Single-tooth punching sheet structure of sectional type permanent magnet motor

Abstract

The utility model discloses a single-tooth punching sheet structure of a sectional type permanent magnet motor, a plurality of single-tooth punching sheets are stacked in sequence to form a single-tooth iron core, a plurality of single-tooth iron cores are assembled along the circumferential direction to form a stator iron core, each single-tooth punching sheet comprises a stator tooth and magnet yokes, the magnet yokes respectively protrude from the front end part of the stator tooth to two sides, and the magnet yokes are arranged on the stator tooth. And the free end of the magnet yoke is provided with a reinforcing part protruding towards the circle center direction of the stator iron core. According to the utility model, the two adjacent single-tooth punching sheets are correspondingly matched and spliced to form the reinforcing convex parts, so that the splicing contact area between the single-tooth punching sheets can be increased, and the stability of the spliced stator iron core is improved; the air gap magnetic resistance of the motor can be reduced, the inductance of the motor is reduced, and the electrical time constant is reduced, so that the response speed of the motor is improved; and moreover, the increased contact surface is also beneficial to dispersing over-concentrated magnetic flux density of the yoke part of the motor, reducing local heating of the motor and reducing the size of the motor. And meanwhile, the service life of the stator punching sheet processing die can be prolonged.

Description

Technical Field

[0001] The utility model relates to a stator punching sheet structure, in particular to a single-tooth punching sheet structure of a segmented permanent magnet motor. Background Art

[0002] Concentrated winding permanent magnet motors are widely used in the field of precision micro permanent magnet motors due to their small winding ends and high efficiency.

[0003] In order to further improve the slot utilization of the motor, in the prior art, the stator core 1 is divided into independent single-tooth cores 10 for assembly. These single-tooth cores 10 are formed by stacking a predetermined number of single-tooth punchings of the same shape in sequence.

[0004] However, considering the mold manufacturing and machining process requirements, after the aforementioned existing segmented core is assembled into an integral circular stator core 1, the yoke joints between the single-tooth cores 10 will become narrower due to the existence of the rounded corner process (e.g., Figure 1 、 Figure 2 As shown, the fillets 11 and 12 at the yoke junction make the yoke width narrower. Such a structure increases the magnetic resistance of the motor and increases the local magnetic flux density of the motor's yoke, which is not conducive to the operation of the motor and the control of heat generation. Utility Model Content

[0005] The utility model aims at the drawbacks of the prior art and provides a single-tooth punching structure of a segmented permanent magnet motor.

[0006] The single-tooth punching structure of the segmented permanent magnet motor described in the present invention is to stack multiple single-tooth punchings in sequence to form a single-tooth iron core, and assemble multiple single-tooth iron cores along the circumferential direction to form a stator iron core. The single-tooth punching includes a stator tooth and a yoke protruding from the front end of the stator tooth to both sides respectively, and a reinforcement portion protruding toward the center of the stator iron core is provided at the free end of the yoke.

[0007] In the single-tooth punching structure of the segmented permanent magnet motor described in the present invention, the magnetic yoke includes a first magnetic yoke and a second magnetic yoke respectively arranged on both sides of the stator tooth, the free end of the first magnetic yoke has a first reinforcement portion protruding toward the center of the stator core, and the free end of the second magnetic yoke has a second reinforcement portion protruding toward the center of the stator core;

[0008] When adjacent single-tooth punching sheets are assembled, the first reinforcement portion of one single-tooth punching sheet and the second reinforcement portion of another single-tooth punching sheet adjacent to one side thereof are correspondingly matched and assembled into a reinforcement convex portion, and the second reinforcement portion of the single-tooth punching sheet and the first reinforcement portion of another single-tooth punching sheet adjacent to the other side thereof are correspondingly matched and assembled into another reinforcement convex portion.

[0009] In the single-tooth punching structure of the segmented permanent magnet motor described in the present invention, the shape of the reinforcement protrusion is a semicircle protruding from the inner edge of the stator core toward the center of the stator core.

[0010] In the single-tooth punching structure of the segmented permanent magnet motor described in the present invention, the end surface of the free end of the first magnetic yoke and the end surface of the free end of the second magnetic yoke are correspondingly matched curved surfaces.

[0011] In the single-tooth punching structure of the segmented permanent magnet motor described in the present invention, the end surface of the free end of the first magnetic yoke and the end surface of the free end of the second magnetic yoke are corresponding matching planes.

[0012] In the single-tooth punching structure of the segmented permanent magnet motor described in the present invention, the middle portion of the end surface of the free end of the first magnetic yoke has an outwardly convex arc surface;

[0013] The middle portion of the end surface of the free end of the second magnetic yoke has an inwardly concave arc surface corresponding to the outwardly convex arc surface.

