A method for laser shock combined surface modification of a bearing raceway surface

Abstract

The application provides a laser impact combined surface modification method for a bearing raceway surface, a pre-processing raceway region and a retainer matching surface, the raceway region reserving a processing allowance layer; a constraint layer is applied to the raceway region; the raceway region is micro-scale laser impact strengthened for at least 3 times without an absorption protective layer, a deep and uniform plastic strengthening layer is formed; the processing allowance layer is removed; an absorption protective layer is attached to the retainer matching surface; and array-arranged oil storage pits are formed on the retainer matching surface through laser impact forming. The method can form a plastic strengthening layer on the raceway region surface through micro-scale laser impact strengthening, can significantly improve the rolling contact fatigue performance and wear performance of the bearing, and can form oil storage pits on the retainer matching surface through laser impact forming, the oil storage pits can lock lubricating oil through the surface tension of the oil, and the problem of insufficient lubrication of the bearing raceway surface is solved.

Description

Technical Field

[0001] This invention relates to the field of laser shock peening technology, and in particular to a laser shock combined surface modification method for bearing raceway surfaces. Background Technology

[0002] The performance requirements for high-end bearings are evolving towards higher DN values, higher temperature environments, heavy loads, longer lifespans, and higher reliability. During service, bearings are prone to wear and scratches, contact fatigue fractures, jamming, and seizure, severely impacting the operational safety of rotating systems. During bearing operation, rollers roll at high speeds and under heavy loads on the raceways, making contact fatigue failure of the raceway surface material unavoidable. This is especially true when the raceway surface is damaged by wear or scratches, which further accelerates the initiation of contact fatigue cracks and the fracture process. Therefore, high-end bearing raceways operate under high-speed, heavy-load conditions for extended periods, placing extremely high demands on their surface finish. Excellent wear resistance and good lubrication are essential for ensuring normal bearing operation.

[0003] Therefore, there is an urgent need to innovate and develop a process that can improve the contact fatigue and wear performance of bearing raceways, as well as their friction and lubrication performance, thereby significantly improving the service life of bearings. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the object of the present invention is:

[0005] Firstly, a laser-shock combined surface modification method for bearing raceway surfaces is provided, the key of which lies in preparing the surface according to the following steps:

[0006] S1. Pre-machining: A raceway region in the middle and retaining ring mating surfaces symmetrically distributed on both sides of the raceway region are formed by machining on the bearing raceway surface. A machining allowance layer is reserved in the raceway region. The thickness of the raceway region is d and the thickness of the machining allowance layer is d0.

[0007] S2. Apply constraint: Do not apply an absorbent protective layer to the raceway area of ​​the bearing; instead, apply a constraint layer only to the surface of the raceway area.

[0008] S3. Laser shock strengthening: Under the condition of no absorption protective layer, a microscale low-energy laser is used to continuously scan the raceway region for shock strengthening, forming a plastic strengthening layer with a depth of d1 in the raceway region, where d1 > d0.

[0009] S4. Remove the reserved processing allowance layer;

[0010] S5. Protective Covering: An absorbent protective layer is applied to the mating surface of the retaining ring, and a constraint layer is applied to the surface of the absorbent protective layer.

[0011] S6. Laser shock forming: A large-spot high-energy laser is used to perform array-distributed shock forming on the mating surface of the retaining ring, forming an array of oil storage pits on the mating surface of the retaining ring.

[0012] In conjunction with the first aspect, in one implementation, the power density of the laser shock enhancement is 15–30 GW / cm². 2 The laser spot diameter is 0.3–0.8 mm, the laser energy is 200–800 mJ, the laser pulse width is 10 ns, and the number of impact passes is 3–5.

[0013] In conjunction with the first aspect, in one implementation, the power density of the laser shock forming is 9–15 GW / cm². 2 The laser spot diameter is 2-3 mm, the laser energy is 6-20 J, the laser pulse width is 20 ns, and the number of impact passes is 1.

[0014] In conjunction with the first aspect, in one implementation, each of the retaining ring mating surfaces has at least two rings of oil reservoirs distributed circumferentially, and the oil reservoirs of adjacent rings are offset in the axial direction of the bearing.

[0015] In conjunction with the first aspect, in one implementation, the diameter of the oil storage pit is D0, and the axial distance between the oil storage pit closest to the raceway region and the edge of the raceway region is at least 2D0.

