Combined stator core and dynamoelectric machine

Abstract

The utility model belongs to permanent magnet brushless DC motor technical field, concretely relates to a combined stator core, including stator (1), the stator includes a plurality of tooth parts (101) and yoke part (102), the outer circumferential surface of yoke part (102) is equipped with the radial convex stripe (102a) consistent with the tooth part quantity, forms a radial slot between any two adjacent radial convex stripe, one end of a plurality of tooth parts (101) is respectively inserted in a plurality of radial slots, provide a power motor simultaneously, the power motor of the utility model adopts this stator core, has the following advantages: 1, low loss, low cost, motor slot full rate is high, and the efficiency is high, 2, starting response is fast, and the small feeling of abruptness is small, and the operation is smooth, 3, motor performance is stable, and the subsequent mechanical winding does not scatter piece, the inner wall of yoke part is equipped with two interval angles 180 degrees's location tooth, and it is convenient for subsequent mechanical winding positioning and limiting motor base, avoids the radial slip.

Description

Technical Field

[0001] This utility model relates to the field of permanent magnet brushless DC motor technology, specifically to a power motor and a stator core used thereon. Background Technology

[0002] With the continuous development of technology, permanent magnet brushless motors are being applied to the emerging field of low-altitude drones, especially in industries such as heavy-duty drones for agricultural spraying, logistics, industrial inspection, and hoisting. This necessitates motors with high power, high efficiency, high torque, and smooth operation. Currently, these brushless motors generally use an external rotor structure, with the stator core typically employing an integrated tooth and yoke design. Stamping requires a wide strip (greater than the maximum outer diameter), resulting in high losses and costs. Furthermore, this type of stator core can only be wound from the outside to the inside using round enameled wire. Limited by slot size and equipment performance, it's difficult to wind low-turn, thick single-strand wire in a single operation, leading to low slot utilization, low overall slot fill factor, and low efficiency. Simultaneously, the main magnetic circuit, composed of the stator core and magnets, has not been significantly optimized, resulting in high cogging torque, slow start-up response, strong jerking, and uneven operation. The motor has high harmonic content, poor electromotive force waveform, and large torque pulsation, making it prone to significant vibration and noise during operation, and hindering subsequent FOC vector control. The stator core structure is primarily constructed using a single-piece stamping and riveting method, resulting in few and unevenly distributed riveting points. This often leads to uneven riveting after stamping, with one or more slots exhibiting issues such as incomplete or improper riveting, excessive stacking height, and looseness. This can cause the winding to scatter and result in unstable motor performance. Furthermore, the lack of clear limiting measures on the stator core makes it prone to loosening and slippage during subsequent assembly into the motor. Utility Model Content

[0003] In order to overcome the shortcomings of the existing technology, one of the objectives of this utility model is to provide a combined stator core.

[0004] The second objective is to provide a power motor that includes the aforementioned stator core.

[0005] The technical solution to achieve the first objective is as follows: a combined stator core, including a stator, a magnet sleeved outside the stator, and a housing sleeved outside the magnet; the stator includes a plurality of teeth and a yoke; the outer circumferential surface of the yoke is provided with radial ribs of the same number as the number of teeth, and a radial groove is formed between any two adjacent radial ribs; one end of each of the plurality of teeth is inserted into the plurality of radial grooves.

[0006] Preferably, the radial protrusion extends outward on both sides to form two side strips integrally formed therewith, the bottom surface of the side strip is an inclined surface and a lower interlocking groove is formed between the side strip and the outer circumferential surface of the yoke; each radial groove is located between two adjacent side strips.

[0007] Preferably, each tooth has a transverse groove on both sides of the end connected to the yoke, and two adjacent side strips are respectively embedded in the two transverse grooves at one end of each tooth.

[0008] Preferably, each tooth has a radial auxiliary groove on its top surface and two radial riveting holes on its vertical surface; the yoke has several riveting holes on its side surface, located at the connection between several radial protrusions and the outer circumference of the yoke; the radius of the radial auxiliary groove is 1.0-1.2 mm.

