Motor shaft with diamond-like coating and preparation method thereof

Abstract

The invention discloses a motor shaft with a diamond-like coating and a preparation method thereof.The motor shaft with the diamond-like coating comprises a motor shaft body, and the diamond-like coating is arranged on the spline shaft head surface and the bearing position surface of the motor shaft body or the whole outer surface of the motor shaft body. The diamond-like carbon coating comprises a metal transition layer and a carbon layer, the carbon layer comprises a plurality of soft carbon layers and a plurality of hard carbon layers, and the soft carbon layers and the hard carbon layers are alternately arranged. By applying the DLC technology, the motor shaft is subjected to DLC treatment, heat treatment can be omitted, deformation and oxidation of the motor shaft are obviously reduced, the hardness, wear resistance, corrosion resistance and oxidation resistance of the motor shaft are obviously improved, defects caused by heat treatment are greatly reduced, many countermeasures needing to be taken for coping with heat treatment defects are reduced, the yield is increased, and the production cost is reduced. And moreover, the service life of the DLC coating motor shaft is remarkably prolonged, and the DLC coating motor shaft can cope with a worse environment.

Description

Technical Field

[0001] The present invention relates to the technical field of motor shafts, and in particular to a motor shaft with a diamond-like coating and a preparation method thereof. Background Art

[0002] The motor shaft is a critical component in a motor. It serves as the link between the motor and the device for electromechanical energy conversion, supporting rotating components, transmitting torque, and determining the relative position of rotating components and the stator. Currently, heat treatment is commonly used to increase the surface hardness of motor shafts. However, this process is prone to deformation, resulting in high heat treatment costs and requiring further processing to meet requirements. Summary of the Invention

[0003] Based on this, the purpose of the present invention is to provide a motor shaft with a diamond-like carbon coating and a preparation method thereof. By applying DLC technology, the motor shaft is treated with DLC, which can eliminate the need for heat treatment, greatly reduce the defects caused by heat treatment, reduce many countermeasures needed to deal with heat treatment defects, and improve the yield.

[0004] To achieve the above object, the present invention adopts the following technical solutions: The present invention first provides a motor shaft with a diamond-like coating, which includes a motor shaft body, and the spline shaft head surface, bearing seat surface or the entire outer surface of the motor shaft body is provided with a diamond-like coating, the diamond-like coating includes a metal transition layer and a carbon layer, the carbon layer includes a plurality of soft carbon layers and a plurality of hard carbon layers, and the soft carbon layers and the hard carbon layers are alternately arranged.

[0005] As a further improvement of the above solution of the present invention, the thickness of the diamond-like carbon coating is 1-15 μm and the hardness is 600-3000 Hv.

[0006] As a further improvement of the above solution of the present invention, the metal transition layer is at least one of a titanium layer, a chromium layer, a tungsten layer, and a nickel layer; and the thickness of the metal transition layer is 0.1-1 μm.

[0007] As a further improvement of the above solution of the present invention, the thickness of the soft carbon layer is 0.1-0.3 μm, and the thickness of the hard carbon layer is 0.5-1 μm.

[0008] As a further improvement of the above solution of the present invention, the hardness of the soft carbon layer is 500-1300 Hv, and the hardness of the hard carbon layer is 1500-3500 Hv.

[0009] The present invention also provides a method for preparing a motor shaft having a diamond-like coating as described above, comprising the following steps: S1. After the polished motor shaft body is cleaned, it is placed in a vacuum chamber, vacuum-baked, and ion-cleaned; S2. A metal transition layer is deposited on the spline shaft head surface of the motor shaft body, the bearing surface, or the entire outer surface of the motor shaft body; S3. Alternately depositing a plurality of soft carbon layers and a plurality of hard carbon layers on the surface of the metal transition layer, and cleaning the layer to obtain a motor shaft having a diamond-like coating.

