Anti-demagnetization magnetic steel slot and rotor

Abstract

The utility model relates to a kind of magnetic steel slots of anti-demagnetization, it is set on rotor core, the whole magnetic steel slot is rectangle, two ends are provided with magnetic bridge, the longer side of magnetic steel slot close to the outer circle of rotor core two ends is provided with the first step projecting to the inside of magnetic steel slot.Compared with prior art, the utility model is close to the outer circle of rotor core side two ends and is provided with the first step projecting to the inside of magnetic steel slot, increases the leakage of magnetic steel close to the outer circle side angle, makes a part of d-axis demagnetization magnetic field pass through leakage path closure, improves the minimum residual magnetism of magnetic steel close to the outer circle edge, with the same operating condition magnetic steel is not easy to demagnetize and the like advantages.

Description

Technical Field

[0001] This utility model relates to motor rotors, and more particularly to a demagnetizing magnetic steel slot and rotor. Background Technology

[0002] The rotor of a motor is the core rotating component, working in conjunction with the stator to convert electromagnetic energy into mechanical energy, ultimately driving the load. Its structure and materials vary depending on the type of motor. Permanent magnet synchronous motor rotors typically use a core made of stacked silicon steel sheets, with slots on the core for embedding permanent magnets to generate a magnetic field. When the rotor rotates at high speed, dynamic balance and mechanical strength must be ensured; its design directly affects the motor's efficiency, torque, and operational stability.

[0003] Existing conventional rotor magnet slot structures, such as Figure 1 As shown, the edge of the magnet near the outer circle of the magnet groove is a straight line, as... Figure 1 The locations indicated by reference numerals 61, 64, 71, and 74 form magnetic bridges after extending from the edge of the magnet (the magnetic permeability of air is much higher than that of silicon steel sheets), such as... Figure 1 The locations indicated by reference numerals 62, 65, 72, and 75 indicate that this structure reduces the minimum remanence of the magnet near its outer corner, making it easier for the magnet to demagnetize under the same operating conditions. This structure uses steps on both sides of the magnet on the inner side of the magnet slot to fix the relative position of the magnets. Figure 1 The positions indicated by numbers 63, 66, 73, and 76, while fixing the position of the magnet, also form a leakage magnetic circuit, slightly reducing the back EMF and output torque.

[0004] The magnetic field generated by the stator current couples and interacts with the structure near the outer circle of the magnet slot. The structure near the outer circle plays a decisive role in the pole arc coefficient, leakage flux coefficient, and air gap magnetic flux density sinusoidal value, while the structure near the inner circle has a smaller impact on the main magnetic circuit. When the stator d-axis current is greater than zero, a demagnetizing magnetic field opposite to that of the permanent magnet will be generated. Generally, the remanence is smallest at the corners of the magnet slot near the outer circle, and demagnetization occurs first (when the minimum remanence is lower than the remanence inflection point of the magnet, irreversible demagnetization will occur, which is called demagnetization).

[0005] A search revealed that authorization announcement number CN220874290U discloses rotor laminations, motor rotors, motors, and vehicles. Specifically, the rotor lamination includes a lamination body and a magnetic slot formed on the lamination body. The magnetic slot is used to hold magnets, and the magnets have multiple magnetic corners. The magnetic slot has a recessed groove formed at the magnetic corner near the air gap side of the rotor lamination. However, this prior art has poor demagnetization resistance.

[0006] In summary, the technical problems that need to be solved are how to design a method to improve the minimum remanence of the magnet near the outer edge corner, optimize the demagnetization performance of the magnet, and design the magnet slot and rotor. Utility Model Content

[0007] The purpose of this invention is to overcome the defects of the prior art and provide a magnet slot and rotor that are resistant to demagnetization.

[0008] The objective of this utility model can be achieved through the following technical solutions.

[0009] According to one aspect of the present invention, a demagnetizing magnetic steel groove is provided, which is disposed on a rotor core. The magnetic steel groove is rectangular in shape and has magnetic isolation bridges at both ends. A first step protruding into the interior of the magnetic steel groove is provided at both ends of a longer side of the magnetic steel groove near the outer circle of the rotor core.

[0010] As a preferred technical solution, the magnet slot has a second step protruding into the magnet slot at both ends of a longer side away from the outer circle of the rotor core.

[0011] As a preferred technical solution, the magnetic isolation bridge near the center of the rotor core in the magnetic steel groove has a first protrusion toward the center of the rotor core.

[0012] As a preferred technical solution, all the magnet slots on the rotor core are divided into multiple magnet slot groups, and each magnet slot group includes two magnet slots that form a V shape.

[0013] As a preferred technical solution, the magnet slot group includes a first magnet slot group and a second magnet slot group, with the first magnet slot group being close to the center of the rotor core.

[0014] As a preferred technical solution, a rectangular hole is provided between the two magnet slots in the first magnet slot group at their closest ends.