[0009] Preferably, the stator has 27 teeth, with a tooth groove between two adjacent teeth, and the number of tooth grooves is 27; the outer diameter of the stator is 127-128 mm, the inner diameter (D4) is 87.5-88.8 mm, and the included angle between adjacent tooth grooves is 13.33°.

[0010] Preferably, the width of the groove opening of the interdental groove is 1.4-1.6 mm, the upper width of the interdental groove is 12.1-12.2 mm, and the lower width is 9.0-9.1 mm; the tooth is integrally formed from the tooth body and the tooth tip; the thickness of the tooth tip is 1.9-2 mm; and the distance from the upper part of the interdental groove to the bottom of the interdental groove is 27-27.2 mm.

[0011] Preferably, the stator has 27 inter-tooth slots, corresponding to 30 rotor poles and 3 phases, with 3 / 10 inter-tooth slots per pole and per phase; the pole pitch angle is 12 degrees; and the radius of the inner arc at the junction of the tooth tip and the tooth body is 1.5-1.6 mm.

[0012] Preferably, the inner wall of the yoke is provided with two positioning teeth spaced 180 degrees apart, that is, the two positioning teeth are respectively set at radially equal positions on the inner wall of the yoke; the width of the positioning teeth is 8-8.2mm; the radial riveting holes and the riveting holes have the same shape, both being square; the width of the radial riveting holes and the riveting holes is 1-1.2mm, and the length is 2-2.2mm; each of the four transition points of the riveting holes is provided with a corner arc, the radius of the corner arc being 0.2-0.3mm; the length direction of the radial riveting holes is consistent with the length direction of the tooth body.

[0013] Preferably, the magnet is a circular body formed by several individual magnets; the thickness of the individual magnets is 2.8-3.3 mm; and the angle between the bottom surfaces of two adjacent side strips is 93-95°.

[0014] The technical solution to achieve the second objective is: a power motor, including the aforementioned stator core.

[0015] Technical advantages: The power motor of this utility model uses this stator core, which has the following advantages: 1. The structural design of separating the teeth and yoke means that after separation, the maximum outer diameter of the strip can be selected that is larger than that of the yoke. The strip required for stamping is narrow, resulting in low loss and low cost. Moreover, when winding, a single thick flat wire can be wound from the teeth individually and then spliced ​​together, resulting in high motor slot fill factor and high efficiency.

[0016] 2. The stator adopts a 27-slot and 30-pole external rotor design, that is, the number of slots per pole per phase is q=3 / 10, which reduces winding harmonics. At the same time, the top surface of each tooth of the stator is provided with radial auxiliary slots; the pole arc coefficient of the magnet is ai=0.73-0.76, the motor cogging torque is small, the starting response is fast, the jerking sensation is small, and the operation is smooth.

[0017] 3. Two radial riveting holes are evenly distributed in the center of the vertical surface of the toothed part, and several riveting holes are evenly distributed in the side surface of the yoke. The riveting and stress are uniform, and there is no situation where a single groove is too high or loose. The motor performance is stable and the subsequent mechanical winding does not break apart. The inner wall of the yoke is provided with two positioning teeth with an angle of 180 degrees, which facilitates the positioning of subsequent mechanical winding and limits the motor seat, and avoids radial slippage. Attached Figure Description

[0018] Figure 1 This is a front view of a partial structure of the motor according to an embodiment of the present utility model; Figure 2 This is a front view of a partial stator structure according to an embodiment of the present utility model; Figure 3 This is a graph comparing the efficiency of stator winding with flat and round wires according to an embodiment of the present invention. Figure 4 A comparison curve of the stator with radial auxiliary grooves and without auxiliary grooves in an embodiment of this utility model; Figure 5 This is a harmonic diagram of the electromotive force in an embodiment of the present invention; Figure 6 This is a waveform diagram of the electromotive force in an embodiment of the present invention; Figure 7 This is a perspective view of the power motor according to an embodiment of the present utility model.

