Spherical roller needle bearing based on vortex dynamics regulation and inner spherical surface micro-morphology reconstruction method

Abstract

The present application relates to the field of high-end bearing precision manufacturing, in particular to a spherical needle bearing based on eddy current dynamics regulation and a method for reconstructing the inner spherical surface micro morphology thereof, and its technical scheme is: the workpiece and the abrasive are loaded into a centrifugal liquid polishing device according to a preset volume ratio, and a working liquid is injected into the inner cavity of the centrifugal liquid polishing device, then a quantitative water-based grinding agent and a surface modification brightener are added in sequence; the centrifugal liquid polishing device is started and driven to rotate in an optimized speed range, so as to excite a three-dimensional spiral vortex field in the cavity, and the workpiece and the abrasive are subjected to random and low-stress micro-interaction in the field for a duration of T, the present application has the beneficial effects that the active and deep regulation of roughness skewness (Rsk) is realized, the excellent surface functional characteristics are obtained, and the perfect preservation of ultra-high geometric precision is realized, and compared with the traditional ultra-precision process, the processing efficiency is improved by more than 300%.

Description

Technical Field

[0001] This invention relates to the field of high-end bearing precision manufacturing, specifically to a spherical needle roller bearing based on eddy current dynamics control and a method for reconstructing the microstructure of its inner spherical surface. Background Technology

[0002] Against the backdrop of the development of electric drive systems for new energy vehicles towards higher speeds and higher power densities, the NVH (noise, vibration, and harshness) performance of transmission bearings has become a key bottleneck restricting the overall quality and reliability of vehicles. The microscopic geometry of the working surface inside the bearing, especially the high symmetry of the roughness profile distribution (i.e., roughness skewness Rsk), directly dominates the oil film formation capability, stress distribution uniformity, and excitation spectrum of vibration and noise under boundary lubrication conditions. Both theoretical analysis and engineering practice show that a surface with significant negative skewness (Rsk<0) and "few peaks and many valleys" is the ideal load-bearing surface for achieving low friction, rapid break-in, excellent anti-seizure properties, and low vibration and noise.

[0003] Currently, for spherical needle roller bearing inner rings with structural features such as hypercurvature, small bore diameter, and locking fillet, the final finishing of the inner spherical surface mainly relies on the following two types of technologies:

[0004] (1) Precision grinding method: As a deterministic removal process, its surface texture is strongly dependent on the shape and dressing state of the grinding wheel. When machining complex curved surfaces, the contact geometry between the grinding wheel and the workpiece is time-varying and the abrasive cutting trajectory is difficult to cover evenly, resulting in poor consistency of the micro-morphology in the axial and circumferential directions, large fluctuations in Rsk value, and often leaving directional grinding textures on the surface, which become a source of vibration excitation.

[0005] (2) Contact ultra-precision grinding method: Although it can improve surface roughness, it is difficult to maintain the conformal contact between the tool and the spherical surface stably, especially in the small curvature area and the rounded corner transition area, uneven pressure, over-grinding or under-grinding are prone to occur; in addition, this method is inefficient and highly dependent on the skills of workers, and cannot meet the stringent requirements of consistency, cycle time and cost for large-scale automated production.

[0006] In summary, both existing processing techniques for the inner ring of spherical needle roller bearings have inherent defects. Therefore, it is necessary to invent a novel method for reconstructing the microstructure of the inner spherical surface of spherical needle roller bearings based on eddy current dynamics control. Summary of the Invention

[0007] To achieve the above objectives, the present invention provides the following technical solution: a method for reconstructing the microstructure of the inner spherical surface of a spherical needle roller bearing based on eddy current dynamics control, comprising steps S1-S5:

[0008] S1. The workpiece that has been precision ground and abrasive of a specific size are loaded into the centrifugal liquid polishing device according to a preset volume ratio. The centrifugal liquid polishing device is closed, and working fluid is injected into the inner cavity of the centrifugal liquid polishing device. The liquid level is set to a specific range that overflows the abrasive accumulation layer. Then, a certain amount of water-based abrasive and surface-modifying brightener are added in sequence.

[0009] S2. Start the centrifugal liquid jetting device and drive its inner cavity to rotate within an optimized speed range, thereby generating a three-dimensional spiral vortex flow field in the cavity, so that the workpiece and the abrasive can perform random, low-stress micro-interactions with a duration of T in the flow field.

[0010] S3. Simultaneously activate the bubble generation mechanism inside the centrifugal liquid polishing device to generate bubbles at the bottom of the inner cavity of the centrifugal liquid polishing device, thereby mitigating the collision between the workpiece and the inner cavity of the centrifugal liquid polishing device under centrifugal action;

[0011] S4. After each consecutive processing cycle, 1.0 to 1.5 kg of new abrasive should be added to the inner cavity of the centrifugal jetting device to maintain the dynamic cutting activity of the process system.

