Manufacturing method of asymmetric thin-wall high-precision bearing ring with high-chromium-molybdenum steel structure

Abstract

The invention discloses a manufacturing method of an asymmetric thin-wall high-precision bearing ring with a high-chromium-molybdenum steel structure, and relates to the technical field of bearing machining. The problems that after an existing thin-wall bearing outer ring of an asymmetric structure is turned, the form and location tolerance of a positioning groove and a locking boss of the end face exceeds the design requirement, the production qualification rate is too low, and cost is increased are solved. The machining method comprises the steps that turning is conducted, specifically, the appearance of the bearing outer ring is turned, and 0.2 mm machining allowance is reserved on each surface; grinding, wherein the machining allowance of all the surfaces of the workpiece is removed through grinding; hard turning: performing hard turning on the workpiece by using a numerical control lathe; hard milling of a plane C: a boss of the workpiece and the plane C are subjected to hard milling in a machining center, and 0.1-0.2 mm machining allowance is reserved during hard milling of the plane C; final grinding of the plane C: removing the machining allowance of the plane C of the workpiece through grinding; and hard milling of the plane A groove: the plane A groove of the workpiece is hard milled in the machining center. The method is used for machining the thin-wall bearing outer ring of the asymmetric structure.

Description

Technical Field

[0001] The invention relates to the technical field of bearing processing, and in particular to a method for manufacturing an asymmetric thin-wall high-precision bearing ring with a high-chromium-molybdenum steel structure. Background Art

[0002] The outer ring of a certain type of thin-walled bearing is an asymmetric structure, which is characterized by a boss structure on one end face and a groove structure on the other end face. The existing bearing outer ring processing usually adopts turning processing, but the asymmetric thin-walled ring has a weak ability to resist deformation during the processing process. At the same time, due to the uneven thermal expansion caused by temperature changes during heat treatment, the shape and position tolerances of the positioning grooves and stop bosses on the rear end face of the processing exceed the design requirements, resulting in a scrap rate of more than 30%, which leads to an increase in production costs, a low pass rate, and a decrease in overall production capacity. Therefore, a new processing method is urgently needed to ensure the product processing pass rate of the asymmetric thin-walled bearing outer ring. Summary of the invention

[0003] In order to solve the problem that after turning of the outer ring of the existing asymmetric thin-walled bearing, the shape and position tolerances of the positioning groove and the stop boss on the end face exceed the design requirements, resulting in a low production qualification rate and increased costs, the present invention proposes a method for manufacturing asymmetric thin-walled high-precision bearing rings with a high chromium-molybdenum steel structure.

[0004] The technical solution adopted by the present invention to solve the above technical problems is:

[0005] The manufacturing method of a high chromium-molybdenum steel structure asymmetric thin-walled high-precision bearing ring comprises the following steps:

[0006] Step 1: Turning: Turn the outer ring of the bearing, leaving a 0.2mm machining allowance on each surface;

[0007] Step 2: Grinding: removing the machining allowance on each surface of the workpiece by grinding;

[0008] Step 3: Hard turning: Use CNC lathe to hard turn the workpiece;

[0009] Step 4: Hard milling plane C: Hard mill the boss and plane C of the workpiece in the machining center, and reserve 0.1-0.2mm machining allowance when hard milling plane C;

[0010] Step 5: Final grinding of plane C: removing the machining allowance of plane C of the workpiece by grinding;

[0011] Step 6. Hard milling of groove on plane A: Hard milling of groove on plane A of workpiece in machining center.

[0012] Furthermore, during turning in step 1, the end face, outer and inner diameter surfaces and chamfers on one side of the workpiece are turned first, and then the end face, outer diameter surface and chamfers on the other side of the workpiece are turned, and then the raceway and raceway chamfers are turned.

[0013] Furthermore, in the step 1, heat treatment is performed after turning, and the workpiece after the heat treatment is then ground.

[0014] Furthermore, during the grinding process in step 2, firstly, each surface of the workpiece is subjected to a rough grinding cycle process, and then a first stabilization process is performed, and then a final grinding process is performed, and finally plane A and plane B are processed.

[0015] Furthermore, during hard turning in step three, the chamfer, outer diameter step and inner slope of the workpiece are hard turned according to the process design.

[0016] Furthermore, when the machining center hard mills the boss and plane C in step 4, the machining is performed based on the ground outer diameter surface and plane A.

[0017] Furthermore, when hard milling the groove of plane A in step six, plane C and the outer diameter surface are used as references.

[0018] Furthermore, after hard milling the groove of plane A in step six, the workpiece is subjected to a second stabilization treatment.

[0019] Furthermore, the first stabilization treatment and the second stabilization treatment in step six are both high-temperature tempering stress relief treatments.