[0015] As a preferred technical solution, a round hole and / or a triangular hole are provided between adjacent first magnet slot groups; the round hole and / or triangular hole are symmetrically rotated 180°.

[0016] As a preferred technical solution, the triangular hole is provided with a marking groove.

[0017] As a preferred technical solution, the rotor core is provided with a shaft hole in the middle; the shaft hole is circular and is interference-fitted with the shaft, or the shaft hole is provided with a double key structure.

[0018] According to another aspect of the present invention, a rotor is provided having anti-demagnetizing magnetic slots on the rotor core.

[0019] Compared with the prior art, the present invention has the following beneficial effects.

[0020] 1) This utility model features a first step protruding into the magnet slot at both ends of the side edge near the outer circumference of the rotor core. This structure increases the leakage magnetic field near the outer circumference corner of the magnet, allowing a portion of the d-axis demagnetizing magnetic field to close through the leakage magnetic path, thereby increasing the minimum residual magnetism near the outer circumference corner of the magnet. Under the same operating conditions, the magnet is less prone to demagnetization. Simultaneously, this step can fix the relative position of the magnet; the side of the magnet slot near the center of the rotor core does not need a fixed step, reducing processing difficulty.

[0021] 2) The magnetic steel groove of this utility model has a second step protruding into the magnetic steel groove at both ends of the side away from the outer circle of the rotor iron core, which facilitates accurate positioning of the magnet.

[0022] 3) The magnetic bridge of this utility model has a first protrusion at the center of the rotor core, and grooves are opened on the edge and below of the magnet and extended downward to increase the area. This can increase the magnetic circuit resistance and increase the magnetic torque, increase the weight of the silicon steel sheet recycled material to reduce the cost, and also reduce the weight of the system.

[0023] 4) In the first magnetic steel slot group of this utility model, a rectangular hole is provided between the two magnetic steel slots that are close to each other, which turns the one rib in the middle of the V-shaped magnetic steel slot group into two ribs. Under the condition that the total width of the ribs is the same, the stress of two ribs is better than that of one rib. Under the same leakage magnetic field, the strength of the rotor lamination can be improved and the maximum operating speed of the motor can be increased. At the same time, the rectangular hole can increase the magnetic circuit reluctance and increase the magnetic reluctance torque, increase the weight of the silicon steel sheet recycled material to reduce the cost, and also reduce the weight of the system.

[0024] 5) The first magnetic steel slot group of this utility model is provided with round holes and / or triangular holes, which facilitates 180° rotation stacking during iron core production, offsets the difference in silicon steel sheet thickness on the same plate, and improves the verticality and flatness of the product. The triangular holes are equipped with marking grooves to distinguish the front and back of the laminations and prevent the laminations from being stacked in reverse during production.

[0025] 6) The present invention can increase the torque transmission capacity by using an interference fit between the shaft hole and the rotating shaft, or by setting a double key structure on the shaft hole to cooperate with the keyway in the rotating shaft to fix the iron core. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of a magnetic steel trough structure in the prior art.

[0027] Figure 2 This is a schematic diagram of the overall structure of the magnet slots on the rotor core in Embodiment 1 of this utility model.

[0028] Figure 3 This utility model Figure 2 A partial structural diagram.

[0029] Figure 4 This is a schematic diagram of the overall structure of the magnet slots on the rotor core in Embodiment 2 of this utility model.

[0030] Figure 5 This utility model Figure 4 A partial structural diagram.

[0031] The numbers in the diagram are as follows: 1. Magnet slot; 101. First step; 102. Second step; 103. First protrusion; 2. Rectangular hole; 3. Round hole; 4. Triangular hole; 40. Marking slot; 5. Shaft hole; 50. Double key. Detailed Implementation

[0032] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of the present utility model. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present utility model.

[0033] Example 1 This embodiment provides a demagnetizing magnet slot 1. The magnet slot 1 is rectangular in shape and has magnetic isolation bridges at both ends. A longer side of the magnet slot 1 near the outer circumference of the rotor core protrudes inwards at both ends, forming a first step 101 that fits against the edge of the magnet. This structure increases the leakage magnetic flux near the outer circumference corner of the magnet, allowing a portion of the d-axis demagnetizing magnetic field to close through the leakage magnetic flux path, thus increasing the minimum residual magnetism near the outer circumference corner of the magnet. Under the same operating conditions, the magnet is less prone to demagnetization.

[0034] The magnetic steel slot 1 has a first protrusion 103 near the center of the rotor core. The first protrusion 103 has slots on the edge and below of the magnet and extends downward to increase the area. This can increase the magnetic circuit resistance and increase the magnetic torque, increase the weight of the recycled silicon steel sheet to reduce costs, and also reduce the weight of the system.

