阅读说明：本技术 一种用于杯型谐波齿轮减速器的固体润滑方法 (Solid lubrication method for cup-shaped harmonic gear reducer ) 是由 高晓明 翁立军 孙嘉奕 胡明 伏彦龙 杨军 王德生 姜栋 王琴琴 于 2020-04-22 设计创作，主要内容包括：本发明提供一种用于杯型谐波齿轮减速器的固体润滑方法,涉及减速器的润滑技术领域。本发明提供的固体润滑方法,包括以下步骤：利用封闭场非平衡磁控溅射法在所述杯型谐波齿轮减速器的柔轮以及波发生器中的大挡片和小挡片表面沉积过渡层；利用等离子体辅助化学气相沉积结合封闭场非平衡磁控溅射在所述过渡层表面沉积C-WC复合薄膜层；利用封闭场非平衡磁控溅射法在所述杯型谐波齿轮减速器的刚轮以及波发生器中的柔性轴承内圈和柔性轴承外圈表面沉积MoS<Sub>2</Sub>/WS<Sub>2</Sub>纳米多层自润滑薄膜层。本发明提供的固体润滑方法,使杯型谐波齿轮减速器在大气环境、真空环境和高低温环境条件下具有低摩擦扭矩,且其传动特性对环境温度不敏感,适应性强。(The invention provides a solid lubrication method for a cup-shaped harmonic gear reducer, and relates to the technical field of lubrication of reducers. The solid lubrication method provided by the invention comprises the following steps: depositing transition layers on the surfaces of a flexible gear of the cup-shaped harmonic gear reducer and a large baffle and a small baffle in a wave generator by using a closed field unbalanced magnetron sputtering method; depositing a C-WC composite film layer on the surface of the transition layer by utilizing plasma-assisted chemical vapor deposition in combination with closed field unbalanced magnetron sputtering; MoS is deposited on the surfaces of a rigid wheel of the cup-shaped harmonic gear reducer and a flexible bearing inner ring and a flexible bearing outer ring in a wave generator by utilizing a closed field unbalanced magnetron sputtering method 2 /WS 2 Nanometer multilayer self-lubricating film layer. The solid lubrication method provided by the invention enables the cup-shaped harmonic gear reducer to have low friction torque under the conditions of atmospheric environment, vacuum environment and high and low temperature environment, and the transmission characteristic of the cup-shaped harmonic gear reducer is insensitive to the environmental temperature and has strong adaptability.)

1. A solid lubrication method for a cup-type harmonic gear reducer, characterized by comprising the steps of:

(1) depositing transition layers on the surfaces of a flexible gear of the cup-shaped harmonic gear reducer and a large baffle and a small baffle in a wave generator by using a closed field unbalanced magnetron sputtering method; the transition layer sequentially comprises a Cr film layer and a WC film layer from inside to outside;

(2) depositing a C-WC composite film layer on the surface of the transition layer by utilizing plasma-assisted chemical vapor deposition in combination with closed field unbalanced magnetron sputtering;

(3) flexible bearing inner ring and flexible bearing outer ring in rigid wheel and wave generator of cup-shaped harmonic gear reducer by using closed field unbalanced magnetron sputtering methodSurface deposition of MoS₂/WS₂Nano-multilayer self-lubricating film layer, said MoS₂/WS₂Nano multilayer self-lubricating film composed of MoS₂Layer and WS₂Alternate deposition of layers;

the step (3) is not in time sequence with the steps (1) and (2).

2. The solid lubrication method according to claim 1, wherein the transition layer and the C-WC composite thin film layer have a total thickness of 1.5 μm to 3.0 μm.

3. The solid lubrication method according to claim 1, wherein the closed field unbalanced magnetron sputtering in the step (1) comprises: the surfaces of a flexible gear of the cup-shaped harmonic gear reducer and a large baffle and a small baffle in a wave generator are sequentially subjected to Cr target sputtering and WC target sputtering, the power supply power of the Cr target sputtering and the WC target sputtering is independently 4 kW-8 kW, the direct-current bias voltage is independently-50V-200V, the deposition time is independently 10 min-20 min, and the rotating speed of a workpiece frame rotation driving motor is independently 1 r/min-10 r/min.

