Slot wedge, stator core and motor

Abstract

The utility model relates to the technical field of motors, particularly provides a slot wedge, a stator iron core and a motor, and aims to solve the problem that the performance of an existing motor is affected due to existence of a stator notch and a slot wedge. In order to achieve the purpose, the utility model discloses a slot wedge which is used for sealing a stator notch of a stator core, and the slot wedge comprises a first part and at least one second part connected with the first part, the magnetic conductivity of the second part is greater than that of the first part, and the first part and the second part extend along the radial direction of the stator iron core, so that magnetic lines can enter the rotor iron core along the second part, and at least part of the magnetic lines are prevented from sequentially passing through the first part and the second part along the circumferential direction of the stator iron core and then returning to the stator iron core. The second part is responsible for improving the phenomenon of non-uniform distribution of air gap magnetic flux and reducing generation of harmonic waves, and the first part is responsible for separating a stator notch along a magnetic circuit in the circumferential direction, so that the phenomenon of magnetic leakage is improved, the leakage reactance of the notch is reduced, and the overall performance of the motor can be improved.

Description

Technical Field

[0001] This application relates to the field of motor technology, specifically providing a slot wedge, a stator core, and a motor. Background Technology

[0002] For most motors today, the windings are embedded in slots in the stator core. At the same time, slot wedges are placed at the slot openings to close the slots, thereby fixing the windings in the slots.

[0003] Motor slot wedges typically include insulating slot wedges and magnetic slot wedges. When using insulating slot wedges, they only serve to fix the windings, and the distribution of magnetic field lines within the motor is essentially the same as when no slot wedges are used. This method results in uneven air gap magnetic flux density, easily causing air gap magnetic field distortion and larger back electromotive force harmonics. While using magnetic slot wedges can ensure that magnetic field lines reach the rotor core evenly through the air gap, optimizing the air gap magnetic field and reducing motor torque ripple to some extent, the fact that magnetic slot wedges completely cover the entire stator slot opening also causes some magnetic field lines to bypass the air gap and directly link with the stator windings themselves, increasing motor leakage flux and affecting motor performance.

[0004] Accordingly, a new technical solution is needed in this field to solve the above problems. Utility Model Content

[0005] This application aims to solve the aforementioned technical problem, namely, to address the issue that the presence of stator slots and slot wedges affects the performance of existing motors.

[0006] In a first aspect, this application provides a slot wedge for closing stator slots in a stator core, the slot wedge comprising:

[0007] The first part and at least one second part connected to the first part;

[0008] The magnetic permeability of the second part is greater than that of the first part. Both the first part and the second part extend radially along the stator core so that magnetic lines of force can enter the rotor core along the second part, and at least some magnetic lines of force are blocked from passing through the first part and the second part in sequence along the circumference of the stator core before returning to the stator core.

[0009] In one of the above-mentioned slot wedge technical solutions, the number of the second part is one, so that when the slot wedge is installed in the stator slot, the first part and the second part respectively contact the two side walls opposite to the stator slot.

[0010] In one technical solution of the above-mentioned slot wedge, the number of the second part is two, and the first part is located between the two second parts, so that when the slot wedge is installed in the stator slot, the two second parts respectively contact the two side walls of the stator slot.

[0011] In one technical solution of the aforementioned slot wedge, the two second parts have the same cross-sectional shape, and the two second parts are symmetrically arranged relative to the first part.

[0012] In one technical solution of the aforementioned slot wedge, the cross-sectional shape of the first part is an axisymmetric structure, and the axis of the axisymmetric structure extends radially along the stator core.

[0013] In one technical solution of the aforementioned slot wedge, the first part is made of a non-magnetic material.

[0014] In one technical solution of the aforementioned groove wedge, the first part and the second part are integrally formed.

[0015] In a second aspect, this application provides a stator core comprising the slot wedge described in any one of the first aspects.

[0016] In a third aspect, this application provides an electric motor comprising:

[0017] Stator, comprising the stator core as described in the second aspect; and

[0018] The rotor forms an air gap with the stator core.

[0019] In one technical solution of the above-mentioned motor, the width of the first part along the circumferential direction of the stator core is greater than the width of the air gap.

[0020] As described above, in the case of adopting the above technical solution, this application sets the slot wedge as a second part with strong magnetic permeability and a first part with weak magnetic permeability. The second part is responsible for allowing magnetic lines of force to pass through and enter the air gap, thereby improving the phenomenon of uneven magnetic flux distribution in the air gap and reducing the generation of harmonics. The first part is responsible for blocking the magnetic lines of force from passing directly along the circumference of the slot wedge and returning to the stator to link with itself, thereby preventing the magnetic lines of force from entering the rotor core. In this way, the first part can separate the magnetic circuit of the stator slot opening along the circumference, thereby improving the leakage flux phenomenon, reducing the slot leakage reactance, and improving the overall performance of the motor.

