Winding copper wire, related products thereof and production equipment and method of winding copper wire

Abstract

The invention relates to a winding copper wire, a related product of the winding copper wire and production equipment and a production method of the winding copper wire. A silicon carbide ceramic layer with the thickness range of 1-5 microns is deposited on the peripheral surface of a wire body of the winding copper wire. The silicon carbide ceramic layer not only has good insulating property, but also has a compact hexahedron metallographic structure and good pressure resistance and ductility, so that the winding copper wire can replace an enameled copper wire to be applied to various occasions, and compared with the enameled copper wire, the winding copper wire has good heat-conducting property, the slot fullness rate of a formed coil is high, and the service life of the coil is prolonged. And the copper wire generates less heat due to eddy current, is resistant to high temperature, can reduce the size of the motor under the condition of the same power, and can achieve the characteristic of larger current output under the condition of the same size.

Description

Technical Field

[0001] The invention relates to a winding copper wire and related products thereof, and also relates to a device and a production method for producing the winding copper wire. Background Art

[0002] The windings of the motor coils of new energy electric vehicles are mostly made of enameled copper wire. This type of copper wire wrapped with insulating varnish has the following problems:

[0003] 1) The temperature resistance range of insulating paint is 100-180℃. When the motor outputs high power, the working current is large, which may easily lead to insulation failure;

[0004] 2) The thickness of the insulating paint on the copper wire is 100-150um on one side. After being formed into a coil, the porosity of the wire slot is large, and the heat generated by eddy current on the copper wire is also large, which is not conducive to the long-term and heavy-load operation of the motor;

[0005] 3) The thermal conductivity of insulating varnish is poor, with a thermal conductivity range of only 0.2-0.3W / m·K, which easily leads to heat accumulation. The accumulated heat will increase the resistance of the copper wire and further limit the current output of the copper wire.

[0006] It can be seen that the above-mentioned copper wires have become a limiting factor in the stable high-power output of new energy electric vehicle motors. Summary of the invention

[0007] The purpose of the present invention is to provide an alternative solution for enameled copper wire, so as to solve the problems that the insulation layer thereof has insufficient temperature resistance, the wire slot has large porosity after being formed into a coil, the eddy current generates a lot of heat, and the insulation layer has poor thermal conductivity.

[0008] The object of the present invention is achieved through the following technical solution: a winding copper wire, characterized in that a silicon carbide ceramic layer with a thickness ranging from 1 to 5 um is deposited on the outer peripheral surface of the wire body.

[0009] The silicon carbide ceramic layer has good insulation performance, and its thermal stability temperature and thermal conductivity are much higher than those of insulating paint. In addition, the thickness is only 1-5um, which can significantly reduce the porosity of the wire slot after forming into a coil and reduce eddy current heat generation. In addition, the silicon carbide ceramic layer has a dense hexagonal metallographic structure, good pressure resistance and ductility, so the winding copper wire of the present invention can completely replace the enameled copper wire and be used in a variety of occasions, such as new energy electric vehicles, drones, low-altitude aircraft, inductors, etc. Of course, different application occasions have different requirements for pressure resistance, and the appropriate ceramic layer thickness will also be different.

[0010] Based on the voltage resistance requirements of new energy electric vehicles: 400v charging piles require the motor windings to withstand an AC breakdown voltage of 1000v at room temperature, and 800v charging piles require the motor windings to withstand an AC breakdown voltage of 1500v at room temperature. When used in this occasion, the recommended ceramic layer thickness range is 2-5um, 2-3um is better, which meets the voltage resistance requirements of the insulation layer while having a relatively low cost.

[0011] Preferably, the silicon carbide ceramic layer is deposited under vacuum conditions by PVD, PECVD or CVD.

[0012] The present invention also provides a motor composed of a coil wound by the copper wire, and an electric vehicle using the motor.

[0013] In addition, the present invention also provides a production device for the winding copper wire, which is a PVD or PECVD or CVD coating device for copper wire coating, which comprises an unwinding chamber, a coating chamber and a winding chamber in sequence, which are respectively connected to a vacuum pumping unit, and when working, the two adjacent chambers are isolated and connected only by a thin copper wire passing channel, so that each chamber can achieve independent control of the vacuum degree;

[0014] The unwinding chamber and the winding chamber are both equipped with tension controllers for adjusting the tension of the copper wire, which cooperate with the unwinding roller of the unwinding chamber and the winding roller of the winding chamber to form an unwinding device and a winding device respectively;

[0015] The coating chamber is equipped with a copper wire turning wheel, which drives the copper wire to rotate in the coating area of ​​the coating chamber so as to uniformly coat a silicon carbide ceramic layer with a thickness ranging from 1 to 5 um on the outer peripheral surface.