[0016] In conjunction with the first aspect, in one implementation, the axial spacing between two adjacent oil storage pits is at least 2D0.

[0017] In conjunction with the first aspect, in one implementation, the absorbent protective layer is made of black tape; the constraint layer is a water curtain formed by applying deionized water.

[0018] In conjunction with the first aspect, in one implementation, the process of removing the reserved machining allowance layer in step S4 involves using a fine grinding and polishing process to remove the machining allowance layer in the raceway area.

[0019] Secondly, a bearing ring is also provided, the key feature of which is that: it includes an inner bearing ring and / or an outer bearing ring, and is treated by the combined surface modification method described in any implementation of the first aspect, forming a plastic reinforcement layer on the raceway groove surface of the inner bearing ring and / or the outer bearing ring, and forming an array of oil reservoirs on the retaining ring mating surfaces on both sides of the raceway groove.

[0020] Thirdly, a bearing is also provided, the key feature of which is that it has the bearing ring described in the second aspect.

[0021] As described above, the laser shock combined surface modification method for bearing raceway surfaces of the present invention includes at least the following beneficial effects: by laser shock strengthening, a plastic strengthening layer with large depth and good uniformity is formed in the raceway area, which can significantly improve the rolling contact fatigue performance and wear performance of the bearing; at the same time, on the retaining ring mating surface, an array of oil storage pits are formed by laser shock forming, and the oil storage pits can lock in the lubricating oil through the surface tension of the oil, thus solving the problem of insufficient lubrication on the bearing raceway surface. Attached image description:

[0022] Figure 1 This is a cross-sectional schematic diagram of the bearing machining process according to the present invention;

[0023] Figure 2 This is a process flow diagram of the present invention;

[0024] Figure 3 A schematic diagram showing the arrangement of oil reservoirs on the mating surface of the retaining ring;

[0025] Figure 4 The results of comparative tests on the contact fatigue performance of bearings treated with the combined surface modification method of the present invention are shown.

[0026] Figure 5 The results show the comparative test results of the friction coefficient of the bearings treated by the combined surface modification method of the present invention.

[0027] Figure 6 The results are comparative test results of volumetric wear of bearings treated with the combined surface modification method of the present invention.

[0028] Figure 7 These are comparative photographs of the wear failure characteristics of bearing steel surfaces treated by the combined surface modification method of the present invention (where a is a photograph of the raceway surface of the blank bearing and b is a photograph of the raceway surface of the bearing in Example 1).

[0029] Explanation of reference numerals in the attached diagram: 1 is the bearing ring, 2 is the raceway area, 3 is the retaining ring mating surface, 4 is the absorption protective layer, 5 is the constraint layer, 6 is the laser shock blasting wave, 7 is the laser shock forming wave, and 8 is the oil reservoir. Detailed Implementation

[0030] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention and not for limiting the scope of protection of the present invention.

[0031] It should be noted that: in this application, microscale laser refers to laser with a spot size of less than 1 mm, and low-energy laser refers to laser with an energy of less than 1 J.

[0032] First, please refer to the appendix. Figure 1 and 2 As shown, the present invention provides a laser-shock combined surface modification method for bearing raceway surfaces, which is prepared according to the following steps:

[0033] S1. Pre-machining: A central raceway region and symmetrically distributed retaining ring mating surfaces are machined on the bearing raceway surface. A machining allowance layer is reserved in the raceway region. The thickness of the raceway region is d, and the thickness of the machining allowance layer is d0. It should be noted that the bearing raceway surface here and the raceway surface mentioned in this article are the outer surface of the bearing inner ring or the inner surface of the bearing outer ring, that is, the entire surface where the raceway is located.

[0034] S2. Applying constraints: It is not necessary to apply an absorbent protective layer to the raceway area of ​​the bearing; a constraint layer can be applied only to the surface of the raceway area.

[0035] S3. Laser shock strengthening: The raceway region is continuously scanned and strengthened by microscale low-energy laser to form a plastic strengthening layer with a depth of d1 in the raceway region, where d1 > d0.

[0036] S4. Remove the reserved processing allowance layer;

[0037] S5. Protective Covering: An absorbent protective layer is applied to the mating surface of the retaining ring, and a constraint layer is applied to the surface of the absorbent protective layer.