[0021] Furthermore, by setting the first part and the second part as an integral molded part, compared with the method of processing them separately and then mechanically connecting them into one piece, the connection strength between the first part and the second part is higher, which can adapt to the high-speed operation conditions of the motor. During the high-speed operation of the motor, the first part and the second part are not easily separated from each other by the influence of centrifugal force, radial force and reciprocating magnetic pull, thereby improving the ability of the slot wedge to resist harsh working conditions and improving the stability of the slot wedge. Attached Figure Description

[0022] The preferred embodiments of this application are described below with reference to the accompanying drawings, in which:

[0023] Figure 1 This is a cross-sectional schematic diagram of the groove wedge according to the first embodiment of this application;

[0024] Figure 2 This is a schematic diagram of a slot wedge installed on a stator core according to an embodiment of this application;

[0025] Figure 3 This is a cross-sectional schematic diagram of the groove wedge according to the second embodiment of this application;

[0026] Figure 4 This is a cross-sectional schematic diagram of the groove wedge according to the third embodiment of this application.

[0027] In the figure, the reference numerals refer to the following:

[0028] 1. First part; 2. Second part; 100. Winding; 200. Core body. Detailed Implementation

[0029] Preferred embodiments of this application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of this application and are not intended to limit the scope of protection of this application. Those skilled in the art can make adjustments as needed to adapt to specific application scenarios.

[0030] It should be noted that in the description of this application, terms such as "upper," "lower," "left," "right," "inner," and "outer," which indicate direction or positional relationship, are based on the direction or positional relationship shown in the accompanying drawings. These terms are used merely for ease of description and do not indicate or imply that the relevant device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, ordinal numbers such as "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0031] Furthermore, it should be noted that, in the description of this application, unless otherwise expressly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0032] To facilitate understanding of the technical solution of this application, a brief introduction to the distribution of magnetic flux lines within the motor is provided first. Specifically, when insulating slot wedges (or non-magnetic slot wedges) are installed on the stator core of the motor, the magnetic flux lines inside the motor originate from the stator core, pass through the air gap to reach the rotor, and then return to the stator windings from the rotor through the air gap. This is the "main magnetic flux" inside the motor. However, due to the installation of insulating slot wedges at the stator slot openings, the magnetic flux lines cannot pass through the slot wedges, and some magnetic flux lines may deviate from their original paths, resulting in localized changes in the distribution of magnetic flux lines. This causes uneven distribution of magnetic flux in the air gap, thereby generating harmonics. When magnetic slot wedges are installed on the stator core of the motor, since the magnetic slot wedges completely cover the stator slot openings, some magnetic flux lines directly pass circumferentially through the magnetic slot wedges and return to the stator to form a link with themselves. The magnetic flux lines cannot pass through the air gap and enter the rotor core, thus increasing the leakage flux of the motor. Specifically, this is "stator leakage flux," which directly affects the overall performance of the motor.

[0033] It is clear that each of the above methods has certain drawbacks.

[0034] In view of this, this application discloses a slot wedge, which includes a first part and a second part connected to each other. The number of second parts can be one or more, wherein the magnetic permeability of the second part is greater than that of the first part. Thus, based on the magnetic permeability, the first part is a weak magnetic permeability region relative to the second part, and the second part is a strong magnetic permeability region relative to the first part. It should be noted that the magnetic permeability of the weak magnetic permeability region described in this application can be zero, that is, the first part can be made of a non-magnetic material.

[0035] Reference Figure 1 This is a schematic cross-sectional view of a slot wedge according to an embodiment of this application. The slot wedge of this application is used to install on the stator core and close the stator slot opening of the stator core. The "cross-section" of the slot wedge mentioned in this application refers to the radial section of the slot wedge along the stator core after it is installed on the stator core. Figure 1 In the embodiment shown, the slot wedge includes a first portion 1 and two second portions 2, the first portion 1 being located between the two second portions 2, and both the first portion 1 and the second portion 2 extending radially along the stator core.

[0036] Reference Figure 2This is a schematic diagram of a slot wedge installed on a stator core according to an embodiment of this application. The stator core includes a winding 100 and a core body 200. The dashed lines in the figure represent the distribution of magnetic field lines. When the slot wedge is installed in the stator slot, the two second parts 2 respectively contact the side walls of the stator slot.