[0019] Reference numerals: Stator-1, Tooth-101, Tooth body-101a, Tooth tip-101b, Yoke-102, Radial ridge-102a, Side ridge-102b, Inter-tooth groove-103, Groove-103a, Positioning tooth-104, Magnet-2, Magnet unit-201, Housing-3, Radial riveting hole-4, Riveting hole-5, Outer diameter-D1, Inner diameter-D4, Housing outer diameter-D5, Housing inner diameter-D6, Radial auxiliary groove-R1, Angle-a, Pole pitch angle-bp, Arc length angle-ap, Inner arc-R2, Corner arc-R3, Angle-b. Detailed Implementation

[0020] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0021] like Figures 1-2 As shown, this utility model embodiment provides a combined stator core, including a stator 1; the stator includes a plurality of teeth 101 and a yoke 102; the outer circumferential surface of the yoke 102 is provided with radial protrusions 102a consistent with the number of teeth, and a radial groove is formed between any two adjacent radial protrusions; one end of each of the plurality of teeth 101 is respectively inserted into the plurality of radial grooves. A magnet 2 is fitted over the stator 1, and a housing 3 is fitted over the magnet. The stator, magnet, and housing constitute the main magnetic circuit of the motor. During processing, the teeth 101 and yoke 102 are mainly made of 0.2mm thick silicon steel strips, which are stamped into single pieces. Multiple pieces are stacked together using existing positioning fixtures, and then riveted together to form their individual units. After the flat enameled wire is wound around the outside of the teeth 101, they are sequentially inserted into the corresponding radial grooves in the stator yoke 102 through the fixtures to form a complete stator core. The yoke 102 is made by stamping silicon steel strip separately. After the flat enameled wire is wound on the single stator tooth 101, it is inserted into the corresponding radial groove in the stator yoke 102. Using a smaller strip to stamp the yoke helps to reduce strip loss, lower costs and increase the winding slot fill factor, thereby improving motor efficiency.

[0022] The magnet 2 is a circular body formed by several individual magnet units 201; the thickness H of each magnet unit is 2.8-3.3mm; the polar arc coefficient ai=0.73-0.76, that is, the included angle ap of the magnet arc length is between 8.76° and 9.12°. The casing 3 is made of low carbon steel, the outer diameter D5 of the casing is between 140-140.5mm, and the inner diameter D6 of the casing is between 134.5-135mm.

[0023] Specifically, the radial protrusion 102a extends outward on both sides to form two side strips 102b integrally formed therewith. The bottom surface of the side strip is an inclined surface and a lower interlocking groove is formed between the side strip and the outer circumferential surface of the yoke 102. Each radial groove is located between two adjacent side strips 102b.

[0024] Each tooth 101 has a transverse groove on both sides of the end connected to the yoke 102. When the tooth and yoke are assembled, two adjacent side strips 102b are respectively embedded in the two transverse grooves at one end of each tooth 101.

[0025] Each tooth 101 has a radial auxiliary groove R1 on its top surface and two radial riveting holes 4 on its vertical surface. The yoke 102 has several riveting holes 5 on its side surface, located at the connection points between several radial protrusions 102a and the outer circumference of the yoke 102. The radius of the radial auxiliary groove is 1.0-1.2 mm. Each tooth 101 has two radial riveting holes evenly distributed in the center of its vertical surface, and the yoke 102 has several riveting holes evenly distributed on its side surface. This ensures uniform riveting and stress distribution, resulting in uniform riveting of the stator core. It can be wound with flat wire, eliminating the risk of loose strands after winding. It has a high slot fill factor, high overall motor efficiency, low cogging torque, a more sinusoidal electromotive force waveform, low harmonic content, and is beneficial for FOC vector control. Subsequent overall vibration and noise are low, with fast start-up response and smooth operation. It can be used in any similar product.

