Machining method of flexible thin-wall bearing ring

Abstract

The invention relates to the field of manufacturing of special metal articles, in particular to a machining method of a flexible thin-wall bearing ring. The machining method is used for solving the problem that in an existing bearing ring machining method, an adopted combined forging piece is prone to deformation in the machining process, and then the subsequent machining precision is affected. The machining method comprises the following steps that (1) a blank is forged to obtain a combined forging piece; (2) machining before heating, heat treatment and machining after heating are conducted on the combined forging piece, and a formed piece is obtained; (3) cutting the formed part to obtain the bearing ring; the combined forging piece obtained by forging the blank comprises a cylindrical main body for obtaining the bearing ring after cutting and a reinforcing convex ring which is located at one end of the cylindrical main body and has the outer diameter larger than that of the cylindrical main body. The reinforcing convex ring can remarkably improve the structural strength of the combined forge piece, meanwhile, the combined forge piece can be clamped through the reinforcing convex ring and machining equipment, the clamping acting force directly acts on the reinforcing convex ring, the combined forge piece is not prone to deformation, and the stability of follow-up machining can be remarkably improved.

Description

Technical Field

[0001] The invention relates to the field of manufacturing special metal articles, and in particular to a method for processing a flexible thin-wall bearing ring. Background Art

[0002] Thin-walled bearings have the characteristics of small aspect ratio and thin wall thickness, which helps to reduce the volume, mass and total cost of instruments and equipment. They are widely used in host component units with limited installation space, high integration and lightweight requirements such as robots, aviation, and aerospace. When the blank rings of thin-walled bearing rings are processed individually according to conventional methods (forging-machining-heat treatment-machining), the size and shape and position tolerances of multiple workpieces are highly discrete, the batch processing consistency is poor, the processing efficiency is low, and the thin-walled bearings are prone to deformation during processing, affecting the accuracy of subsequent processing.

[0003] The Chinese invention patent with application publication number CN117283244A discloses a method for processing thin-walled bearing rings, which includes the following steps: using a process of forging multiple blanks to obtain a forged part during the forging process, and then turning, heat treating, machining and cutting the forged part. The forged part composed of multiple blanks has a certain stability, and through forging, multiple blank rings can be processed at the same time, thereby shortening the production cycle and improving production efficiency. However, due to its thin wall thickness, the forged part still cannot well improve its easy deformation during processing, which still affects the accuracy of subsequent processing. Summary of the invention

[0004] The object of the present invention is to provide a method for processing a flexible thin-walled bearing ring, so as to solve the problem that the forgings used in the existing thin-walled bearing ring processing method are easily deformed during processing, thereby affecting the subsequent processing accuracy.

[0005] To solve the above technical problems, the present invention provides a processing method for a flexible thin-walled bearing ring, comprising the following steps: 1) forging a blank to obtain a forged part; 2) performing pre-heat machining, heat treatment, and post-heat machining on the forged part to obtain a molded part; 3) cutting the molded part to obtain a bearing ring; it is characterized in that the forged part obtained by forging the blank comprises a cylindrical main body for obtaining a bearing ring after cutting, and a reinforcing body at one end of the cylindrical main body, wherein the reinforcing body is a reinforcing convex ring having an outer diameter greater than the outer diameter of the cylindrical main body.

[0006] Furthermore, the outer diameter D1 of the reinforcing convex ring satisfies the following relationship: D1=D+ΔD+ΔD1+30 Formula 1; Wherein, D1 is the outer diameter of the reinforcing convex ring, ΔD1 is the machining allowance of the outer diameter of the reinforcing convex ring, ΔD is the machining allowance of the outer diameter of the cylindrical body, and D is the outer diameter of the cylindrical body.

[0007] Furthermore, the machining allowance ΔD1 of the outer diameter of the reinforcing convex ring is set according to the outer diameter D of the cylindrical body, and the following relationship is satisfied between ΔD1 and D: when 100mm≤D<250mm, ΔD1 is 0.2-0.3mm; when 250mm≤D<400mm, ΔD1 is 0.4-0.55mm; when 400mm≤D<600mm, ΔD1 is 0.7-0.9mm; when 600mm≤D<800mm, ΔD1 is 1-1.5mm.