[0012] S5. After processing, manually open the abrasive separation filter screen in the centrifugal liquid polishing device, continue to start the centrifugal liquid polishing device, drive its inner cavity to rotate and use centrifugal force to screen out the abrasive, so that the abrasive is separated from the workpiece, and finally take out the workpiece for cleaning and rust prevention treatment.

[0013] The abrasive particle size (d) and the minimum aperture (D) of the inner spherical surface of the workpiece satisfy: d ≈ (1 / 5 to 1 / 3)D; and the rotation speed, time and additive concentration work together to actively adjust the roughness skew (Rsk) of the inner spherical surface to the negative depth range, while maintaining its original geometric accuracy within the submicron tolerance range.

[0014] Preferably, the volume ratio in step S1 is workpiece volume: abrasive volume ≤ 1:2, and the total volume of the workpiece and abrasive does not exceed 50% of the effective volume of the cavity in the centrifugal liquid polishing device.

[0015] Preferably, in step S1, the water-based abrasive is an H316TA type additive with surface oxide layer softening function, and the addition amount is 20-30 mL / processing unit; the brightener is LM-182 type, and the addition amount is 100-150 mL / processing unit; the abrasive is equilateral triangular brown corundum abrasive.

[0016] Preferably, the rotational speed range in step S2 is 120–140 r / min, the processing time T is 30–35 minutes, and one processing cycle in step S3 is 30–35 minutes.

[0017] Preferably, the rust prevention treatment in step S5 uses a KSO40 rust inhibitor aqueous solution with a concentration of 1% to 2% and a pH value of 8 to 9. The workpiece is immersed in the KSO40 rust inhibitor aqueous solution for 5 to 30 minutes.

[0018] Preferably, the centrifugal liquid slurry device in S3 includes a liquid slurry tank base, a rotating outer cylinder rotatably mounted on the top surface of the liquid slurry tank base, a liquid slurry tank turntable fixedly mounted on the top surface of the rotating outer cylinder, a central sleeve mounted in the middle of the liquid slurry tank turntable, a motor base mounted at the bottom of the liquid slurry tank base, a motor mounted on a baffle plate of the motor base, a drive rod connected to the upper output end of the motor, and the drive rod passing through the motor base and the liquid slurry tank base and fixedly mounted at the center of the rotating outer cylinder and the central sleeve.

[0019] Preferably, a lower guide wall for the liquid jetting cylinder is installed around the top of the rotary table, and a number of fixing slots are provided on the top of the lower guide wall. An upper guide wall for the liquid jetting cylinder is installed above the lower guide wall. A fixing pin that can be inserted into the fixing slot is provided at the bottom of the upper guide wall. A handle is installed at the upper end of the upper guide wall.

[0020] Preferably, the abrasive separation filter screen in the centrifugal liquid blasting device is an abrasive screen, which is embedded in the upper part of the rotating outer cylinder. An outer sleeve is installed on the outside of the liquid blasting barrel base, and an abrasive discharge pipe is provided at the bottom of the outer sleeve. A liquid blasting barrel top cover is installed on the top of the outer sleeve and the upper wall of the liquid blasting barrel guide, and a feeding pipe is installed on the liquid blasting barrel top cover.

[0021] Preferably, the bubble generating mechanism of the centrifugal liquid splatter device includes a bubble generating valve, which is embedded in the rotating disk of the liquid splatter cylinder. The density of the bubble generating valves increases from the center of the rotating disk to the periphery. The top of the liquid splatter cylinder base is provided with a base groove, and the bottom of the rotating outer cylinder is provided with a plurality of air holes connecting the bubble generating valves and the base groove. An air injection pipe is installed at the bottom of the liquid splatter cylinder base, with the output end of the air injection pipe connected to the base groove and the input end connected to an air pump through a conduit.

[0022] The spherical needle roller bearing manufactured using the above method has the following inner spherical surface satisfaction:

[0023] a. The axial roughness skewness Rsnnk value is between -0.35 and -1.0;

[0024] b. The circumferential roughness skewness Rsk value is between -0.3 and -0.7;

[0025] c. Arithmetic mean roughness Ra ≤ 0.20 μm, maximum profile height Rz ≤ 1.3 μm.

[0026] The beneficial effects of this invention are:

[0027] (1) Active and depth control of roughness skew (Rsk) was achieved, and the axial Rsk of the inner spherical surface was successfully controlled in the negative range of -0.35 to -1.0 and the circumferential Rsk was controlled in the negative range of -0.3 to -0.7. The surface bearing peak density was reduced by more than 70%, which greatly improved the oil film retention capability of the bearing. Furthermore, while achieving a deep negative Rsk, the Ra value was further reduced to ≤0.20μm, Rz≤1.3μm, Wa≤0.24μm, and Wt≤1.5μm, achieving comprehensive optimization of morphology from micro to meso scale.