[0038] S6. Laser Shock Forming: A large-spot, high-energy laser is used to perform array-distributed shock forming on the mating surface of the retaining ring, creating an array of oil-retaining pits on the mating surface, such as... Figure 3 As shown.

[0039] Microscale, low-energy laser shock peening is employed to treat bearing raceways, forming a high-amplitude, deep, and uniformly distributed residual compressive stress layer and work-hardened layer, which improves rolling contact fatigue and wear performance. Large-spot, high-energy laser shock forming is used to treat both sides of the bearing raceway, creating an array of oil-retaining pits to store lubricating oil, thus improving friction performance. By comprehensively utilizing the functions of laser shock peening and laser shock forming, the rolling contact fatigue and friction wear performance of high-end bearing raceways are significantly improved. This method also features simple technical principles, strong operability, good functional integration, and strong engineering applicability, making it suitable for high-end bearings in aero-engines, gas turbines, steam turbines, and high-speed trains, and can also be extended to bearings in other equipment.

[0040] In some embodiments, the power density of the laser shock enhancement is 15–30 GW / cm². 2 The laser spot diameter is 0.3–0.8 mm, the laser energy is 200–800 mJ, the laser pulse width is 10 ns, and the number of impact passes is 3–5. Higher power density results in greater surface plastic deformation. Furthermore, through 3–5 sweeping impact passes, the uniformity of residual stress and hardness distribution can be significantly improved, with numerical fluctuations controlled within ±10%, thereby significantly enhancing the contact fatigue performance and wear resistance of the raceway.

[0041] In some embodiments, the power density of the laser shock forming is 9–15 GW / cm². 2 The laser spot diameter is 2-3 mm, the laser energy is 6-20 J, the laser pulse width is 20 ns, and the number of impact passes is 1. Large spot high-energy laser impact forming can form pits with small diameter and shallow depth on the narrow area of ​​the retaining ring mating surface. This can obtain pits with oil-locking effect while maintaining the performance of the raceway surface.

[0042] In some embodiments, each retaining ring has at least two circumferentially distributed oil reservoirs on its mating surface, with adjacent rings of oil reservoirs offset in the axial direction of the bearing. This improves the oil retention effect and provides more comprehensive coverage.

[0043] In some embodiments, such as Figure 3 The diameter of the oil reservoir pit shown is D0. The axial distance between the oil reservoir pit closest to the edge of the raceway region and the edge of the raceway region is at least 2D0. During laser shock forming of the oil reservoir pit, a certain amount of extrusion deformation and residual stress distribution will be caused around it. In order to avoid the pit affecting the deformation and residual stress distribution of the raceway region, a reasonable spacing needs to be determined according to the influence range of the plastic deformation of the pit.

[0044] In some embodiments, such as Figure 3 The axial spacing between two adjacent oil reservoirs shown is at least 2D0. During laser shock forming of the oil reservoirs, the surrounding material is deformed by compression. To prevent further deformation of adjacent reservoirs, a certain distance needs to be maintained between the reservoirs.

[0045] In some embodiments, the absorbent protective layer is black tape; the constraint layer is a water curtain formed by applying deionized water.

[0046] In some embodiments, the removal of the reserved machining allowance layer in step S4 is performed by a fine grinding and polishing process on the machining allowance layer in the raceway area. A certain thickness of material is removed and smoothed in the reinforced area, removing the damaged layer on the material surface and ensuring that the surface finish of the raceway area meets relevant technical requirements.

[0047] Furthermore, in some embodiments, a bearing ring is provided, including an inner bearing ring and / or an outer bearing ring, which is treated using the combined surface modification method described in any of the above embodiments to form a plastic reinforcement layer on the raceway groove surface of the inner bearing ring and / or the outer bearing ring, and to form an array of oil reservoirs on the retaining ring mating surfaces on both sides of the raceway groove.

[0048] Furthermore, in some embodiments, a bearing is provided having the bearing rings described in the above embodiments.

[0049] The present invention will be described in detail below through specific examples and embodiments. It should also be understood that the following embodiments are only for specific illustration of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above description of the present invention are within the scope of protection of the present invention. The specific process parameters, etc., in the following examples are merely examples within a suitable range; that is, those skilled in the art can make appropriate selections within the appropriate range based on the description herein, and are not intended to be limited to the specific values ​​in the examples below.

