Machining method for outer ring of large carburized tapered roller bearing

Abstract

The invention relates to a machining method for a large-scale carburized tapered roller bearing outer ring, in particular to a machining method for a carburized tapered roller bearing outer ring, and aims to solve the problem that the rejection rate is high after the large-scale tapered roller bearing outer ring is machined. After the machining process of the bearing outer ring is optimized, the steps of fine turning of end faces, outer and inner diameter faces and chamfering, fine turning of the end faces, outer diameter faces and chamfering, rolling way and chamfering, carburization, high-temperature tempering, heat treatment, uniform grinding of the two end faces, hard turning of the end faces, the outer diameter, a flange plate and chamfering, hard turning of the end faces and chamfering, hard milling of the flange plate, stabilizing treatment and grinding are conducted. By optimizing the technological process and the allowance of the outer ring of the large carburized tapered roller bearing, the technical problem of product scrapping caused by large deformation after carburization and heat treatment of the ferrule can be solved, the rejection rate is reduced, and the method is applied to the technical field of turning and grinding.

Description

TECHNICAL FIELD

[0001] The present application relates to a large carburizing tapered roller bearing outer ring processing method. BACKGROUND

[0002] The large carburizing tapered roller bearing outer ring is characterized by a tapered raceway and carburizing steel material. During processing, carburizing treatment is required. The wall thickness difference between the two ends is large, and clamping deformation is easily generated during turning. After heat treatment, the expansion and shrinkage amounts of the large and small end faces are inconsistent, causing the taper deformation of the ring and the difficulty in controlling the variation of the single plane outer diameter. Once the deformation amount is large and exceeds the allowance range for grinding processing, the size precision of the ring is unqualified, resulting in waste products. Even if the deformation amount does not exceed the grinding allowance, there is also the problem of uneven carburizing. However, if the allowance is greatly increased to change the deformation amount, the size precision can be ensured, but the grinding difficulty and processing time are increased. SUMMARY

[0003] The present application is to solve the problem of high waste rate of large tapered roller bearing outer rings after processing, and provides a large carburizing tapered roller bearing outer ring processing method.

[0004] The large carburizing tapered roller bearing outer ring processing method of the present application is as follows:

[0005] I. Turning the end face and the outer and inner diameter face of one side of the tapered roller bearing outer ring, and leaving a machining allowance for the end face and the outer and inner diameter face, wherein the outer and inner diameter face is turned with a raceway machining allowance of 0.5-1.0 mm;

[0006] II. Clamping the end face and the outer and inner diameter face processed in step I, and turning the other end face and the outer diameter face, both leaving a machining allowance;

[0007] III. Machining the raceway and the inner chamfer, with a cutting speed V of 90-120 (m / min), a cutting depth ap≤0.5 mm, and a feed rate of 0.4-1 mm / rev;

[0008] IV. Carburizing, high-temperature tempering and heat treatment processing of the tapered roller bearing processed in step III, then removing the machining allowance left on the end face, and then using the end face as a reference to correct the outer diameter deformation by aligning the raceway, i.e. completing the processing; wherein the machining allowance left on the end face and the outer diameter face is adjusted according to the carbon layer depth of carburizing, and the machining allowance left on the end face and the outer diameter face is greater than the carbon layer depth by 0.5-1 mm.

[0009] The present application optimizes the process flow and allowance of the large carburizing tapered roller bearing outer ring, solves the technical problem of large deformation of the ring after carburizing and heat treatment, effectively guarantees the size and precision of the large carburizing tapered roller bearing outer ring, and reduces the waste rate. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 Figure 1 is a schematic view of a bearing outer ring before carburizing. DETAILED DESCRIPTION

[0011] The technical solution of the present application is not limited to the following specific embodiments, but also includes any combination of the specific embodiments.

[0012] Specific embodiment one: the processing method of the large carburized tapered roller bearing outer ring of the present embodiment is as follows:

[0013] I. The end face and the outer inner diameter face of the tapered roller bearing outer ring are machined, and machining allowances are left on the end face and the outer inner diameter face, wherein a 0.5-1.0mm machining allowance is left on the outer inner diameter face during machining;

[0014] II. The end face and the outer inner diameter face machined in step I are clamped, and the other end face and the outer diameter face are machined, both leaving machining allowances;

[0015] III. The raceway and the inner chamfer are machined, the cutting speed V is 90-120(m / min), the cutting depth ap≤0.5mm, and the feed rate is 0.4-1mm / rev;

[0016] IV. The tapered roller bearing machined in step III is carburized, high-temperature tempered, and heat treated, and then the machining allowance left on the end face is removed. Then, the outer diameter deformation is trimmed by aligning the raceway with the end face as the reference, and the machining is completed. The machining allowances left on the end face and the outer diameter face are both adjusted according to the carbon layer depth of carburizing, and the machining allowances left on the end face and the outer diameter face are both greater than the carbon layer depth by 0.5-1mm.

[0017] The processing flow of the large bearing outer ring of the present embodiment is optimized as follows: fine machining of the end face, the outer inner diameter face, and the chamfer → fine machining of the end face, the outer diameter face, and the chamfer → machining of the raceway and the chamfer → carburizing → high-temperature tempering → heat treatment → equalizing of the two end faces → hard machining of the end face, the outer diameter, the flange, and the chamfer → hard machining of the end face and the chamfer → hard milling of the flange → stable treatment → grinding.