[0037] As can be seen, this application divides the slot wedge into a first part 1 with weaker magnetic permeability and a second part 2 with stronger magnetic permeability. During motor operation, the second part 2 can serve as a pathway for air gap magnetic flux. Magnetic lines of force enter the air gap from the winding 100 through the second part 2 and eventually reach the rotor. Similarly, magnetic lines of force can also return from the rotor to the winding 100 via the air gap and the second part 2. This improves the uniformity of air gap magnetic flux distribution and reduces harmonics. Simultaneously, since the first part 1 extends radially along the stator core and penetrates the slot wedge body, and its magnetic permeability is low, it can prevent at least some magnetic lines of force from sequentially passing through the second part 2 and the first part 1 along the circumference of the stator core before returning to the core body 200 and forming a link with the winding 100 itself, thereby improving stator leakage flux.

[0038] Understandably, when the first part 1 is made of a non-magnetic material, most of the magnetic field lines will not be able to pass through the first part 1.

[0039] Although in the above Figure 1 and Figure 2 The illustrated embodiment is described using the example of a slotted wedge comprising a first portion 1 and two second portions 2, but this does not constitute a limitation of this application. For example, refer to... Figure 3 In some other implementations of this application, the slot wedge may consist of only a first part 1 and a second part 2. In this case, when the first part 1 and the second part 2 are installed in the stator slot, the first part 1 and the second part 2 respectively contact the sidewall of the stator slot. Thus, along the circumferential direction of the stator core, the first part 1 separates the core body 200 from the second part 2, allowing some magnetic lines of force to enter the air gap through the second part 2, thereby improving the uneven distribution of magnetic flux in the air gap. At the same time, the first part 1 can block at least some magnetic lines of force from passing sequentially through the second part 2 and the first part 1 along the circumferential direction, thereby forming a closed loop of magnetic lines of force and improving magnetic leakage.

[0040] As described above, this application sets the slot wedge as a second part 2 with strong magnetic permeability and a first part 1 with weak magnetic permeability. The second part 2 is responsible for allowing magnetic lines of force to pass through and enter the air gap, thereby improving the uneven distribution of magnetic flux in the air gap and reducing the generation of harmonics. The first part 1 is responsible for blocking the magnetic lines of force from directly passing through the circumference of the slot wedge and returning to the stator to link with itself, thereby preventing the magnetic lines of force from entering the rotor core. In this way, the first part 1 can separate the magnetic circuit of the stator slot opening along the circumference, thereby improving the leakage flux phenomenon, reducing the slot leakage reactance, and improving the overall performance of the motor.

[0041] As one possible implementation of this application, based on an embodiment where the slot wedge includes two second parts 2, the two second parts 2 have the same cross-sectional shape and are symmetrically arranged relative to the first part 1. In this way, the distribution of magnetic field lines within the motor is also symmetrically arranged, thereby improving the distortion of the air gap magnetic field and enhancing the uniformity of the air gap magnetic flux distribution.

[0042] Furthermore, the cross-sectional shape of the first part 1 is set to an axisymmetric structure, such as a rectangle or an isosceles trapezoid, and the axis of symmetry of this axisymmetric structure extends radially along the stator core. Since both the rotor and stator of the motor are cylindrical rotating structures, this also causes part of the path of the magnetic lines of force within the motor cross-section to extend approximately along the radial direction of the stator core. Therefore, setting the cross-section of the first part 1 to the above shape is beneficial to the distribution of magnetic lines of force, reduces the phenomenon of magnetic lines of force deviating from their original paths and thus forming distortion, thereby improving the performance of the motor.

[0043] Based on the above principle, when the cross-sectional shape of the first part 1 is an isosceles trapezoid or other cross-sectional shapes with a gradual change, the width of the cross-section of the first part 1 should gradually decrease along the direction toward the rotor axis.

[0044] It should be noted that, although in the above Figure 1 and Figure 3 In the illustrated embodiment, the overall cross-sectional shape of the slot wedge is exemplarily described as trapezoidal, but this does not constitute a limitation of this application. The cross-sectional shape of the slot wedge can be adaptively adjusted according to the structural design of the stator core. Specifically, the cross-sectional shape of the slot wedge can be triangular, rhomboid, elliptical, or any other irregular shape. This application does not impose any limitations on this, for example, in... Figure 4 In one embodiment shown, the cross-section of the slot wedge is irregular in shape, as long as it can be easily fixed to the stator slot to close the stator slot.