[0028] (2) While achieving excellent surface functional properties, it also perfectly preserves ultra-high geometric precision, breaking through the traditional processing paradox that "improving surface texture inevitably leads to a loss of geometric precision," specifically manifested as follows:

[0029] In terms of dimensional stability, the inner ball diameter change is ≤0.002mm, and the lock opening size change is ≤0.005mm;

[0030] In terms of shape accuracy, the inner spherical profile ΔCurp1 ≤ 0.004mm, and the profile with reference ΔCurp2 ≤ 0.008mm;

[0031] (3) Compared with traditional ultra-precision processes, the processing efficiency is increased by more than 300%, and the number of workpieces processed in a single clamping is large. The entire process parameters are digitally controlled, completely eliminating the dependence on manual operation skills. It is perfectly adapted to 24-hour automated continuous production lines and can meet the annual production needs of millions.

[0032] (4) Bearings treated by this method:

[0033] In terms of vibration and noise, the vibration value of Group Z is reduced by an average of 4-6 dB, reaching an industry-leading level of quietness.

[0034] In terms of fatigue life, under the same working conditions, the rated life L10 is increased by about 30%, and the reliability is significantly enhanced.

[0035] In terms of friction and wear, the starting friction torque is reduced by about 15%, the temperature rise is reduced, and the energy efficiency is improved. Attached Figure Description

[0036] Figure 1 The liquid polishing process flow diagram provided by this invention;

[0037] Figure 2 This is a main sectional view of the inner ring of the inner and outer spherical needle roller bearing provided by the present invention.

[0038] Figure 3 This is a schematic diagram of the workpiece rotation provided by the present invention;

[0039] Figure 4 This is a schematic diagram illustrating the working principle of the centrifugal liquid slurry device provided by the present invention.

[0040] Figure 5 This is a front view of the centrifugal liquid throwing device provided by the present invention;

[0041] Figure 6 A cross-sectional view of the centrifugal liquid throwing device provided by the present invention;

[0042] Figure 7 This is a schematic diagram of the removal of the upper wall of the liquid jetting cylinder provided by the present invention;

[0043] Figure 8 This is a schematic diagram of the abrasive screen in the open state provided by the present invention;

[0044] Figure 9 Provided by the present invention Figure 8 Detail image A;

[0045] Figure 10 A top view of the centrifugal liquid throwing device provided by the present invention;

[0046] Figure 11 This is a top view of the abrasive screen in the open state provided by the present invention;

[0047] Figure 12 The present invention provides a line graph showing the Rsk tilt state before liquid polishing;

[0048] Figure 13 The line graph showing the Rsk skew state after liquid polishing provided by this invention.

[0049] In the diagram: 111. Liquid polishing barrel base; 112. Outer sleeve; 113. Abrasive discharge pipe; 114. Base groove; 115. Air injection pipe; 121. Liquid polishing barrel top cover; 122. Feeding pipe; 131. Rotating outer cylinder; 132. Abrasive screen; 133. Air hole; 141. Motor base; 142. Motor; 143. Drive rod; 151. Liquid polishing barrel rotary table; 152. Bubble generating valve; 153. Liquid polishing barrel lower guide wall; 154. Fixing slot; 155. Liquid polishing barrel upper guide wall; 156. Fixing pin; 157. Central sleeve; 158. Handle; 16. Workpiece; 17. Abrasive. Detailed Implementation

[0050] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0051] like Figure 1 - Figure 4As shown, the method for reconstructing the microstructure of the inner spherical surface of a spherical needle roller bearing based on eddy current dynamics control is based on a multi-parameter collaborative control process system, including steps S1-S5:

[0052] S1. The workpiece 16 that has been precision ground and the abrasive 17 of a specific size are loaded into the centrifugal liquid polishing device according to a preset volume ratio. The centrifugal liquid polishing device is closed, and the working fluid is injected into the inner cavity of the centrifugal liquid polishing device. The liquid level is set to a specific range that overflows the abrasive accumulation layer. Then, a certain amount of water-based abrasive and surface-modifying brightener are added in sequence.

[0053] S2. Start the centrifugal liquid blasting device and drive its inner cavity to rotate within an optimized speed range, thereby generating a three-dimensional spiral vortex flow field in the cavity, so that the workpiece and the abrasive can engage in random, low-stress micro-interactions with a duration of T in the flow field.