[0014] In the single-tooth punching structure of the segmented permanent magnet motor described in the present invention, by correspondingly fitting and splicing two adjacent single-tooth punchings to form a reinforcement convex portion, not only can the contact area between the single-tooth punchings be increased, thereby improving the stability of the stator core after splicing, but also by increasing the contact area, the air gap magnetic resistance of the motor, the motor inductance, and the electrical time constant can be reduced, thereby improving the motor's response speed. Furthermore, the increased contact surface helps to disperse the excessively concentrated magnetic flux density of the motor yoke, reducing localized heating and reducing the motor's size. Simultaneously, it helps to extend the service life of the stator punching processing die. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural diagram of a stator core in the prior art;

[0016] Figure 2 It is a partial schematic diagram of the assembly of a single-tooth iron core in the prior art;

[0017] Figure 3 This is a schematic structural diagram of the stator core of the segmented permanent magnet motor of the present invention;

[0018] Figure 4 This is a structural diagram of a single-tooth punching of the segmented permanent magnet motor of the utility model;

[0019] Figure 5 It is a partial schematic diagram of the assembly of a single-tooth iron core of the segmented permanent magnet motor of the present invention;

[0020] Figure 6This is another partial schematic diagram of the assembly of a single-tooth iron core of the segmented permanent magnet motor described in the present invention. DETAILED DESCRIPTION

[0021] The present invention will be described in further detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0022] like Figure 3 、 Figure 4 As shown, the single-tooth punching structure of the segmented permanent magnet motor described in the present invention is characterized by stacking a predetermined number (the predetermined number can be set according to the performance indicators of the motor) of single-tooth punchings 2 in sequence to form a single-tooth iron core 10, and assembling multiple single-tooth iron cores 10 along the circumferential direction to form a stator iron core 1. The single-tooth punching 2 includes a stator tooth 20 and a yoke protruding from the front end of the stator tooth 20 to both sides. The free end of the yoke has a reinforcement portion protruding toward the center of the stator iron core 1.

[0023] Specifically, if Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 As shown, in the single-tooth punching structure of the segmented permanent magnet motor of the present invention, the yoke includes a first yoke 21 and a second yoke 22 arranged on both sides of the stator tooth 20.

[0024] The free end of the first magnetic yoke 21 has a first reinforcement portion 211 protruding toward the center of the stator core 1, and the free end of the second magnetic yoke 22 has a second reinforcement portion 221 protruding toward the center of the stator core 1. Figure 3 Taking the assembly of adjacent single-tooth punches 101, 102, and 103 as an example, the first reinforcement portion 211 of one single-tooth punch (such as the single-tooth punch 101) and the second reinforcement portion 221 of another single-tooth punch (such as the single-tooth punch 102) adjacent to one side thereof are correspondingly matched and assembled into a reinforcement protrusion 30, and the second reinforcement portion 221 of the single-tooth punch (such as the single-tooth punch 101) and the first reinforcement portion 211 of another single-tooth punch (such as the single-tooth punch 103) adjacent to the other side thereof are correspondingly matched and assembled into another reinforcement protrusion 30. The shape of the assembled reinforcement protrusion 30 can be a semicircular shape protruding from the inner edge of the stator core 1 toward the center of the stator core 1, or other shapes suitable for being arranged between two single-tooth cores wound with windings 51 and 52, and a blank space 50 formed by the outer contours of the windings 51 and 52 on the two single-tooth cores at the bottom between the single-tooth cores (such as Figure 6 The empty space 50 shown has a triangular convex shape.

[0025] In the single-tooth punching structure of the segmented permanent magnet motor described in the present invention, by correspondingly fitting and splicing two adjacent single-tooth punchings to form a reinforcement protrusion 30, not only can the contact area between the single-tooth punchings be increased, thereby improving the stability of the stator core after splicing, but also, by increasing the contact area, the magnetic resistance of the motor yoke can be reduced, especially the magnetic resistance at the connection between each tooth, reducing the motor inductance and the electrical time constant, thereby improving the response speed of the motor. Moreover, the increased contact surface also helps to disperse the overly concentrated magnetic flux density of the motor yoke, reduce local heating of the motor, and reduce the size of the motor. At the same time, from the perspective of processing single-tooth punchings, increasing the contact area increases the size of the yoke, which helps to extend the service life of the single-tooth punching processing mold (because a yoke that is too small will also cause the size of the processing mold at the corresponding position to approach the limit, and an excessively small limit size makes the processing mold extremely easy to damage).

[0026] In this example, three brushless DC motors with a stator outer diameter of 33 mm were selected for comparative testing. Using identical winding parameters and performance parameters, the motor with an integral stamping structure was designated motor #1, the motor with a conventional segmented iron core structure was designated motor #2, and the motor with the single-tooth stamping structure described in this example was designated motor #3. The magnetic flux density distribution of motor #1's yoke was uniform, but the overall magnetic flux density amplitude was higher, with a maximum yoke flux density of 1.5 T.

