Stator core with notch pole shoes provided with chamfers and stator assembly

Abstract

The utility model relates to the technical field of flat wire motors, in particular to a stator core with chamfers on notch pole shoes and a stator assembly. The whole stator core is cylindrical, and a plurality of stator grooves are distributed in the stator core in the circumferential direction of the stator core. One side, close to the rotor, of each stator groove is provided with two mutually symmetrical pole shoes; a stator notch is arranged between the two pole shoes; a pole shoe top edge and a chamfer edge are arranged on one side, positioned in the stator slot, of the pole shoe; wherein the top edges of the pole shoes are arranged close to stator teeth, and the chamfered edges are arranged close to stator notches; and from the top edge of the pole shoe to the notch of the stator, the thickness of the pole shoe part where the chamfer edge is located is gradually reduced along the radial direction of the stator iron core. According to the utility model, the stator core effectively improves the peak torque of the motor; the torque fluctuation of the motor is almost reduced by half, the back electromotive force harmonic content is reduced, and the no-load peak back electromotive force is lower.

Description

TECHNICAL FIELD

[0001] The utility model belongs to flat wire motor technical field, especially relate to a slot pole shoe sets chamfer's stator core and stator assembly. BACKGROUND

[0002] The peak torque of a motor refers to the maximum torque value at a moment, which usually reaches the peak torque when the motor starts and accelerates. The peak torque is the ability of the motor to produce the maximum output torque, and is one of the key indicators to judge the performance of the motor. In some high-performance applications, such as robots, automated production lines, etc., the motor needs to provide a larger peak torque to cope with sudden loads.

[0003] Increasing the peak torque of the motor is always an important content of motor research and development. Currently, the methods to increase the peak torque of the motor include torque compensation, increasing the number of coils, and increasing the current. Among them, torque compensation and increasing the current improve the motor operating conditions by adjusting the motor operating voltage and current, without changing the actual performance of the motor. Increasing the number of coils can enhance the magnetic force of the electromagnet, thereby increasing the torque. However, this method increases the size and production cost of the motor. SUMMARY

[0004] To solve the above problems, the utility model provides a slot pole shoe sets chamfer's stator core, the stator core whole presents cylindrical, there is a plurality of stator slots on the stator core along its circumferential direction distribution;The stator slot is close to the rotor one side and is provided with two mutually symmetrical pole shoes;Two pole shoes are provided with stator slot in the middle;

[0005] The pole shoe is provided with a pole shoe top edge and a chamfer edge on the side inside the stator slot;Among them, the pole shoe top edge is close to the stator tooth setting, and the chamfer edge is close to the stator slot setting;From the pole shoe top edge to the stator slot direction, the thickness of the pole shoe part where the chamfer edge is gradually reduced along the radial direction of the stator core.

[0006] Further, the length b of the chamfer edge along the circumferential direction of the stator core is not more than the length a of the pole shoe along the circumferential direction of the stator core;

[0007] The ratio of the minimum thickness d of the pole shoe part where the chamfer edge is along the radial direction of the stator core to the maximum thickness c of the pole shoe along the radial direction of the stator core is in the range of 0.1-0.9.

[0008] Further, the ratio of the length b of the chamfer edge along the circumferential direction of the stator core to the length a of the pole shoe along the circumferential direction of the stator core is in the range of 0.4-0.9.

[0009] Further, the ratio of the minimum thickness d of the pole shoe part where the chamfer edge is along the radial direction of the stator core to the maximum thickness c of the pole shoe along the radial direction of the stator core is 0.5.

[0010] Further, the maximum thickness c of the pole shoe along the radial direction of the stator core ranges from 0.1 mm to 5 mm.

[0011] Further, the chamfered edge can be an arc surface or a plane.

[0012] The utility model also provides a slot pole shoe setting chamfer's stator assembly, the stator assembly includes above -mentioned stator core.

[0013] The utility model has the advantages of:

[0014] 1. The peak torque of the motor is effectively improved.

[0015] 2. The torque fluctuation of the motor is almost reduced by half. The energy loss of the motor operation is reduced with the reduction of torque fluctuation, and the operation effect of the motor is improved. Smaller torque fluctuation can reduce the mechanical vibration and noise of the motor, and improve the stability of the operation system.

[0016] 3. The content of back EMF harmonic is reduced. The harmonic loss in the motor can be reduced, thereby improving the overall efficiency. Back EMF harmonic is an important factor causing torque fluctuation, and reducing the content of back EMF harmonic helps to reduce torque fluctuation and improve the operation stability of the motor. Back EMF harmonic may cause electromagnetic interference, affecting the normal work of the motor and other electrical equipment, and reducing the harmonic content helps to reduce such interference. The reduction of back EMF harmonic content can improve the control response of the motor, making the motor control system more stable and accurate. The reduction of back EMF harmonic helps to reduce the noise and vibration generated during the operation of the motor, and improves the working environment. The output power of the motor can be improved, so that it can better meet the high performance requirements.