[0054] S3. Simultaneously activate the bubble generation mechanism inside the centrifugal liquid polishing device to generate bubbles at the bottom of the inner cavity of the centrifugal liquid polishing device, thereby mitigating the collision between the workpiece 16 and the inner cavity of the centrifugal liquid polishing device under centrifugal action.

[0055] S4. After each consecutive processing cycle, 1.0 to 1.5 kg of new abrasive should be added to the inner cavity of the centrifugal jetting device to maintain the dynamic cutting activity of the process system.

[0056] S5. After processing, manually open the abrasive separation filter screen in the centrifugal liquid polishing device, continue to start the centrifugal liquid polishing device, drive its inner cavity to rotate and use centrifugal force to screen out the abrasive 17, so that the abrasive 17 is separated from the workpiece 16, and finally take out the workpiece 16 for cleaning and rust prevention treatment.

[0057] Among them, the particle size d of abrasive 17 and the minimum aperture D of the inner spherical surface of workpiece 16 satisfy: d ≈ (1 / 5~1 / 3)D; and the rotation speed, time and additive concentration work together to actively adjust the roughness skew Rsk of the inner spherical surface to the negative depth range, while maintaining its original geometric accuracy within the submicron tolerance range.

[0058] In the above embodiments, it should be noted that the core process system of this method includes an abrasive system, a chemical media system, key process parameter control, and a centrifugal liquid sintering device, as detailed below:

[0059] (1) Abrasive system:

[0060] The abrasive 17 is made of high-toughness, self-sharpening, and equilateral triangular brown corundum abrasive, which combines excellent rolling flow, stable cutting edges, and anti-breakage ability. The grit size of the abrasive 17 is preferably 120 grit, and the maximum outer circle diameter of each abrasive 17 must be strictly controlled to be 1 / 5 to 1 / 3 of the minimum aperture of the spherical surface inside the workpiece 16. This ratio range is a verified key parameter that ensures that the abrasive can flow fully and make effective contact in the complex spherical cavity, and that the abrasive can produce effective micro-cutting in the complex curved flow channel without clogging or ineffective collisions. This is a key hydrodynamic threshold that can be met. It also avoids jamming due to excessive size or low grinding efficiency due to excessively small size.

[0061] Dynamic balancing maintenance: After each standard machining cycle (30-35 minutes), 1.0-1.5 kg of new abrasive is added to the liquid polishing system to counteract abrasive passivation and maintain the dynamic stability of the system's cutting capability.

[0062] (2) Chemical media system:

[0063] The water-based abrasive is an H316TA type additive with surface oxide layer softening function. Its core function is to selectively soften the extremely thin oxide layer and microscopic protruding peaks on the workpiece surface, significantly reducing its micro-yield strength, making subsequent micromechanical removal more likely to occur on the "peaks" rather than the "valleys", thereby actively promoting the formation of negative skew morphology; the amount of water-based abrasive added is 20-30 mL / processing unit.

[0064] The brightener is LM-182, containing special surfactants and corrosion inhibitors. Its functions are: ① High-efficiency cleaning, removing residual grease and particles from the workpiece surface; ② Surface modification, forming a temporary protective film on the surface of new metal to enhance gloss; ③ Assisting in rust prevention; The amount of brightener added is 100-150 mL / processing unit.

[0065] (3) Control of key process parameters:

[0066] This invention does not simply set a few parameters, but establishes a set of mutually coupled "process parameter matrices" that jointly determine the final surface morphology:

[0067] a. Loading procedure: The volume ratio of workpiece 16 to abrasive 17 should be ≤ 1:2, and the total volume of workpiece 16 and abrasive 17 should not exceed 50% of the effective volume of the cavity in the centrifugal liquid jetting device; to ensure that the medium has sufficient flow space and kinetic energy.

[0068] b. Liquid-solid environment: Inject clean water, and the liquid level should be 10-15 mm above the static abrasive deposit layer to form a stable fluidized working environment;

[0069] c. Dynamic parameters: The rotational speed of the inner cavity of the centrifugal liquid polishing device is set to 130 r / min (with a process window adjustment of ±10 r / min). This speed is optimized to achieve the best balance between generating sufficient grinding eddy current intensity and ensuring workpiece safety and accuracy retention.

[0070] d. Processing time: The processing time T is 30 to 35 minutes. This time window is sufficient to stably correct the surface Rsk value to the target negative range, while avoiding dimensional changes exceeding tolerance due to over-processing.

[0071] e. Post-treatment: After processing, the workpiece is centrifuged and rinsed with clean water, and then immediately immersed in KSO40 water-based rust inhibitor with a concentration of 1% to 2% and a pH value of 8 to 9 for neutralization and passivation treatment, and then dried. Note that the soaking time should not exceed 30 minutes.