[0050] Example 1: Taking the inner and outer rings of a certain type of aero-engine main bearing as an example, a combined strengthening process is implemented. The material is M50 steel, the raceway width is 50mm, and the raceway thickness is 10mm. (See attached...) Figure 1 and 2 As shown, the specific implementation process is as follows:

[0051] (1) The bearing blank is machined by cutting, turning and other machining processes, and then rough grinding is performed on a grinding machine. The grinding is stopped when the raceway thickness is 10.2mm. A raceway area in the middle and retaining ring mating surfaces symmetrically distributed on both sides of the raceway area are formed on the bearing raceway surface. A machining allowance layer with a thickness d0 of 0.2mm is reserved in the raceway area. The axial width of the raceway area is D = 20mm.

[0052] (2) Fix the bearing on the 5-axis robot arm, and then apply deionized water flow to the raceway area through the universal water-saving pipe to ensure that a water curtain of 1-2 mm is formed in the raceway area as a constraint layer.

[0053] (3) In the microscale laser shock peening integrated control system, the parameters for laser shock peening are set as follows: laser energy is 300 mJ, spot diameter is 0.5 mm, pulse width is 10 ns, and the number of shock passes is 5. At this time, the laser power density is 30.57 GW / cm². 2It can form a plastic reinforcement layer with a maximum residual stress of over 800 MPa and a depth of over 1.0 mm in the bearing raceway area. Through 5 impacts, the uniformity of residual stress and hardness distribution can be greatly improved, and the numerical fluctuation range can be controlled within ±10%, thereby significantly improving the contact fatigue performance and wear resistance of the raceway.

[0054] (4) The reinforced bearing is mounted on a grinding machine and the raceway is precision machined by processes such as fine grinding and polishing to remove the machining allowance d0, so that the thickness of the bearing raceway is 10mm and its surface finish meets the relevant technical requirements.

[0055] (5) Use black tape as an absorbent protective layer again, apply it to the surface of the retaining ring mating surface, and then fix the bearing on the 5-axis robot arm. Then apply deionized water flow to the raceway area through the universal water-saving pipe to ensure that a 1-2 mm water curtain is formed on the surface of the retaining ring mating surface as a constraint layer.

[0056] (6) In the integrated control system for laser shock strengthening, the parameters for laser shock forming are set as follows: laser energy is 8J, spot diameter is 2mm, pulse width is 20ns, and the number of shock passes is 1. At this time, the laser power density is 15.92GW / cm². 2 ,like Figure 3 As shown: Two rings of oil reservoirs are formed on the mating surfaces of the retaining rings on both sides of the raceway area. The two rings of oil reservoirs are offset in the axial direction of the bearing. The diameter of the oil reservoir is 1 mm. The inner ring of oil reservoirs is at least 2 mm away from the edge of the raceway area in the axial direction. The distance between the two reservoirs in the axial direction is at least 2 mm.

[0057] (7) After the inner ring and outer ring of the bearing are processed, they are assembled to obtain the bearing.

[0058] Example 2: Taking the inner and outer rings of a certain type of aero-engine main bearing as an example, a combined strengthening process is implemented. The material is M50 steel, the raceway width is 50mm, and the raceway thickness is 10mm. (See attached...) Figure 1 and 2 As shown, the specific implementation process is as follows:

[0059] (1) The bearing blank is machined by cutting, turning and other machining processes, and then rough grinding is performed on a grinding machine. The grinding is stopped when the raceway thickness is 10.2mm. A raceway area in the middle and retaining ring mating surfaces symmetrically distributed on both sides of the raceway area are formed on the bearing raceway surface. A machining allowance layer with a thickness d0 of 0.2mm is reserved in the raceway area. The axial width of the raceway area is D = 20mm.

[0060] (2) Then fix the bearing on the 5-axis robot arm, and then apply deionized water flow to the raceway area through the universal water-saving pipe to ensure that a water curtain of 1-2 mm is formed in the raceway area as a constraint layer.

[0061] (3) In the microscale laser shock peening integrated control system, the parameters for laser shock peening are set as follows: laser energy of 800 mJ, spot diameter of 0.8 mm, pulse width of 10 ns, and number of shock passes of 5. At this time, the laser power density is 15.92 GW / cm². 2 It can form a plastic reinforcement layer with a maximum residual stress of over 500MPa and a depth of over 0.6mm in the bearing raceway area. Through 5 impacts, the uniformity of residual stress and hardness distribution can be greatly improved, and the numerical fluctuation range can be controlled within ±10%, thereby significantly improving the contact fatigue performance and wear resistance of the raceway.

