Measure for reducing eddy current loss of magnetic steel

Abstract

The invention relates to the technical field of motors, and discloses a magnetic steel eddy current loss reducing measure which comprises the following steps: S1, magnetic steel cutting: mounting magnetic steel on a workbench, fixing the magnetic steel by adopting a corresponding fixing device, and then linearly cutting the magnetic steel by adopting a laser cutting machine; s2, chippings are cleared away, specifically, chippings generated by cutting are cleared away from a workbench, and a collecting box is adopted to collect the chippings; and S3, testing: carrying out high-speed testing on the cut magnetic steel and the existing adhesive magnetic steel, recording two groups of experimental data, and carrying out data comparison. According to the invention, a whole piece of magnetic steel is divided into blocks in a manner of carrying out gap linear cutting on the whole piece of magnetic steel, the main body of each block of magnetic steel is also connected together to form a whole body, adhesive treatment is not needed, the efficiency of reducing eddy current loss by block division is also achieved, and waste generated by gap linear cutting can be recycled.

Description

Technical Field

[0001] The invention belongs to the technical field of motors, and specifically relates to a measure for reducing eddy current loss of magnetic steel. Background Art

[0002] At present, permanent magnet synchronous motors have been widely used in new energy vehicle drive motors due to their characteristics such as pursuit of high power density. However, under the action of high-frequency alternating magnetic field, the eddy currents generated inside the magnetic material of the rotor magnet cause energy loss, resulting in an increase in rotor temperature. When the temperature exceeds a certain limit, the rotor magnet will undergo irreversible demagnetization, affecting the motor performance.

[0003] like Figure 1 As shown, in order to reduce the eddy current loss of the motor magnet and prevent the motor from demagnetizing at high temperature, the permanent magnet synchronous motors on the market currently mostly adopt the method of segmented gluing of the magnet. A whole piece of magnet is divided into several parts and then glued together. However, the method of gluing the magnet has very high requirements on the glue, which needs to be resistant to high temperature and vibration. In addition, the use of glue to gluing the magnet in the production line will increase the material cost, and the gluing process will affect the production efficiency of the magnet. Summary of the invention

[0004] To achieve the above object, the present invention provides the following technical solution: a measure to reduce eddy current loss of magnetic steel, comprising the following steps:

[0005] S1. Magnetic steel cutting: install the magnetic steel on the workbench and fix it with the corresponding fixing device, and then use the laser cutting machine to perform linear cutting on the magnetic steel;

[0006] S2. Cleaning up the debris: Clean up the debris generated by cutting from the workbench and collect the debris in a collection box;

[0007] S3. Testing: Conduct high-speed testing on the cut magnetic steel and the existing glued magnetic steel, and record two sets of experimental data for data comparison.

[0008] Preferably, the laser cutting machine used in S1 can be replaced by an auxiliary cutting device to ensure that the magnetic steel is cut completely.

[0009] Preferably, the debris collection in S2 can be carried out by manual cleaning to save costs.

[0010] Preferably, the debris collection in S2 can be cleaned by an auxiliary robotic arm to improve work efficiency.

[0011] Preferably, the high-speed test in S3 needs to control the rotation speed of the two sets of motors to reach 6000 rpm.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] 1. The present invention divides a whole block of magnetic steel into blocks by wire cutting the gaps. The main bodies of the divided magnetic steels are still connected together as a whole, and no gluing treatment is required. The efficiency of reducing eddy current loss by dividing the blocks is achieved, and the waste generated by the gaps of wire cutting can be recycled.

[0014] 2. The present invention divides a whole piece of magnetic steel into blocks by wire cutting gaps, which can reduce the material cost of the magnetic steel and improve the production efficiency of the magnetic steel. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0016] Figure 1 It is a schematic diagram of existing magnetic steel cutting;

[0017] Figure 2 This is a schematic diagram of magnetic steel cutting according to the present invention;

[0018] Figure 3 This is the existing magnetic steel high-speed rotation data diagram;

[0019] Figure 4 This is a data diagram of high-speed rotation of the magnetic steel of the present invention. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0021] Example, by Figure 1-4 It is given that the present invention includes a measure for reducing eddy current loss of magnetic steel, comprising the following steps:

[0022] S1. Magnetic steel cutting: install the magnetic steel on the workbench and fix it with the corresponding fixing device, and then use the laser cutting machine to perform linear cutting on the magnetic steel; the laser cutting machine used can be replaced by auxiliary cutting equipment to ensure that the magnetic steel is cut.

[0023] S2. Cleaning up the debris: Clean up the debris generated by cutting from the workbench and collect the debris in a collection box;

[0024] Specifically, debris collection can be done by manual cleaning, which saves costs;

[0025] Specifically, debris collection can be cleaned by auxiliary mechanical arms to improve work efficiency;

[0026] S3, testing: conduct high-speed testing on the cut magnetic steel and the existing glued magnetic steel, and record two sets of experimental data for data comparison;

[0027] Specifically, the high-speed test requires controlling the speed of the two sets of motors to reach 6000rpm.

[0028] Working principle: During operation, the motors equipped with two kinds of magnetic steel rotors were run at the highest speed of 6000rpm, 45kW continuous working condition, and the back electromotive force test was carried out for 30 minutes. The results of the two motors were basically the same, indicating that the block reduction of magnetic steel eddy current loss can achieve the same effect as viscose magnetic steel;

[0029] The magnetic steel is divided into multiple small sections by cutting equipment, thereby reducing the area of ​​the eddy current circuit; at the same time, the magnetic steel sections are still connected, avoiding the use of glue for bonding;

[0030] Eddy current loss is proportional to the resistivity of the material, the rate of change of magnetic flux density and the area of ​​the eddy current loop. By segmenting, the area of ​​the eddy current loop in each small segment is reduced, and the eddy current intensity is reduced, thereby effectively reducing eddy current loss.

[0031] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0032] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A measure to reduce eddy current loss of magnetic steel, characterized by: The following steps are involved: S1. Magnetic steel cutting: install the magnetic steel on the workbench and fix it with the corresponding fixing device, and then use the laser cutting machine to perform linear cutting on the magnetic steel; S2. Cleaning up the debris: Clean up the debris generated by cutting from the workbench and collect the debris in a collection box; S3. Testing: Conduct high-speed testing on the cut magnetic steel and the existing glued magnetic steel, and record two sets of experimental data for data comparison.

2. A measure for reducing eddy current loss of magnetic steel according to claim 1, characterized in that: The laser cutting machine used in the S1 can be replaced by an auxiliary cutting device to ensure that the magnetic steel is cut completely.

3. The method for reducing eddy current loss of magnetic steel according to claim 1, characterized in that: The debris collection in S2 can be done by manual cleaning, which saves costs.

4. The method for reducing eddy current loss of magnetic steel according to claim 1, characterized in that: The debris collection in S2 can be cleaned by an auxiliary mechanical arm to improve work efficiency.

5. The method for reducing eddy current loss of magnetic steel according to claim 1, characterized in that: The high-speed test in S3 requires controlling the rotation speed of the two motors to reach 6000 rpm.

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