[0072] Through the aforementioned core process system, this invention achieves comprehensive and superior effects that traditional methods cannot match:

[0073] (1) Active and depth control of roughness skew (Rsk) was achieved, and the axial Rsk of the inner spherical surface was successfully controlled in the negative range of -0.35 to -1.0 and the circumferential Rsk was controlled in the negative range of -0.3 to -0.7. The surface bearing peak density was reduced by more than 70%, which greatly improved the oil film retention capability of the bearing. Furthermore, while achieving a deep negative Rsk, the Ra value was further reduced to ≤0.20μm, Rz≤1.3μm, Wa≤0.24μm, and Wt≤1.5μm, achieving comprehensive optimization of morphology from micro to meso scale.

[0074] (2) While achieving excellent surface functional properties, it also perfectly preserves ultra-high geometric precision, breaking through the traditional processing paradox that "improving surface texture inevitably leads to a loss of geometric precision," specifically manifested as follows:

[0075] In terms of dimensional stability, the inner ball diameter change is ≤0.002mm, and the lock opening size change is ≤0.005mm;

[0076] In terms of shape accuracy, the inner spherical profile ΔCurp1 ≤ 0.004mm, and the profile with reference ΔCurp2 ≤ 0.008mm;

[0077] (3) Compared with traditional ultra-precision processes, the processing efficiency is increased by more than 300%, and the number of workpieces processed in a single clamping is large. The entire process parameters are digitally controlled, completely eliminating the dependence on manual operation skills. It is perfectly adapted to 24-hour automated continuous production lines and can meet the annual production needs of millions.

[0078] (4) Bearings treated by this method:

[0079] In terms of vibration and noise, the vibration value of Group Z is reduced by an average of 4-6 dB, reaching an industry-leading level of quietness.

[0080] In terms of fatigue life, under the same working conditions, the rated life L10 is increased by about 30%, and the reliability is significantly enhanced.

[0081] In terms of friction and wear, the starting friction torque is reduced by about 15%, the temperature rise is reduced, and the energy efficiency is improved.

[0082] The present invention will be further described in detail below with reference to specific embodiments. The following embodiments are used to illustrate the present invention and are not intended to limit its scope of protection.

[0083] Example: Machining the inner ring of a spherical needle roller bearing for a certain series of new energy vehicle drive shafts;

[0084] (1) Basic conditions and parameter settings (taking a workpiece with an inner diameter of Φ22.101mm as an example):

[0085] Equipment: Linked centrifugal liquid slurry mill, PU-lined chamber volume approximately 300L;

[0086] Abrasive: 120 equilateral triangular brown corundum, approximately 7mm in size (about 1 / 3.2 of the inner diameter of the workpiece).

[0087] Chemical agents: abrasive H316TA, brightener LM-182, rust inhibitor KSO40;

[0088] Process parameters:

[0089] a. Workpiece to abrasive volume ratio: ~1:1.8;

[0090] b. Liquid level height: 12mm above the abrasive layer;

[0091] c. Abrasive addition amount: 25 mL / chamber;

[0092] d. Brightener addition amount: 120 mL / chamber;

[0093] e. Liquid blasting cylinder rotation speed: 130 r / min;

[0094] f. Processing time: 32 minutes;

[0095] g. Rust prevention treatment: Immersion in 1.5% KSO40 aqueous solution;

[0096] (2) Operation procedure:

[0097] Feeding: Approximately 110 kg of abrasive and a batch of workpieces are loaded into the feeding system in proportion and automatically fed into the liquid polishing chamber;

[0098] Solution preparation: Automatically inject clean water to the set level, then add H316TA abrasive and LM-182 brightener according to the specified amount;

[0099] Liquid polishing: Start the equipment and run it for 32 minutes at the set parameters;

[0100] Separation and post-processing: The program automatically completes drainage, separation of workpiece and abrasive, and discharge; the workpiece is conveyed into the anti-rust tank for treatment, and then taken out and dried;

[0101] Quality inspection: High-precision profilometers and measuring instruments are used to perform full-item inspection on the processed workpieces;

[0102] (3) Implementation effect data

[0103] The table below shows typical test data for workpieces with different inner diameters processed using the same core process parameters, demonstrating the wide applicability and stability of this method:

[0104]

[0105] Note: The same core process parameters (abrasive ratio, rotation speed, time, additive ratio) are used in the implementation, with only the total load adjusted slightly due to the workpiece size; "before implementation" in the table refers to the state after precision grinding and before liquid polishing; "≤" indicates that the test result meets the upper limit value.

