Roller machining method for improving lubricating performance of flange of large tapered roller bearing

Abstract

The invention provides a roller machining method for improving the lubricating performance of a flange of a large-scale tapered roller bearing, which comprises the following steps: carrying out heat treatment on a semi-finished tapered roller product, and then turning and supergrinding to finish the machining of the tapered roller, the machining process of the turning procedure comprises the steps that according to the rotating direction of the roller working in the bearing, integrated turning is conducted on the outer circle and the spherical base face of the roller in a specified turning mode; after turning is completed; according to the working state of the tapered roller in the bearing, the outer circle face and the spherical base face of the roller are turned in a specified cutting mode, so that the outer diameter of the roller forms the grains in the specified rotating direction, and therefore when the roller works, lubricating oil or lubricating grease in the bearing moves in the direction of the inner ring flange along the grains; the problems of serious frictional wear, burn and stress concentration between a roller ball base surface and an inner ring flange are relieved, and the service life of the bearing is prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of roller processing of large tapered roller bearings, and in particular relates to a roller processing method for improving the lubrication performance of the ribs of large tapered roller bearings. Background Art

[0002] Bearings are one of the most commonly used parts in the machinery industry, and their mechanical properties directly affect the performance of mechanical equipment. Among them, tapered roller bearings are widely used in wind power generation, automobiles, rolling mills, mining, metallurgy, petroleum, plastic machinery and other industries due to their good load-bearing performance, high limit speed ratio and long service life.

[0003] The precision of the tapered roller inside the bearing is a key factor that restricts the service life of the bearing. The traditional processing of tapered rollers includes forging, rough turning, fine turning, heat treatment, rough grinding, fine grinding and super fine grinding. That is, after heat treatment, the tapered roller needs to be rough ground and fine ground on different grinders. However, due to the large size of the roller, high precision requirements, high reliability requirements and long service life, this method cannot ensure that the actual accuracy of the roller reaches the design accuracy. This is because after heat treatment, the roller needs to be ground on the outer diameter surface and the ball base surface separately on different grinders with different clamping and positioning methods. After processing, the runout of the ball base surface of the finished roller to the outer diameter surface does not meet the design requirements. After actual testing, the runout can only reach about 0.05mm, which belongs to Grade III accuracy, far from the quality requirements of Grade I roller accuracy.

[0004] In order to solve the above problems, a Chinese patent with application number 202210647904.8 discloses a method for processing tapered rollers of high-power wind turbine tapered roller bearings. The rough grinding and fine grinding processes of the existing tapered rollers after heat treatment are replaced by turning. That is, a high-precision CNC lathe is used to clamp and position the rollers once, and the outer diameter surface and the end spherical base surface of the rollers are turned in this positioning state. After the rollers are processed, the runout of the spherical base surface relative to the outer diameter surface can reach 0.002 mm, meeting the precision requirements of Class I rollers.

[0005] However, although the above processing method can solve the problem of tapered roller processing accuracy, the abnormal contact between the large rib of the inner ring of the bearing and the base surface of the roller ball during the use of the roller also affects the service life of the bearing. This is because the base surface of the roller ball and the large rib of the inner ring are both working surfaces. They will produce sliding friction during operation. When poor lubrication occurs, serious friction, wear, burns and stress concentration problems will occur between the two, which will lead to early fatigue peeling and failure of the bearing raceway, roller ball base surface and outer diameter. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a roller processing method for improving the lubrication performance of the rib of a large tapered roller bearing. According to the working state of the tapered roller inside the bearing, the outer cylindrical surface and the ball base surface of the roller are turned using a specified cutting method, so that the outer diameter of the roller forms a pattern with a specified rotation direction. In this way, when the roller is working, the lubricating oil or grease inside the bearing can move along the pattern toward the inner ring rib, so as to alleviate the problems of severe friction, wear, burns and stress concentration between the roller ball base surface and the inner ring rib, thereby extending the service life of the bearing.

[0007] The technical solution adopted by the present invention is: a roller processing method for improving the lubrication performance of the rib of a large tapered roller bearing, comprising: performing turning and super-fine grinding on the semi-finished tapered roller after heat treatment, thereby completing the processing of the tapered roller; The turning process is as follows: according to the rotation direction of the roller when working in the bearing, the outer circle of the roller and the ball base surface are integrally turned in a specified turning method; after the turning is completed, the outer circle surface of the roller is enlarged to form a texture with a specified rotation direction, so that when the roller rotates during operation, the lubricant entering the bearing moves along the texture toward the inner ring rib.

[0008] The specified turning method is: after the roller is clamped on the lathe chuck, the lathe spindle rotates forward and the turning tool moves from the tailstock to the headstock of the machine tool; or the lathe spindle rotates forward and the turning tool moves from the headstock to the tailstock of the machine tool.

[0009] The bearing is a single-row tapered roller bearing, a double-row tapered roller bearing or a four-row tapered roller bearing.