[0026] Specifically, in this embodiment, in order to more easily achieve low speed and high torque and subsequent flat wire winding, the stator core adopts a 27-slot combination design, that is, there are 27 teeth 101 provided in the stator, and there is a tooth slot 103 between two adjacent teeth, and the number of tooth slots is 27; the outer diameter D1 of the stator 1 is 127-128mm, and the inner diameter D4 is 87.5-88.8mm; the included angle α between adjacent tooth slots 103 is 13.33°, that is, 360° / 27=13.33°.

[0027] To reduce the cogging torque of the motor and improve back EMF harmonics, the stator core selects a smaller slot opening 103a width for the inter-tooth slot 103, specifically, the slot opening width is Bs0 = 1.4-1.6 mm, the upper width Bs1 of the inter-tooth slot is 12.1-12.2 mm, and the lower width Bs2 is 9.0-9.1 mm. The tooth 101 is integrally formed from the tooth body 101a and the tooth tip 101b; the thickness Hs0 of the tooth tip is 1.9-2 mm; and the distance Hs2 from the upper part to the bottom of the inter-tooth slot is 27-27.2 mm.

[0028] Since the stator 1 has 27 slots, the corresponding rotor pole number is 30, the number of phases is 3, and the number of slots per pole per phase is 3 / 10, that is, 27 / 3 x 30 = 3 / 10; in order to optimize the magnetic circuit design, further reduce the inter-slot torque of the motor, make the electromotive force more sinusoidal, and reduce the proportion of harmonics, the motor adopts a 2P=30 pole design. At this time, the pole pitch angle bp=360 / 2p=12°, that is, the pole pitch angle bp is 12 degrees; the radius of the inner arc R2 at the junction of the tooth tip 101b and the tooth body 101a is 1.5-1.6mm.

[0029] To facilitate subsequent mechanical winding positioning and prevent radial slippage after mounting on the motor mount, the inner wall of the yoke 102 is provided with two positioning teeth 104 spaced 180 degrees apart, i.e., the two positioning teeth are respectively set at radially equidistant positions on the inner wall of the yoke; the width L3 of the positioning teeth is 8-8.2mm; the radial riveting holes 4 and 5 have the same shape, both being square; the width L1 of the radial riveting holes and the rivet holes is 1-1.2mm, and the length L2 is 2-2.2mm; each of the four transition points of the rivet holes is provided with a corner arc R3, the radius of which is 0.2-0.3mm; the length direction of the radial riveting holes 5 is consistent with the length direction of the tooth body 101a.

[0030] The angle b between the bottom surfaces of two adjacent side strips is 93-95°, that is, the angle between the two inclined planes is between 93-95°.

[0031] like Figure 7 As shown, a power motor includes the aforementioned stator core.

[0032] like Figure 3 As shown, with the same stator core, except for the difference between flat wire and round wire, other factors such as speed and voltage are almost identical, and the efficiency of the Hairpin flat wire motor is significantly higher than that of the Round wire motor.

[0033] like Figure 4 As shown, for the same stator core, except for the difference that the top surface of the tooth 101 has a radial auxiliary groove R1, under otherwise similar conditions, the slotting torque of the Hairpin-R flat wire motor with the radial auxiliary groove is significantly lower than that of the Hairpin flat wire motor without the radial auxiliary groove.

[0034] like Figure 5 As shown, it is a harmonic diagram of the motor electromotive force of an embodiment of this utility model.

[0035] like Figure 6 As shown, it is a waveform diagram of the electromotive force of the motor in an embodiment of this utility model.

[0036] As shown in the table below, after overall optimization, the motor's electromotive force waveform is better, with no obvious distortion, and the proportion of each harmonic is significantly lower. Harmonic Proportion Table:

[0037] In the above description, it should be noted that the terms "installation", "connection", "connection" and other related terms should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components; "set at" should be understood as "installed at" or "set at", including installation methods such as fixed installation and movable installation.