[0016] Preferably, the coating chamber is composed of two or more discrete coating chambers connected in series, which are isolated from each other during operation and connected only by a thin copper wire crossing channel. Each discrete coating chamber is equipped with a copper wire turning wheel, and each discrete coating chamber is connected to a vacuum pumping unit respectively.

[0017] Preferably, the production equipment is a high-power pulsed magnetron sputtering coating equipment, and is equipped with a sputtering source with a peak voltage of 2000V, a peak current of 1000A, and a peak power of 2MW.

[0018] The present invention also provides a production method using the production equipment, firstly performing ion cleaning on the moving copper wire body, and then using a high-power pulse sputtering silicon target to deposit a single crystal silicon transition layer and a silicon carbide ceramic layer with a thickness ranging from 1 to 5 um on the outer peripheral surface of the copper wire body.

[0019] Beneficial effects:

[0020] 1) The silicon carbide ceramic layer not only has good insulation performance, but also has a dense hexagonal metallographic structure, good pressure resistance and ductility, so the winding copper wire of the present invention can replace the enameled copper wire and be used in various occasions, and compared with the enameled copper wire, it also has the following characteristics:

[0021] a) The thermal conductivity of the insulating varnish is 0.2-0.3W / m·K, and the thermal conductivity of the silicon carbide ceramic layer is much higher than that of the insulating varnish. Replacing the enameled copper wire in the prior art with the winding copper wire of the present invention can greatly improve the thermal conductivity of the motor;

[0022] b) The thickness of the film layer deposited on the outer peripheral surface of the copper wire body of the present invention is only 1-5um. Compared with the enameled copper wire solution, the wire slot filling rate is high after being formed into a coil, and the heat generated by eddy current on the copper wire is small;

[0023] c) The temperature resistance of insulating paint is only 100-180℃, and the thermal stability temperature of silicon carbide ceramic layer is much higher than that of insulating paint, which can greatly improve the temperature resistance of motor windings. When there is no problem with voltage resistance, there will be no insulation failure problem;

[0024] d) The thickness of the insulating layer attached to the copper wire body of the present invention is greatly reduced, and the wire slot full rate is high after being formed into a coil. The motor with the same power can be made into a smaller volume, and the same volume can have a larger current output;

[0025] 2) The present invention provides a continuous roll-to-roll coating device, and in particular, the present invention provides a device and method for coating a silicon carbide ceramic layer by PVD. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of a preferred production equipment of the present invention;

[0027] Figure 2 , 3 for Figure 1 Schematic diagram of the structure of the copper wire turning wheel. DETAILED DESCRIPTION

[0028] Embodiment 1

[0029] A winding copper wire has a silicon carbide ceramic layer deposited on the outer peripheral surface of the wire body.

[0030] Silicon carbide ceramic layer has good insulation performance, and the insulation resistance range is 1*10 8 -5*10 9 Ohm, and has a dense hexagonal metallographic structure, good pressure resistance and ductility, so the winding copper wire of this embodiment can replace the enameled copper wire and be applied to various occasions, such as new energy electric vehicles, drones, low-altitude aircraft, inductors, etc. After testing, the elongation and pressure resistance of the winding copper wire of this embodiment meet the national standard requirements of insulating enamel enameled wire in corresponding application scenarios.

[0031] For inductors, the voltage resistance requirement is generally not too high, and you can choose to deposit a ceramic layer of about 1um. Of course, for application scenarios with high voltage resistance requirements, the voltage resistance level can be improved by increasing the thickness of the ceramic layer. For example, for new energy electric vehicles, 400v charging piles require the windings of their motors to withstand an AC breakdown voltage of 1000v at room temperature, and 800v charging piles require the windings of their motors to withstand an AC breakdown voltage of 1500v at room temperature. For this, you can choose to deposit a 2-5um thick ceramic layer. Of course, 2-3um is more recommended for cost considerations.

[0032] Replacing the enameled copper wire with the winding copper wire of this embodiment also has the following advantages:

[0033] 1) The thermal conductivity of the insulating varnish is 0.2-0.3W / m·K, and the thermal conductivity of the silicon carbide ceramic layer is much higher than that of the insulating varnish. Therefore, the winding copper wire of this embodiment is used to replace the enameled copper wire in the prior art, which can greatly improve the thermal conductivity of the motor;

[0034] 2) The thickness of the deposited layer on the outer peripheral surface of the winding copper wire in this embodiment is much lower than that of the enameled copper wire. After being formed into a coil, the wire slot filling rate is high, and the heat generated by eddy current on the copper wire is small;

[0035] 3) The temperature resistance of the insulating paint is only 100-180°C, and the thermal stability temperature of the silicon carbide ceramic layer is much higher than that of the insulating paint. This embodiment can greatly improve the temperature resistance of the motor winding. When there is no problem with the voltage resistance, there will be no insulation failure problem;

[0036] 4) In this embodiment, the thickness of the insulating layer attached to the outside of the copper wire body is greatly reduced, and the wire slot fill rate is high after being formed into a coil. The motor with the same power can be made smaller in size, and the same volume can have a larger current output.