[0010] The texture formed after the outer cylindrical surface of the roller is enlarged has a left-handed or right-handed texture.

[0011] The roller undergoes raw material cutting, forging, roller rough turning and heat treatment processes in sequence before turning and superfinishing processes.

[0012] After the roller is processed by superfine grinding, the surface roughness of the roller is 0.4-0.2 μm.

[0013] The lubricant is lubricating oil or lubricating grease.

[0014] The beneficial effects of the present invention are: The present invention uses a specified cutting method to turn the outer cylindrical surface and the ball base surface of the roller according to the working state of the tapered roller inside the bearing, so that the outer diameter of the roller forms a pattern with a specified rotation direction. In this way, when the roller is working, the lubricating oil or grease inside the bearing can move along the pattern toward the inner ring rib, so as to alleviate the problems of severe friction, wear, burns and stress concentration between the roller ball base surface and the inner ring rib, thereby extending the service life of the bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a cross-sectional view of a single-row tapered roller bearing of the present invention; Figure 2 is a cross-sectional view of a double-row tapered roller bearing of the present invention; Figure 3 It is the structural diagram of the tapered roller of the present invention.

[0016] Markings in the figure: 1. Outer ring; 2. Inner ring; 3. Roller; 4. Rib; 5. Texture. Implementation

[0017] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0018] As shown in the figure, a roller processing method for improving the lubrication performance of the rib of a large tapered roller bearing includes raw material cutting, forging, roller rough turning and heat treatment processes of the tapered roller. The above processing steps belong to conventional technical means in the prior art, and its processing principle and processing are not described in detail here; after the semi-finished product processing of the above roller 3 is completed, turning and super-finishing grinding are carried out. This turning process after heat treatment is fine turning. After the fine turning and super-finishing grinding processes are completed, the entire processing process of the tapered roller 3 is completed.

[0019] Among them, the turning process after heat treatment is: according to the rotation direction and installation position of the roller 3 when working in the bearing, the outer circle and the spherical base surface of the roller 3 are turned in an integrated manner in a specified turning method. This integrated turning method means that the roller 3 is clamped on the lathe chuck, and the outer circle and the spherical base surface of the roller 3 are turned while the roller 3 is always clamped. This integrated turning process allows the runout of the spherical base surface relative to the outer diameter surface to reach 0.002mm, reaching the accuracy standard of the grade I roller 3 and improving the accuracy grade of the tapered roller 3.

[0020] The rotation direction of the roller 3 in the bearing is the self-rotation direction of the roller 3. Since the tapered roller bearing can be divided into single-row tapered roller bearings (such as Figure 1 As shown), double row tapered roller 3 (as shown Figure 2As shown in the figure) and four-row tapered roller bearings (not shown in the figure), single-row tapered roller bearings are taken as an example. Single-row tapered roller bearings are usually used in pairs. The installation directions of the two bearings used in pairs on the shaft are opposite, which results in the opposite orientation of the spherical base surfaces of the tapered rollers 3 (i.e., the directions of the large and small heads of the rollers 3 are opposite). Since the inner rings 2 of the two single-row tapered roller bearings rotate in the same direction, when the rollers 3 are working, the tapered rollers 3 on the two single-row tapered roller bearings rotate in different directions (here, the viewing angle is the small head end face of the rollers 3). According to the different rotation directions of different rollers 3 at work, the rollers 3 are selectively turned according to the specified cutting method. Similarly, when double-row tapered roller bearings and four-row tapered roller bearings are working, different rollers 3 also rotate in different directions.

[0021] Specifically, the above-specified turning method is: after the roller 3 is clamped on the lathe chuck, the lathe spindle drives the chuck to rotate forward, and the turning tool moves from the tailstock to the headstock of the machine tool, and the outer circle of the roller 3 processed according to this turning method has a right-handed texture 5; or the lathe spindle rotates forward, and the turning tool moves from the headstock to the tailstock of the machine tool, and the outer circle of the roller 3 processed according to this turning method has a left-handed texture 5. The turning method in this example is not limited to the above two methods, and the lathe spindle can also be reversed to achieve left-handed or right-handed texture 5 on the outer circle surface of the roller 3 according to different moving trajectories of the turning tool.

[0022] Among them, the above-mentioned left-handed texture 5 and right-handed texture 5 refer to the micro-geometric shape composed of small spacing and peaks and valleys formed on the outer cylindrical surface of the roller 3 after turning is completed and the product roughness requirements are met. During turning, the left-handed or right-handed texture 5 is formed by turning as required in advance according to the rotation direction of the roller 3 and the position of the inner ring 2 flange 4.

[0023] The above-mentioned lines 5 cannot be observed with the naked eye and need to be observed with a high-power magnifying glass, such as Figure 3 As shown, the texture 5 on the outer circumferential surface of the roller 3 is right-handed.