[0017] 4. The peak back EMF under no load is lower. If the back EMF of the motor is too high, it may exceed the withstand voltage range of the motor and its control elements (such as IGBT), thereby causing the risk of damaging the equipment. Reducing the peak back EMF under no load can improve the safety of the motor equipment.

[0018] 5. The greater the minimum thickness d of the pole shoe part where the chamfered edge is located along the radial direction of the stator core, the lower the cogging torque. By adjusting the minimum thickness of the pole shoe, the peak torque of the motor can be improved while the cogging torque is reduced.

[0019] Other features and advantages of the utility model will be set forth in the subsequent description, and some of them will become apparent from the description, or will be understood by practicing the utility model. The purpose and other advantages of the utility model can be realized and obtained by the structure indicated in the description and the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings described below are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0021] Figure 1 A front view of a stator assembly of an embodiment of the present application is shown.

[0022] Figure 2 A front view of a stator assembly of an embodiment of the present application is shown. Figure 1 An enlarged view of part A in the figure is shown.

[0023] Figure 3 An enlarged view of part B in the figure is shown. Figure 1 An enlarged view of part B in the figure is shown.

[0024] Figure 4 A partial view of a pole shoe with an arc-shaped chamfer edge of an embodiment of the present application is shown.

[0025] In the figure: 1 - stator core; 2 - stator slot; 3 - pole shoe; 4 - pole shoe top edge; 5 - chamfer edge; 6 - stator slot opening. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the following will combine the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0027] An embodiment of the present application provides a stator assembly with a slot opening pole shoe with a chamfer, as shown in Figure 1 and Figure 2 The stator assembly includes a stator core 1, which is overall cylindrical. A plurality of stator slots 2 are distributed along the circumferential direction of the stator core 1. Two mutually symmetrical pole shoes 3 are arranged on the side of the stator slots 2 close to the rotor. A stator slot opening 6 is arranged in the middle of the two pole shoes 3.

[0028] A pole shoe top edge 4 and a chamfer edge 5 are arranged on one side of the pole shoe 3 inside the stator slot 2. The pole shoe top edge 4 is arranged close to the stator tooth, and the chamfer edge 5 is arranged close to the stator slot opening 6. From the pole shoe top edge 4 to the direction of the stator slot opening 6, the thickness of the part of the pole shoe 3 where the chamfer edge 5 is located gradually decreases along the radial direction of the stator core.

[0029] The chamfered edge is arranged on the pole shoe, which is equivalent to digging a chamfer on the pole shoe. For example, the motor of embodiment 1 and the motor of comparative example 1 are both of 185 mm diameter size, and each of the stator cores has 24 stator slots, and each of the stator slots has 22 layers of rectangular conductors arranged along the radial direction of the stator slot. The difference between the two is that the pole shoe of embodiment 1 is provided with a chamfered edge, and the pole shoe of comparative example 1 is not provided with a chamfered edge. The performance parameters of embodiment 1 and comparative example 1 are shown in Table 1. The peak torque of embodiment 1 is improved relative to comparative example 1, and the torque fluctuation, back EMF harmonic content and no-load peak back EMF of embodiment 1 are all significantly reduced relative to comparative example 1.

[0030] Table 1: Comparison of performance parameters of embodiment 1 and comparative example 1

[0031] Example 1 Comparative Example 1 Peak Torque (Nm) 13.84 13.73 Torque Ripple (%) 2.84 5.3 Back EMF Harmonic Content (%) 1.75 2.76 No Load Peak Back EMF (V) 429 440

[0032] The stator core and the stator assembly provided by the utility model can effectively improve the peak torque of the motor, and reduce the torque fluctuation, back EMF harmonic content and no-load peak back EMF, thereby significantly improving the performance of the motor.

[0033] Further, as shown in Figure 3 The length b of the chamfered edge 5 along the circumferential direction of the stator core is not more than the length a of the pole shoe 3 along the circumferential direction of the stator core.

[0034] The ratio of the minimum thickness d of the part of the pole shoe 3 where the chamfered edge 5 is located along the radial direction of the stator core to the maximum thickness c of the pole shoe 3 along the radial direction of the stator core is in the range of 0.1-0.9.

[0035] Preferably, the ratio of the length b of the chamfered edge 5 along the circumferential direction of the stator core to the length a of the pole shoe 3 along the circumferential direction of the stator core is in the range of 0.4-0.9.

[0036] As shown in Table 2, based on the motor size of embodiment 1, when the ratio of the minimum thickness d of the part of the pole shoe 3 where the chamfered edge 5 is located along the radial direction of the stator core to the maximum thickness c of the pole shoe 3 along the radial direction of the stator core is 0.5, the length b of the chamfered edge 5 and the length a of the pole shoe 3 are in different ratios, and the corresponding performance parameters of the motor are shown in Table 2. When the ratio of the length b of the chamfered edge 5 along the circumferential direction of the stator core to the length a of the pole shoe 3 along the circumferential direction of the stator core is in the range of 0.4-0.9, the peak torque, torque fluctuation, back EMF harmonic content and no-load peak back EMF of the motor reach the optimal state.