4. The solid lubrication method according to claim 3, wherein the Cr target sputtering and the WC target sputtering are performed in argon gas, and the partial pressure of the argon gas is independently 2.0Pa to 10.0 Pa.

5. The solid lubrication method of claim 1, wherein the plasma assisted chemical vapor deposition is combined with closed field unbalanced magnetron sputtering at C₂H₂In a gas, said C₂H₂The partial pressure of the gas is 0.5Pa to 2.0 Pa.

6. The solid lubrication method according to claim 5, wherein the power of the WC target sputtering by the combination of the plasma-assisted chemical vapor deposition and the closed field unbalanced magnetron sputtering is 2kW to 4kW, the DC bias voltage is-500V to-700V, the deposition time is 60min to 90min, and the rotating speed of the workpiece holder rotation driving motor is 1r/min to 10 r/min.

7. The solid lubrication method according to claim 1, wherein the closed field unbalanced magnetron sputtering in the step (3) comprises: alternately carrying out MoS on the surfaces of a rigid wheel of the cup-shaped harmonic gear reducer and the surfaces of a flexible bearing inner ring and a flexible bearing outer ring in a wave generator₂Target sputtering and WS₂Target sputtering of said MoS₂Target sputtering and WS₂The power of a power supply for target sputtering is independently 4 kW-6 kW, the direct-current bias voltage is independently-50V-100V, the deposition time is independently 60 min-90 min, and the rotating speed of a workpiece frame rotation driving motor is independently 1 r/min-3 r/min.

8. The solid lubrication method according to claim 7, wherein said MoS₂Target sputtering and WS₂The target sputtering is performed in argon gas, and the partial pressure of the argon gas is independently 2.0Pa to 10.0 Pa.

9. The solid lubrication method according to claim 1, 3 or 4, wherein before the closed field unbalanced magnetron sputtering in the step (1), the method further comprises performing argon plasma cleaning on the surfaces of a flexible gear of the cup-shaped harmonic gear reducer and a large baffle and a small baffle in a wave generator, wherein the direct current bias current of the argon plasma cleaning is 300 mA-600 mA, and the time is 10 min-30 min.

10. The solid lubrication method according to claim 1, 7 or 8, wherein before the closed field unbalanced magnetron sputtering in the step (3), argon plasma cleaning is performed on the surfaces of a rigid gear of the cup-shaped harmonic gear reducer and the surfaces of a flexible bearing inner ring and a flexible bearing outer ring in a wave generator, and the direct current bias current of the argon plasma cleaning is 300 mA-600 mA for 10 min-30 min.

Technical Field

The invention relates to the technical field of lubrication of speed reducers, in particular to a solid lubrication method for a cup-shaped harmonic gear speed reducer.

Background

The harmonic gear reducer has the technical characteristics of large transmission ratio, high transmission precision, small volume, light weight and the like, so the harmonic gear reducer has wide application in the technical field of aerospace. The use of a proper lubricating mode or a lubricating material is the key for realizing the long service life of the harmonic gear reducer in the aerospace field.

From the current research reports at home and abroad, the harmonic gear reducer for spaceflight mainly has two main modes of solid lubrication and solid-liquid composite lubrication, wherein the solid lubrication is mostly lubricated by adopting a soft metal or disulfide laminar structure compound film, and the solid-liquid composite lubrication is mainly compounded lubricated by adopting a soft metal and low saturated vapor pressure lubricating grease. However, in comparison, the solid lubrication has the outstanding advantages of no volatilization in vacuum or low volatilization, insensitivity of tribological performance to environmental temperature and the like, so the solid lubrication is a lubrication mode which is commonly used for harmonic gear reducers in the field of aerospace at present.

In the solid lubrication technology of the harmonic gear reducer in the aerospace field at present, the used solid lubrication materials such as soft metal, disulfide layered structure compound and the like have good lubrication performance under the vacuum environment condition, but the hardness is low, the wear resistance is limited, and the tribological performance is sensitive to the atmospheric environment.