[0037] The ceramic layer can be deposited under vacuum conditions by PVD, PECVD or CVD.

[0038] Embodiment 2

[0039] The prior art relates to obtaining a silicon carbide ceramic layer by PECVD or CVD. This embodiment aims to provide a device and method for obtaining a silicon carbide ceramic layer by PVD.

[0040] Figure 2 It is a continuous winding high-power pulsed magnetron sputtering coating equipment, which is used for continuous coating of copper wire, including an unwinding chamber, a first coating chamber, a second coating chamber and a winding chamber connected in sequence, which are respectively connected to a vacuum pumping unit (not shown), and when working, the two adjacent chambers are isolated and connected only by a thin copper wire passing through a channel 4, so that each chamber can achieve independent control of the vacuum degree.

[0041] The unwinding chamber and the winding chamber are respectively provided with tension controllers 2 and 8 for adjusting the tension of the copper wire, which cooperate with the unwinding roller 1 of the unwinding chamber and the winding roller 7 of the winding chamber to form an unwinding device and a winding device.

[0042] The first and second coating chambers are equipped with synchronously operated copper wire turning wheels 6 (the copper wire turning wheel in this embodiment is a structure that drives the copper wire to turn continuously. In other embodiments, the turning angle and turning wheel structure can be selected according to the configuration of the planar cathode), which drives the copper wire 10 to rotate in the coating area of ​​each coating chamber to form a uniform coating on the outer peripheral surface. A relatively isolated ion cleaning area is also formed in the front of the first coating chamber.

[0043] Figure 1 3 is a guide wheel, which is arranged in each chamber and is used to guide the unwinding copper wire 10 so that it can smoothly pass through the copper wire crossing channel 4 into the first coating chamber, then into the second coating chamber, and finally into the winding chamber and finally wound up by the winding device. 5 is a planar cathode.

[0044] Figure 2 , 3 for Figure 1 Schematic diagram of the structure of the copper wire turning wheel 6. As shown in the figure, it is a gear, which is rotated by the motor 91 through the gear 92, and the copper wire 10 passes between the two rollers 61 set in the middle. After adjusting the distance between the two rollers 61 to clamp the copper wire 10, the copper wire 10 can be driven to rotate by the motor, and the copper wire 10 will not be hindered by the rolling of the two rollers 61.

[0045] The two rollers 61 are installed as follows Figure 3 As shown, two cantilevers extend out from the hole wall of the inner ring hole of the copper wire turning wheel 6. The rotating shafts of the two rollers 61 are connected to the two cantilevers by bolts 11 from one side through their two ends. The two rollers 61 are opposite to each other in the gap between the two cantilevers, and the copper wire 10 passes through and is clamped therebetween.

[0046] When obtaining silicon carbide ceramic layers by PECVD or CVD, Figure 1 Coating equipment with similar structure, but with different design of coating area.

[0047] The coating process of the above equipment is as follows:

[0048] 1. Open the unwinding chamber door and place the copper wire on the unwinding roller 1, and Figure 1 Load the copper wire through each chamber and close all chamber doors.

[0049] 2. Start the vacuum unit to evacuate and preheat the equipment. When the vacuum reaches 5E-3Pa and the temperature reaches 100 degrees, fill the cleaning chamber with argon to 5E-1Pa, the copper wire bias is negative 50-100v, turn on the ion source power and set it to 2kw, perform ion cleaning on the copper wire, and at the same time start the wire feeding and collecting mechanism at a speed of 1m / min.

[0050] 3. When the copper wire after ion cleaning enters the coating area in the first coating chamber, the argon gas is turned on to 2E-1Pa, and the output power of the high-power pulsed sputtering silicon target as the planar cathode 5 is set to 2-5kw, and a single crystal silicon transition layer is deposited on the surface of the copper wire to enhance the film-base bonding force. During the coating process, it is important to drive the copper wire 10 to flip through the flip wheel 6 so that the entire surface of the copper wire 10 can be cleaned and a uniform coating is deposited.

[0051] 4. After the copper wire is evenly coated with the base layer, it enters the second coating chamber, is filled with argon and acetylene to 5E-1Pa, and high-power pulse sputtering is turned on with the silicon target power set to 2-5kw to deposit a silicon carbide ceramic layer on the surface of the copper wire.