[0038] Obviously, the embodiments described above are only some embodiments of this utility model, not all embodiments. The accompanying drawings show preferred embodiments of this utility model, but do not limit the patent scope of this utility model. This utility model can be implemented in many different forms; rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure of this utility model. Any equivalent structures made based on the description and drawings of this utility model, directly or indirectly applied to other related technical fields, are similarly within the patent protection scope of this utility model.

Claims

1. A composite stator core, comprising a stator (1), a magnet (2) sleeved on the outside of the stator, and a housing sleeved on the outside of the magnet; the stator includes a plurality of teeth (101) and a yoke (102); characterized in that, The outer circumferential surface of the yoke (102) is provided with radial protrusions (102a) that are the same number as the teeth, and a radial groove is formed between any two adjacent radial protrusions; one end of each of the teeth (101) is inserted into the radial groove.

2. A composite stator core as described in claim 1, characterized in that, The radial protrusion (102a) extends outward on both sides to form two side strips (102b) integrally formed therewith. The bottom surface of the side strip is an inclined surface and a lower interlocking groove is formed between the side strip and the outer circumferential surface of the yoke (102). Each radial groove is located between two adjacent side strips (102b).

3. A composite stator core as described in claim 2, characterized in that, Each tooth (101) has a transverse groove on each side of the end connected to the yoke (102), and two adjacent side strips (102b) are respectively embedded in the two transverse grooves at one end of each tooth (101).

4. A composite stator core as described in claim 2, characterized in that, Each tooth (101) has a radial auxiliary groove (R1) on its top surface and two radial riveting holes (4) on its vertical surface; the yoke (102) has several riveting holes (5) on its side surface, which are located at the connection between several radial protrusions (102a) and the outer circumference of the yoke (102); the radius of the radial auxiliary groove is 1.0-1.2 mm.

5. A composite stator core as described in claim 2, characterized in that, The stator has 27 teeth (101) and there is a tooth groove (103) between two adjacent teeth. The number of tooth grooves is 27. The outer diameter (D1) of the stator (1) is 127-128 mm and the inner diameter (D4) is 87.5-88.8 mm. The included angle (a) between adjacent tooth grooves (103) is 13.33°.

6. A composite stator core as described in claim 5, characterized in that, The groove (103a) of the interdental groove (103) has a width of 1.4-1.6 mm, an upper width of 12.1-12.2 mm, and a lower width of 9.0-9.1 mm; the tooth (101) is integrally formed from the tooth body (101a) and the tooth tip (101b); the thickness of the tooth tip is 1.9-2 mm; and the distance from the upper part of the interdental groove to the bottom of the interdental groove is 27-27.2 mm.

7. A composite stator core as described in claim 6, characterized in that, The stator (1) has 27 slots between teeth, corresponding to 30 poles and 3 phases. The number of slots between teeth per pole and per phase is 3 / 10. The pole pitch angle (bp) is 12 degrees. The radius of the inner arc (R2) at the junction of the tooth tip (101b) and the tooth body (101a) is 1.5-1.6 mm.

8. A composite stator core as described in claim 7, characterized in that, The inner wall of the yoke (102) is provided with two positioning teeth (104) spaced at 180-degree intervals, that is, the two positioning teeth are respectively set at radially equidistant positions on the inner wall of the yoke; the width (L3) of the positioning teeth is 8-8.2mm; the radial riveting hole (4) and the riveting hole (5) have the same shape, both being square; the width of the radial riveting hole and the riveting hole is 1-1.2mm, and the length is 2-2.2mm; the four transition points of the riveting hole are provided with corner arcs (R3), the radius of the corner arcs is 0.2-0.3mm; the length direction of the radial riveting hole (4) is consistent with the length direction of the tooth body (101a).

9. A composite stator core as described in claim 2, characterized in that, The magnet (2) is a circular body formed by several magnet units (201); the thickness (H) of the magnet unit is 2.8-3.3mm; the angle (b) between the bottom surfaces of two adjacent side strips is 93-95°.

10. A power motor, characterized in that, Includes the stator core as described in any one of claims 1-9.

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