[0045] It should also be noted that the slot wedge of this application can be manufactured using an integral molding process, such as lamination, molding, or drawing, so that the first part 1 and the second part 2 are integrally molded parts. Specifically, in actual processing, after the integral molding of the slot wedge is completed, the slot wedge can be cut, ground, or otherwise shaped as required to form the slot wedge into the desired shape.

[0046] In this application, the first part 1 and the second part 2 are processed into an integral part in the above manner. On the one hand, compared with the method of processing them separately and then mechanically connecting them into one piece, the connection strength between the first part 1 and the second part 2 is higher, which can adapt to the high-speed operation conditions of the motor. During the high-speed operation of the motor, the first part 1 and the second part 2 are not easily separated from each other by the influence of centrifugal force, radial force and reciprocating magnetic pull, thereby improving the ability of the slot wedge to resist harsh working conditions and improving the stability of the slot wedge.

[0047] On the other hand, by adopting the above method, in actual processing, based on the strength requirements of the magnetic conductivity of the first part 1 and the second part 2, materials such as magnetic conductive powder can be added to the first part 1 and the second part 2 in a targeted manner, which is conducive to achieving precise control of the magnetic conductivity of the first part 1 and the second part 2.

[0048] This application also discloses a stator core, which includes a slot wedge of any of the above embodiments, the slot wedge being installed in the stator slot of the stator core.

[0049] This application also discloses an electric motor, which includes a stator, a rotor, and other necessary components such as a housing, which will not be described in detail here. The stator includes the stator core as described in the above embodiments, and an air gap is formed between the stator and the rotor.

[0050] As one implementation of this application, the width of the first part 1 along the circumferential direction of the stator core is greater than the width of the air gap. It should be noted that when the cross-section of the first part 1 is rectangular, the aforementioned "width of the first part 1 along the circumferential direction of the stator core" refers to the width of the rectangle. When the cross-section of the first part 1 is an isosceles trapezoid or other shape with a gradually changing cross-sectional size along the radial direction of the stator core, the aforementioned "width of the first part 1 along the circumferential direction of the stator core" specifically refers to the minimum width of the first part 1.

[0051] This is because the first part 1 is set to reduce magnetic leakage reactance. If the width of the first part 1 is too small, the effect of reducing magnetic leakage reactance will not be particularly obvious. Therefore, the width of the first part 1 is set to be greater than the width of the air gap in order to ensure that the magnetic resistance at the position of the first part 1 is greater than the magnetic resistance of the air gap, so that the magnetic flux can pass through the air gap more easily instead of through the slot wedge, which is conducive to improving the performance of the motor.

[0052] The technical solutions of this application have been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of this application is obviously not limited to these specific embodiments. Without departing from the principles of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of this application.

Claims

1. A slot wedge for closing stator slots in a stator core, characterized in that, include: The first part (1) and at least one second part (2) connected to the first part (1); The magnetic permeability of the second part (2) is greater than that of the first part (1). Both the first part (1) and the second part (2) extend radially along the stator core so that magnetic lines of force can enter the stator core along the second part (2) and block at least a portion of the magnetic lines of force from passing through the first part (1) and the second part (2) in sequence along the circumference of the stator core before returning to the stator core.

2. The slotted wedge according to claim 1, characterized in that, The second part (2) is one in number, so that when the slot wedge is installed in the stator slot, the first part (1) and the second part (2) respectively contact the two side walls opposite to the stator slot.

3. The slotted wedge according to claim 1, characterized in that, The number of the second part (2) is two, and the first part (1) is located between the two second parts (2), so that when the slot wedge is installed in the stator slot, the two second parts (2) respectively contact the two side walls of the stator slot.

4. The slotted wedge according to claim 3, characterized in that, The two second parts (2) have the same cross-sectional shape, and the two second parts (2) are arranged symmetrically relative to the first part (1).

5. The slot wedge according to claim 4, characterized in that, The first part (1) has an axisymmetric cross-sectional shape, and the axis of the axisymmetric structure extends radially along the stator core.

6. The slot wedge according to claim 1, characterized in that, The first part (1) is made of a non-magnetic material.

7. The slotted wedge according to any one of claims 1 to 6, characterized in that, The first part (1) and the second part (2) are integrally formed.

8. A stator core, characterized in that, Includes the slotted wedge according to any one of claims 1 to 7.

9. An electric motor, characterized in that, include: Stator, comprising the stator core as described in claim 8; as well as The rotor forms an air gap with the stator core.

10. The motor according to claim 9, characterized in that, The width of the first part (1) along the circumferential direction of the stator core is greater than the width of the air gap.

Images