[0008] Furthermore, the turning allowance ΔD of the outer diameter of the cylindrical body is set according to the outer diameter D of the cylindrical body, and the following relationship is satisfied between ΔD and D: when 100mm≤D<250mm, ΔD is 0.25-0.4mm; when 250mm≤D<400mm, ΔD is 0.45-0.6mm; when 400mm≤D<600mm, ΔD is 0.8-1.1mm; when 600mm≤D<800mm, ΔD is 1.2-1.4mm.

[0009] Furthermore, the number X of bearing rings obtained by cutting the cylindrical body is set according to the outer diameter D of the cylindrical body and the radial rigidity ratio S / D of the cylindrical body. The relationship between X, D and S / D is as follows: When 100mm≤D<250mm: If S / D<0.035, X is 2 to 3; If 0.035≤S / D<1, X is 4 to 6; If S / D≤1, X is 7 to 9; When 250mm≤D<400mm: If S / D<0.035, X is 3 to 5; If 0.035≤S / D<1, X is 6 to 9; If S / D≤1, X is 9 to 11; When 400mm≤D<600mm: If S / D<0.035, X is 4 to 7; If S / D≥0.035, X is 8 to 11; When 600mm≤D<800mm: If S / D<0.035, X is 4 to 8; If S / D≥0.035, X is 8 to 12.

[0010] Furthermore, an overtravel groove is provided at the boundary line between the cylindrical body and the reinforcing convex ring.

[0011] Furthermore, the pre-heat machining in step 2) includes rough turning, tempering, semi-finishing turning and finishing turning.

[0012] Furthermore, the heat treatment in step 2) includes quenching, high temperature tempering, cold treatment, and secondary tempering.

[0013] Furthermore, the post-heat machining in step 2) includes hard turning, tempering and grinding.

[0014] Furthermore, when cutting the molded part, the cutter is withdrawn when it cuts from the outer diameter of the molded part to 2 / 3 of the wall thickness of the molded part, and the cut surface is wrapped with transparent tape. Then, the molded part is cut in half at the inner diameter of the molded part using the cutter until the corresponding bearing ring is cut off.

[0015] The present invention proposes an improved technical solution, in which a reinforcing convex ring having an outer diameter greater than that of the cylindrical body is provided at one end of the original cylindrical body used to obtain the bearing ring after cutting. The reinforcing convex ring can significantly improve the structural strength of the forged part and avoid deformation of the cylindrical body as much as possible. At the same time, the reinforcing convex ring can be used to clamp with the processing equipment during clamping, and the force during clamping directly acts on the reinforcing convex ring, so that the forged part is not easy to deform. In this way, the stability of subsequent processing can be significantly improved to ensure the processing accuracy during processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of a flexible thin-walled bearing ring; Figure 2 It is a schematic structural diagram of a forged part obtained by the processing method of the flexible thin-walled bearing ring of the present invention.

[0017] In the figure: 1, forging; 11, cylindrical body; 12, reinforcing convex ring; 13, overtravel groove; 2, flexible thin-walled bearing ring. DETAILED DESCRIPTION

[0018] The present invention proposes an improved technical solution to the problems existing in the above technical solution. The core concept of the present invention is: a reinforcing convex ring with an outer diameter larger than the outer diameter of the cylindrical body is provided at one end of the original cylindrical body used to obtain the bearing ring after cutting. The reinforcing convex ring can significantly improve the structural strength of the forged part. At the same time, the reinforcing convex ring can be used to clamp with the processing equipment during clamping. The force during clamping directly acts on the reinforcing convex ring, and the forged part is not easy to deform. In this way, the stability of subsequent processing can be significantly improved.