[0062] (4) The reinforced bearing is mounted on a grinding machine and the raceway is precision machined by processes such as fine grinding and polishing to remove the machining allowance d0, so that the thickness of the bearing raceway is 10mm and its surface finish meets the relevant technical requirements.

[0063] (5) Use black tape as an absorbent protective layer again, apply it to the surface of the retaining ring mating surface, and then fix the bearing on the 5-axis robot arm. Then apply deionized water flow to the raceway area through the universal water-saving pipe to ensure that a 1-2 mm water curtain is formed on the surface of the retaining ring mating surface as a constraint layer.

[0064] (6) In the integrated control system for laser shock strengthening, the parameters for laser shock forming are set as follows: laser energy is 6J, spot diameter is 2mm, pulse width is 20ns, and the number of shock passes is 1. At this time, the laser power density is 9.55GW / cm². 2 ,like Figure 3 As shown: Two rings of oil reservoirs are formed on the mating surfaces of the retaining rings on both sides of the raceway area. The two rings of oil reservoirs are offset in the axial direction of the bearing. The diameter of the oil reservoir is 1 mm. The inner ring of oil reservoirs is at least 2 mm away from the edge of the raceway area in the axial direction. The distance between the two reservoirs in the axial direction is at least 2 mm.

[0065] (7) After the inner ring and outer ring of the bearing are processed, they are assembled to obtain the bearing.

[0066] Example 3: Taking the inner and outer rings of a certain type of aero-engine main bearing as an example, a combined strengthening process is implemented. The material is M50 steel, the raceway width is 50mm, and the raceway thickness is 10mm. (See attached...) Figure 1 and 2 As shown, the specific implementation process is as follows:

[0067] (1) The bearing blank is machined by cutting, turning and other machining processes, and then rough grinding is performed on a grinding machine. The grinding is stopped when the raceway thickness is 10.2mm. A raceway area in the middle and retaining ring mating surfaces symmetrically distributed on both sides of the raceway area are formed on the bearing raceway surface. A machining allowance layer with a thickness d0 of 0.2mm is reserved in the raceway area. The axial width of the raceway area is D = 20mm.

[0068] (2) Fix the bearing on the 5-axis robot arm, and then apply deionized water flow to the raceway area through the universal water-saving pipe to ensure that a water curtain of 1-2 mm is formed in the raceway area as a constraint layer.

[0069] (3) In the microscale laser shock peening integrated control system, the parameters for laser shock peening are set as follows: laser energy of 200 mJ, spot diameter of 0.3 mm, pulse width of 10 ns, and number of shock passes of 5. At this time, the laser power density is 28.31 GW / cm². 2 It can form a plastic reinforcement layer with a maximum residual stress of over 800MPa and a depth of over 1.5mm in the bearing raceway area. Through 5 impacts, the uniformity of residual stress and hardness distribution can be greatly improved, and the numerical fluctuation range can be controlled within ±10%, thereby significantly improving the contact fatigue performance and wear resistance of the raceway.

[0070] (4) The reinforced bearing is mounted on a grinding machine and the raceway is precision machined by processes such as fine grinding and polishing to remove the machining allowance d0, so that the thickness of the bearing raceway is 10mm and its surface finish meets the relevant technical requirements.

[0071] (5) Use black tape as an absorbent protective layer again, apply it to the surface of the retaining ring mating surface, and then fix the bearing on the 5-axis robot arm. Then apply deionized water flow to the raceway area through the universal water-saving pipe to ensure that a 1-2 mm water curtain is formed on the surface of the retaining ring mating surface as a constraint layer.

[0072] (6) In the integrated control system for laser shock strengthening, the parameters for laser shock forming are set as follows: laser energy of 20J, spot diameter of 3mm, pulse width of 20ns, and number of shock passes of 1. At this time, the laser power density is 14.15GW / cm². 2 ,like Figure 3 As shown: Two rings of oil reservoirs are formed on the mating surfaces of the retaining rings on both sides of the raceway area. The two rings of oil reservoirs are offset in the axial direction of the bearing. The diameter of the oil reservoir is 1 mm. The inner ring of oil reservoirs is at least 2 mm away from the edge of the raceway area in the axial direction. The distance between the two reservoirs in the axial direction is at least 2 mm.