[0024] After turning is completed, the outer surface of the roller 3 is enlarged to form a pattern 5 of a specified rotation direction (left-hand or right-hand), so that when the roller 3 rotates, the lubricant entering the bearing moves along the pattern 5 toward the rib 4 of the inner ring 2. Specifically, the lubricant can be lubricating oil or grease according to different bearing working conditions.

[0025] The lubricant is moved along the groove 5 toward the inner ring 2 flange 4, mainly to allow the lubricant to enter the position where the ball base surface of the roller 3 and the inner ring 2 flange 4 are located when the roller 3 rotates, thereby reducing the sliding friction between the ball base surface of the roller 3 and the inner ring 2 flange 4, thereby preventing burns, fatigue, and stress concentration problems in this area, thereby extending the service life of the bearing.

[0026] The above principle is: since the outer surface of the roller 3 has a texture 5 with a specified rotation direction, the lubricant can enter the recessed groove of the texture 5 (the recessed groove is a thread groove with a specified rotation direction). When the roller 3 rotates, the lubricant is pushed to the position between the ball base surface and the inner ring 2 rib 4 in a manner similar to spiral conveying.

[0027] After the roller 3 is super-finished, its surface roughness is 0.4-0.2μm. The super-finishing of the roller 3 can further improve the roughness of the surface of the roller 3, and can remove the parts with higher peaks in the outer circle texture 5 of the roller 3, making the surface of the roller 3 smoother, but the texture 5 still exists. After the roller 3 is super-finished, the roller 3 is installed in the specified position of the bearing, which can meet the requirement that when the roller 3 rotates, the lubricant moves along the texture 5 toward the inner ring 2 rib 4.

[0028] As an embodiment of this solution, Figure 1 As shown, the bearing is a single-row tapered roller bearing. Assuming that the rotation direction of roller 3 in the bearing is as shown by the arrow (when facing the small end of roller 3, roller 3 rotates clockwise), and the position of inner ring 2 rib 4 and the ball base surface is at the right end of the figure, during turning, roller 3 needs to be turned on the outer diameter surface of roller 3 in a right-handed pattern 5, so that when the bearing is working, the lubricant entering between inner ring 2 and outer ring 1 can gradually move toward the ball base surface and rib 4.

[0029] As another embodiment of this solution, Figure 2 As shown, the bearing is a double-row tapered roller bearing. Assuming that the inner ring 2 rotates counterclockwise when viewed from left to right, the rotation directions of the rollers 3 on both sides are shown by the arrows in the figure. Since the contact position between the ball base surface of the left roller 3 and the inner ring 2 flange 4 is on the left side of the roller 3, and the contact position between the ball base surface of the right roller 3 and the inner ring 2 flange 4 is on the right side of the roller 3, during turning, the outer diameter surface of the left roller 3 needs to be processed with a left-handed texture 5, and the outer diameter surface of the right roller 3 needs to be processed with a right-handed texture 5, so as to ensure that the lubricant can move toward the direction of the large flange 4 of the inner ring 2 respectively, so as to reduce the sliding friction between the ball base surface and the flange 4.

Claims

1. A roller processing method for improving the lubrication performance of the rib of a large tapered roller bearing, characterized in that: The process includes turning and super-finishing the semi-finished tapered roller after heat treatment, thereby completing the processing of the tapered roller; The turning process is as follows: according to the rotation direction of the roller when working in the bearing, the outer circle of the roller and the ball base surface are integrally turned in a specified turning method; after the turning is completed, the outer circle surface of the roller is enlarged to form a texture with a specified rotation direction, so that when the roller rotates during operation, the lubricant entering the bearing moves along the texture toward the inner ring rib.

2. A roller processing method for improving the lubrication performance of the rib of a large tapered roller bearing according to claim 1, characterized in that: The specified turning method is: after the roller is clamped on the lathe chuck, the lathe spindle rotates forward and the turning tool moves from the tailstock to the headstock of the machine tool; or the lathe spindle rotates forward and the turning tool moves from the headstock to the tailstock of the machine tool.

3. The roller processing method for improving the lubrication performance of the rib of a large tapered roller bearing according to claim 1, characterized in that: The bearings are single-row tapered roller bearings, double-row tapered roller bearings or four-row tapered roller bearings.

4. The roller processing method for improving the lubrication performance of the rib of a large tapered roller bearing according to claim 1, characterized in that: The texture formed on the outer cylindrical surface of the roller after magnification has a left-hand or right-hand rotation direction.

5. The roller processing method for improving the lubrication performance of the rib of a large tapered roller bearing according to claim 1, characterized in that: Before turning and super-finishing, the roller goes through raw material cutting, forging, roller rough turning and heat treatment processes.

6. The roller processing method for improving the lubrication performance of the rib of a large tapered roller bearing according to claim 1, characterized in that: After super-fine grinding, the surface roughness of the roller is 0.4-0.2μm.

7. The roller processing method for improving the lubrication performance of the rib of a large tapered roller bearing according to claim 1, characterized in that: The lubricant is oil or grease.

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