[0019] Based on the above invention concept, a processing method of a flexible thin-walled bearing ring of the present invention comprises the following steps: 1) Forging the blank to obtain a forged part 1; 2) Pre-heat machining, heat treatment, and post-heat machining are performed on the forged part 1 to obtain a formed part; 3) The formed part is cut to obtain a bearing ring (i.e., Figure 1The forged piece 1 obtained by forging the blank includes a cylindrical body 11 for obtaining the bearing ring after cutting, and a reinforcing body at one end of the cylindrical body 11, the reinforcing body being as shown in FIG. Figure 2 The reinforcing convex ring 12 shown has an outer diameter greater than the outer diameter of the cylindrical body. The reinforcing convex ring 12 can significantly improve the structural strength of the forged part 1 and avoid deformation of the cylindrical body as much as possible. At the same time, the reinforcing convex ring 12 can be used to clamp with the processing equipment during clamping. The force during clamping directly acts on the reinforcing convex ring 12, and the forged part 1 is not easy to deform. In this way, the stability of subsequent processing can be significantly improved to ensure the processing accuracy during processing.

[0020] In this embodiment, the outer diameter D1 of the reinforcing convex ring satisfies the following relationship: D1=D+ΔD+ΔD1+30 Formula 1; Wherein, D1 is the outer diameter of the reinforcing convex ring, ΔD1 is the machining allowance of the outer diameter of the reinforcing convex ring, ΔD is the machining allowance of the outer diameter of the cylindrical body, and D is the outer diameter of the cylindrical body. The reinforcing convex ring 12 with such an outer diameter can maximize its reinforcing effect on the forged part 1.

[0021] In this embodiment, the machining allowance ΔD1 of the outer diameter of the reinforcing convex ring is set according to the outer diameter D of the cylindrical body, and the following relationship is satisfied between ΔD1 and D: when 100mm≤D<250mm, ΔD1 is 0.2~0.3mm; when 250mm≤D<400mm, ΔD1 is 0.4~0.55mm; when 400mm≤D<600mm, ΔD1 is 0.7~0.9mm; when 600mm≤D<800mm, ΔD1 is 1~1.5mm.

[0022] In a preferred embodiment, the machining allowance ΔD of the outer diameter of the cylindrical body is set according to the outer diameter D of the cylindrical body, and the following relationship is satisfied between ΔD and D: when 100mm≤D<250mm, ΔD is 0.25-0.4mm; when 250mm≤D<400mm, ΔD is 0.45-0.6mm; when 400mm≤D<600mm, ΔD is 0.8-1.1mm; when 600mm≤D<800mm, ΔD is 1.2-1.4mm.

[0023] In a preferred embodiment, the number X of bearing rings obtained by cutting the cylindrical body 11 is set according to the outer diameter D of the cylindrical body and the radial rigidity ratio S / D of the cylindrical body. The relationship between X, D and S / D is as follows: When 100mm≤D<250mm: If S / D<0.035, X is 2 to 3; If 0.035≤S / D<1, X is 4 to 6; If S / D≤1, X is 7 to 9; When 250mm≤D<400mm: If S / D<0.035, X is 3 to 5; If 0.035≤S / D<1, X is 6 to 9; If S / D≤1, X is 9 to 11; When 400mm≤D<600mm: If S / D<0.035, X is 4 to 7; If S / D≥0.035, X is 8 to 11; When 600mm≤D<800mm: If S / D<0.035, X is 4 to 8; If S / D≥0.035, X is 8 to 12.

[0024] Wherein, S is the wall thickness of the bearing ring. The number X of the bearing rings is selected according to the above, which ensures the rigidity of the combined forging 1 and the reliability of the combined forging 1 during processing.

[0025] In such Figure 2 In the illustrated embodiment, an overrun groove 13 is provided at the boundary line between the cylindrical body 11 and the reinforcing convex ring 12. Without the overrun groove 13, the tool may collide with the workpiece when withdrawing, resulting in damage to the tool or scratches on the surface of the workpiece. The presence of the overrun groove 13 simplifies the withdrawal process of the tool, reduces the resistance that the tool may encounter when withdrawing, protects the integrity of the tool, helps to speed up the processing speed, and improves production efficiency.