[0037] Table 2: Performance parameters of the motor when the chamfered edge has different lengths

[0038]

[0039] Further preferably, the ratio of the minimum thickness d of the portion of the pole shoe 3 where the chamfer edge 5 is located along the radial direction of the stator core to the maximum thickness c of the pole shoe 3 along the radial direction of the stator core is 0.5.

[0040] As shown in Table 3, when the ratio of the length b of the chamfer edge 5 along the circumferential direction of the stator core to the length a of the pole shoe 3 along the circumferential direction of the stator core is 0.7 based on the motor size of Example 1, the motor corresponding performance parameters are set when the chamfer edge 5 adopts different minimum thickness d. When the ratio of the minimum thickness d of the portion of the pole shoe 3 where the chamfer edge 5 is located along the radial direction of the stator core to the maximum thickness c of the pole shoe 3 along the radial direction of the stator core is 0.5, the motor comprehensive performance such as peak torque, torque fluctuation, back EMF harmonic content and no-load peak back EMF reaches the optimal state.

[0041] Table 3 Performance parameter table when chamfer edge adopts different thickness

[0042]

[0043] Further, the maximum thickness c of the pole shoe 3 along the radial direction of the stator core ranges from 0.1mm to 5mm.

[0044] The larger the minimum thickness d of the portion of the pole shoe 3 where the chamfer edge 5 is located along the radial direction of the stator core, the lower the cogging torque. By adjusting the minimum thickness of the pole shoe, the peak torque of the motor can be improved while the cogging torque is reduced.

[0045] Further, the chamfer edge 5 can be provided as an arc surface, as shown in Figure 2 and Figure 3 The chamfer edge 5 can also be provided as a flat surface, as shown in Figure 4 .

[0046] Preferably, the chamfer edge 5 is an arc surface.

[0047] The chamfer edge provided as an arc surface can reduce the magnetic flux density at the pole shoe, thereby reducing the magnetic field energy at the pole shoe, and the cogging torque and torque fluctuation can be reduced.

[0048] Further, the pole shoe 3 and the stator slot 6 can be provided on the inner circle side of the stator core 1 or on the outer circle side of the stator core 1.

[0049] When the pole shoe 3 and the stator slot 6 can be provided on the inner circle side of the stator core 1, the stator assembly is suitable for an internal rotor motor; when the pole shoe 3 and the stator slot 6 can be provided on the outer circle side of the stator core 1, the stator assembly is suitable for an external rotor motor.

[0050] The stator core and stator assembly scheme provided by the utility model have wide application range and provide optional motor schemes for different application scenarios.

[0051] Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features therein can be replaced equivalently, and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the utility model.

Claims

1. A slot pole shoe chamfered stator core characterized by, The stator core is cylindrical in whole, and a plurality of stator slots (2) are distributed on the stator core along the circumferential direction thereof; two mutually symmetrical pole shoes (3) are arranged on the side of the stator slots (2) close to the rotor; a stator slot opening (6) is arranged between the two pole shoes (3). The pole shoe (3) is provided with a pole shoe top edge (4) and a chamfered edge (5) on the side inside the stator slot (2); the pole shoe top edge (4) is arranged close to the stator tooth, and the chamfered edge (5) is arranged close to the stator slot opening (6); the thickness of the pole shoe (3) part where the chamfered edge (5) is located gradually decreases along the radial direction of the stator core from the pole shoe top edge (4) to the stator slot opening (6).

2. The stator core with chamfered slot pole shoes according to claim 1, characterized in that The length b of the chamfered edge (5) along the circumferential direction of the stator core is not more than the length a of the pole shoe (3) along the circumferential direction of the stator core. The ratio of the minimum thickness d of the pole shoe (3) part where the chamfered edge (5) is located along the radial direction of the stator core to the maximum thickness c of the pole shoe (3) along the radial direction of the stator core is in the range of 0.1-0.

9.

3. The notched pole piece chamfered stator core according to claim 2, characterized by The ratio of the length b of the chamfered edge (5) along the circumferential direction of the stator core to the length a of the pole shoe (3) along the circumferential direction of the stator core is in the range of 0.4-0.

9.

4. The notched pole piece chamfered stator core of claim 2, wherein The ratio of the minimum thickness d of the pole shoe (3) part where the chamfered edge (5) is located along the radial direction of the stator core to the maximum thickness c of the pole shoe (3) along the radial direction of the stator core is 0.

5.

5. A notched pole piece provided with a chamfered stator core according to any one of claims 2 to 4, characterized in that, The maximum thickness c of the pole shoe (3) along the radial direction of the stator core is in the range of 0.1mm-5mm.

6. The notched pole piece chamfered stator core of claim 1, wherein The chamfered edge (5) can be arranged as an arc surface or a plane.

7. A slotted pole shoe chamfered stator assembly characterized by, The stator assembly comprises the stator core according to any one of claims 1-6.

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