[0106] like Figure 4 - Figure 11As shown, the method for reconstructing the microstructure of the inner spherical surface of a spherical needle roller bearing based on eddy current dynamics control also includes the following: the centrifugal liquid blasting device in S3 includes a liquid blasting tank base 111, a rotating outer cylinder 131 rotatably mounted on the top surface of the liquid blasting tank base 111, a liquid blasting tank rotary disk 151 fixedly mounted on the top surface of the rotating outer cylinder 131, a central sleeve 157 installed in the middle of the liquid blasting tank rotary disk 151, a motor base 141 installed at the bottom of the liquid blasting tank base 111, a motor 142 mounted on the baffle of the motor base 141, and an upper output of the motor 142. The output end is connected to the drive rod 143, which passes through the motor base 141 and the liquid jetting tank base 111 and is fixedly installed in the center of the rotating outer cylinder 131 and the central sleeve 157. A lower liquid jetting tank guide wall 153 is installed around the top of the liquid jetting tank rotary disk 151. Several fixing slots 154 are provided at the top of the lower liquid jetting tank guide wall 153. An upper liquid jetting tank guide wall 155 is installed above the lower liquid jetting tank guide wall 153. A fixing pin 156, capable of inserting into the fixing slots 154, is provided at the bottom of the upper liquid jetting tank guide wall 155. A handle 158 is installed at the upper end of the upper wall 155 of the centrifugal liquid slurry device. The abrasive separation filter screen inside the centrifugal liquid slurry device is an abrasive screen 132, which is embedded in the upper part of the rotating outer cylinder 131. An outer sleeve 112 is installed on the outside of the liquid slurry tank base 111. An abrasive discharge pipe 113 is provided at the bottom of the outer sleeve 112. A liquid slurry tank top cover 121 is installed on the top of the outer sleeve 112 and the upper wall 155 of the liquid slurry tank. A feeding pipe 122 is installed on the liquid slurry tank top cover 121. The bubble generation mechanism of the centrifugal liquid slurry device includes a gas... A bubble generating valve 152 is embedded in the rotary table 151 of the liquid blasting cylinder. The density of the bubble generating valves 152 increases from the center of the rotary table 151 to the periphery. A base groove 114 is provided on the top of the liquid blasting cylinder base 111. Several air holes 133 connecting the bubble generating valves 152 and the base groove 114 are provided on the bottom of the rotating outer cylinder 131. An air injection pipe 115 is installed on the bottom of the liquid blasting cylinder base 111. The output end of the air injection pipe 115 is connected to the base groove 114, and the input end is connected to the air pump through a conduit.

[0107] In the above embodiments, it should be noted that the motor 142 is connected to an external power supply and a microcontroller. The microcontroller is used for timing, calculation and control logic. Common choices include Arduino, Raspberry Pi, PLC (Programmable Logic Controller) or other industrial controllers.

[0108] The microcontroller drives the motor 142 to rotate the drive rod 143, which in turn drives the outer cylinder 131, the central sleeve 157, and the rotary disk 151 of the liquid polishing cylinder to rotate, thereby creating a spiral vortex effect within the rotary disk 151 and the lower guide wall 153 of the liquid polishing cylinder. In this three-dimensional vortex, the workpiece 16 and the abrasive 17 not only revolve with the cylinder but also undergo complex rotation and tumbling due to mutual collisions, friction, and fluid action. This achieves non-directional, full-coverage, flexible, and uniform micro-grinding of the spherical surface within the workpiece 16. This method of action can flatten micro-peaks in all directions without discrimination, while avoiding excessive impact on valleys and the substrate or the generation of new directional textures. This is the physical basis for achieving uniform negative Rsk.

[0109] Both the lower wall 153 and the upper wall 155 of the liquid jetting cylinder are provided with longitudinal guide grooves. Under high-speed rotation conditions, the guide grooves can play a straightening role, reduce the intensity of turbulence, and make the spiral vortex more stable, thereby improving the overall working performance and safety.

[0110] The aperture of the abrasive screen 132 is smaller than the outer diameter of the workpiece 16, and the aperture of the abrasive screen 132 is larger than the outer diameter of the abrasive 17. The centrifugal force generated by the rotation of the rotary disc 151 and the lower guide wall 153 of the liquid polishing cylinder throws the abrasive 17 to the outside and, under the action of the abrasive screen 132, sieves the abrasive 17 into the outer sleeve 112. Finally, it is discharged through the abrasive discharge pipe 113 at the bottom of the outer sleeve 112. The working fluid, water-based abrasive, surface modifier and brightener, and supplementary abrasive are injected through the feeding pipe 122.

[0111] Air is injected into the air injection pipe 115 by an air pump. The air enters the base groove 114 through the air injection pipe 115 and then passes through the air hole 133 to be introduced into the bubble generating valve 152. The upper end of the bubble generating valve 152 adopts a tension microporous structure. The gas enters the liquid through the microporous structure and forms small bubbles. At the same time, the design of the bubble generating valve 152 with the density increasing from the center to the periphery makes the bubbles closer to the side wall of the liquid polishing tank more dense and the bubbles farther away from the side wall more sparse, so as to reduce the collision between the workpiece 16 and the side wall of the liquid polishing tank under centrifugal force.