[0026] In this embodiment, the pre-heat machining of step 2) includes rough turning, tempering, semi-finishing turning, and finishing turning. Specifically, the process is: rough turning the end face, outer diameter, outer diameter of the flange, and raceway, additional tempering, semi-finishing turning the end face, outer diameter, and raceway, and finishing turning the end face, outer diameter, outer diameter of the flange, and raceway. Rough turning can remove most of the excess to improve the shape error and surface defects of the forging 1, and then additional tempering is performed. The tempering temperature is 180°C ± 10°C, for example, 183°C, and the time is 10 hours. Then semi-finishing turning and finishing turning gradually improve the accuracy of the forging 1 until the forging 1 reaches the finished product size. In this way, the turning allowance is reasonably distributed, reducing the processing stress caused by large feed processing. Additional tempering between rough turning and semi-finishing turning can reduce the brittleness of the forging 1, ensure the toughness of the forging 1 during subsequent processing, and help reduce deformation. In addition, in other embodiments, the pre-heat machining process of step 2) may be consistent with the pre-heat machining process in the processing method of thin-walled bearing rings with application publication number CN117283244A, that is, including rough turning, annealing, and finish turning.

[0027] In this embodiment, the heat treatment in step 2) includes quenching, high temperature tempering, cold treatment (liquid nitrogen), and secondary tempering. The high temperature tempering temperature is 220°C±10°C, and the tempering time is 4 hours; the cold treatment temperature is not higher than -90°C, for example, -100°C, and the time is set to 3 hours.

[0028] In this embodiment, the post-heat machining in step 2) includes hard turning, tempering, and grinding. During hard turning, a pneumatic or hydraulically driven 2N (N≥2) jaw chuck (such as a pneumatic 6-jaw chuck) is used to clamp the reinforcing convex ring 12. When the workpiece is placed on the machine tool and the position is adjusted, the deviation between the center of the workpiece and the center of the machine tool worktable is ensured to be no greater than 0.15mm. The roundness variation in the diameter direction of the hard-turned bearing ring is no greater than 0.1mm. The hard turning amount is 75% of the remainder after the overall heat treatment. The hard turning method is more convenient, which can save time in removing the remainder and improve processing efficiency. After hard turning, tempering is performed at 180°C±10°C for 10 hours. Tempering can reduce the brittleness of the forging 1, ensure the toughness of the forging 1 during subsequent processing, and help reduce deformation. During the grinding process, the magnetic pole of the grinder is firstly ground with a flat grinding wheel, and then the magnetic pole end face is measured with a dial indicator to ensure that its runout is not greater than 0.02 mm. The grinding feed rate is set to 0.005 mm / s, and the single grinding feed rate is not greater than 0.008 mm / s. After grinding, the cylindrical body 11 is ground to the finished product size. In addition, in other embodiments, the post-heat machining process of step 2) can be consistent with the post-heat machining process in the processing method of the thin-walled bearing ring with the application publication number CN117283244A, that is, it includes rough grinding, tempering, semi-finishing grinding, and fine grinding.

[0029] In this embodiment, when the molded part is cut, the cutter is withdrawn when the cutter cuts from the outer diameter of the molded part to 2 / 3 of the wall thickness of the molded part, and the cut surface is wrapped with transparent tape. Then, the molded part is cut in half at the inner diameter of the molded part with the cutter until the corresponding bearing ring is cut off. The above steps are repeated to obtain the remaining bearing rings. This method facilitates the cutting of the bearing ring. In addition, in other embodiments, the cutter can also be used to directly cut the bearing ring from the outer diameter of the molded part.

[0030] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. The patent protection scope of the present invention shall be based on the claims. All equivalent structural changes made using the contents of the description and drawings of the present invention should also be included in the protection scope of the present invention.

