Method for improving insulation performance of flat wire motor stator of new energy automobile

Abstract

The invention discloses a method for improving the insulation performance of a flat wire motor stator of a new energy automobile, and the method comprises the steps: employing a material with the insulation grade of 220 as the insulation material of a wire embedding groove of a stator iron core, and enabling the material with the insulation grade of 220 to be combined in the wire embedding groove of the stator iron core in an embedding or injection molding manner; an enameled flat wire with the insulation grade of 240 is adopted to manufacture a winding; and the exposed part of the winding is wrapped by a coating material with an insulation grade of 200. The insulation performance required by a motor with the voltage of 750V or above can be met.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicles, and in particular to a method for improving the insulation performance of a stator of a flat wire motor of a new energy vehicle. Background Art

[0002] As new energy vehicles gradually develop towards high voltage and high efficiency, the drive motor, as the driving device of new energy vehicles, has higher requirements for its insulation performance and heat dissipation from various manufacturers. Its insulation structure will directly affect the safety and performance of new energy vehicles.

[0003] The stator of a flat wire motor consists of a stator core and a copper conductor. The inner wall of the core is provided with a wire embedding groove, and the copper conductor is assembled in the wire embedding groove. In order to increase the safety performance between the stator core and the copper conductor, insulating paint is usually set in the wire embedding groove of the stator core, and insulating paint is set on the surface of the copper conductor. That is, the current motor insulation structure is generally composed of multiple materials that cooperate with each other, which generally includes enameled wire, slot insulation, insulating paint, and coating. The insulation structure generally has heat dissipation and support functions. And it directly affects the life and safety reliability of the motor.

[0004] The existing insulation structure does not meet the requirements for motors above 750V, which may cause the motor to burn out. Specifically, the enameled wire, slot insulation, insulating paint, and coating materials used are generally 180 degrees (H-level insulation) in temperature resistance, have poor heat dissipation, lack corona resistance, and the motor manufacturing process is complex and costly. Summary of the invention

[0005] The present invention provides a method for improving the insulation performance of a stator of a flat wire motor of a new energy vehicle, and the present invention can meet the insulation performance requirements of motors above 750V.

[0006] The technical solutions to the above problems are as follows: Methods for improving the stator insulation performance of flat wire motors for new energy vehicles include: Using materials with insulation grade of 220 as the wire-embedded slot insulation material of the stator core, and combining the materials with insulation grade of 220 in the wire-embedded slot of the stator core by potting or injection molding; The winding is made of enameled flat wire with insulation grade of 240; The exposed parts of the winding are wrapped with a coating material with insulation grade 200.

[0007] Furthermore, the material with insulation grade of 220 is a liquid crystal polymer material.

[0008] Furthermore, the enameled flat wire with an insulation grade of 240 includes a copper wire and a paint film. The paint film is made of polyetheretherketone, and the polyetheretherketone is evenly wrapped on the copper wire through coating, extrusion and baking.

[0009] Furthermore, the total impurity content of the copper wire is ≤0.0065%, and the oxygen content is ≤0.001%.

[0010] Furthermore, the coating material with insulation grade of 200 is epoxy resin glue or polyphenylene sulfide.

[0011] The improvement method of the present invention reduces the number of parts of the existing insulation structure by selecting potting materials, enameled wires, and coating materials with higher insulation grades and controlling key insulation performance, thereby effectively increasing the life and heat dissipation of the motor at a low cost, reducing failures caused by motor heating and insulation failure, and improving the safety and reliability of the motor.

[0012] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The present invention is a flow chart of a method for improving the stator insulation performance of a flat wire motor for new energy vehicles.

[0014] Figure 2 The figure shows the assembly of the stator core and the winding made of enameled rectangular wire.

[0015] Figure 3 for Figure 2 Enlarged view of part P in .

[0016] Figure 4 Schematic diagram of enameled flat wire.

[0017] Markings in the attached drawings: Stator core 1, wire embedding slot 1a, enameled rectangular wire 2, copper wire 2a, paint film 2b, exposed part 2c, slot insulation layer 10. DETAILED DESCRIPTION

[0018] like Figures 1 to 4 As shown, the method for improving the stator insulation performance of a flat wire motor for a new energy vehicle of the present invention comprises the following steps: The material with insulation grade of 220 is used as the wire-embedded slot insulation material of the stator core, and the material with insulation grade of 220 is combined in the wire-embedded slot 1a of the stator core 1 by potting or injection molding to form a slot insulation layer 10. In the present invention, the material with insulation grade of 220 is a liquid crystal polymer material. Liquid crystal polymer material, also called liquid crystal polymer, is a new type of polymer material, which generally becomes a liquid crystal under a certain heating state.