Disclosure of Invention

In view of the above, the present invention aims to provide a solid lubrication method for a cup-shaped harmonic gear reducer, which enables the harmonic gear reducer to have a characteristic of low friction torque under different temperature conditions of vacuum and atmospheric environment.

In order to achieve the above purpose, the invention provides the following technical scheme:

the invention provides a solid lubrication method for a cup-shaped harmonic gear reducer, which comprises the following steps:

(1) depositing transition layers on the surfaces of a flexible gear of the cup-shaped harmonic gear reducer and a large baffle and a small baffle in a wave generator by using a closed field unbalanced magnetron sputtering method; the transition layer sequentially comprises a Cr film layer and a WC film layer from inside to outside;

(2) depositing a C-WC composite film layer on the surface of the transition layer by utilizing plasma-assisted chemical vapor deposition in combination with closed field unbalanced magnetron sputtering;

(3) by means of closuresMoS is deposited on the surfaces of a rigid wheel of the cup-shaped harmonic gear reducer and a flexible bearing inner ring and a flexible bearing outer ring in a wave generator by a field unbalanced magnetron sputtering method₂/WS₂Nano-multilayer self-lubricating film layer, said MoS₂/WS₂Nano multilayer self-lubricating film composed of MoS₂Layer and WS₂Alternate deposition of layers;

the step (3) is not in time sequence with the steps (1) and (2).

Preferably, the total thickness of the transition layer and the C-WC composite film layer is 1.5-3.0 μm.

Preferably, the closed field unbalanced magnetron sputtering in the step (1) comprises: the surfaces of a flexible gear of the cup-shaped harmonic gear reducer and a large baffle and a small baffle in a wave generator are sequentially subjected to Cr target sputtering and WC target sputtering, the power supply power of the Cr target sputtering and the WC target sputtering is independently 4 kW-8 kW, the direct-current bias voltage is independently-50V-200V, the deposition time is independently 10 min-20 min, and the rotating speed of a workpiece frame rotation driving motor is independently 1 r/min-10 r/min.

Preferably, the Cr target sputtering and the WC target sputtering are performed in argon gas, and the partial pressure of the argon gas is independently 2.0Pa to 10.0 Pa.

Preferably, the plasma-assisted chemical vapor deposition is combined with closed field unbalanced magnetron sputtering at C₂H₂In a gas, said C₂H₂The partial pressure of the gas is 0.5Pa to 2.0 Pa.

Preferably, the power supply power of the WC target sputtering combining the plasma-assisted chemical vapor deposition and the closed field unbalanced magnetron sputtering is 2 kW-4 kW, the direct-current bias voltage is-500V-700V, the deposition time is 60 min-90 min, and the rotating speed of a workpiece rack rotation driving motor is 1 r/min-10 r/min.

Preferably, the closed field unbalanced magnetron sputtering in the step (3) comprises: alternately carrying out MoS on the surfaces of a rigid wheel of the cup-shaped harmonic gear reducer and the surfaces of a flexible bearing inner ring and a flexible bearing outer ring in a wave generator₂Target sputtering and WS₂Target sputtering of said MoS₂Target sputtering and WS₂Power source power of target sputteringThe vertical field is 4 kW-6 kW, the direct current bias voltage is independently-50V-100V, the deposition time is independently 60 min-90 min, and the rotating speed of the workpiece frame rotation driving motor is independently 1 r/min-3 r/min.

Preferably, the MoS₂Target sputtering and WS₂The target sputtering is performed in argon gas, and the partial pressure of the argon gas is independently 2.0Pa to 10.0 Pa.

Preferably, before the closed field unbalanced magnetron sputtering in the step (1), argon plasma cleaning is performed on the surfaces of a flexible gear of the cup-shaped harmonic gear reducer and a large baffle and a small baffle in a wave generator, wherein the direct current bias current of the argon plasma cleaning is 300 to 600mA, and the time is 10 to 30 min.

Preferably, before the closed field unbalanced magnetron sputtering in the step (3), argon plasma cleaning is further performed on the surfaces of a rigid wheel of the cup-shaped harmonic gear reducer and the inner ring and the outer ring of a flexible bearing in a wave generator, wherein the direct current bias current of the argon plasma cleaning is 300mA to 600mA, and the time is 10min to 30 min.