[0010] As a further improvement of the above solution of the present invention, in step S1, the cleaning method is: ultrasonically cleaning the motor shaft body at 50-80°C for 30-50 minutes, wiping the spline shaft head surface, bearing seat surface or the entire outer surface of the motor shaft body with acetone; the vacuum baking is carried out at a vacuum degree of 1×10 -3 ~5×10 -3 Pa, and maintain the temperature at 120-180°C for 20-40 minutes; the ion cleaning conditions are: argon flow rate of 100-1000 sccm, and vacuum degree of 1×10 -2 ~8×10 -2 Pa, and the bias voltage is -600 to -1000 V. In step S1, the motor shaft body is polished by a polishing device, and the oxide film on the coating portion is removed after sufficient polishing.

[0011] As a further improvement of the above solution of the present invention, in step S2, the step of depositing the metal transition layer is: S21. Adjust the vacuum degree to 1×10 -4 ~5×10 -4 Pa, temperature 110~150℃, argon flow rate 800~1200sccm, start the magnetron sputtering metal target and adjust the metal target current to 100~140A, adjust the bias voltage to -400~-600V, and the deposition time to 1200~7200s; S22. Turn off the magnetron sputtering metal target and adjust the vacuum to 1×10 -3 ~5×10 -3 Pa, temperature 100~130℃, argon flow rate 900~1500sccm; Wherein, the metal target is at least one of a titanium target, a chromium target, a tungsten target, and a nickel target.

[0012] As a further improvement of the above solution of the present invention, in step S3, the step of alternately depositing a plurality of soft carbon layers and a plurality of hard carbon layers is as follows: S31. Turn on the arc carbon target and adjust the vacuum to 1×10 -4 ~1×10 -2Pa, bias voltage is -500~-700V, a soft carbon layer is deposited on the surface of the metal transition layer, and the coating time is controlled to be 1000~2000s; S32. Turn off the arc carbon target, turn on the magnetron sputtering carbon target, and adjust the vacuum degree to 1×10 -4 ~1×10 -2 The hard carbon layer was deposited on the surface of the soft carbon layer at a pressure of 0.5 Pa, a temperature of 110-140°C, a bias voltage of -1000-2000 V, an argon flow rate of 900-1500 sccm, and a coating time of 1500-3000 s. S33. Steps S31 and S32 are repeated alternately 10 to 50 times.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The present invention applies DLC technology to treat the motor shaft through DLC, which can save heat treatment, significantly reduce the deformation and oxidation of the motor shaft, and significantly improve the hardness, wear resistance, corrosion resistance and oxidation resistance of the motor shaft, greatly reduce the defects caused by heat treatment, and reduce many countermeasures needed to deal with heat treatment defects, thereby improving the yield and reducing costs. In addition, the service life of the DLC-coated motor shaft is significantly increased, and it can cope with more severe environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A schematic structural diagram of a motor shaft with a diamond-like coating proposed in an embodiment of the present invention; Figure 2 This is a process flow chart for processing a motor shaft with a diamond-like coating according to an embodiment of the present invention.

[0015] Reference numerals: 1, motor shaft; 11, spline shaft head; 12, bearing seat. DETAILED DESCRIPTION

[0016] To facilitate understanding of the present invention, the present invention will be described more fully below in conjunction with specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of the present invention.

[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0018] Reference Figure 1This embodiment proposes a motor shaft with a diamond-like coating, including a motor shaft body 1. The outer surfaces of the spline shaft head 11 and the bearing seat 12 of the motor shaft body 1 are provided with a diamond-like coating (DLC). The diamond-like coating includes a metal transition layer and a carbon layer. The carbon layer includes a plurality of soft carbon layers and a plurality of hard carbon layers, and the soft carbon layers and the hard carbon layers are alternately arranged.

[0019] In this embodiment, the thickness of the diamond-like carbon coating is 1-15 μm, wherein the thickness of the metal transition layer is 0.1-1 μm, the thickness of each soft carbon layer is 0.1-0.3 μm, and the thickness of each hard carbon layer is 0.5-1 μm.

[0020] In this embodiment, the hardness of the diamond-like carbon coating is 600-3000 Hv, the hardness of the soft carbon layer is 500-1300 Hv, and the hardness of the hard carbon layer is 1500-3500 Hv.