Claims

1. A method for processing a flexible thin-walled bearing ring, comprising the following steps: 1) Forging the blank to obtain a forged part; 2) Performing pre-heat machining, heat treatment, and post-heat machining on the forged part to obtain a formed part; 3) Cutting the formed part to obtain a bearing ring; It is characterized in that the forged part obtained by forging the blank includes a cylindrical body for obtaining a bearing ring after cutting, and a reinforcing body at one end of the cylindrical body, wherein the reinforcing body is a reinforcing convex ring with an outer diameter greater than the outer diameter of the cylindrical body.

2. The method for processing a flexible thin-walled bearing ring according to claim 1, characterized in that: The outer diameter D1 of the reinforcing convex ring satisfies the following relationship: D1=D+ΔD+ΔD1+30 Formula 1; Wherein, D1 is the outer diameter of the reinforcing convex ring, ΔD1 is the machining allowance of the outer diameter of the reinforcing convex ring, ΔD is the machining allowance of the outer diameter of the cylindrical body, and D is the outer diameter of the cylindrical body.

3. The method for processing a flexible thin-walled bearing ring according to claim 2, characterized in that: The machining allowance ΔD1 of the outer diameter of the reinforcing convex ring is set according to the outer diameter D of the cylindrical body, and the following relationship is satisfied between ΔD1 and D: when 100mm≤D<250mm, ΔD1 is 0.2-0.3mm; when 250mm≤D<400mm, ΔD1 is 0.4-0.55mm; when 400mm≤D<600mm, ΔD1 is 0.7-0.9mm; when 600mm≤D<800mm, ΔD1 is 1-1.5mm.

4. The method for processing a flexible thin-walled bearing ring according to claim 2 or 3, characterized in that: The turning allowance ΔD of the outer diameter of the cylindrical body is set according to the outer diameter D of the cylindrical body, and the following relationship is satisfied between ΔD and D: when 100mm≤D<250mm, ΔD is 0.25-0.4mm; when 250mm≤D<400mm, ΔD is 0.45-0.6mm; when 400mm≤D<600mm, ΔD is 0.8-1.1mm; when 600mm≤D<800mm, ΔD is 1.2-1.4mm.

5. The method for processing a flexible thin-walled bearing ring according to any one of claims 1 to 3, characterized in that: The number X of bearing rings obtained by cutting the cylindrical body is set according to the outer diameter D of the cylindrical body and the radial rigidity ratio S / D of the cylindrical body. The relationship between X, D and S / D is as follows: When 100mm≤D<250mm: If S / D<0.035, X is 2 to 3; If 0.035≤S / D<1, X is 4 to 6; If S / D≤1, X is 7 to 9; When 250mm≤D<400mm: If S / D<0.035, X is 3 to 5; If 0.035≤S / D<1, X is 6 to 9; If S / D≤1, X is 9 to 11; When 400mm≤D<600mm: If S / D<0.035, X is 4 to 7; If S / D≥0.035, X is 8 to 11; When 600mm≤D<800mm: If S / D<0.035, X is 4 to 8; If S / D≥0.035, X is 8 to 12.

6. The method for processing a flexible thin-walled bearing ring according to any one of claims 1 to 3, characterized in that: An overtravel groove is arranged at the boundary line between the cylindrical body and the reinforcing convex ring.

7. The method for processing a flexible thin-walled bearing ring according to any one of claims 1 to 3, characterized in that: Step 2) pre-heat machining includes rough turning, tempering, semi-finishing turning and finishing turning.

8. The method for processing a flexible thin-walled bearing ring according to any one of claims 1 to 3, characterized in that: The heat treatment in step 2) includes quenching, high temperature tempering, cold treatment and secondary tempering.

9. The method for processing a flexible thin-walled bearing ring according to any one of claims 1 to 3, characterized in that: The post-heat machining in step 2) includes hard turning, tempering and grinding.

10. The method for processing a flexible thin-walled bearing ring according to any one of claims 1 to 3, characterized in that: When cutting the molded part, the cutter is withdrawn when it cuts from the outer diameter of the molded part to 2 / 3 of the wall thickness of the molded part, and the cut surface is wrapped with transparent tape. Then, the molded part is cut in half at the inner diameter of the molded part using the cutter until the corresponding bearing ring is cut off.

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