[0018] Specific embodiment two: the difference between the present embodiment and specific embodiment one is that in step I, the outer inner diameter face is only used as a clamping reference, and the dimensional tolerance is controlled to be ±0.05mm, and the ovality is ≤0.1mm. The others are the same as specific embodiment one.

[0019] Specific embodiment three: the difference between the present embodiment and specific embodiment two is that in step III, the cutting speed V is 100m / min. The others are the same as specific embodiment two.

[0020] Specific embodiment four: the difference between the present embodiment and specific embodiment two or three is that in step III, the cutting depth ap is 0.5mm. The others are the same as specific embodiment two or three.

[0021] Specific implementation five: the difference between this implementation and one of specific implementations two to four is that the feed amount in step three is 0.5 mm / rev. The others are the same as one of specific implementations two to four.

[0022] Specific implementation six: the difference between this implementation and one of specific implementations two to five is that the outer diameter deformation is modified in step four to make the outer diameter ovality VDsp≤0.15 mm and the edge face degree 2△Cir≤0.15 mm. The others are the same as one of specific implementations two to five.

[0023] The beneficial effects of the present application are verified by the following examples:

[0024] Example one: the machining method of the large-scale carburized tapered roller bearing outer ring in this example is:

[0025] I. The one side end face and the outer inner diameter face of the tapered roller bearing outer ring are machined, and a 0.5-1.0 mm machining allowance of the raceway is left during the machining of the outer inner diameter face. The end face allowance is adjusted according to the carbon layer depth of carburization (the carbon layer depth is determined according to the selected carburization process), and the end face allowance is greater than the carbon layer depth by 0.5-1 mm;

[0026] II. The other side end face and the outer diameter face are machined by clamping the end face and the outer inner diameter face machined in step one, and the end face and the outer diameter allowance are adjusted according to the carbon layer depth of carburization. The end face and the outer diameter allowance are both greater than the carbon layer depth by 0.5-1 mm;

[0027] III. The raceway and the inner side chamfer are machined, the cutting speed V is 100 m / min, the cutting depth ap is 0.5 mm, and the feed amount is 0.5 mm / rev;

[0028] IV. The tapered roller bearing machined in step III is subjected to carburization, high-temperature tempering and heat treatment processing, and then the excess end face allowance is removed. Then, the outer diameter deformation is modified by taking the end face as the reference and aligning the raceway, so that the outer diameter ovality VDsp≤0.15 mm and the edge face degree 2△Cir≤0.15 mm, i.e. the machining is completed.

[0029] Figure 1 This example solves the technical problem of large deformation of the sleeve ring after carburization and heat treatment, which leads to product scrap, by optimizing the process flow and allowance of the large-scale carburized tapered roller bearing outer ring. The size and precision of the large-scale carburized tapered roller bearing outer ring are effectively guaranteed, the scrap rate is reduced, and the qualified rate is greater than 91%, and the highest can reach 100%.

Claims

1. A method for machining the outer ring of a large carburized tapered roller bearing, characterized in that, The method is as follows:

1. Machining one end face and the outer inner diameter face of the tapered roller bearing outer ring, leaving machining allowance for both the end face and the outer inner diameter face, with a raceway machining allowance of 0.5-1.0mm when machining the outer inner diameter face; 2. Clamping Step 1: After machining the end face and outer and inner diameter surfaces, machine the other end face and outer diameter surface, leaving machining allowance in all cases.

3. Machining the raceway and inner chamfer, with a cutting speed V of 90~120 (m / min), a cutting depth ap≤0.5mm, and a feed rate of 0.4~1mm / rev; Fourth, the tapered roller bearing processed in step three is subjected to carburizing, high-temperature tempering and heat treatment. Then, the machining allowance left on the end face is removed. Using the end face as a reference, the bearing is aligned through the raceway and the outer diameter deformation is corrected to complete the process. The machining allowance left on both the end face and the outer diameter is adjusted according to the depth of the carburized carbon layer. The machining allowance left on both the end face and the outer diameter is 0.5-1mm greater than the carbon layer depth.

2. The method for machining the outer ring of a large carburized tapered roller bearing according to claim 1, characterized in that, In step one, the outer and inner diameter surfaces are used only as clamping references, and their dimensional tolerances are controlled to be ±0.05mm and ellipticity ≤0.1mm.

3. The method for machining the outer ring of a large carburized tapered roller bearing according to claim 1, characterized in that, In step three, the cutting speed V is 100 m / min.

4. The method for machining the outer ring of a large carburized tapered roller bearing according to claim 1, characterized in that, In step three, the cutting depth ap is 0.5 mm.

5. The method for machining the outer ring of a large carburized tapered roller bearing according to claim 1, characterized in that, In step three, the feed rate is 0.5 mm / rev.

6. The method for machining the outer ring of a large carburized tapered roller bearing according to claim 1, characterized in that, In step four, the outer diameter deformation is adjusted so that the outer diameter ellipticity VDsp ≤ 0.15 mm and the facet 2△Cir ≤ 0.15 mm.

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