[0021] Reference Figure 2 The method for processing a motor shaft with a diamond-like coating of this embodiment includes the following steps: S1. The motor shaft body 1 is formed as a single piece through forging, rough turning, fine turning, rough toothing, and keyway milling. A splined shaft head 11 is formed at one axial end of the motor shaft body 1, and bearing seats 12 are formed at both ends. The motor shaft body 1 is then polished and cleaned, and then placed in the vacuum chamber of the DLC equipment for vacuum baking and ion cleaning.

[0022] In this embodiment, the motor shaft body is polished using existing polishing equipment, and the oxide film on the coating portion is removed after sufficient polishing.

[0023] In this embodiment, the motor shaft body 1 after polishing is cleaned by ultrasonic cleaning at 50-80° C. for 30-50 minutes, and the surfaces of the spline shaft head 11 and the bearing seat 12 of the motor shaft body are wiped with acetone.

[0024] In this embodiment, the vacuum baking conditions are: vacuum degree is 1×10 -3 ~5×10 -3 Pa, temperature is kept at 120~180℃ for 20~40min; In this embodiment, the ion cleaning conditions are: the argon flow rate is 100~1000sccm, and the vacuum degree is adjusted to 1×10 -2 ~8×10 -2 Pa, bias voltage -600~-1000 V. The surface of the motor shaft can be activated by ion cleaning.

[0025] It should be noted that when the motor shaft body 1 is placed in a vacuum chamber, a mask plate is needed to cover the motor shaft body 1 to expose the position to be plated.

[0026] S2. Depositing a metal transition layer on the surface of the spline shaft head 11 and the bearing seat 12 of the motor shaft body 1. Specifically comprising: S21. Adjust the vacuum degree to 1×10 -4 ~5×10 -4 Pa, temperature 110-150°C, argon flow rate 800-1200 sccm, start the magnetron sputtering metal target and adjust the metal target current to 100-140A, adjust the bias voltage to -400-600V, and the deposition time to 1200-7200s; wherein the metal target is at least one of a titanium target, a chromium target, a tungsten target, and a nickel target; S22. Turn off the magnetron sputtering metal target and adjust the vacuum to 1×10 -3 ~5×10 -3 Pa, temperature is 100~130℃, and argon flow rate is 900~1500sccm.

[0027] S3. Alternately deposit several soft carbon layers and several hard carbon layers on the surface of the metal transition layer. Specifically including: S31. Turn on the arc carbon target and adjust the vacuum to 1×10 -4 ~1×10 -2 Pa, bias voltage is -500~-700V, and coating time is controlled to be 1000~2000s to deposit a soft carbon layer on the surface of the metal transition layer; S32. Turn off the arc carbon target, turn on the magnetron sputtering carbon target, and adjust the vacuum degree to 1×10 -4 ~1×10 -2 Pa, temperature 110~140℃, bias voltage -1000~-2000V, argon flow rate 900-1500sccm, and coating time controlled at 1500~3000s to deposit a hard carbon layer on the surface of the soft carbon layer; S33. Steps S31 and S32 are repeated alternately 10 to 50 times, and finally cleaned to obtain a motor shaft with a diamond-like coating.

[0028] The present invention applies DLC technology to treat the motor shaft through DLC, which can eliminate the need for heat treatment, significantly reduce the deformation and oxidation of the motor shaft, and significantly improve the hardness, wear resistance, corrosion resistance and oxidation resistance of the motor shaft. It greatly reduces the defects caused by heat treatment and reduces many countermeasures required to deal with heat treatment defects, thereby improving the yield rate and reducing costs. In addition, the service life of the DLC-coated motor shaft is significantly increased, and it can cope with more severe environments. It should be noted that the location of the diamond-like carbon coating treatment is not limited to the spline shaft head 11 and the bearing position 12, but can also be the entire surface of the motor shaft body.