[0020] Furthermore, after the second stabilization treatment in step six, the workpiece is subjected to fine grinding and final grinding cycles.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention optimizes the process flow and processing method of a certain type of asymmetric thin-walled bearing outer ring, avoids the influence of uncertain factors caused by heat treatment on asymmetric thin-walled rings, reduces thermal deformation, and improves the qualified rate of form and position tolerances of positioning grooves and stop bosses on the end faces of a certain type of bearing rings, so that various dimensions, precisions and form and position tolerances of a certain type of thin-walled bearing outer ring are effectively guaranteed, the scrap rate is reduced to less than 5%, the production cost is reduced, the product qualified rate is guaranteed, thereby improving the production capacity and ensuring the overall production capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure after lathe processing of the present invention;

[0024] Figure 2 It is a schematic structural diagram of the outer ring of the asymmetric thin-walled bearing of the present invention. DETAILED DESCRIPTION

[0025] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0026] Specific implementation method 1: Combination Figure 1 to Figure 2 The present embodiment is described. The manufacturing method of the asymmetric thin-walled high-precision bearing ring with a high chromium-molybdenum steel structure described in the present embodiment comprises the following steps:

[0027] Step 1: Turning: Turn the outer ring of the bearing, leaving a 0.2mm machining allowance on each surface;

[0028] Step 2: Grinding: removing the machining allowance on each surface of the workpiece by grinding;

[0029] Step 3: Hard turning: Use CNC lathe to hard turn the workpiece;

[0030] Step 4: Hard milling plane C: Hard mill the boss and plane C of the workpiece in the machining center, and reserve 0.1-0.2mm machining allowance when hard milling plane C;

[0031] Step 5: Final grinding of plane C: removing the machining allowance of plane C of the workpiece by grinding;

[0032] Step 6. Hard milling of groove on plane A: Hard milling of groove on plane A of workpiece in machining center.

[0033] In order to avoid asymmetric deformation of the outer ring, sufficient grinding allowance should be reserved during turning.

[0034] Specific implementation method 2: Combination Figure 1 to Figure 2 To illustrate this embodiment, during turning in step 1 described in this embodiment, the end face, outer and inner diameter surfaces and chamfers on one side of the workpiece are first turned, and then the end face, outer diameter surface and chamfers on the other side of the workpiece are turned, and then the raceway and raceway chamfers are turned.

[0035] The undisclosed technical features in this embodiment are the same as those in the first embodiment.

[0036] Specific implementation method three: Combination Figure 1 to Figure 2 To illustrate this embodiment, in step 1 of this embodiment, heat treatment is performed after turning, and the workpiece after the heat treatment is then ground.

[0037] The undisclosed technical features in this embodiment are the same as those in the second embodiment.

[0038] Specific implementation method four: Combination Figure 1 to Figure 2In this embodiment, during the grinding process in step 2 of this embodiment, the surfaces of the workpiece are first subjected to a rough grinding cycle, and then subjected to a first stabilization treatment, and then subjected to a final grinding process, and finally plane A and plane B are processed.

[0039] The undisclosed technical features in this embodiment are the same as those in the first embodiment.

[0040] After the grinding process in step 2, the parallelism difference VCs of plane A to plane B is ≤0.002mm, the flatness δ is ≤0.002mm, the outer diameter ovality VDsp is <0.08mm, the edge surface degree 2△Cir is <0.08mm, the outer raceway ovality VDep is <0.1mm, and the wall thickness difference Ke is <0.1mm.

[0041] The outer raceway deformation is corrected during grinding to provide a good processing benchmark for hard turning and hard milling.

[0042] In the step 3, the cutting speed V during hard turning is 80-100 m / min, the cutting depth ap≤0.5 mm, and the feed rate is 0.05-0.1 mm / rev.

[0043] When hard turning, use a CNC lathe to hard turn chamfers, outer diameter steps, and inner slopes to improve the dimensional consistency of chamfers and other processed parts.

[0044] Specific implementation method five: Combination Figure 1 to Figure 2 To illustrate this embodiment, in step three of this embodiment, hard turning is performed on the chamfer, outer diameter step and inner slope of the workpiece according to the process design.

[0045] The undisclosed technical features in this embodiment are the same as those in the first embodiment.

[0046] Specific implementation method six: Combination Figure 1 to Figure 2 To explain this embodiment, in step 4 of this embodiment, when the machining center hard mills the boss and plane C, the grinding outer diameter surface and plane A are used as references for machining.

[0047] The undisclosed technical features in this embodiment are the same as those in the fourth embodiment.

[0048] In the step 4, the cutting speed V during hard milling is 10-30 m / min, the cutting depth ap≤1 mm, and the feed rate f is 20-40 mm / min.