The solid lubrication method provided by the invention comprises the following steps: (1) depositing transition layers on the surfaces of a flexible gear of the cup-shaped harmonic gear reducer and a large baffle and a small baffle in a wave generator by using a closed field unbalanced magnetron sputtering method; the transition layer sequentially comprises a Cr film layer and a WC film layer from inside to outside; (2) depositing a C-WC composite film layer on the surface of the transition layer by utilizing plasma-assisted chemical vapor deposition in combination with closed field unbalanced magnetron sputtering; (3) MoS is deposited on the surfaces of a rigid wheel of the cup-shaped harmonic gear reducer and a flexible bearing inner ring and a flexible bearing outer ring in a wave generator by utilizing a closed field unbalanced magnetron sputtering method₂/WS₂Nano-multilayer self-lubricating film layer, said MoS₂/WS₂Nano multilayer self-lubricating film composed of MoS₂Layer and WS₂Alternate deposition of layers; the step (3) is not in time sequence with the steps (1) and (2). In the invention, the transition layer obtained by utilizing the closed field unbalanced magnetron sputtering deposition has good film-substrate binding performance, and is beneficial to realizing the force between the C-WC composite film layer and the steel substrateThe transition of chemical property and thermal expansion coefficient, thus improving the good film-substrate binding property of the C-WC composite film layer and further playing a role in lubrication. In the invention, the C-WC composite film layer obtained by combining plasma-assisted chemical vapor deposition with closed field unbalanced magnetron sputtering has the characteristics of high hardness and low friction, and has good chemical inertness. The invention deposits the C-WC composite film layer on the surfaces of the large baffle plate and the small baffle plate in the flexible gear and the wave generator of the cup-shaped harmonic gear reducer, so that the cup-shaped harmonic gear reducer has the characteristics of low friction and high wear resistance under the atmospheric environment condition. In the present invention, the MoS is prepared by closed field unbalanced magnetron sputtering₂/WS₂The nano multilayer film has the characteristics of low friction and low abrasion under the vacuum environment condition. The invention relates to MoS₂/WS₂The nanometer multilayer film is sputtered on the surfaces of a rigid wheel of the cup-shaped harmonic gear reducer, a flexible bearing inner ring and a flexible bearing outer ring in a wave generator, so that the cup-shaped harmonic gear reducer has the characteristics of low friction and low abrasion under the vacuum environment condition. Therefore, the invention respectively introduces the C-WC composite film layer and the MoS according to the friction modes of different elements of the cup-shaped harmonic gear reducer₂/WS₂The nano multilayer film carries out solid lubrication treatment on different elements of the cup-shaped harmonic gear reducer so as to realize the characteristics of low friction and low abrasion of the cup-shaped harmonic gear reducer under the conditions of atmospheric environment, vacuum environment and high and low temperature environment, and the transmission characteristic of the cup-shaped harmonic gear reducer is insensitive to the environmental temperature (-60 ℃ to +115 ℃), so that the cup-shaped harmonic gear reducer can meet the requirement of the harmonic reducer in the aerospace field on strong environmental adaptability (atmospheric environment, ground storage and test, in-orbit service, vacuum and high and low temperature alternation).

Drawings

FIG. 1 is a structural diagram of a cup-shaped harmonic gear reducer of the present invention, wherein 1, a flexible gear, 2, a rigid gear, 3, a wave generator, 4, a flexible bearing outer ring, 5, a flexible bearing inner ring, 6, a small baffle, 7, a steel ball, 8, a flexible bearing retainer, 9, a cam, 10, a large baffle, and the right side is an enlarged view of the wave generator 3;

FIG. 2 is a schematic diagram of an embodiment of the present invention combining PECVD with a closed field depositionSchematic cross-sectional structure diagram of a balanced magnetron sputtering device, wherein a.Cr target sputtering power supply, b.vacuum chamber, c.argon valve, d.gas charging valve and e.C₂H₂Air valve, f. workpiece rack and g.MoS₂Target sputtering power supply, h.DC bias power supply, i.WS₂The sputtering device comprises a target sputtering power supply, a j-workpiece frame rotation driving motor, a k-air release valve, a l-molecular pump, an m-mechanical pump and an n-WC target sputtering power supply;