[0029] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0030] The above-described embodiments merely represent several implementation methods of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A motor shaft with a diamond-like coating, characterized in that: It includes a motor shaft body, the spline shaft head surface, the bearing seat surface or the entire outer surface of the motor shaft body is provided with a diamond-like coating, the diamond-like coating includes a metal transition layer and a carbon layer, the carbon layer includes several soft carbon layers and several hard carbon layers, and the soft carbon layers and the hard carbon layers are alternately arranged.

2. The motor shaft with diamond-like coating according to claim 1, characterized in that The thickness of the diamond-like carbon coating is 1-15 μm, and the hardness is 600-3000 Hv.

3. The motor shaft with diamond-like coating according to claim 1, characterized in that The metal transition layer is at least one of a titanium layer, a chromium layer, a tungsten layer, and a nickel layer; and the thickness of the metal transition layer is 0.1-1 μm.

4. The motor shaft with diamond-like coating according to claim 1, characterized in that The thickness of the soft carbon layer is 0.1-0.3 μm, and the thickness of the hard carbon layer is 0.5-1 μm.

5. The motor shaft with diamond-like coating according to claim 1, characterized in that The hardness of the soft carbon layer is 500-1300 Hv, and the hardness of the hard carbon layer is 1500-3500 Hv.

6. A method for preparing a motor shaft having a diamond-like coating according to any one of claims 1 to 5, characterized in that: It includes the following steps: S1. After the polished motor shaft body is cleaned, it is placed in a vacuum chamber, vacuum-baked, and ion-cleaned; S2. A metal transition layer is deposited on the spline shaft head surface of the motor shaft body, the bearing surface, or the entire outer surface of the motor shaft body; S3. Alternately depositing a plurality of soft carbon layers and a plurality of hard carbon layers on the surface of the metal transition layer, and cleaning the layer to obtain a motor shaft having a diamond-like coating.

7. The method for preparing a motor shaft having a diamond-like coating according to claim 6, characterized in that: In step S1, the cleaning method is: ultrasonically clean the motor shaft body at 50-80°C for 30-50 minutes, and wipe the spline shaft head surface, bearing seat surface or the entire outer surface of the motor shaft body with acetone; the vacuum baking is carried out at a vacuum degree of 1×10 -3 ~5×10 -3 Pa, and maintain the temperature at 120-180°C for 20-40 minutes; the ion cleaning conditions are: argon flow rate of 100-1000 sccm, and vacuum degree of 1×10 -2 ~8×10 -2 Pa, bias voltage is -600~-1000V.

8. The method for preparing a motor shaft having a diamond-like coating according to claim 6, characterized in that: In step S2, the step of depositing the metal transition layer is as follows: S21. Adjust the vacuum degree to 1×10 -4 ~5×10 -4 Pa, temperature 110~150℃, argon flow rate 800-1200sccm, start the magnetron sputtering metal target and adjust the metal target current to 100~140A, adjust the bias voltage to -400~-600V, and the deposition time to 1200~7200s; S22. Turn off the magnetron sputtering metal target and adjust the vacuum to 1×10 -3 ~5×10 -3 Pa, temperature 100~130℃, argon flow rate 900~1500sccm; Wherein, the metal target is at least one of a titanium target, a chromium target, a tungsten target, and a nickel target.

9. The method for preparing a motor shaft with a diamond-like coating according to claim 8, characterized in that: In step S3, the steps of alternately depositing a plurality of soft carbon layers and a plurality of hard carbon layers are: S31. Turn on the arc carbon target and adjust the vacuum to 1×10 -4 ~1×10 -2 Pa, bias voltage is -500~-700V, a soft carbon layer is deposited on the surface of the metal transition layer, and the coating time is controlled to be 1000~2000s; S32. Turn off the arc carbon target, turn on the magnetron sputtering carbon target, and adjust the vacuum degree to 1×10 -4 ~1×10 -2 The hard carbon layer was deposited on the surface of the soft carbon layer at a pressure of 0.5 Pa, a temperature of 110-140°C, a bias voltage of -1000-2000 V, an argon flow rate of 900-1500 sccm, and a coating time of 1500-3000 s. S33. Steps S31 and S32 are repeated alternately 10 to 50 times.

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