[0049] After the final grinding of plane C in step 5, the parallelism difference VCs of plane C to plane A is ≤0.002mm, which provides precision guarantee for hard milling of the groove of plane A.

[0050] Specific implementation method seven: Combination Figure 1 to Figure 2To explain this embodiment, in step six of this embodiment, when hard milling the groove of plane A, plane C and the outer diameter surface are used as references.

[0051] The undisclosed technical features in this embodiment are the same as those in the fourth embodiment.

[0052] In the step 6, the cutting speed V during hard milling of the groove of plane A is 10-30 m / min, the cutting depth ap≤1 mm, and the feed rate f is 20-40 mm / min.

[0053] Specific implementation method eight: Combination Figure 1 to Figure 2 To illustrate this embodiment, after hard milling the groove of plane A in step six of this embodiment, the workpiece is subjected to a second stabilization treatment.

[0054] The undisclosed technical features in this embodiment are the same as those in the seventh embodiment.

[0055] Specific implementation method nine: Combination Figure 1 to Figure 2 To illustrate this embodiment, the first stabilization treatment and the second stabilization treatment in step six of this embodiment are both high-temperature tempering stress relief treatments.

[0056] The undisclosed technical features in this embodiment are the same as those in the eighth embodiment.

[0057] Specific implementation method ten: Combination Figure 1 to Figure 2 To explain this embodiment, after the second stabilization treatment in step six of this embodiment, the workpiece is subjected to fine grinding and final grinding cycles.

[0058] The undisclosed technical features in this embodiment are the same as those in the ninth embodiment.

[0059] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for manufacturing asymmetric thin-walled high-precision bearing rings with high chromium-molybdenum steel structure, characterized in that: The method comprises the following steps: Step 1: Turning: Turn the outer ring of the bearing, leaving a 0.2mm machining allowance on each surface; Step 2: Grinding: removing the machining allowance on each surface of the workpiece by grinding; Step 3: Hard turning: Use CNC lathe to hard turn the workpiece; Step 4: Hard milling plane C: Hard mill the boss and plane C of the workpiece in the machining center, and reserve 0.1-0.2mm machining allowance when hard milling plane C; Step 5: Final grinding of plane C: removing the machining allowance of plane C of the workpiece by grinding; Step 6. Hard milling of groove on plane A: Hard milling of groove on plane A of workpiece in machining center.

2. The method for manufacturing asymmetric thin-walled high-precision bearing rings with high chromium-molybdenum steel structure according to claim 1 is characterized in that: During turning in step 1, the end face, outer and inner diameter surfaces and chamfers on one side of the workpiece are turned first, and then the end face, outer diameter surface and chamfers on the other side of the workpiece are turned, and then the raceway and raceway chamfers are turned.

3. The method for manufacturing asymmetric thin-walled high-precision bearing rings with high chromium-molybdenum steel structure according to claim 2 is characterized in that: In the step 1, heat treatment is performed after turning, and the workpiece after heat treatment is then ground.

4. The method for manufacturing asymmetric thin-walled high-precision bearing rings with high chromium-molybdenum steel structure according to claim 1 is characterized in that: During the grinding process in step 2, firstly, each surface of the workpiece is subjected to a rough grinding cycle, then a first stabilization treatment is performed, and then a final grinding process is performed, and finally plane A and plane B are processed.

5. The method for manufacturing asymmetric thin-walled high-precision bearing rings with high chromium-molybdenum steel structure according to claim 1 is characterized in that: During hard turning in step three, the chamfer, outer diameter step and inner slope of the workpiece are hard turned according to the process design.

6. The method for manufacturing asymmetric thin-walled high-precision bearing rings with high chromium-molybdenum steel structure according to claim 4 is characterized by: When the machining center hard mills the boss and plane C in step 4, the grinding outer diameter surface and plane A are used as references for machining.

7. The method for manufacturing asymmetric thin-walled high-precision bearing rings with high chromium-molybdenum steel structure according to claim 4 is characterized by: When hard milling the groove of plane A in step 6, plane C and the outer diameter surface are used as references.

8. The method for manufacturing asymmetric thin-walled high-precision bearing rings with high chromium-molybdenum steel structure according to claim 7 is characterized in that: After the groove of plane A is hard milled in step 6, the workpiece is subjected to a second stabilization treatment.

9. The method for manufacturing asymmetric thin-walled high-precision bearing rings with high chromium-molybdenum steel structure according to claim 8 is characterized in that: The first stabilization treatment and the second stabilization treatment in step six are both high-temperature tempering stress relief treatments.

10. The method for manufacturing asymmetric thin-walled high-precision bearing rings with high chromium-molybdenum steel structure according to claim 9, characterized in that: After the second stabilization treatment in step six, the workpiece is subjected to fine grinding and final grinding cycles.

Images