FIG. 3 is a photograph of a rigid gear, a flexible gear and a wave generator of a cup-type harmonic gear reducer of XBS-80-100 type after solid lubrication treatment in example 1, wherein 1. WS is deposited on a working surface₂/MoS₂A rigid gear of an XBS-80-100 model cup type harmonic gear reducer with nano multilayer films, a flexible gear of the XBS-80-100 model cup type harmonic gear reducer with 2 working surface C-WC film layers, and 3 working surface C-WC film layers and WS₂/MoS₂An XBS-80-100 model cup-shaped harmonic gear reducer wave generator behind the nanometer multilayer film;

FIG. 4 shows the deposition of a C-WC composite thin film layer in example 1 under vacuum with WS₂/MoS₂The sliding friction curve of the nano multilayer film to the grinder;

FIG. 5 shows the transmission characteristics of the XBS-80-100 cup-shaped harmonic gear reducer of example 1 after the solid lubrication treatment under vacuum and high and low temperature conditions.

Detailed Description

The invention provides a solid lubrication method for a cup-shaped harmonic gear reducer, which comprises the following steps:

(1) depositing transition layers on the surfaces of a flexible gear of the cup-shaped harmonic gear reducer and a large baffle and a small baffle in a wave generator by using a closed field unbalanced magnetron sputtering method; the transition layer sequentially comprises a Cr film layer and a WC film layer from inside to outside;

(2) depositing a C-WC composite film layer on the surface of the transition layer by utilizing plasma-assisted chemical vapor deposition in combination with closed field unbalanced magnetron sputtering;

(3) flexible bearing inner ring and flexible bearing outer ring meter in rigid wheel and wave generator of cup-shaped harmonic gear reducer by utilizing closed field unbalanced magnetron sputtering methodSurface deposition of MoS₂/WS₂Nano-multilayer self-lubricating film layer, said MoS₂/WS₂Nano multilayer self-lubricating film composed of MoS₂Layer and WS₂Alternate deposition of layers;

the step (3) is not in time sequence with the steps (1) and (2).

In the present invention, the cup type harmonic gear reducer is preferably a cup type harmonic gear reducer well known to those skilled in the art, and its specific structure is shown in fig. 1, fig. 1 is a structural diagram of the cup type harmonic gear reducer of the present invention, wherein, 1, a flexible gear, 2, a rigid gear, 3, a wave generator, 4, a flexible bearing outer ring, 5, a flexible bearing inner ring, 6, a small baffle, 7, a steel ball, 8, a flexible bearing retainer, 9, a cam, 10, a large baffle, and the right side is an enlarged view of the wave generator 3.

Before the solid lubrication, the elements of the cup-shaped harmonic gear reducer are preferably disassembled into a rigid gear, a flexible bearing inner ring, a flexible bearing outer ring, a flexible bearing steel ball, a cam and a baffle plate, and then the surfaces of the elements are sequentially cleaned and dried. In the present invention, the cleaning method is preferably ultrasonic cleaning in gasoline and acetone in this order. The ultrasonic cleaning method of the present invention is not particularly limited, and may be any ultrasonic cleaning method known to those skilled in the art. In the present invention, the drying is preferably air drying or oven drying. In the present invention, the drying time and the drying temperature are not particularly limited, and the cleaning agent on the surface of the element may be removed.

The invention utilizes a closed field unbalanced magnetron sputtering method to deposit transition layers on the surfaces of a flexible gear of the cup-shaped harmonic gear reducer and a large baffle and a small baffle in a wave generator.

In the invention, the transition layer sequentially comprises a Cr film layer and a WC film layer from inside to outside.