[0073] (7) After the inner ring and outer ring of the bearing are processed, they are assembled to obtain the bearing.

[0074] Experimental comparison and results:

[0075] In Example 1, bearings from the same batch that had not undergone combined surface modification served as a blank group. After the raceways were precision-machined using processes such as fine grinding and polishing, the bearings from Example 1 that had undergone combined surface modification were compared and analyzed.

[0076] 1. The contact fatigue life of the two types of bearings mentioned above was tested, and the results are as follows: Figure 4 As shown. According to Figure 4 It can be seen that the average contact fatigue life of the unreinforced bearing is much lower than that of the reinforced bearing in Example 1, indicating that the method of this application significantly improves the contact fatigue performance of the bearing.

[0077] 2. The friction coefficient and volumetric wear of the above two types of bearings were tested, and the results are as follows: Figure 5 and 6 As shown. According to Figure 5 and 6 It can be seen that the bearing after strengthening treatment has a lower coefficient of friction and volumetric wear rate than the bearing without strengthening treatment, indicating that the method of this application significantly improves the friction and wear performance of the bearing.

[0078] 3. Inspection of bearing raceway surface wear and oxidation, results are as follows: Figure 7 As shown. According to Figure 7 It can be seen that the blank bearings showed more obvious wear and obvious oxidation marks on the surface, while the bearings after the strengthening treatment had uniform and smooth surface wear marks and almost no oxidation marks, indicating that the method of this application significantly improved the uniformity of residual stress and hardness distribution on the raceway surface.

[0079] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for laser-shock combined surface modification of bearing raceway surfaces, characterized in that... Prepare according to the following steps: S1. Pre-machining: A central raceway region and symmetrically distributed retaining ring mating surfaces on both sides of the raceway region are machined on the bearing raceway surface. A machining allowance layer is reserved in the raceway region, and the thickness of the raceway region is [missing information]. d The thickness of the machining allowance layer is d 0; S2. Apply constraint: Apply a constraint layer to the surface of the raceway region; S3. Laser Shock Enhancement: Under conditions without an absorption protective layer, a microscale low-energy laser is used to perform continuous scanning shock enhancement on the raceway region, forming a layer in the raceway region with a depth of... d 1. Plastic reinforcement layer, d 1> d 0; The power density of the laser shock enhancement is 15~30 GW / cm². 2 The laser spot diameter is 0.3~0.8mm, the laser energy is 200~800mJ, the laser pulse width is 10ns, and the number of impact passes is 3~5. S4. Remove the reserved processing allowance layer; S5. Protective Covering: An absorbent protective layer is applied to the mating surface of the retaining ring, and a constraint layer is applied to the surface of the absorbent protective layer. S6. Laser shock forming: A large-spot high-energy laser is used to perform array-distributed shock forming on the mating surface of the retaining ring, forming an array of oil storage pits on the mating surface of the retaining ring. The power density of the laser shock forming is 9~15 GW / cm². 2 The laser spot diameter is 2~3mm, the laser energy is 6~20J, the laser pulse width is 20ns, and the number of impact passes is 1.

2. The laser-shock combined surface modification method for bearing raceways according to claim 1, characterized in that: Each of the aforementioned retaining ring mating surfaces has at least two rings of oil reservoirs distributed circumferentially, and the oil reservoirs of adjacent two rings are offset in the axial direction of the bearing.

3. The laser-shock combined surface modification method for bearing raceways according to claim 2, characterized in that: The diameter of the oil storage pit is D0, and the axial distance between the oil storage pit closest to the raceway region and the edge of the raceway region is at least 2D0.

4. The laser-shock combined surface modification method for bearing raceways according to claim 3, characterized in that: The axial distance between two adjacent oil storage pits is at least 2D0.

5. The laser-shock combined surface modification method for bearing raceways according to any one of claims 1 to 4, characterized in that: The absorbent protective layer is made of black tape; the constraint layer is a water curtain formed by applying deionized water.

6. The laser-shock combined surface modification method for bearing raceways according to any one of claims 1 to 4, characterized in that: In step S4, the reserved machining allowance layer is removed by a fine grinding and polishing process to remove the machining allowance layer in the raceway area.

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