(20% to 40%)*(hj2+h2) / tan(180° / Z1), wherein Z1 is the number of the stator units and hj2 is the minimum width of the yoke (3).

10. The double-tooth stator core according to claim 9, characterized in that: A second protrusion (11) is provided at both ends of the stator punching sheet, the two second protrusions (11) are arranged opposite to each other, and the second protrusions (11) are located on the end of the stator punching sheet relatively far away from the first protrusion (9).

11. A motor, characterized in that: The invention comprises the double-tooth stator core according to any one of claims 1 to 10.

Images