[0052] 5. The copper wire 10 is completely recovered from the unwinding device to the rewinding device, and the coating is completed. The unwinding device is stopped, and the planar cathode 5 is stopped.

[0053] 6. Turn off the vacuum unit, release the air, and break the vacuum.

[0054] 7. Open the door of the winding room and take out the plated products.

[0055] When obtaining a silicon carbide ceramic layer by PVD, in addition to using single crystal silicon for base coating, first of all, attention should be paid to selecting a high-power pulse magnetron sputtering coating device to obtain sufficient bonding force. Secondly, the configuration of the sputtering source must meet the requirements to ensure the ionization rate. In this embodiment, the power supply is configured as follows: TruPlasma hipims4002G220kw, the power supply has a peak voltage of 2000v, a peak current of 1000A, a power of 20KW, a frequency of 10-3000Hz, a pulse width of 1-1000us, and a peak power of 2 megawatts. In addition, during the coating process, attention should also be paid to the matching of the sputtering rate (affected by power) and the deposition rate (copper wire speed), and the copper wire temperature also needs to be controlled (influencing factors include speed, etc.).

[0056] The copper wire (silicon carbide ceramic layer thickness 2.5-3um) plated by the device and method has the following test performance:

[0057] 1. The resistance between the coating on the copper wire surface and between the coating and the copper wire can reach 1*10 8 Ohm or above;

[0058] 2. Between the copper wire and the coating, and between the coatings, the resistance does not change when tested with a 1500V megohmmeter at 2 rpm for 120 seconds, and the AC breakdown voltage exceeds 1500V;

[0059] 3. After 2mm*4mm (common specifications for tram motors) flat copper wire is wound on a 16mm diameter round rod and unfolded, there is no cracking on the surface coating of the copper wire.

[0060] 4. Other data are shown in Table 1.

[0061] Table 1

[0062]

[0063] It should be noted that the above-mentioned breakdown voltage test (1500V) is only a test performed in accordance with the requirements of the enameled wire GB. In fact, the copper wire of this embodiment has passed the tests of the normal temperature breakdown voltage AC5000 and AC7000. Compared with the enameled wire, it can be used in scenarios with higher voltage resistance requirements.

Claims

1. A winding copper wire, characterized in that: A silicon carbide ceramic layer with a thickness ranging from 1 to 5 um is deposited on the outer peripheral surface of the wire body.

2. The winding copper wire according to claim 1, characterized in that: The thickness of the silicon carbide ceramic layer is in the range of 2-5 um.

3. The winding copper wire according to claim 2, characterized in that: The thickness of the silicon carbide ceramic layer is in the range of 2-3 um.

4. The winding copper wire according to claim 1, characterized in that: The silicon carbide ceramic layer is deposited under vacuum conditions by PVD, PECVD or CVD.

5. A motor composed of a coil wound with the copper wire according to claim 2 or 3.

6. An electric vehicle using the motor according to claim 5.

7. A production device for the winding copper wire according to any one of claims 1 to 4, characterized in that: It is a PVD or PECVD or CVD coating equipment for copper wire coating, which includes an unwinding chamber, a coating chamber and a winding chamber in sequence, which are respectively connected to a vacuum pumping unit, and when working, the two adjacent chambers are isolated and connected only by a thin copper wire through a channel, so that each chamber can achieve independent control of the vacuum degree; The unwinding chamber and the winding chamber are both equipped with tension controllers for adjusting the tension of the copper wire, which cooperate with the unwinding roller of the unwinding chamber and the winding roller of the winding chamber to form an unwinding device and a winding device respectively; The coating chamber is equipped with a copper wire turning wheel, which drives the copper wire to rotate in the coating area of ​​the coating chamber so as to uniformly coat a silicon carbide ceramic layer with a thickness ranging from 1 to 5 um on the outer peripheral surface.

8. The production equipment according to claim 7, characterized in that: The coating chamber is composed of two or more discrete coating chambers connected in series, which are isolated from each other during operation and connected only by a thin copper wire through a channel. Each discrete coating chamber is equipped with a copper wire turning wheel, and each discrete coating chamber is connected to a vacuum pumping unit.

9. The production equipment according to claim 8, characterized in that: The production equipment is a high-power pulsed magnetron sputtering coating equipment, and it is equipped with a sputtering source with a peak voltage of 2000V, a peak current of 1000A, and a peak power of 2MW.

10. A production method using the production equipment according to claim 9, characterized in that: The traveling copper wire body is first ion cleaned, and then a single crystal silicon transition layer and a silicon carbide ceramic layer with a thickness ranging from 1 to 5 um are deposited on the outer peripheral surface of the copper wire body by using a high-power pulse sputtering silicon target.

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