In the invention, the surfaces of a flexible gear of the cup-shaped harmonic gear reducer and a large baffle and a small baffle in a wave generator are preferably subjected to argon plasma cleaning, and then closed field unbalanced magnetron sputtering is carried out. In the invention, the argon plasma cleaning is excellentIs carried out in a vacuum chamber with the vacuum degree of preferably less than or equal to 5.0 × 10^-3Pa. In the invention, preferably, argon is introduced after vacuum pumping. In the present invention, the partial pressure of the argon gas is preferably 2.0Pa to 10.0Pa, and more preferably 4.0Pa to 8.0 Pa. In the present invention, the dc bias current for the argon plasma cleaning is preferably 300mA to 600mA, more preferably 350mA to 500mA, and the time for the argon plasma cleaning is preferably 10min to 30min, more preferably 15min to 25 min.

In the invention, the closed field unbalanced magnetron sputtering preferably comprises Cr target sputtering and WC target sputtering on the surfaces of a flexible gear of the cup-shaped harmonic gear reducer, a large baffle plate and a small baffle plate in a wave generator in sequence.

In the present invention, the Cr target sputtering and the WC target sputtering are independently preferably performed in a vacuum chamber having a degree of vacuum of preferably 5.0 × 10 or less^-3Pa. In the invention, preferably, argon is introduced after vacuum pumping. In the present invention, the partial pressure of the argon gas is independently preferably 2.0Pa to 10.0Pa, and more preferably 3.0Pa to 7.0 Pa. In the present invention, the power source power of the Cr target sputtering and the WC target sputtering is preferably 4kW to 8kW, and more preferably 5kW to 6kW independently; the DC bias voltage of the Cr target sputtering and the WC target sputtering is preferably-50V to-200V, and is further preferably-80V to-160V; the deposition time of the Cr target sputtering and the WC target sputtering is preferably 10min to 20min independently, and more preferably 13min to 17min independently; the rotating speed of the workpiece rack rotating driving motor for the Cr target sputtering and the WC target sputtering is preferably 1 r/min-10 r/min, and more preferably 3 r/min-7 r/min independently.

After transition layers are deposited on the surfaces of a flexible gear of the cup-shaped harmonic gear reducer and large and small baffle plates in a wave generator, a C-WC composite film layer is deposited on the surfaces of the transition layers by utilizing a plasma-assisted chemical vapor deposition combined with a closed field unbalanced magnetron sputtering method.

In the present invention, the total thickness of the transition layer and the C-WC composite thin film layer is preferably 1.5 μm to 3.0. mu.m.

In the present invention, the plasma-assisted chemical vapor deposition bonding sealThe closed-field unbalanced magnetron sputtering is preferably carried out in a vacuum chamber with a vacuum degree of preferably ≤ 5.0 × 10^-3Pa. In the invention, the C is preferably introduced after the vacuum pumping₂H₂Gas, said C₂H₂The partial pressure of the gas is preferably 0.5Pa to 2.0Pa, and more preferably 0.8Pa to 1.5 Pa. In the invention, the power of the power supply for the WC target sputtering combining the plasma-assisted chemical vapor deposition and the closed field unbalanced magnetron sputtering is preferably 2kW to 4kW, and more preferably 2.5kW to 3 kW; the direct current bias voltage of the plasma-assisted chemical vapor deposition combined with closed field unbalanced magnetron sputtering is preferably-500V to-700V, and more preferably-550V to-600V; the deposition time of the plasma-assisted chemical vapor deposition combined with the closed field unbalanced magnetron sputtering is preferably 60min to 90min, and more preferably 70min to 80 min; said C is₂H₂The rotating speed of the workpiece rack rotating driving motor for the gas plasma assisted chemical vapor deposition is preferably 1r/min to 10r/min, and more preferably 3r/min to 7 r/min.

After plasma-assisted chemical vapor deposition is combined with closed field unbalanced magnetron sputtering, the flexible gear of the cup-shaped harmonic gear reducer after deposition, a large baffle plate and a small baffle plate in a wave generator are preferably naturally cooled to room temperature along with the furnace.