[0035] All the magnet slots 1 are divided into multiple magnet slot groups, and each magnet slot group includes two magnet slots 1 that form a V shape. The magnet slot groups include a first magnet slot group and a second magnet slot group, with the first magnet slot group being closer to the center of the rotor core.

[0036] A rectangular hole 2 is set between the two magnet slots 1 in the first magnet slot group, which are close to each other. This turns the V-shaped middle rib into two ribs. Under the condition that the total width of the ribs is the same, the stress of two ribs is better than that of one rib. Under the same leakage magnetic field, the strength of the rotor lamination can be improved and the maximum operating speed of the motor can be increased. At the same time, the rectangular hole 2 can increase the magnetic circuit reluctance and increase the magnetic reluctance torque. It can also increase the weight of the silicon steel sheet recycled material to reduce the cost and reduce the weight of the system.

[0037] Example 2 like Figure 2 and Figure 3 As shown, this embodiment provides a demagnetizing magnet slot 1. Unlike embodiment 1, adjacent first magnet slots are provided with a circular hole 3 and a triangular hole 4, with the triangular hole 4 close to the center of the rotor core. Both the circular hole 3 and the triangular hole 4 are 180° symmetrically rotated, facilitating 180° rotational stacking during core production, offsetting differences in the silicon steel sheets, and improving product perpendicularity and flatness. The three corners of the triangular hole 4 are rounded. Marking grooves 40 are added to the right, top, and left sides of the triangular hole 4 to distinguish the front and back of the laminations and prevent reverse stacking of the laminations during production. Figure 2 As shown, the triangular hole 4 has marking slots 40 set on the right, top and left sides in sequence.

[0038] Example 3 like Figure 3 As shown, this embodiment provides a magnet slot 1 that resists demagnetization. Unlike embodiment 1, the magnet slot 1 has a longer side edge away from the outer circle of the rotor core that protrudes into the interior of the magnet slot 1 at both ends, forming a second step 102 that fits against the edge of the magnet. The second step 102 can fix the relative position of the magnet.

[0039] Example 4 like Figure 4 and Figure 5 As shown, this embodiment provides a demagnetizing magnet slot 1. Unlike embodiment 1, a circular hole 3 or a triangular hole 4 is provided between two adjacent first magnet slot groups. A shaft hole 5 is provided in the middle of the rotor core. The shaft hole 5 is interference-fitted with the rotating shaft, or a double key 50 structure is added to the shaft hole 5 to cooperate with the keyway in the rotating shaft to circumferentially fix the rotor core, which can greatly increase the torque transmission capacity.

[0040] Example 5 This embodiment provides a rotor, the rotor core of which has any of the anti-demagnetizing magnetic steel slots 1 in embodiments 1 to 4.

[0041] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A demagnetizing magnetic slot (1) disposed on a rotor core, characterized in that, The magnetic steel groove (1) is rectangular in shape and has magnetic isolation bridges at both ends. The magnetic steel groove (1) has a first step (101) protruding into the interior of the magnetic steel groove (1) at both ends of a longer side near the outer circle of the rotor core.

2. The anti-demagnetizing magnetic steel trough (1) according to claim 1, characterized in that, The magnet slot (1) has a second step (102) protruding into the inside of the magnet slot (1) at both ends of a longer side away from the outer circle of the rotor core.

3. The anti-demagnetizing magnetic steel trough (1) according to claim 1, characterized in that, The magnetic steel groove (1) has a first protrusion (103) near the center of the rotor core on the magnetic isolation bridge.

4. The anti-demagnetizing magnetic steel trough (1) according to claim 1, characterized in that, All the magnet slots (1) on the rotor core are divided into multiple magnet slot groups, and each magnet slot group includes two magnet slots (1) that form a V shape.

5. The anti-demagnetizing magnetic steel trough (1) according to claim 4, characterized in that, The magnet slot group includes a first magnet slot group and a second magnet slot group, with the first magnet slot group being close to the center of the rotor core.

6. The anti-demagnetizing magnetic steel trough (1) according to claim 5, characterized in that, A rectangular hole (2) is provided between the two magnet slots (1) in the first magnet slot group that are close to each other.

7. The anti-demagnetizing magnetic steel trough (1) according to claim 5, characterized in that, A round hole (3) and / or a triangular hole (4) are provided between adjacent first magnetic steel slot groups; the round hole (3) and / or the triangular hole (4) are symmetrically rotated 180°.

8. The anti-demagnetizing magnetic steel trough (1) according to claim 7, characterized in that, The triangular hole (4) is provided with a marking groove (40).

9. The anti-demagnetizing magnetic steel trough (1) according to claim 1, characterized in that, The rotor core has a shaft hole (5) in the middle; the shaft hole (5) is circular and is interference-fitted with the shaft, or the shaft hole (5) has a double key (50) structure.

10. A rotor, characterized in that, The rotor core has a demagnetizing magnetic groove (1) as described in any one of claims 1 to 9.

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