[0112] Analysis of the design principle of bubble generating valve 152:

[0113] (1) Buoyancy and flow of bubbles: Dense bubbles can generate stronger buoyancy and upward flow in the area near the side wall, which helps to alleviate the lateral centrifugal force on the inner ring of the bearing, making it more stably suspended in the liquid.

[0114] (2) Fluid dynamics effect: By setting up a bubble generating device, the fluid velocity near the side wall is faster, which can form a certain lateral flow, change the movement trajectory of the inner circle, and reduce the probability of it contacting the barrel wall.

[0115] (3) Effect of rising bubbles: Bubbles near the sidewall generate more upward flow, which can provide more buoyancy to the inner ring, increase its stability in the liquid, and thus prevent it from adhering to the sidewall due to centrifugal force.

[0116] like Figure 1 , Figure 12 and Figure 13 As shown, the inner ring of the spherical needle roller bearing manufactured using the above method satisfies the following requirements for the inner spherical surface:

[0117] a. The axial roughness skewness Rsk value is between -0.35 and -1.0;

[0118] b. The circumferential roughness skewness Rsk value is between -0.3 and -0.7;

[0119] c. Arithmetic mean roughness Ra ≤ 0.20 μm, maximum profile height Rz ≤ 1.3 μm.

[0120] In the above embodiments, it should be noted that before processing, the workpiece 16 is the inner ring of a spherical needle roller bearing that has undergone final grinding of the inner spherical surface. Its inner spherical surface is usually a complex curved surface with double curvature tangential connection and a locking structure. The curved surface connection adopts a rounded transition with a radius of 0.3 to 0.5 mm. After grinding, the workpiece has met the basic dimensional and shape tolerances, and the surface roughness Ra is usually between 0.20 and 0.25 μm. It is waiting to achieve functional micromorphological reconstruction through this method.

[0121] like Figure 12 The display shows that the contour curve of workpiece 16 before liquid polishing should exhibit numerous sharp peaks, with Rsk being positive or close to zero; for example... Figure 13 The display shows that after liquid polishing, the contour curve of workpiece 16 should become smooth, with significantly reduced and rounded peaks, relatively more and gentler troughs, and Rsk in a negative skew state.

[0122] The spherical needle roller bearing, which is composed of the machined workpiece 16, exhibits a vibration acceleration value at least 3 dB lower than that of a similar bearing with a conventionally ultra-precision machined inner ring in standard NVH testing.

[0123] The above description is merely a preferred embodiment of the present invention. Any person skilled in the art can modify the present invention or modify it into an equivalent technical solution using the technical solutions described above. Therefore, any simple modifications or equivalent substitutions made based on the technical solutions of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A method for reconstructing the microstructure of the inner spherical surface of a spherical needle roller bearing based on eddy current dynamics control, characterized in that, The method is based on a multi-parameter collaborative control process system, including steps S1-S5: S1. Load the precision-ground workpiece and abrasive into the centrifugal liquid polishing device according to a preset volume ratio, close the centrifugal liquid polishing device, and inject working fluid into the inner cavity of the centrifugal liquid polishing device. The liquid level is set to cover the abrasive accumulation layer by 10-15 mm. Then, add a certain amount of water-based abrasive and surface-modifying brightener in sequence. S2. Start the centrifugal liquid jetting device and drive its inner cavity to rotate within an optimized speed range, thereby generating a three-dimensional spiral vortex flow field in the cavity, so that the workpiece and the abrasive can perform random, low-stress micro-interactions with a duration of T in the flow field. S3. Simultaneously activate the bubble generation mechanism inside the centrifugal liquid polishing device to generate bubbles at the bottom of the inner cavity of the centrifugal liquid polishing device, thereby mitigating the collision between the workpiece and the inner cavity of the centrifugal liquid polishing device under centrifugal action; S4. After each consecutive processing cycle, 1.0 to 1.5 kg of new abrasive should be added to the inner cavity of the centrifugal jetting device to maintain the dynamic cutting activity of the process system. S5. After processing, manually open the abrasive separation filter screen in the centrifugal liquid polishing device, continue to start the centrifugal liquid polishing device, drive its inner cavity to rotate and use centrifugal force to screen out the abrasive, so that the abrasive is separated from the workpiece, and finally take out the workpiece for cleaning and rust prevention treatment. Wherein, the particle size d of the abrasive and the minimum aperture D of the inner spherical surface of the workpiece satisfy: d ≈ (1 / 5~1 / 3)D; and the combined effect of the rotation speed, time and additive concentration can actively adjust the roughness skew Rsk of the inner spherical surface to the negative depth range, while maintaining its original geometric accuracy within the submicron tolerance range; the volume ratio in step S1 is workpiece volume: abrasive volume ≤ 1:2, and the total volume of the workpiece and abrasive does not exceed 50% of the effective volume of the cavity in the centrifugal liquid polishing device.