[0027] The yoke width of motor 2# is 1 mm. After the filleting, the actual yoke width is 0.8 mm, a 20% reduction. The yoke of motor 2# exhibits poor magnetic flux distribution. At the junction of the two single-tooth cores, the filleting causes the maximum magnetic flux amplitude to reach 1.5 / 0.8 = 1.875 T, reaching the saturation amplitude of the silicon steel sheet and significantly increasing heat generation. Furthermore, due to the increased magnetic resistance of motor 2#, to maintain the same air gap flux amplitude as motor 1# after the increase in magnetic resistance, the amount of magnetic steel required must be increased. While this yields the same performance, it also increases the motor's manufacturing cost. Furthermore, increasing the thickness of magnetic steel with the same performance to increase the air gap flux density also increases the rotor's moment of inertia and significantly increases the motor's weight.

[0028] The maximum yoke magnetic flux amplitude of the 3# motor is the same as the air gap magnetic flux amplitude of the 1# motor with an integral punching structure. However, due to the presence of a reinforcing protrusion at the junction of the two single-tooth punchings, the yoke part is amplified and strengthened. When the air gap magnetic flux amplitude is the same as that of the 1# motor, the maximum magnetic flux of the yoke part is 1.5T, while the magnetic flux amplitude of the reinforcing part is significantly lower than 1.5T, which is beneficial to the control of motor heating. In addition, although the presence of the reinforcing protrusion causes the volume of the yoke part to increase, from the perspective of actual stamping processing, the actual amount of silicon steel sheets consumed to obtain the single-tooth punching in this embodiment has not increased, and the actual total amount of silicon steel sheets consumed remains unchanged, and the material cost has not increased. Moreover, from the perspective of reducing mold loss and improving processing efficiency in stamping processing, the presence of the reinforcing protrusion extends the service life of the mold, improves processing efficiency, and helps to reduce costs. Therefore, the comprehensive performance and cost performance of the 3# motor are more superior.

[0029] In the single-tooth punching structure of the segmented permanent magnet motor described in the present invention, the end face 213 of the free end of the first magnetic yoke 21 and the end face 233 of the free end of the second magnetic yoke 22 are corresponding matching curved surfaces, or the end face 213 of the free end of the first magnetic yoke 21 and the end face 223 of the free end of the second magnetic yoke 22 are corresponding matching planes. That is to say, during actual assembly, the first magnetic yoke (or second magnetic yoke) of one of the two adjacent single-tooth punchings is matched with the second magnetic yoke (or first magnetic yoke) of the other single-tooth punching. For this reason, in the present invention, the end face 213 of the free end of the first magnetic yoke 21 of the single-tooth punching and the end face 233 of the free end of the second magnetic yoke 22 are set as corresponding matching curved surfaces or planes, so that the two adjacent single-tooth punchings can be flatly fitted. Furthermore, a convex arc surface 212 can be provided in the middle of the end face 213 of the free end of the first magnetic yoke 21, and correspondingly, a concave arc surface 222 can be provided in the middle of the end face 223 of the free end of the second magnetic yoke 22 to correspond to the convex arc surface 212, thereby further increasing the contact area of ​​the two single-tooth punchings and improving the stability of the stator core after splicing.

[0030] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with this field, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A single-tooth punching sheet structure of a segmented permanent magnet motor, wherein a plurality of single-tooth punching sheets are stacked in sequence to form a single-tooth iron core, and a plurality of single-tooth iron cores are assembled along a circumferential direction to form a stator iron core, characterized in that: The single-tooth punching sheet comprises a stator tooth and a yoke protruding from the front end of the stator tooth to both sides respectively, and a reinforcing portion protruding toward the center of the stator core is provided at the free end of the yoke.

2. The single-tooth punching structure of the segmented permanent magnet motor according to claim 1, characterized in that: The yoke comprises a first yoke and a second yoke respectively arranged on both sides of the stator tooth, the free end of the first yoke has a first reinforcement portion protruding toward the center of the stator core, and the free end of the second yoke has a second reinforcement portion protruding toward the center of the stator core; When adjacent single-tooth punching sheets are assembled, the first reinforcement portion of one of the single-tooth punching sheets and the second reinforcement portion of another single-tooth punching sheet adjacent to one side thereof are correspondingly matched and assembled into a reinforcement convex portion, and the second reinforcement portion of the single-tooth punching sheet and the first reinforcement portion of another single-tooth punching sheet adjacent to the other side thereof are correspondingly matched and assembled into another reinforcement convex portion.

3. The single-tooth punching structure of the segmented permanent magnet motor according to claim 2, characterized in that: The reinforcing protrusion is in the shape of a semicircle protruding from the inner edge of the stator core toward the center of the stator core.

4. The single-tooth punching structure of the segmented permanent magnet motor according to claim 2, characterized in that: The end surface of the free end of the first magnetic yoke and the end surface of the free end of the second magnetic yoke are correspondingly matched curved surfaces.

5. The single-tooth punching structure of the segmented permanent magnet motor according to claim 2, characterized in that: The end surface of the free end of the first magnetic yoke and the end surface of the free end of the second magnetic yoke are corresponding matching planes.

6. The single-tooth punching structure of the segmented permanent magnet motor according to claim 4, characterized in that: The middle part of the end surface of the free end of the first magnetic yoke has a convex arc surface; The middle portion of the end surface of the free end of the second yoke has a concave arc surface corresponding to the convex arc surface.

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