FIG. 2 is a schematic cross-sectional view of an embodiment of the present invention, wherein a.Cr target sputtering power source, b.vacuum chamber, c.argon valve, d.gas charging valve, e.C₂H₂Air valve, f. workpiece rack and g.MoS₂Target sputtering power supply, h.DC bias power supply, i.WS₂The device comprises a target sputtering power supply, j, a workpiece rack rotation driving motor, k, an air release valve, l, a molecular pump, m, a mechanical pump and n, WC target sputtering power supply. In the present invention, the plasma-assisted chemical vapor deposition and closed field unbalanced magnetron sputtering apparatus is preferably a plasma-assisted chemical vapor deposition and closed field unbalanced magnetron sputtering apparatus well known to those skilled in the art.

After the C-WC composite film layer is deposited on the surface of the transition layer, the invention utilizes a closed field unbalanced magnetron sputtering methodMoS is deposited on the surfaces of a rigid wheel of the cup-shaped harmonic gear reducer and flexible bearing inner rings and flexible bearing outer rings in a wave generator₂/WS₂Nano multilayer self-lubricating film.

In the present invention, the MoS₂/WS₂Nano multilayer self-lubricating film through MoS₂Layer and WS₂Alternating deposition of layers is achieved. In the present invention, the alternating deposition preferably comprises first depositing MoS₂After layering, redepositing WS₂Layer and first deposited WS₂After layering, redepositing MoS₂And (3) a layer. In the present invention, a single layer of MoS₂The thickness of the thin film layer is preferably 10 nm-20 nm; single layer WS₂The thickness of the thin film layer is preferably 10nm to 20 nm. In the present invention, the MoS₂/WS₂The thickness of the nano multilayer self-lubricating film is preferably 1-3 μm.

In the present invention, the argon plasma cleaning is preferably performed in a vacuum chamber filled with argon gas, the argon gas partial pressure is preferably 2.0 to 10.0Pa, more preferably 4.0 to 8.0 Pa. in the present invention, the vacuum degree of the vacuum chamber is preferably not more than 5.0 × 10^{- 3}Pa. In the present invention, the dc bias current for the argon plasma cleaning is preferably 300mA to 600mA, more preferably 350mA to 500mA, and the time for the argon plasma cleaning is preferably 10min to 30min, more preferably 15min to 25 min.

In the invention, the closed field unbalanced magnetron sputtering preferably comprises alternately carrying out MoS on the surfaces of a rigid wheel of the cup-shaped harmonic gear reducer and the surfaces of a flexible bearing inner ring and a flexible bearing outer ring in a wave generator₂Target sputtering and WS₂Target sputtering of said MoS₂Target sputtering and WS₂The target sputtering is preferably performed in a vacuum chamber filled with argon gas, the partial pressure of the argon gas is preferably 2.0Pa to 10.0Pa, more preferably 3.0Pa to 7.0 Pa. in the present invention, the degree of vacuum of the vacuum chamber is preferably 5.0Pa or less and 5.0 × 10 percent or less^-3Pa. In the present invention, the MoS₂Target sputtering and WS₂The power of a power supply for target sputtering is preferably 4kW to 6kW independently, and more preferably 5kW to 6 kW; the MoS₂Target sputtering and WS₂The DC bias voltage for target sputtering is independently-50V to-100V, more preferably-60V to-80V; the MoS₂Target sputtering and WS₂The deposition time of target sputtering is independently 60min to 90min, and more preferably 65min to 80 min; the MoS₂Target sputtering and WS₂The rotating speed of a workpiece frame rotating driving motor for target sputtering is independently 1 r/min-3 r/min, and more preferably 1.5 r/min-2.5 r/min. In the invention, the conditions of the closed field unbalanced magnetron sputtering of the rigid gear of the cup-shaped harmonic gear reducer and the flexible bearing inner ring and the flexible bearing outer ring in the wave generator are preferably consistent.

After the closed field unbalanced magnetron sputtering is finished, the deposited rigid wheel of the cup-shaped harmonic gear reducer, the flexible bearing inner ring and the flexible bearing outer ring in the wave generator are preferably naturally cooled to room temperature along with the furnace.

The following describes the method of solid lubrication of a cup-type harmonic gear reducer according to the present invention in detail with reference to the following examples, but they should not be construed as limiting the scope of the present invention.