2. The method for reconstructing the microstructure of the inner spherical surface of a spherical needle roller bearing based on eddy current dynamics control according to claim 1, characterized in that: In step S1, the water-based abrasive is H316TA type additive with surface oxide layer softening function, and the addition amount is 20-30 mL / processing unit; the brightener is LM-182 type, and the addition amount is 100-150 mL / processing unit; the abrasive is equilateral triangular brown corundum abrasive.

3. The method for reconstructing the microstructure of the inner spherical surface of a spherical needle roller bearing based on eddy current dynamics control according to claim 1, characterized in that: The rotational speed range in step S2 is 120–140 r / min, and the processing time T is 30–35 minutes. One processing cycle in step S3 is 30–35 minutes.

4. The method for reconstructing the microstructure of the inner spherical surface of a spherical needle roller bearing based on eddy current dynamics control according to claim 1, characterized in that: The rust prevention treatment in step S5 uses a KSO40 rust inhibitor aqueous solution with a concentration of 1% to 2% and a pH value of 8 to 9. The workpiece is immersed in the KSO40 rust inhibitor aqueous solution for 5 to 30 minutes.

5. The method for reconstructing the microstructure of the inner spherical surface of a spherical needle roller bearing based on eddy current dynamics control according to claim 1, characterized in that: The centrifugal liquid slurry device in S3 includes a liquid slurry tank base, a rotating outer cylinder rotatably mounted on the top surface of the liquid slurry tank base, a liquid slurry tank turntable fixedly mounted on the top surface of the rotating outer cylinder, a central sleeve mounted in the middle of the liquid slurry tank turntable, a motor base mounted at the bottom of the liquid slurry tank base, a motor mounted at the bottom of the motor base, a drive rod connected to the upper output end of the motor, and the drive rod passing through the motor base and the liquid slurry tank base and fixedly mounted at the center of the rotating outer cylinder and the central sleeve.

6. The method for reconstructing the microstructure of the inner spherical surface of a spherical needle roller bearing based on eddy current dynamics control according to claim 5, characterized in that: The liquid jetting cylinder rotary table is equipped with a liquid jetting cylinder guide lower wall around its top. The top of the liquid jetting cylinder guide lower wall is provided with several fixing slots. The liquid jetting cylinder guide upper wall is installed above the liquid jetting cylinder guide lower wall. The bottom of the liquid jetting cylinder guide upper wall is provided with a fixing pin that can be inserted into the fixing slots. A handle is installed at the upper end of the liquid jetting cylinder guide upper wall.

7. The method for reconstructing the microstructure of the inner spherical surface of a spherical needle roller bearing based on eddy current dynamics control according to claim 6, characterized in that: The abrasive separation filter screen in the centrifugal liquid blasting device is an abrasive screen. The abrasive screen is embedded in the upper part of the rotating outer cylinder. An outer sleeve is installed on the outside of the liquid blasting barrel base. An abrasive discharge pipe is provided at the bottom of the outer sleeve. A liquid blasting barrel top cover is installed on the top of the outer sleeve and the upper wall of the liquid blasting barrel guide. A feeding pipe is installed on the liquid blasting barrel top cover.

8. The method for reconstructing the microstructure of the inner spherical surface of a spherical needle roller bearing based on eddy current dynamics control according to claim 7, characterized in that: The bubble generating mechanism of the centrifugal liquid splatter device includes a bubble generating valve, which is embedded in the rotating disk of the liquid splatter cylinder. The density of the bubble generating valves increases from the center of the rotating disk to the periphery. The top of the liquid splatter cylinder base is provided with a base groove, and the bottom of the rotating outer cylinder is provided with several air holes that connect the bubble generating valves and the base groove. An air injection pipe is installed at the bottom of the liquid splatter cylinder base. The output end of the air injection pipe is connected to the base groove, and the input end is connected to an air pump through a conduit.

9. A spherical needle roller bearing manufactured using the method described in any one of claims 1 to 8, characterized in that: The inner spherical surface of the bearing satisfies: a. The axial roughness skewness Rsnnk value is between -0.35 and -1.0; b. The circumferential roughness skewness Rsk value is between -0.3 and -0.7; c. Arithmetic mean roughness Ra ≤ 0.20 μm, maximum profile height Rz ≤ 1.3 μm.

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