[0019] In the present invention, the liquid crystal polymer material is injected into the wire embedding groove of the stator core 1 in an environment of 150°C, and fills the gap between the enameled flat wire 2 and the stator wire embedding groove. After the liquid crystal polymer material is cured, a slot insulation layer 10 is formed between the enameled flat wire 2 and the stator core 1, thereby replacing the insulating paper. The liquid crystal polymer has the following characteristics: dielectric constant 4.2 (60Hz), thermal conductivity 0.3 W (m·K) -1 The insulation grade is 220, which is superior to the existing insulation paper. After eliminating the insulation paper, a series of motor manufacturing processes are reduced.

[0020] The winding is made of an enameled flat wire 2 with an insulation grade of 240. In the present invention, the enameled flat wire 2 with an insulation grade of 240 includes a copper wire 2a and a paint film 2b. The paint film 2b is made of polyetheretherketone, which is uniformly wrapped on the copper wire 2a by coating, extrusion, and baking. The total impurity content of the copper wire is ≤0.0065%, and the oxygen content is ≤0.001%.

[0021] In the present invention, the copper wire 2a preferably uses a TU1 copper rod, and polyetheretherketone is uniformly wrapped on the TU1 copper rod by coating, extrusion, and baking to serve as a paint film of the TU1 copper rod. The insulation grade of polyetheretherketone is 240, and the service life is 4-8 times longer than that of the existing 180-grade material at the same temperature. The thermal conductivity of polyetheretherketone is 0.25W (m·K) -1 , 0.12W(m·K) more than the existing materials -1 The heat dissipation capacity is increased by 50%. The dielectric loss of polyetheretherketone is 0.001, which is lower than the existing material 0.004. It has longer corona resistance and voltage breakdown resistance at the same thickness.

[0022] The exposed part 2c of the winding is wrapped with a coating material with an insulation grade of 200. The coating material with an insulation grade of 200 is epoxy resin glue or polyphenylene sulfide. Epoxy resin is a thermosetting plastic with excellent adhesion, electrical insulation and chemical stability. It is widely used in coatings, composite materials, casting resins, adhesives and other fields. Polyphenylene sulfide (PPS) is a new high-performance thermoplastic resin with the advantages of high mechanical strength, high temperature resistance, chemical resistance, flame retardancy, good thermal stability, excellent electrical properties, etc. It is widely used in electronics, automobiles, machinery and chemical fields. In the present invention, epoxy resin glue is preferably used as the coating material with an insulation grade of 200.

[0023] The improvement method of the present invention reduces the number of parts of the existing insulation structure by selecting injection molding materials, enameled wires, and coatings with higher insulation grades and controlling key insulation properties, thereby effectively increasing the life and heat dissipation of the motor at a low cost, reducing failures caused by motor heating and insulation failure, and improving the safety and reliability of the motor.

[0024] The thermal conductivity of the material in the insulation structure of the present invention is good, which is more conducive to the heat dissipation of the motor; and no paint dripping is required, and batch production on the production line saves the process flow and speeds up the manufacturing cycle.

[0025] The above embodiments are part of the embodiments of the present invention. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but cannot be simply understood as limiting the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

Claims

1. A method for improving the stator insulation performance of a flat wire motor for new energy vehicles, characterized in that: include: Using materials with insulation grade of 220 as the wire-embedded slot insulation material of the stator core, and combining the materials with insulation grade of 220 in the wire-embedded slot of the stator core by potting or injection molding; The winding is made of enameled flat wire with insulation grade of 240; The exposed parts of the winding are wrapped with a coating material with an insulation grade of 200.

2. The method for improving the stator insulation performance of a flat wire motor for new energy vehicles according to claim 1, characterized in that: The material with insulation grade of 220 is liquid crystal polymer material.

3. The method for improving the stator insulation performance of a flat wire motor for new energy vehicles according to claim 1, characterized in that: The enameled flat wire with insulation grade of 240 includes copper wire and paint film. The material of the paint film is polyetheretherketone, which is evenly wrapped on the copper wire through coating, extrusion and baking.

4. The method for improving the stator insulation performance of a flat wire motor for new energy vehicles according to claim 3, characterized in that: The total amount of impurities in the copper wire is ≤0.0065%, and the oxygen content is ≤0.001%.

5. The method for improving the stator insulation performance of a flat wire motor for new energy vehicles according to claim 1, characterized in that: The coating material for insulation grade 200 is epoxy resin glue or polyphenylene sulfide.

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